PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (1012249)

Clipboard (0)
None

Related Articles

1.  Effect of rubbing on the in vitro skin permeation of diclofenac-diethylamine 1.16% gel 
BMC Research Notes  2012;5:321.
Background
Rubbing a topical NSAID (non steroidal anti-inflammatory drug) on the skin may increase local drug permeation, affecting its distribution to the site of pain and inflammation. The present study evaluates this hypothesis, by assessing in vitro the effect on skin permeation of applying diclofenac-dieythylamine 1.16% gel with or without rubbing.
Methods
A single dose of 5 mg/cm2 diclofenac-diethylamine 1.16% gel was applied on excised human skin mounted in Franz-type diffusion cells without or with rubbing for 45 s. Drug penetration into the skin layers was determined after 1 h using the tape stripping technique. In vitro cutaneous permeation into the receptor fluid of the diffusion chamber was measured up to 24 h. Skin electrical resistance was also recorded.
Results
Application of diclofenac-diethylamine 1.16% gel with rubbing resulted to a 5-fold higher flux of diclofenac through the skin than when applied without rubbing at 8 h (P = 0.04). Skin rubbing for 45 s decreased by 2-fold skin electrical resistance when compared to the standard application. Application of diclofenac-diethylamine 1.16% gel with rubbing tended to result in higher accumulation in the stripped skin vs. the superficial skin layers when applied without rubbing (P = 0.2).
Conclusion
These results suggest that rubbing may alter the superficial skin layer resulting in a transient faster initial diffusion of topically applied diclofenac through the stratum corneum into the deeper skin layer of the dermis to the tissue target.
doi:10.1186/1756-0500-5-321
PMCID: PMC3424122  PMID: 22720797
2.  In vivo pharmacokinetics and pharmacodynamics of topical ketoconazole and miconazole in human stratum corneum. 
A direct study evaluating whether differential drug uptake of topical 2% miconazole and 2% ketoconazole from cream formulations into human stratum corneum correlated with differential pharmacological activity against Candida albicans was investigated in healthy human subjects. A single 24-h topical dose of 2% ketoconazole cream or 2% miconazole cream was applied unoccluded, at the same dose (2.6 mg of formulation per cm2 of surface area), at four skin sites on both ventral forearms of six human subjects. At the end of the treatment, residual drug was removed with a tissue from all sites and the treated site was tape stripped 11 times, either 1, 4, 8, or 24 h later. The first tape disc was discarded. The remaining tape discs, 2 through 11, were combined and extracted for drug quantification by high-performance liquid chromatography and bioactivity against C. albicans growth in vitro. Topical 2% ketoconazole produced 14-, 10-, and 7-fold greater drug concentrations in stratum corneum than 2% miconazole at 1, 4, and 8 h after a single topical dose. Ketoconazole and miconazole concentrations in the stratum corneum were similar 24 h after drug removal. Tape disc extracts from 2% ketoconazole-treated skin sites demonstrated significantly greater bioactivity in the bioassay than 2% miconazole. The increased efficacy of 2% ketoconazole compared with that of 2% miconazole in vitro reflects their differential uptake into the stratum corneum and inherent pharmacological activity. Tape stripping the drug-treated site in conjunction with a bioassay is therefore a useful approach in the determination of bioavailability of topical antifungal agents.
PMCID: PMC284402  PMID: 8141586
3.  Enhanced skin permeation using polyarginine modified nanostructured lipid carriers 
The objective of the present study was to investigate the effect of polyarginine chain length on topical delivery of surface modified NLCs. Design of experiments (DOE) was used to optimize number of arginines required to deliver active drug into deeper skin layers. The NLCs were prepared by hot-melt technique and the surface of NLCs was modified with six-histidine tagged cell penentrating peptides (CPPs) or YKA. In vivo confocal microscopy and raman confocal spectroscopy studies were performed using fluorescent dye encapsulated NLCs and NLC-CPPs. Spantide II (SP) and ketoprofen (KP) were used as model drugs for combined delivery. In vitro skin permeation and drug release studies were performed using Franz diffusion cells. Inflammatory response corresponding to higher skin permeation was investigated in allergic contact dermatitis (ACD) mouse model. NLCs had a particle size of 140 ± 20 nm with higher encapsulation efficiencies. The negative charge of NLC was reduced from −17.54 to −8.47 mV after surface modification with CPPs. In vivo confocal microscopy and raman confocal spectroscopy studies suggested that a peptide containing 11 arginines (R11) had significant permeation enhancing ability than other polyarginines and TAT peptides. The amount of SP and KP retained in dermis after topical application of NLC-R11 was significantly higher than solution and NLC after 24 h of skin permeation. SP was not found in receiver compartment. However, KP was found in receiver compartment and the amount of KP present in receiver compartment was increased approximately 7.9 and 2.6 times compared to the control solution and NLCs, respectively. In an ACD mouse model, SP+KP-NLC-R11 showed significant reduction (p<0.05) in ear thickness compared to SP+KP solution and SP+KP-NLC. Our results strongly suggest that the surface modification of NLC with R11 improved transport of SP and KP across the deeper skin layers and thus result in reduction of inflammation associated with ACD.
doi:10.1016/j.jconrel.2012.05.011
PMCID: PMC3412947  PMID: 22617521
Skin delivery; nanostructured lipid carriers (NLC); cell penetrating peptide (CPP); allergic contact dermatitis (ACD); polyarginine peptide
4.  Formulation and in Vitro, ex Vivo and in Vivo Evaluation of Elastic Liposomes for Transdermal Delivery of Ketorolac Tromethamine 
Pharmaceutics  2011;3(4):954-970.
The objective of the current study was to formulate ketorolac tromethamine-loaded elastic liposomes and evaluate their in vitro drug release and their ex vivo and in vivo transdermal delivery. Ketorolac tromethamine (KT), which is a potent analgesic, was formulated in elastic liposomes using Tween 80 as an edge activator. The elastic vesicles were prepared by film hydration after optimizing the sonication time and number of extrusions. The vesicles exhibited an entrapment efficiency of 73 ± 11%, vesicle size of 127.8 ± 3.4 nm and a zeta potential of −12 mV. In vitro drug release was analyzed from liposomes and an aqueous solution, using Franz diffusion cells and a cellophane dialysis membrane with molecular weight cut-off of 8000 Da. Ex vivo permeation of KT across pig ear skin was studied using a Franz diffusion cell, with phosphate buffer (pH 7.4) at 32 °C as receptor solution. An in vivo drug permeation study was conducted on healthy human volunteers using a tape-stripping technique. The in vitro results showed (i) a delayed release when KT was included in elastic liposomes, compared to an aqueous solution of the drug; (ii) a flux of 0.278 μg/cm2h and a lag time of about 10 h for ex vivo permeation studies, which may indicate that KT remains in the skin (with the possibility of exerting a local effect) before reaching the receptor medium; (iii) a good correlation between the total amount permeated, the penetration distance (both determined by tape stripping) and transepidermal water loss (TEWL) measured during the in vivo permeation studies. Elastic liposomes have the potential to transport the drug through the skin, keep their size and drug charge, and release the drug into deep skin layers. Therefore, elastic liposomes hold promise for the effective topical delivery of KT.
doi:10.3390/pharmaceutics3040954
PMCID: PMC3857066  PMID: 24309316
elastic liposomes; ketorolac tromethamine; skin permeation; tape stripping; TEWL
5.  Extracorporeal Photophoresis 
Executive Summary
Objective
To assess the effectiveness, safety and cost-effectiveness of extracorporeal photophoresis (ECP) for the treatment of refractory erythrodermic cutaneous T cell lymphoma (CTCL) and refractory chronic graft versus host disease (cGvHD).
Background
Cutaneous T Cell Lymphoma
Cutaneous T cell lymphoma (CTCL) is a general name for a group of skin affecting disorders caused by malignant white blood cells (T lymphocytes). Cutaneous T cell lymphoma is relatively uncommon and represents slightly more than 2% of all lymphomas in the United States. The most frequently diagnosed form of CTCL is mycosis fungoides (MF) and its leukemic variant Sezary syndrome (SS). The relative frequency and disease-specific 5-year survival of 1,905 primary cutaneous lymphomas classified according to the World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification (Appendix 1). Mycosis fungoides had a frequency of 44% and a disease specific 5-year survival of 88%. Sezary syndrome had a frequency of 3% and a disease specific 5-year survival of 24%.
Cutaneous T cell lymphoma has an annual incidence of approximately 0.4 per 100,000 and it mainly occurs in the 5th to 6th decade of life, with a male/female ratio of 2:1. Mycosis fungoides is an indolent lymphoma with patients often having several years of eczematous or dermatitic skin lesions before the diagnosis is finally established. Mycosis fungoides commonly presents as chronic eczematous patches or plaques and can remain stable for many years. Early in the disease biopsies are often difficult to interpret and the diagnosis may only become apparent by observing the patient over time.
The clinical course of MF is unpredictable. Most patients will live normal lives and experience skin symptoms without serious complications. Approximately 10% of MF patients will experience progressive disease involving lymph nodes, peripheral blood, bone marrow and visceral organs. A particular syndrome in these patients involves erythroderma (intense and usually widespread reddening of the skin from dilation of blood vessels, often preceding or associated with exfoliation), and circulating tumour cells. This is known as SS. It has been estimated that approximately 5-10% of CTCL patients have SS. Patients with SS have a median survival of approximately 30 months.
Chronic Graft Versus Host Disease
Allogeneic hematopoietic cell transplantation (HCT) is a treatment used for a variety of malignant and nonmalignant disease of the bone marrow and immune system. The procedure is often associated with serious immunological complications, particularly graft versus host disease (GvHD). A chronic form of GvHD (cGvHD) afflicts many allogeneic HCT recipients, which results in dysfunction of numerous organ systems or even a profound state of immunodeficiency. Chronic GVHD is the most frequent cause of poor long-term outcome and quality of life after allogeneic HCT. The syndrome typically develops several months after transplantation, when the patient may no longer be under the direct care of the transplant team.
Approximately 50% of patients with cGvHD have limited disease and a good prognosis. Of the patients with extensive disease, approximately 60% will respond to treatment and eventually be able to discontinue immunosuppressive therapy. The remaining patients will develop opportunistic infection, or require prolonged treatment with immunosuppressive agents.
Chronic GvHD occurs in at least 30% to 50% of recipients of transplants from human leukocyte antigen matched siblings and at least 60% to 70% of recipients of transplants from unrelated donors. Risk factors include older age of patient or donor, higher degree of histoincompatibility, unrelated versus related donor, use of hematopoietic cells obtained from the blood rather than the marrow, and previous acute GvHD. Bhushan and Collins estimated that the incidence of severe cGvHD has probably increased in recent years because of the use of more unrelated transplants, donor leukocyte infusions, nonmyeloablative transplants and stem cells obtained from the blood rather than the marrow. The syndrome typically occurs 4 to 7 months after transplantation but may begin as early as 2 months or as late as 2 or more years after transplantation. Chronic GvHD may occur by itself, evolve from acute GvHD, or occur after resolution of acute GvHD.
The onset of the syndrome may be abrupt but is frequently insidious with manifestations evolving gradually for several weeks. The extent of involvement varies significantly from mild involvement limited to a few patches of skin to severe involvement of numerous organ systems and profound immunodeficiency. The most commonly involved tissues are the skin, liver, mouth, and eyes. Patients with limited disease have localized skin involvement, evidence of liver dysfunction, or both, whereas those with more involvement of the skin or involvement of other organs have extensive disease.
Treatment
 
Cutaneous T Cell Lymphoma
The optimal management of MF is undetermined because of its low prevalence, and its highly variable natural history, with frequent spontaneous remissions and exacerbations and often prolonged survival.
Nonaggressive approaches to therapy are usually warranted with treatment aimed at improving symptoms and physical appearance while limiting toxicity. Given that multiple skin sites are usually involved, the initial treatment choices are usually topical or intralesional corticosteroids or phototherapy using psoralen (a compound found in plants which make the skin temporarily sensitive to ultraviolet A) (PUVA). PUVA is not curative and its influence on disease progression remains uncertain. Repeated courses are usually required which may lead to an increased risk of both melanoma and nonmelanoma skin cancer. For thicker plaques, particularly if localized, radiotherapy with superficial electrons is an option.
“Second line” therapy for early stage disease is often topical chemotherapy, radiotherapy or total skin electron beam radiation (TSEB).
Treatment of advanced stage (IIB-IV) MF usually consists of topical or systemic therapy in refractory or rapidly progressive SS.
Bone marrow transplantation and peripheral blood stem cell transplantation have been used to treat many malignant hematologic disorders (e.g., leukemias) that are refractory to conventional treatment. Reports on the use of these procedures for the treatment of CTCL are limited and mostly consist of case reports or small case series.
Chronic Graft Versus Host Disease
Patients who develop cGvHD require reinstitution of immunosuppressive medication (if already discontinued) or an increase in dosage and possibly addition of other agents. The current literature regarding cGvHD therapy is less than optimal and many recommendations about therapy are based on common practices that await definitive testing. Patients with disease that is extensive by definition but is indolent in clinical appearance may respond to prednisone. However, patients with more aggressive disease are treated with higher doses of corticosteroids and/or cyclosporine.
Numerous salvage therapies have been considered in patients with refractory cGvHD, including ECP. Due to uncertainty around salvage therapies, Bhushan and Collins suggested that ideally, patients with refractory cGvHD should be entered into clinical trials.
Two Ontario expert consultants jointly estimated that there may be approximately 30 new erythrodermic treatment resistant CTCL patients and 30 new treatment resistant cGvHD patients per year who are unresponsive to other forms of therapy and may be candidates for ECP.
Extracorporeal photopheresis is a procedure that was initially developed as a treatment for CTCL, particularly SS.
Current Technique
Extracorporeal photopheresis is an immunomodulatory technique based on pheresis of light sensitive cells. Whole blood is removed from patients followed by pheresis. Lymphocytes are separated by centrifugation to create a concentrated layer of white blood cells. The lymphocyte layer is treated with methoxsalen (a drug that sensitizes the lymphocytes to light) and exposed to UVA, following which the lymphocytes are returned to the patient. Red blood cells and plasma are returned to the patient between each cycle.
Photosensitization is achieved by administering methoxsalen to the patient orally 2 hours before the procedure, or by injecting methoxsalen directly ino the leucocyte rich fraction. The latter approach avoids potential side effects such as nausea, and provides a more consistent drug level within the machine.
In general, from the time the intravenous line is inserted until the white blood cells are returned to the patient takes approximately 2.5-3.5 hours.
For CTCL, the treatment schedule is generally 2 consecutive days every 4 weeks for a median of 6 months. For cGvHD, an expert in the field estimated that the treatment schedule would be 3 times a week for the 1st month, then 2 consecutive days every 2 weeks after that (i.e., 4 treatments a month) for a median of 6 to 9 months.
Regulatory Status
The UVAR XTS Photopheresis System is licensed by Health Canada as a Class 3 medical device (license # 7703) for the “palliative treatment of skin manifestations of CTCL.” It is not licensed for the treatment of cGvHD.
UVADEX (sterile solution methoxsalen) is not licensed by Health Canada, but can be used in Canada via the Special Access Program. (Personal communication, Therakos, February 16, 2006)
According to the manufacturer, the UVAR XTS photopheresis system licensed by Health Canada can also be used with oral methoxsalen. (Personal communication, Therakos, February 16, 2006) However, oral methoxsalen is associated with side effects, must be taken by the patient in advance of ECP, and has variable absorption in the gastrointestinal tract.
According to Health Canada, UVADEX is not approved for use in Canada. In addition, a review of the Product Monographs of the methoxsalen products that have been approved in Canada showed that none of them have been approved for oral administration in combination with the UVAR XTS photophoresis system for “the palliative treatment of the skin manifestations of cutaneous T-cell Lymphoma”.
In the United States, the UVAR XTS Photopheresis System is approved by the Food and Drug Administration (FDA) for “use in the ultraviolet-A (UVA) irradiation in the presence of the photoactive drug methoxsalen of extracorporeally circulating leukocyte-enriched blood in the palliative treatment of the skin manifestations of CTCL in persons who have not been responsive to other therapy.”
UVADEX is approved by the FDA for use in conjunction with UVR XTS photopheresis system for “use in the ultraviolet-A (UVA) irradiation in the presence of the photoactive drug methoxsalen of extracorporeally circulating leukocyte-enriched blood in the palliative treatment of the skin manifestations of CTCL in persons who have not been responsive to other therapy.”
The use of the UVAR XTS photopheresis system or UVADEX for cGvHD is an off-label use of a FDA approved device/drug.
Summary of Findings
The quality of the trials was examined.
As stated by the GRADE Working Group, the following definitions were used in grading the quality of the evidence.
Cutaneous T Cell Lymphoma
Overall, there is low-quality evidence that ECP improves response rates and survival in patients with refractory erythrodermic CTCL (Table 1).
Limitations in the literature related to ECP for the treatment of refractory erythrodermic CTCL include the following:
Different treatment regimens.
Variety of forms of CTCL (and not necessarily treatment resistant) - MF, erythrodermic MF, SS.
SS with peripheral blood involvement → role of T cell clonality reporting?
Case series (1 small crossover RCT with several limitations)
Small sample sizes.
Retrospective.
Response criteria not clearly defined/consistent.
Unclear how concomitant therapy contributed to responses.
Variation in definitions of concomitant therapy
Comparison to historical controls.
Some patients were excluded from analysis because of progression of disease, toxicity and other reasons.
Unclear/strange statistics
Quality of life not reported as an outcome of interest.
The reported CR range is ~ 16% to 23% and the overall reported CR/PR range is ~ 33% to 80%.
The wide range in reported responses to ECP appears to be due to the variability of the patients treated and the way in which the data were presented and analyzed.
Many patients, in mostly retrospective case series, were concurrently on other therapies and were not assessed for comparability of diagnosis or disease stage (MF versus SS; erythrodermic versus not erythrodermic). Blood involvement in patients receiving ECP (e.g., T cell clonality) was not consistently reported, especially in earlier studies. The definitions of partial and complete response also are not standardized or consistent between studies.
Quality of life was reported in one study; however, the scale was developed by the authors and is not a standard validated scale.
Adverse events associated with ECP appear to be uncommon and most involve catheter related infections and hypotension caused by volume depletion.
GRADE Quality of Studies – Extracorporeal Photopheresis for Refractory Erythrodermic Cutaneous T-Cell Lymphoma
Chronic Graft-Versus-Host Disease
Overall, there is low-quality evidence that ECP improves response rates and survival in patients with refractory cGvHD (Table 2).
Patients in the studies had stem cell transplants due to a variety of hematological disorders (e.g., leukemias, aplastic anemia, thalassemia major, Hodgkin’s lymphoma, non Hodgkin’s lymphoma).
In 2001, The Blue Cross Blue Shield Technology Evaluation Centre concluded that ECP meets the TEC criteria as treatment of cGvHD that is refractory to established therapy.
The Catalan health technology assessment (also published in 2001) concluded that ECP is a new but experimental therapeutic alternative for the treatment of the erythrodermal phase of CTCL and cGvHD in allogenic HPTC and that this therapy should be evaluated in the framework of a RCT.
Quality of life (Lansky/Karnofsky play performance score) was reported in 1 study.
The patients in the studies were all refractory to steroids and other immunosuppressive agents, and these drugs were frequently continued concomitantly with ECP.
Criteria for assessment of organ improvement in cGvHD are variable, but PR was typically defined as >50% improvement from baseline parameters and CR as complete resolution of organ involvement.
Followup was variable and incomplete among the studies.
GRADE Quality of Studies – ECP for Refractory cGvHD
Conclusion
As per the GRADE Working Group, overall recommendations consider 4 main factors.
The tradeoffs, taking into account the estimated size of the effect for the main outcome, the confidence limits around those estimates and the relative value placed on the outcome.
The quality of the evidence (Tables 1 and 2).
Translation of the evidence into practice in a specific setting, taking into consideration important factors that could be expected to modify the size of the expected effects such as proximity to a hospital or availability of necessary expertise.
Uncertainty about the baseline risk for the population of interest.
The GRADE Working Group also recommends that incremental costs of healthcare alternatives should be considered explicitly alongside the expected health benefits and harms. Recommendations rely on judgments about the value of the incremental health benefits in relation to the incremental costs. The last column in Table 3 is the overall trade-off between benefits and harms and incorporates any risk/uncertainty.
For refractory erythrodermic CTCL, the overall GRADE and strength of the recommendation is “weak” – the quality of the evidence is “low” (uncertainties due to methodological limitations in the study design in terms of study quality and directness), and the corresponding risk/uncertainty is increased due to an annual budget impact of approximately $1.5M Cdn (based on 30 patients) while the cost-effectiveness of ECP is unknown and difficult to estimate considering that there are no high quality studies of effectiveness. The device is licensed by Health Canada, but the sterile solution of methoxsalen is not licensed.
With an annual budget impact of $1.5 M Cdn (based on 30 patients), and the current expenditure is $1.3M Cdn (for out of country for 7 patients), the potential cost savings based on 30 patients with refractory erythrodermic CTCL is about $3.8 M Cdn (annual).
For refractory cGvHD, the overall GRADE and strength of the recommendation is “weak” – the quality of the evidence is “low” (uncertainties due to methodological limitations in the study design in terms of study quality and directness), and the corresponding risk/uncertainty is increased due to a budget impact of approximately $1.5M Cdn while the cost-effectiveness of ECP is unknown and difficult to estimate considering that there are no high quality studies of effectiveness. Both the device and sterile solution are not licensed by Health Canada for the treatment of cGvHD.
If all the ECP procedures for patients with refractory erythrodermic CTCL and refractory cGvHD were performed in Ontario, the annual budget impact would be approximately $3M Cdn.
Overall GRADE and Strength of Recommendation (Including Uncertainty)
PMCID: PMC3379535  PMID: 23074497
6.  Imaging Drug Delivery to Skin with Stimulated Raman Scattering Microscopy 
Molecular pharmaceutics  2011;8(3):969-975.
Efficient drug delivery to the skin is essential for the treatment of major dermatologic diseases, such as eczema, psoriasis and acne. However, many compounds penetrate the skin barrier poorly and require optimized formulations to ensure their bioavailability. Here, stimulated Raman scattering (SRS) microscopy, a recently-developed, label-free chemical imaging tool, is used to acquire high resolution images of multiple chemical components of a topical formulation as it penetrates into mammalian skin. This technique uniquely provides label-free, non-destructive, three-dimensional images with high spatiotemporal resolution. It reveals novel features of (trans)dermal drug delivery in the tissue environment: different rates of drug penetration via hair follicles as compared to the intercellular pathway across the stratum corneum are directly observed, and the precipitation of drug crystals on the skin surface is visualized after the percutaneous penetration of the co-solvent excipient in the formulation. The high speed three-dimensional imaging capability of SRS thus reveals features that cannot be seen with other techniques, providing both kinetic information and mechanistic insight into the (trans)dermal drug delivery process.
doi:10.1021/mp200122w
PMCID: PMC3109166  PMID: 21548600
Skin; topical drug delivery; stimulated Raman scattering microscopy; skin penetration pathways; dermatopharmacokinetics
7.  Enhanced transdermal delivery of evodiamine and rutaecarpine using microemulsion 
Objective
The purpose of this study was to improve skin permeation of evodiamine and rutaecarpine for transdermal delivery with microemulsion as vehicle and investigate real-time cutaneous absorption of the drugs via in vivo microdialysis.
Methods
Pseudoternary phase diagrams were constructed to evaluate microemulsion regions with various surfactants and cosurfactants. Nine formulations of oil in water microemulsions were selected as vehicles for assessing skin permeation of evodiamine and rutaecarpine in ex vivo transdermal experiments. With a microdialysis hollow fiber membrane implanted in the skin beneath the site of topical drug administration, dialysis sampling was maintained for 10 hours and the samples were detected directly by high performance liquid chromatography. Real-time concentrations of the drugs in rat skin were investigated and compared with those of conventional formulations, such as ointment and tincture. Furthermore, the drugs were applied to various regions of the skin using microemulsion as vehicle.
Results
In ex vivo transdermal experiments, cutaneous fluxes of evodiamine and rutaecarpine microemulsions were 2.55-fold to 11.36-fold and 1.17-fold to 6.33-fold higher, respectively, than those of aqueous suspensions. Different drug loadings, microemulsion water content, and transdermal enhancers markedly influenced the permeation of evodiamine and rutaecarpine. In microemulsion application with in vivo microdialysis, the maximum concentration of the drugs (evodiamine: 18.23 ± 1.54 ng/mL; rutaecarpine: 16.04 ± 0.69 ng/mL) were the highest, and the area under the curve0–t of evodiamine and rutaecarpine was 1.52-fold and 2.27-fold higher than ointment and 3.06-fold and 4.23-fold higher than tincture, respectively. A greater amount of drugs penetrated through and was absorbed by rat abdominal skin than shoulder and chest, and a reservoir in the skin was found to supply drugs even after the microemulsion was withdrawn.
Conclusion
Compared to conventional formulations, higher cutaneous fluxes of evodiamine and rutaecarpine were achieved with microemulsion. Based on this novel transdermal delivery, the transdermal route was effective for the administration of the two active alkaloids.
doi:10.2147/IJN.S25258
PMCID: PMC3205141  PMID: 22072882
microemulsion; evodiamine; rutaecarpine; transdermal delivery; microdialysis
8.  Quantitative Analysis of Microbicide Concentrations in Fluids, Gels and Tissues Using Confocal Raman Spectroscopy 
PLoS ONE  2013;8(12):e85124.
Topical vaginal anti-HIV microbicides are an important focus in female-based strategies to prevent the sexual transmission of HIV. Understanding microbicide pharmacokinetics is essential to development, characterization and implementation of efficacious microbicide drug delivery formulations. Current methods to measure drug concentrations in tissue (e.g., LC-MS/MS, liquid chromatography coupled with tandem mass spectrometry) are highly sensitive, but destructive and complex. This project explored the use of confocal Raman spectroscopy to detect microbicide drugs and to measure their local concentrations in fluids, drug delivery gels, and tissues. We evaluated three candidate microbicide drugs: tenofovir, Dapivirine and IQP-0528. Measurements were performed in freshly excised porcine buccal tissue specimens, gel vehicles and fluids using two Horiba Raman microscopes, one of which is confocal. Characteristic spectral peak calibrations for each drug were obtained using serial dilutions in the three matrices. These specific Raman bands demonstrated strong linear concentration dependences in the matrices and were characterized with respect to their unique vibrational signatures. At least one specific Raman feature was identified for each drug as a marker band for detection in tissue. Sensitivity of detection was evaluated in the three matrices. A specific peak was also identified for tenofovir diphosphate, the anti-HIV bioactive product of tenofovir after phosphorylation in host cells. Z-scans of drug concentrations vs. depth in excised tissue specimens, incubated under layers of tenofovir solution in a Transwell assay, showed decreasing concentration with depth from the surface into the tissue. Time-dependent concentration profiles were obtained from tissue samples incubated in the Transwell assay, for times ranging 30 minutes - 6 hours. Calibrations and measurements from tissue permeation studies for tenofovir showed good correlation with gold standard LC-MS/MS data. These results demonstrate that confocal Raman spectroscopy holds promise as a tool for practical, minimally invasive, label-free measurement of microbicide drug concentrations in fluids, gels and tissues.
doi:10.1371/journal.pone.0085124
PMCID: PMC3875564  PMID: 24386455
9.  Optimization of Topical Therapy for Leishmania major Localized Cutaneous Leishmaniasis Using a Reliable C57BL/6 Model 
Background
Because topical therapy is easy and usually painless, it is an attractive first-line option for the treatment of localized cutaneous leishmaniasis (LCL). Promising ointments are in the final stages of development. One main objective was to help optimize the treatment modalities of human LCL with WR279396, a topical formulation of aminoglycosides that was recently proven to be efficient and safe for use in humans.
Methodology/Principal Findings
C57BL/6 mice were inoculated in the ear with luciferase transgenic L. major and then treated with WR279396. The treatment period spanned lesion onset, and the evolution of clinical signs and bioluminescent parasite loads could be followed for several months without killing the mice. As judged by clinical healing and a 1.5-3 log parasite load decrease in less than 2 weeks, the 94% efficacy of 10 daily applications of WR279396 in mice was very similar to what had been previously observed in clinical trials. When WR279396 was applied with an occlusive dressing, parasitological and clinical efficacy was significantly increased and no rebound of parasite load was observed. In addition, 5 applications under occlusion were more efficient when done every other day for 10 days than daily for 5 days, showing that length of therapy is a more important determinant of treatment efficacy than the total dose topically applied.
Conclusions/Significance
Occlusion has a significant adjuvant effect on aminoglycoside ointment therapy of experimental cutaneaous leishmaniasis (CL), a concept that might apply to other antileishmanial or antimicrobial ointments. Generated in a laboratory mouse-based model that closely mimics the course of LCL in humans, our results support a schedule based on discontinuous applications for a few weeks rather than several daily applications for a few days.
Author Summary
When initiating the cutaneous disease named cutaneous leishmaniasis (CL), Leishmania parasites develop within the parasitophorous vacuoles of phagocytes residing in and/or recruited to the dermis, a process leading to more or less chronic dermis and epidermis-damaging inflammatory processes. Topical treatment of CL could be a mainstay in its management. Any improvements of topicals, such as new vehicles and shorter optimal contact regimes, could facilitate their use as an ambulatory treatment. Recently, WR279396, a third-generation aminoglycoside ointment, was designed with the aim to provide stability and optimal bioavailability for the molecules expected to target intracellular Leishmania. Two endpoints were expected to be reached: i) accelerated clearance of the maximal number of parasites, and ii) accelerated and stable repair processes without scars. A mouse model of CL was designed: it relies on the intradermal inoculation of luciferase-expressing Leishmania, allowing for in vivo bioluminescence imaging of the parasite load fluctuation, which can then be quantified simultaneously with the onset and resolution of clinical signs. These quantitative readout assays, deployed in real time, provide robust methods to rapidly assess efficacy of drugs/compounds i) to screen treatment modalities and ii) allow standardized comparison of different therapeutic agents.
doi:10.1371/journal.pntd.0000034
PMCID: PMC2100369  PMID: 18060082
10.  Evaluation of Paeonol Skin-Target Delivery from Its Microsponge Formulation: In Vitro Skin Permeation and In Vivo Microdialysis 
PLoS ONE  2013;8(11):e79881.
The aim of the present study was to design a novel topical skin-target drug-delivery system, the paeonol microsponge, and to investigate its drug-release patterns in dosage form, both in vitro and in vivo. Paeonol microsponges were prepared using the quasi-emulsion solvent-diffusion method. In vitro release studies were carried out using Franz diffusion cells, while in vivo studies were investigated by microdialysis after the paeonol microsponges were incorporated into a cream base. In vitro release studies showed that the drug delivered via microsponges increased the paeonol permeation rate. Ex vivo drug-deposition studies showed that the microsponge formulation improved drug residence in skin. In addition, in vivo microdialysis showed that the values for the area under the concentration versus time curve (AUC) for the paeonol microsponge cream was much higher than that of paeonol cream without microsponges. Maximum time (Tmax) was 220 min for paeonol microsponge cream and 480 min for paeonol cream, while the half-life (t1/2) of paeonol microsponge cream (935.1 min) was almost twice that of paeonol cream (548.6 min) in the skin (n = 3). Meanwhile, in the plasma, the AUC value for paeonol microsponge cream was half that of the paeonol cream. Based on these results, paeonol-loaded microsponge formulations could be a better alternative for treating skin disease, as the formulation increases drug bioavailability by lengthening the time of drug residence in the skin and should reduce side-effects because of the lower levels of paeonol moving into the circulation.
doi:10.1371/journal.pone.0079881
PMCID: PMC3835837  PMID: 24278204
11.  Direct Comparison of the Efficacy and Safety of Oral Treatments with Oleylphosphocholine (OlPC) and Miltefosine in a Mouse Model of L. major Cutaneous Leishmaniasis 
Background
Cutaneous leishmaniasis (CL) represents a range of skin diseases caused by infection with Leishmania parasites and associated with tissue inflammation and skin ulceration. CL is clinically widespread in both the Old and New World but lacks treatments that are well tolerated, effective and inexpensive. Oleylphosphocholine (OlPC) is a new orally bioavailable drug of the alkylphosphocholine family with potent antileishmanial activity against a broad range of Leishmania species/strains.
Methodology/principal findings
The potential of OlPC against Old World CL was evaluated in a mouse model of Leishmania (L.) major infection in BALB/c mice. Initial dose-response experiments showed that an oral daily dose of 40 mg/kg of OlPC was needed to impact time to cure and lesion sizes. This dose was then used to directly compare the efficacy of OlPC to the efficacy of the antileishmanial drugs miltefosine (40 mg/kg/day), fluconazole (160 mg/kg/day) and amphotericin B (25 mg/kg/day). OlPC, miltefosine and fluconazole were given orally for 21 days while amphotericin B was administered intraperitoneally for 10 days. Ulcer sizes and animal weights were followed up on a weekly basis and parasitemia was determined by means of a real-time in vivo imaging system which detects luminescence emitted from luciferase-expressing infecting L. major parasites. Amphotericin B and OlPC showed excellent efficacy against L. major lesions in terms of reduction of parasitic loads and by inducing complete healing of established lesions. In contrast, treatment with miltefosine did not significantly affect parasitemia and lesion sizes, while fluconazole was completely ineffective at the dose regimen tested.
Conclusions/Significance
Given the data showing the outstanding efficacy and tolerability of OlPC, our results suggest that OlPC is a promising new drug candidate to improve and simplify current clinical management of L. major CL.
Author Summary
Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease transmitted to humans by sandflies and characterized by local ulcerative skin lesions. The disease is linked to poverty in the Middle-East, North and East Africa, South-Central Asia and South America, with 0.7 to 1.2 million new annual cases estimated. In most endemic regions CL treatment relies on injections with pentavalent antimonials, old generation drugs with considerable side effects and long treatment regimens. CL is therefore a highly undertreated disease in need of easy-to-administer, orally bioavailable and well-tolerated agents with broad clinical activity. To date, the only oral drug with acceptable efficacy against leishmaniasis is miltefosine, an alkylphosphocholine with a narrow therapeutic window that limits its use. Given the existing clinical need for CL, we tested the efficacy of oleylphosphocholine (OlPC) in a validated mouse model of Old World (Leishmania major) CL. OlPC is a new orally bioavailable drug of the same family as miltefosine with potent and broad leishmanicidal activity. In direct comparison with miltefosine, our results indicate that OlPC induces higher parasite clearance and lesion healing with measurable improved tolerance. These promising observations warrant further research on OlPC as a new drug to improve clinical management of CL.
doi:10.1371/journal.pntd.0003144
PMCID: PMC4161350  PMID: 25210745
12.  Translocation of Cell Penetrating Peptide Engrafted Nanoparticles Across Skin Layers 
Biomaterials  2010;31(21):5598-5607.
The objective of the current study was to evaluate the ability of cell penetrating peptides (CPP) to translocate the lipid payload into the skin layers. Fluorescent dye (DID-oil) encapsulated nano lipid crystal nanoparticles (FNLCN) were prepared using Compritol, Miglyol and DOGS-NTA-Ni lipids by hot melt homogenization technique. The FNLCN surface was coated with TAT peptide (FNLCNT) or control YKA peptide (FNLCNY) and in vitro rat skin permeation studies were performed using Franz diffusion cells. Observation of lateral skin sections obtained using cryotome with a confocal microscope demonstrated that skin permeation of FNLCNT was time dependent and after 24 h, fluorescence was observed upto a depth of 120 µm which was localized in the hair follicles and epidermis. In case of FNLCN and FNLCNY formulations fluorescence was mainly observed in the hair follicles. This observation was further supported by confocal Raman spectroscopy where higher fluorescence signal intensity was observed at 80 and 120 µm depth with FNLCNT treated skin and intensity of fluorescence peaks was in the ratio of 2:1:1 and 5:3:1 for FNLCNT, FNLCN, and FNLCNY treated skin sections, respectively. Furthermore, replacement of DID-oil with celecoxib (Cxb), a model lipophilic drug showed similar results and after 24 h, the CXBNT formulation increased the Cxb concentration in SC by 3 and 6 fold and in epidermis by 2 and 3 fold as compared to CXBN and CXBNY formulations respectively. Our results strongly suggest that CPP can translocate nanoparticles with their payloads into deeper skin layers.
doi:10.1016/j.biomaterials.2010.03.010
PMCID: PMC2875303  PMID: 20413152
Nanoparticles; TAT peptide; Topical delivery; Transdermal delivery; Cell Penetrating Peptides
13.  Dopamine Signaling in the Nucleus Accumbens of Animals Self-Administering Drugs of Abuse 
Abuse of psychoactive substances can lead to drug addiction. In animals, addiction is best modeled by drug self-administration paradigms. It has been proposed that the crucial common denominator for the development of drug addiction is the ability of drugs of abuse to increase extracellular concentrations of dopamine in the nucleus accumbens (NAcc). Studies using in vivo microdialysis and chronoamperometry in the behaving animal have demonstrated that drugs of abuse increase tonic dopamine concentrations in the NAcc. However, it is known that dopamine neurons respond to reward-related stimuli on a subsecond timescale. Thus, it is necessary to collect neurochemical information with this level of temporal resolution, as achieved with in vivo fast-scan cyclic voltammetry (FSCV), to fully understand the role of phasic dopamine release in normal behavior and drug addiction. We review studies that investigated the effects of drugs of abuse on NAcc dopamine levels in freely-moving animals using in vivo microdialysis, chronoamperometry and FSCV. After a brief introduction of dopamine anatomy and signal transduction, and a section on current theories of dopamine in natural goal-directed behavior, a discussion of techniques for the in vivo assessment of extracellular dopamine behaving animals is presented. Then, we review studies using these techniques to investigate changes in phasic and tonic dopamine signaling in the NAcc during 1) response-dependent and –independent administration of abused drugs, 2) drug-conditioned stimuli and operant behavior in self-administration paradigms, 3) drug withdrawal, and 4) cue-induced reinstatement of drug seeking. These results are then integrated with current ideas on the role of dopamine in addiction with an emphasis on a model illustrating phasic and tonic NAcc dopamine signaling during different stages of drug addiction. This model predicts that phasic dopamine release in response to drug-related stimuli will be enhanced over stimuli associated with natural reinforcers, which may result in aberrant goal-directed behaviors contributing to drug addiction.
doi:10.1007/7854_2009_27
PMCID: PMC3766749  PMID: 21161749
14.  Validation and use of microdialysis for determination of pharmacokinetic properties of the chemotherapeutic agent mitomycin C - an experimental study 
BMC Cancer  2010;10:469.
Background
Mitomycin C is a chemotherapeutic agent used in the treatment of peritoneal surface malignancies, administered as hyperthermic intraperitoneal chemotherapy after cytoreductive surgery. Pharmacokinetic studies have been based on analyses of blood, urine and abdominal perfusate, but actual tissue concentrations of the drug have never been determined. Microdialysis is an established method for continuous monitoring of low-molecular substances in tissues, and in the present study microdialysis of mitomycin C was studied in vitro and in vivo.
Methods
Using in vitro microdialysis, relative recovery was determined when varying drug concentration, temperature and perfusion flow rate. In vivo microdialysis was performed in rats to verify long-term stability of relative recovery in four compartments (vein, peritoneum, extraperitoneal space and hind leg muscle). Subsequently, intravenous and intraperitoneal bolus infusion experiments were performed and pharmacokinetic parameters were calculated.
Results
In vitro, compatibility of mitomycin C and microdialysis equipment was demonstrated, and relative recovery was stable over an adequate concentration range, moderately increased by raising medium temperature and increased when flow rate was reduced, all according to theory. In vivo, stable relative recovery was observed over seven hours. Mitomycin C exhibited fast and even distribution in rat tissues, and equal bioavailability was achieved by intravenous and intraperitoneal infusion. The half-life of mitomycin C calculated after intravenous infusion was 40 minutes.
Conclusions
Mitomycin C concentration can be reliable monitored in vivo using microdialysis, suggesting that this technique can be used in pharmacokinetic studies of this drug during hyperthermic intraperitoneal chemotherapy.
doi:10.1186/1471-2407-10-469
PMCID: PMC2940807  PMID: 20809961
15.  Cefodizime in serum and skin blister fluid after single intravenous and intramuscular doses in healthy volunteers. 
Antimicrobial Agents and Chemotherapy  1987;31(11):1822-1825.
In gonorrhea therapy, cephalosporins are conventionally administered by intramuscular (i.m.) injection, which rather frequently leads to local side effects. To investigate whether the well-tolerated intravenous (i.v.) injection of cephalosporins may be of comparable gonocidal effect, levels of cefodizime, a new broad-spectrum cephalosporin, in serum and tissue fluid (suction blister and cantharides blister fluid) were determined in six healthy men. Single doses of 1 g of cefodizime were injected i.v. and i.m. according to a randomized crossover design. On i.m. injection the drug was completely bioavailable, and the peak concentration in serum was 75 +/- 8 micrograms/ml. The terminal half-life of serum levels was 2.4 h. Cefodizime concentrations in the blister fluids increased for 1.5 to 3 h after the i.v. dose and for at least 3 h on i.m. administration. The concentrations of non-protein-bound cefodizime in blister fluid already exceeded the MIC for 90% of Neisseria gonorrhoeae strains 10 min after i.v. injection and 20 to 30 min after the i.m. dose. At 6 h after each dose, active concentrations were still present in serum. The results suggest that cefodizime administered i.v. and i.m. has equivalent high cure rates in uncomplicated gonorrhea. This hypothesis should be tested further by a controlled clinical trial. If equivalent, i.v. administration excels because it is better tolerated locally.
PMCID: PMC175046  PMID: 3435129
16.  Mechanical injury polarizes skin dendritic cells to elicit a Th2 response by inducing cutaneous TSLP expression 
Biochemical pharmacology  1990;39(1):19-26.
Background
Atopic dermatitis (AD) is characterized by scratching and by Th2-dominated immune response to cutaneously introduced antigens. Antigen application to skin mechanically injured by tape stripping results in Th2-dominated skin inflammation.
Objective
To examine the effect of tape stripping on the capacity of skin dendritic cells (DCs) to polarize T cells towards a Th2 phenotype.
Methods
CD11c+ DCs were isolated from skin of BALB/c or C57BL/6 mice. FITC+ and FITC− DCs were isolated from draining lymph nodes (DLN) 24 hrs after painting the skin with FITC. DCs were assessed for their ability to induce cytokine secretion by OVA stimulated naïve CD4+ T cells from TCR-OVA transgenic DO11.10 mice. Cytokine mRNA levels were examined by quantitative PCR.
Results
DCs isolated from the skin of wild-type (WT), but not TSLPR−/− or IL-10−/−, mice 6 hrs after tape stripping elicited significantly more IL-4 and IL-13, and significantly less interferon-γ production by CD4+ cells, than DCs isolated from unmanipulated skin, and expressed significantly more mRNA for the Th2 skewing molecules IL-10, Jagged1, and Jagged2, but significantly less mRNA for the Th1 skewing cytokine IL-12. CD11c+FITC+ cells isolated from DLN of shaved and tape stripped skin of WT, but not TSLPR−/− or IL-10−/−, mice polarized T cells significantly more towards Th2 and expressed significantly more IL-10, Jagged1 and Jagged2 mRNA than CD11c+FITC+ cells isolated from DLN of shaved skin. Tape stripping significantly increased TSLP levels in the skin, and TSLP was shown to play an essential role in the Th2 polarization of skin DCs by tape stripping.
Conclusions
Tape stripping upregulates TSLP levels in the skin, which polarizes skin DCs to elicit a Th2 response via the induction of IL-10.
Clinical Implications
Mechanical injury inflicted by scratching in patients with AD may cause skin DCs to polarize T cells to secrete Th2 cytokines.
Capsule Summary
Mechanical injury to the skin, such as that caused by scratching in AD, may cause skin DCs to polarize T cells to secrete more allergy-mediating Th2 cytokines.
PMCID: PMC2998067  PMID: 2105094
Atopic dermatitis; scratching; mechanical injury; thymic stromal lymphopoietin; IL-10; Th2 cytokines
17.  Raman Assessment of Bone Quality 
Background
Progress in the diagnosis and prediction of fragility fractures depends on improvements to the understating of the compositional contributors of bone quality to mechanical competence. Raman spectroscopy has been used to evaluate alterations to bone composition associated with aging, disease, or injury.
Questions/purposes
In this survey we will (1) review the use of Raman-based compositional measures of bone quality, including mineral-to-matrix ratio, carbonate-to-phosphate ratio, collagen quality, and crystallinity; (2) review literature correlating Raman spectra with biomechanical and other physiochemical measurements and with bone health; and (3) discuss prospects for ex vivo and in vivo human subject measurements.
Methods
ISI Web of Science was searched for references to bone Raman spectroscopy in peer-reviewed journals. Papers from other topics have been excluded from this review, including those on pharmaceutical topics, dental tissue, tissue engineering, stem cells, and implant integration.
Results
Raman spectra have been reported for human and animal bone as a function of age, biomechanical status, pathology, and other quality parameters. Current literature supports the use of mineral-to-matrix ratio, carbonate-to-phosphate ratio, and mineral crystallinity as measures of bone quality. Discrepancies between reports arise from the use of band intensity ratios rather than true composition ratios, primarily as a result of differing collagen band selections.
Conclusions
Raman spectroscopy shows promise for evaluating the compositional contributors of bone quality in ex vivo specimens, although further validation is still needed. Methodology for noninvasive in vivo assessments is still under development.
doi:10.1007/s11999-010-1692-y
PMCID: PMC3126952  PMID: 21116756
18.  Nanosizing of a poorly soluble drug: technique optimization, factorial analysis, and pharmacokinetic study in healthy human volunteers 
Context
Diacerein (DCN) has low aqueous solubility (3.197 mg/L) and, consequently, low oral bioavailability (35%–56%). To increase both the solubility and dissolution rate of DCN while maintaining its crystalline nature, high pressure homogenization was used but with only a few homogenization cycles preceded by a simple bottom-up technique.
Methods
The nanosuspensions of DCN were prepared using a combined bottom-up/top-down technique. Different surfactants – polyvinyl alcohol, sodium deoxycholate, and sodium dodecyl sulfate – with different concentrations were used for the stabilization of the nanosuspensions. Full factorial experimental design was employed to investigate the influence of formulation variables on nanosuspension characteristics using Design-Expert® Software. Particle size (PS), zeta potential, saturation solubility, in vitro dissolution, and drug crystallinity were studied. Moreover, the in vivo performance of the optimized formula was assessed by bioavailability determination in healthy human volunteers.
Results
The concentration of surfactant had a significant effect on both the PS and polydispersity index values. The 1% surfactant concentration showed the lowest PS and polydispersity index values compared with other concentrations. Both type and concentration of surfactant had significant effects on the zeta potential. Formula F8 (containing 1% sodium deoxycholate) and Formula F12 (containing 1% sodium dodecyl sulfate) had the highest desirability values (0.952 and 0.927, respectively). Hence, they were selected for further characterization. The saturated solubility and mean dissolution time, in the case of F8 and F12, were significantly higher than the coarse drug powder. Techniques utilized in the nanocrystals’ preparation had no effect on DCN crystalline state. The selected formula (F12) showed a higher bioavailability compared to the reference market product with relative bioavailability of 131.4%.
Conclusion
The saturation solubility, in vitro dissolution rate and relative bioavailability of DCN were significantly increased after nanocrystallization. Less time and power consumption were applied by the combination of bottom-up and top-down techniques.
doi:10.2147/IJN.S63395
PMCID: PMC4069131  PMID: 24971006
nanocrystals; high pressure homogenization; diacerein; factorial analysis; pharmacokinetic study
19.  Water-filtered infrared-A (wIRA) can act as a penetration enhancer for topically applied substances 
Background: Water-filtered infrared-A (wIRA) irradiation has been shown to enhance penetration of clinically used topically applied substances in humans through investigation of functional effects of penetrated substances like vasoconstriction by cortisone.
Aim of the study: Investigation of the influence of wIRA irradiation on the dermatopharmacokinetics of topically applied substances by use of optical methods, especially to localize penetrating substances, in a prospective randomised controlled study in humans.
Methods: The penetration profiles of the hydrophilic dye fluorescein and the lipophilic dye curcumin in separate standard water-in-oil emulsions were determined on the inner forearm of test persons by tape stripping in combination with spectroscopic measurements. Additionally, the penetration was investigated in vivo by laser scanning microscopy. Transepidermal water loss, hydration of the epidermis, and surface temperature were determined. Three different procedures (modes A, B, C) were used in a randomised order on three separate days of investigation in each of 12 test persons. In mode A, the two dyes were applied on different skin areas without water-filtered infrared-A (wIRA) irradiation. In mode B, the skin surface was irradiated with wIRA over 30 min before application of the two dyes (Hydrosun® radiator type 501, 10 mm water cuvette, orange filter OG590, water-filtered spectrum: 590–1400 nm with dominant amount of wIRA). In mode C, the two dyes were applied and immediately afterwards the skin was irradiated with wIRA over 30 min. In all modes, tape stripping started 30 min after application of the formulations. Main variable of interest was the ratio of the amount of the dye in the deeper (second) 10% of the stratum corneum to the amount of the dye in the upper 10% of the stratum corneum.
Results: The penetration profiles of the hydrophilic fluorescein showed in case of pretreatment or treatment with wIRA (modes B and C) an increased penetration depth compared to the non-irradiated skin (mode A): The ratio of the amount of the dye in the deeper (second) 10% of the stratum corneum to the amount of the dye in the upper 10% of the stratum corneum showed medians and interquartile ranges for mode A of 0.017 (0.007/0.050), for mode B of 0.084 (0.021/0.106), for mode C of 0.104 (0.069/0.192) (difference between modes: p=0.0112, significant; comparison mode A with mode C: p<0.01, significant). In contrast to fluorescein, the lipophilic curcumin showed no differences in the penetration kinetics, in reference to whether the skin was irradiated with wIRA or not. These effects were confirmed by laser scanning microscopy. Water-filtered infrared-A irradiation increased the hydration of the stratum corneum: transepidermal water loss rose from approximately 8.8 g m-2 h-1 before wIRA irradiation to 14.2 g m-2 h-1 after wIRA irradiation and skin hydration rose from 67 to 87 relative units. Skin surface temperature increased from 32.8°C before wIRA to 36.4°C after wIRA irradiation.
Discussion: The better penetration of the hydrophilic dye fluorescein after or during skin irradiation (modes B and C) can be explained by increased hydration of the stratum corneum by irradiation with wIRA.
Conclusions: As most topically applied substances for the treatment of patients are mainly hydrophilic, wIRA can be used to improve the penetration of substances before or after application of substances – in the first case even of thermolabile substances – with a broad clinical relevance as a contact free alternative to an occlusive dressing.
PMCID: PMC2703260  PMID: 19675735
water-filtered infrared-A (wIRA); penetration; stratum corneum; skin barrier; penetration enhancer; dermatopharmacokinetics; dye; fluorescein; curcumin; tape stripping method; spectroscopy; laser scanning microscopy; transepidermal water loss (TEWL); hydration of the epidermis; corneometry; skin surface temperature; hydrophilic; lipophilic; occlusive dressing
20.  Serum and blister fluid pharmacokinetics and bactericidal activities of ampicillin-sulbactam, cefotetan, cefoxitin, ceftizoxime, and ticarcillin-clavulanate. 
Antimicrobial Agents and Chemotherapy  1992;36(10):2233-2238.
Ampicillin-sulbactam, ticarcillin-clavulanate, cefoxitin, cefotetan, and ceftizoxime are promoted for the treatment of mixed aerobic-anaerobic bacterial infections. Their activities have been compared in vitro but not in vivo. In order to assess the in vivo activities of these agents in serum and interstitial fluid, we administered single, intravenous doses of these antimicrobial agents to healthy subjects. Concentrations of the antimicrobial agents in serum and suction-induced blister fluid and bactericidal activity were measured by high-pressure liquid chromatography and the standard methodology of the National Committee for Clinical Laboratory Standards, respectively. The organisms used for bactericidal activity tests were one isolate each of Staphylococcus aureus, Klebsiella pneumoniae, and Bacteroides fragilis. Pharmacokinetic parameters in serum and blister fluid were similar to those derived in other investigations. Of note were the high and prolonged concentrations of ticarcillin and cefotetan in blister fluid, despite high-level serum protein binding. The bactericidal activities in serum and blister fluid reflected the relative in vitro activities and kinetic dispositions of the various antimicrobial agents except for the bactericidal activity of cefotetan, which was substantially lower in blister fluid than serum, despite a blister fluid:serum area under the concentration-time curve ratio of 1.5. Similarly, the activity of ticarcillin-clavulanate in blister fluid was also substantially less than would have been predicted by the blister fluid:serum ratio of the area under the concentration-time curve of 1.1, possibly because of the low concentrations of clavulanate in blister fluid. The rankings of the in vivo bactericidal activities of the five drugs were as follows: for S. aureus, ampicillin-sulbactam > ticarcillin-clavulanate > ceftizoxime > cefoxitin > cefotetan; for K. pneumoniae, ceftizoxime > cefotetan > ampicillin-sulbactam = ticarcillin-clavulanate > cefoxitin; and for B.fragilis, ticarcillin-clavulanate > cefotetan > ceftizoxime > ampicillin-sulbactam = cefoxitin.
PMCID: PMC245482  PMID: 1444304
21.  Evaluation of the in vitro skin permeation of antiviral drugs from penciclovir 1% cream and acyclovir 5% cream used to treat herpes simplex virus infection 
BMC Dermatology  2009;9:3.
Background
Herpes simplex virus infection (HSV) is a common and ubiquitous infection of the skin which causes mucocutaneous lesions called cold sores (herpes labialis) or fever blisters. It is estimated that approximately 80% of the population worldwide are carriers of the Herpes simplex virus, approximately 40% suffer from recurrent recurrent infections. This study evaluates the in vitro skin permeation and penetration of penciclovir and acyclovir from commercialized creams for the treatment of herpes labialis (cold sores), using non viable excised human abdominal skin samples, which were exposed to 5 mg/cm2 of acyclovir 5% cream or penciclovir 1% cream.
Methods
After 24 h of cream application, excess cream was washed off and layers of stratum corneum were removed by successive tape stripping. Amounts of active ingredients having penetrated through the skin were measured, as well as the amounts in the washed-off cream, in skin strips and creams remaining in the skin. Molecular modelling was used to evaluate physico-chemical differences between the drugs. Western blot analysis enabled to determine whether the marker of basal cells keratin 5 could be detected in the various tape strips.
Results
Application of penciclovir 1% cream yielded higher concentration of drug in the deeper layers of the epidermis as well as a higher drug flux through the skin. Molecular modelling showed two higher hydrophobic moieties for acyclovir. Presence of the basal cell marker keratin 5 was underscored in the deeper tape strips from the skin, giving evidence that both drugs can reach their target cells.
Conclusion
Penciclovir 1% cream has the tendency to facilitate the diffusion of the drug through the stratum corneum into the deeper epidermis layers, in which it could reach the target basal cells at effective therapeutical concentration. The small difference in the surface properties between both molecules might also contribute to favour the passage of penciclovir through the epidermis into the deeper basal cells.
doi:10.1186/1471-5945-9-3
PMCID: PMC2675515  PMID: 19341466
22.  Preparation, characterization, and in vivo evaluation of a self-nanoemulsifying drug delivery system (SNEDDS) loaded with morin-phospholipid complex 
Background
As a poorly water-soluble drug, the oral application of morin is limited by its low oral bioavailability. In this study, a new self-nanoemulsifying drug delivery system (SNEDDS), based on the phospholipid complex technique, was developed to improve the oral bioavailability of morin.
Methods
Morin-phospholipid complex (MPC) was prepared by a solvent evaporation method and characterized by infrared spectroscopy and X-ray diffraction. After formation of MPC, it was found that the liposolubility of morin was significantly increased, as verified through solubility studies. An orthogonal design was employed to screen the blank SNEDDS, using emulsifying rate and particle size as evaluation indices. Ternary phase diagrams were then constructed to investigate the effects of drug loading on the self-emulsifying performance of the optimized blank SNEDDS. Subsequently, in vivo pharmacokinetic parameters of the morin-phospholipid complex self-nanoemulsifying drug delivery system (MPC-SNEDDS) were investigated in Wistar rats (200 mg/kg of morin by oral administration).
Results
The optimum formulation was composed of Labrafil® M 1944 CS, Cremophor® RH 40, and Transcutol® P (3:5:3, w/w), which gave a mean particle size of approximately 140 nm. Oral delivery of the MPC-SNEDDS exhibited a significantly greater Cmax (28.60 μg/mL) than the morin suspension (5.53 μg/mL) or MPC suspension (23.74 μg/mL) (all P < 0.05). Tmax was prolonged from 0.48 to 0.77 hours and to 1 hour for MPC and MPC-SNEDDS, respectively. In addition, the relative oral bioavailability of morin formulated in the MPC-SNEDDS was 6.23-fold higher than that of the morin suspension, and was significantly higher than that of the MPC suspension (P < 0.05).
Conclusion
The study demonstrated that a SNEDDS combined with the phospholipid complex technique was a promising strategy to enhance the oral bioavailability of morin.
doi:10.2147/IJN.S25824
PMCID: PMC3260034  PMID: 22267925
morin; phospholipid complex; self-nanoemulsifying drug delivery system; oral bioavailability
23.  Mechanical injury polarizes skin dendritic cells to elicit a Th2 response by inducing cutaneous TSLP expression 
Atopic dermatitis (AD) is characterized by intense scratching and a Th2 dominated systemic and local immune response to cutaneously introduced antigens. Because scratching inflicts mechanical injury to the skin, we examined the effect of mechanical injury inflicted by tape stripping on the capacity of skin dendritic cells (DCs) to polarize T cells towards a Th2 phenotype. DCs isolated from skin 6 hrs after tape stripping elicited significantly higher production of IL-4 and IL-13, and significantly lower production of interferon-γ (IFN-γ) by OVA stimulated CD4+ DO.11.10 cells, than DCs isolated from unmanipulated skin, and expressed significantly more mRNA for the Th2 skewing molecules IL-10 and the Notch ligands Jagged1 and Jagged2, but significantly less mRNA for the Th1 skewing cytokine IL-12. CD11c+FITC+ cells isolated from draining lymph nodes (DLN) of shaved and tape stripped mouse skin 24 hrs after painting with FITC polarized T cells towards Th2 significantly more than CD11c+FITC+ cells isolated from DLN of shaved non tape stripped skin, and expressed significantly more IL-10, Jagged1 and Jagged2 mRNA, but significantly less IL-12 mRNA. Tape stripping significantly increased TSLP levels in the skin. Studies in TSLPR−/− mice demonstrated that TSLP played an essential role in the Th2 polarization effect of tape stripping on skin DCs. These results suggest that mechanical injury inflicted by scratching in patients with AD polarizes skin DCs to elicit a Th2 response by upregulating local expression of TSLP.
doi:10.1016/j.jaci.2010.08.041
PMCID: PMC3085022  PMID: 21050944
24.  Concentration Profiling in Rat Tissue by High-Resolution Magic-Angle Spinning NMR Spectroscopy: Investigation of a Model Drug 
Analytical chemistry  2005;77(9):2978-2984.
The utility of high-resolution magic-angle spinning (HR-MAS) NMR for studying drug delivery in whole tissues was explored by dosing female Sprague–Dawley rats with topical or injectable benzoic acid (BA). In principle, HR-MAS NMR permits the detection of both intra- and extracellular compounds. This is an advantage over the previous detection of topically applied BA using microdialysis coupled to HPLC/UV as microdialysis samples only the extracellular space. Skin and muscle samples were analyzed by 1H HR-MAS NMR, and BA levels were determined using an external standard solution added to the sample rotor. One to two percent of the BA topical dose was detected in the muscle, showing that BA penetrated through the dermal and subcutaneous layers. Since BA was not detected in the muscle in the microdialysis studies, the NMR spectra revealed the intracellular localization of BA. The amount of BA detected in muscle after subcutaneous injection correlated with the distance from the dosing site. Overall, the results suggest that HR-MAS NMR can distinguish differences in the local concentration of BA varying with tissue type, dosage method, and tissue proximity to the dosing site. The results illustrate the potential of this technique for quantitative analysis of drug delivery and distribution and the challenges to be addressed as the method is refined.
doi:10.1021/ac0482817
PMCID: PMC2519809  PMID: 15859619
25.  Skin barrier disruption by acetone: observations in a hairless mouse skin model 
Archives of Dermatological Research  2009;301(8):609-613.
To disrupt the barrier function of the skin, different in vivo methods have been established, e.g., by acetone wiping or tape-stripping. In this study, the acetone-induced barrier disruption of hairless mice was investigated in order to establish a reliable model to study beneficial, long-term effects on barrier recovery after topical application. For both treatments (i.e., acetone treatment and tape-stripping) the transepidermal water loss directly after disruption and the subsequent barrier recovery profile were similar. Histological assessment showed significant lower number of corneocyte layers in acetone-treated and tape-stripped skin compared to untreated skin, while there was no statistical difference between the two treatments. Lipid analysis of acetone-treated skin revealed that only small fraction of lipids were extracted consisting of predominantly nonpolar lipids. Importantly, the ratio of the barrier lipids, i.e., cholesterol, free fatty acids and ceramides, remained similar between control and acetone-treated skin. This reflects the undisrupted lipid organization, as determined by small-angle X-ray diffraction measurements: the long-periodicity lamellar phase was still present after acetone treatment. Our results contradict earlier studies which reported no mechanical stratum corneum removal, a substantial extraction of lipids and disruption in lipid organization. In conclusion, our studies demonstrate that barrier disruption due to acetone treatment is mainly due to removal of corneocytes.
doi:10.1007/s00403-009-0946-6
PMCID: PMC2728065  PMID: 19350255
Lipid organization; Skin barrier perturbation; Murine model

Results 1-25 (1012249)