Recently, a clear association has been found between the progression of motor neurodegenerative disorders (MNDs) and carotid atherosclerosis. Significant vascular abnormalities with arterial hypertension were shown to be in patients with familial antecedents of MNDs. The main scope of this work is to explore the feasibility of recently developed integrated nano-based imaging modalities for the assessment of early diagnosis of the inflammatory processes associated with the neurological disorder syndromes, with the implication of recently developed nanopharmaceutical therapeutic interventions.
Central nervous system; nanoparticles neurological disorders; oxides
Informed consent is an ethical and legal requirement for research involving human participants. It is the process where a participant is informed about all aspects of the trial, which are important for the participant to make a decision and after studying all aspects of the trial the participant voluntarily confirms his or her willingness to participate in a particular clinical trial and significance of the research for advancement of medical knowledge and social welfare. The concept of informed consent is embedded in the principles of Nuremberg Code, The Declaration of Helsinki and The Belmont Report. Informed consent is an inevitable requirement prior to every research involving human being as subjects for study. Obtaining consent involves informing the subject about his or her rights, the purpose of the study, procedures to be undertaken, potential risks and benefits of participation, expected duration of study, extent of confidentiality of personal identification and demographic data, so that the participation of subjects in the study is entirely voluntary. This article provides an overview of issues in informed consent: The obligations of investigator, sponsor and Institutional Review Board to protect rights and welfare of human research subjects. It discusses about the basic elements of informed consent and the process to be followed while obtaining informed consent. Some of the circumstances under which informed consent can be waived and ethical challenges faced by physicians in obtaining informed consent from subjects are also highlighted in this article.
Human subjects; informed consent; institutional review board
Ciprofloxacin is a fluoroquinolone and is used against a broad spectrum of gram-negative and gram-positive bacteria. The aim of the study is to investigate the effect of structural vehicles and other formulating factors on physical stability and rheological behavior of ciprofloxacin suspension. To formulate the suspensions, the effect of glycerin and polysorbate 80 as wetting agents was evaluated. Then to achieve controlled flocculation, different concentrations of sodium chloride and calcium chloride were added. After choosing suitable wetting and flocculating agents, structural vehicles such as sodium carboxyl methyl cellulose (NaCMC), hydroxypropylmethylcellulose (HPMC) and Veegum were evaluated. Physical stability parameters such as sedimentation volume, the degree of flocculation and the ease of redispersion of the suspensions and growth of crystals were evaluated. After incorporation of structural vehicles, the rheological properties of formulations containing were also studied to find out their rheological behavior. According to the results, suspension containing glycerin (0.2% w/v) and sodium chloride (0.05% w/v) as wetting agent and flocculating agent, respectively, were the most stable formulations regarding their F and N. Microscopic observations showed the growth of crystals in ciprofloxacin suspension in formulation without excipients and the minimum amount of crystal growth was seen in suspension containing NaCMC (0.25% w/v), Veegum (0.1% w/v) and NaCl (0.05% w/v). Rheological studies showed that almost all of the formulations had psuedoplastic behavior with different degree of thixotropy. The formulation containing NaCMC (0.25% w/v), Veegum (0.1% w/v) and NaCl (0.05% w/v) was the most stable formulation. It may be concluded that by altering the amount ratios of formulation factors, the best rheological behavior and the most proper thixotropy may be achieved.
Suspension; ciprofloxacin; wetting agents; flocculating agents; rheology
β-sitosterol is an important component in food and herbal products and beneficial in hyperlipidemia. Its higher concentrations in serum may lead to coronary artery disease in case of sitosterolemia. Therefore, it is essential to determine the quantity of β-sitosterol in food and herbal drugs. Saraca asoca and its preparations have been widely used by traditional healers are also a source of β-sitosterol. In the present study, quantitative estimation of β-sitosterol present in hot and cold water extracts of bark, regenerated bark, leaves and flowers of the S. asoca and Ashokarista drugs were carried out first time using high performance liquid chromatography coupled (HPLC) with quadrupole time-of-flight mass spectrometry. Different concentrations of β-sitosterol and crude extracts were estimated by HPLC and targeted mass spectrometry. Standard curve for β-sitosterol was prepared from the intensities of transitions (397.50 → 147.0987 m/z) having regression coefficient (r2) 0.9952. Out of eight extracts and two drugs used in the study bark water, leaves water and leaves hot water extracts were found to have a considerable quantity of β-sitosterol, i.e. 170, 123.5 and 19.3 ng/mL, respectively. The results showed significant differences in the distribution of β-sitosterol among different organs of S. asoca and drugs prepared from its bark. HPLC/electrospray ionizationmass spectroscopy method is accurate, reproducible and requires less specimen, sample preparation and analysis time over HPLC assay. This type of approaches could be helpful for the quality control of herbal medicines and provides necessary information for the rational utilization of plant resources.
Liquid chromatography-mass spectrometry; natural products; quantitative analysis; Saraca asoca; β-sitosterol
Clobazam is a newer 1,5-benzodiazepine used for the treatment of epilepsy. It is better tolerated and less sedating than other benzodiazepines. Absorption of the drug can be impacted by oral fast dissolving dosage form; this may have implications for epilepsy in pediatrics and those having difficulty in swallowing tablets/capsules resulting in improved patient compliance. The purpose of the present investigation was to formulate and optimize clobazam oro-dissolving tablets by direct compression method using response surface methodology (RSM). Oro-dispersible tablets of clobazam were prepared by direct compression method using crospovidone (2-6%) as a superdisintegrant, microcrystalline cellulose (MCC) (20-40%) was used as diluents along with directly compressible mannitol to enhance mouth feel. A 32 full factorial design was applied to investigate the combined effect of two formulation variables: amount of crospovidone and MCC over the independent variables disintegration time, wetting time and percent drug release. Disintegration time showed by all formulations was found to be in the range of 24.3-193 s based on evaluation parameters the formulation containing 6% of crospovidone and 30% of MCC showed promising performance against all other formulations. The results demonstrated that the RSM could efficiently be applied for the formulation of clobazam oro-dispersible tablets; therefore, constitute an advance in the management of epileptic attacks.
Antiepileptics; crospovidone; disintegration; microcrystalline cellulose; response surface methodology
A simple, specific, accurate, precise and robust high-performance thin-layer chromatographic method has been developed and validated for estimation of Lawsone in Trichup herbal hair powder (coded as a THHP), polyherbal formulation. The chromatographic development was carried out on aluminum plates pre-coated with silica gel 60F254 and good resolution was achieved with Toluene: Ethyl acetate: Glacial acetic acid (8:1:1 v/v/v) as mobile phase. Lawsone detection was carried out densitometrically at 277 nm and obtained retardation factor value was 0.46 ± 0.02. The method was validated with respect to specificity, linearity, accuracy, precision and robustness. The calibration curve was achieved to be linear over a range of 5-60 μg/ml and regression coefficient was obtained 0.998. Accuracy of chromatographic method was evaluated by standard addition method; recovery was obtained 99.25 ± 0.61%. The peak purity of Lawsone was achieved 0.999 r. Relative standard deviation for intraday and inter-day precision was 0.37-0.56% and 0.42-0.55%, respectively. The limit of detection and limit of quantification of the Lawsone were found to be 1.08 μg/m land 3.28 μg/ml, respectively. This result shows that the method was well validated. In the present study, the Lawsone content was found 0.322 ± 0.014% in THHP. This study reveals that the proposed high performance thin layer chromatography method is accurate, fast and cost- effective for routine estimation of Lawsone in polyherbal formulation.
Henna; high-performance thin-layer chromatography; Lawsone; Trichup herbal hair powder; validation
Mixed dyslipidemia is characterized by increased low-density lipoprotein cholesterol (LDL-C) elevated triglycerides (TGs) and decrease high-density lipoprotein cholesterol (HDL-C). It is more common in diabetes and is associated with an increased risk of coronary artery disease. Monotherapy with statins or fibrates may not effectively control all lipid parameters. The atorvastatin-fenofibrate combination has been shown to have highly beneficial effect on lipid parameters in type 2 diabetes associated with combined hyperlipidemia (CHL). In an open-label study, we evaluated the efficacy of atorvastatin alone and in combination with fenofibrate in 60 types 2 diabetes mellitus patients associated with hyperlipidemia. Patients were randomly assigned to receive atorvastatin 10 mg (Group 1) or combination of atorvastatin 10 mg and fenofibrate 145 mg (Group 2) once daily for 12 weeks. The effect of drugs on lipid profile was evaluated before and after treatment. After 12 weeks, the reduction in total cholesterol (TC), TGs, LDL-C, VLDL-C was 28%, 20%, 37% and 20% in Group 1 (P < 0.001 for all) as compared with 31%, 39%, 33% and 40% in Group 2 (P < 0.001 for all). There was insignificant rise in HDL-C in Group 1 (P = 0.71) and insignificant decrease in HDL-C (P = 0.70) in Group 2. During the combination therapy, the decrease in TC, TGs and VLDL-C was greater than atorvastatin alone. The combination of atorvastatin with fenofibrate in type 2 diabetes patients with CHL may have a favorable effect on some major coronary artery disease risk factors.
Atorvastatin; fenofibrate; hyperlipidemia
The aim of the present study was to develop controlled-release pellets of diltiazem HCl with ethyl cellulose and hydroxylpropyl methylcellulose phthalate as the release rate retarding polymers by fluid bed coating technique. The prepared pellets were evaluated for drug content, particle size, subjected to Scanning Electron Microscopy (SEM) and Differential Scanning Calori metry (DSC), and evaluated for in vitro release. Stability studies were carried out on the optimized formulations for a period of 3 months. The drug content was in the range of 97%-101%. The mean particle size of the drug-loaded pellets was in the range 700-785 μm. The drug release rate decreased as the concentration of ethyl cellulose increased in the pellet formulations. Among the prepared formulations, FDL10 and FDL11 showed 80% drug release in 16 h, matching with USP dissolution test 6 for diltiazem HCl extended-release capsules. SEM photographs confirmed that the prepared formulations were spherical in nature with a smooth surface. The compatibility between drug and polymers in the drug-loaded pellets was confirmed by DSC studies. Stability studies indicated that the pellets were stable.
Controlled release; diltiazem HCl; fluid bed coating; multiparticulate dosage forms; sustained release
Multifactorial metabolic diseases, for instance diabetes develop several complications like hyperlipidemia, hepatic toxicity, immunodeficiency etc., Hence, instead of mono-drug therapy the management of the disease requires the combination of herbs. Marketed herbal drugs comprise of irrational combinations, which makes their quality control more difficult. Phytoconstituents, despite having excellent bioactivity in vitro demonstrate less or no in vivo actions due to their poor lipid solubility, resulting in high therapeutic dose regimen; phospholipids encapsulation can overcome this problem. Hence, present study was designed to develop a phospholipids encapsulated polyherbal anti-diabetic formulation. In the present study, polyherbal formulation comprises of lyophilized hydro-alcoholic (50% v/v) extracts of Momordica charantia, Trigonella foenum-graecum and Withania somnifera 2:2:1, respectively, named HA, optimized based on oral glucose tolerance test model in normal Wistar rats. The optimized formulation (HA) entrapped in the phosphatidylcholine and cholesterol (8:2) vesicle system is named HA lipids (HAL). The vesicles were characterized for shape, morphology, entrapment efficiency, polar-dispersity index and release profile in the gastric pH. The antidiabetic potential of HA, marketed polyherbal formulation (D-fit) and HAL was compared in streptozotocin-induced diabetic rat model of 21 days study. The parameters evaluated were behavioral changes, body weight, serum glucose level, lipid profile and oxidative stress. The antidiabetic potential of HA (1000 mg/kg) was at par with the D-fit (1000 mg/kg). However, the potential was enhanced by phospholipids encapsulation; as HAL (500 mg/kg) has shown more significant (P < 0.05) potential in comparison to HA (1000 mg/kg) and at par with metformin (500 mg/kg).
Antihyperglycemic; antioxidant; metformin; streptozotocin
The main objective of the present study was isolation, purification, and characterization of actinomycetes from soil samples, having antimicrobial activity against 12 selected pathogenic strains. Soils samples were taken from different niche habitats of Sheopur district, Madhya Pradesh, India. These samples were serially diluted and plated on actinomycete isolation agar media. Potential colonies were screened, purified, and stored in glycerol stock. Isolates were morphologically and biochemically characterized. These isolates were subjected to extraction for production of the antibacterial compound. Antibacterial activity and Minimum Inhibitory Concentration (MIC) of the purified extract of isolates were evaluated. Totally 31 actinomycete isolates were tested for antagonistic activity against 12 pathogenic microorganisms. Isolates AS14, AS27, and AS28 were highly active, while AS1 showed less activity against the pathogenic microorganisms. Isolate AS7 exhibited the highest antagonistic activity against Bacillus cereus (24 mm) and AS16 showed the highest activity against Enterococcus faecalis (21 mm). MIC was also determined for actinomycete isolates against all the tested microorganisms. MIC of actinomycete isolates was found to be 2.5 mg/ml against Shigella dysenteriae, Vancomycin-resistant enterococci, and Klebsiella pneumoniae, and was 1.25 mg/ml for Staphylococcus saprophyticus, Streptococcus pyogenes, Staphylococcus epidermidis, Methicillin-resistant Staphylococcus, Bacillus cereus, Staphylococcus xylosus, Methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, and Staphylococcus aureus. All actinomycetes isolates showed antibacterial activity against S. aureus, while they showed less activity against S. dysenteriae. These isolates had antibacterial activity and could be used in the development of new antibiotics for pharmaceutical or agricultural purposes.
Agar well diffusion method; antimicrobial activity; minimum inhibitory concentration; pathogenic microorganisms; Sheopur
Advancement of materials technology has been immense, especially in the past 30 years. Ceramics has not been new to dentistry. Porcelain crowns, silica fillers in composite resins, and glass ionomer cements have already been proved to be successful. Materials used in the replacement of tissues have come a long way from being inert, to compatible, and now regenerative. When hydroxyapatite was believed to be the best biocompatible replacement material, Larry Hench developed a material using silica (glass) as the host material, incorporated with calcium and phosphorous to fuse broken bones. This material mimics bone material and stimulates the regrowth of new bone material. Thus, due to its biocompatibility and osteogenic capacity it came to be known as “bioactive glass-bioglass.” It is now encompassed, along with synthetic hydroxyapatite, in the field of biomaterials science known as “bioactive ceramics.” The aim of this article is to give a bird's-eye view, of the various uses in dentistry, of this novel, miracle material which can bond, induce osteogenesis, and also regenerate bone.
Biocompatible; bioinert; bioregenerative; hydroxyapatite; osteogenic
Drug information centre refer to facility specially set aside for, and specializing in the provision of drug information and related issues. The purpose of drug information center is to provide authentic individualized, accurate, relevant and unbiased drug information to the consumers and healthcare professionals regarding medication related inquiries to the nation for health care and drug safety aspects by answering their call regarding the all critical problems on drug information, their uses and their side effects. Apart from that the center also provides in-depth, impartial source of crucial drug information to meet the needs of the practicing physicians, pharmacists and other health care professionals to safeguard the health, financial and legal interests of the patient and to broaden the pharmacist role visible in the society and community. The service should include collecting, reviewing, evaluating, indexing and distributing information on drugs to health workers. Drug and poisons information centers are best established within major teaching hospitals. This allows access to clinical experience, libraries, research facilities and educational activities. Information present in the current paper will not only enlighten the role of drug information center but also focused on the rational use of drug.
Drug information center; drug information services; health care; illegal drug information center; Role of WHO
Saussurea lappa Clarke (Compositae), is commonly known as Kushta. In Ayurvedha, it is mentioned that the aqueous extract of the root S. lappa was used for treatment of angina pectoris. The present study was designed to investigate the cardioprotective effect of aqueous extract of root of S. lappa against isoproterenol induced myocardial injury. Myocardial injury in rat was induced by the administration of isoproterenol at a dose of 85 mg/kg, i.p., The rats were pretreated with the aqueous extract of S. lappa (AESL) in three different doses (100, 200 and 300 mg/kg, p.o.) through the oral route. Isoproterenol alone-treated rats showed increased serum concentration of lactate dehydrogenase (LDH), creatinine kinase (CK), and aspartate transaminase (AST), increased myocardial thiobarbituric acid reactive substances (TBARS) level, and decreased myocardial glutathione (GSH) level due to myocardial damage produced by isoproterenol. This is further conformed by histopathological changes. Chronic oral administration of AESL in three different doses significantly restored the level of myocardial LDH, CK, AST, TBARS, and GSH. The extract effect was compared with the reference standard α-tocopherol which also offered similar protection in biochemical and histopathological changes. The overall beneficial effect which was observed with the dose of 200 mg/kg indicated that AESL produced significant dose-dependent activity against isoproterenol induced myocardial injury.
Antioxidants; lactate dehydrogenase; myocardial infarction; oxidative stress; Saussurea lappa
A high-performance liquid chromatographic (HPLC) and ultraviolet (UV) methods were developed and validated for the quantitative determination of Ambroxol hydrochloride (AMH) in pharmaceutical dosage form. HPLC was carried out by reversed phase (RP) technique on an RP-18 column with a mobile phase composed of acetonitrile and water (pH 3.5 adjusted with orthophosphoric acid [60:40, v/v]). UV method was performed with the λmax at 250 nm. Both the methods showed good linearity, reproducibility, and precision. No spectral or chromatographic interferences from the tablet excipients were found in UV and HPLC. The method was successfully applied to commercial tablets. Validation parameters such as linearity, precision, accuracy, and specificity were determined. The HPLC Limit of detection (LOD) and Limit of quantification (LOQ) for Ambroxol were found to be 1 and 5 ng/ml, respectively. The UV LOD and LOQ for Ambroxol were found to be 1 and 4 μg/ml, respectively. The results were statistically compared using one-way analysis of variance. The proposed economical method could be applicable for routine analysis of AMH and monitoring of the quality of marketed drugs.
Ambroxol hydrochloride; high-performance liquid chromatographic; tablets; ultraviolet
The purpose of the present investigation was to prepare matrix tablets of naproxen using a hydrophobic polymer, i.e., Eudragit RLPO, RSPO, and combination of both, by wet granulation method. The tablets were further coated with different concentrations of Eudragit S-100, a pH-sensitive polymer, by dip immerse method. In vitro drug release studies of tablets were carried out in different dissolution media, i.e., 0.1 N HCl (pH 1.2), phosphate buffers pH 6.8 and 7.4, with or without rat cecal content. The swelling studies of the optimized formulation were carried out. The physicochemical parameters of all the formulations were found to be in compliance with the pharmacopoeial standards. The effect of dissolution medium on the surface of matrix tablet was determined by using Scanning Electron Microscopy technique. The stability studies of all formulations were performed as per ICH guidelines. The results demonstrated that the tablets coated with Eudragit S-100 (2% w/v) showed a sustained release of 94.67% for 24 h, but drug release increased to about 98.60% for 24 h in the presence of rat cecal content while the uncoated tablets released the drug within 5 h. With regard to release kinetics, the data were best fitted with the Higuchi model with non-Fickian drug release kinetics mechanism. The stability studies of tablets showed less degradation during accelerated and room temperature storage conditions for 6 months. The enteric-coated Eudragit S-100 coated matrix tablets of naproxen showed promising site-specific drug delivery in the colon region.
Eudragit S-100; matrix tablets; naproxen; non-Fickian; rat cecal
Marsilea minuta L., an aquatic or sub-aquatic fern used as a vegetable, has wide applications in traditional/folk medicine in India and Bangladesh. In our study, we evaluated the antitussive, expectorant activity of M. minuta crude extracts. The antitussive activity of M. minuta methanol, ethyl acetate, and petroleum ether extracts was evaluated using ammonia and sulfur dioxide induced mice coughing. The expectorant activity was evaluated by the volume of phenol red in mice's tracheas. Extracts significantly increased mice's cough latent period and inhibited the frequency of cough induced by ammonia and sulfur dioxide, and improved tracheal phenol red output in expectorant evaluation. Methanol extract produced the highest activity in all tested models. Methanol extract at 500 mg/kg showed 59.5% and 55.8% inhibition in the number of coughing induced by ammonium liquor and SO2, respectively, while it showed 89.3% increase in phenol red secretion at the same dose, which showed superior activity compared to other extracts. The present study provided evidence for M. minuta to be used as an antitussive and expectorant in Indian folk medicine.
Antitussive; expectorant; folk medicine; Marsilea minuta
The objective of the study was to prepare semisolid capsules (SSCs) of poorly water-soluble drug amlodipine besilate (AB) using a combination of technologies involving solid dispersion (SD) preparation and converting it into semisolid matrix filled in hard gelatin capsules (termed as SSCs) with the aim of reducing lag time in drug release and to improve the dissolution rate. AB is used for its anti-arrhythmic, anti-anginal, and anti-hypertensive activity. These are the emergency activities which should be treated as fast as possible like in the case of angina attack (heart attack). Any lag time that is generated due to its poor dissolution can add on in this emergency and that can be avoided by developing a readily dissolvable formulation: SDs of AB. SD of AB was prepared by fusion method using varying combinations of Poloxamer 407 and Plasdone S630. A total of nine batches (SD1–SD9) were characterized for the in vitro dissolution behavior in phosphate buffer pH7.4. SD8 with 95.8% cumulative drug release in 60 min, t50% = 4.1 min and DE30 Min = 84.2% were selected for the development of the semisolid matrix. Differential scanning calorimetry of SD8 revealed molecular dispersion of AB and Plasdone S630 in Poloxamer 407. SD8 was then formulated as SSCs using gelucire 44/14 and PEG 400 as semisolid components and PEG 6000 as a suspending agent to achieve the reduction in lag time for drug release. A total of seven SSC formulations were prepared and evaluated for drug release. Formulation of SSC4 showed maximum cumulative drug release (CDR) of 98.9% within 20 min that was almost a threefold reduction in the time required to achieve similar CDR by SD of AB. Thus, SSCs present an excellent approach to enhance the dissolution as well as to reduce the lag time of dissolution for poor water-soluble drugs especially to those therapeutic classes that are intended for faster onset of action.
Amlodipine besilate; dissolution; semisolid capsules; solid dispersions
Shankhpushpi is a cognition boosting traditional ayurvedic brain supplement. Convolvulus pluricaulis (Convolvulaceae), Evolvulus alsinoides (Convolvulaceae), Clitoria ternatea (Papilionaceae), and Canscora decussata (Gentianaceae) are botanical claimants of Shankhpushpi. This investigation is to focus the identification of the compound based on biological marker differentiation of four botanical claimants of Shankhpushpi for their antioxidant evaluation on thin layer chromatography (TLC) by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. A rapid TLC-DPPH method was developed to identify and differentiate four botanical claimants of Shankhpushpi in terms of presence of β-carotene, rutin, scopoletin, chlorogenic acid, and mangiferin. C. pluricaulis shows presence of scopoletin; E. alsinoides shows presence of β-carotene, scopoletin, and chlorogenic acid; C. ternatea shows presence of β-carotene, scopoletin, and rutin; and C. decussata shows presence of β-carotene, scopoletin, and mangiferin. The order, they followed, based on their antioxidant potential is β-carotene < mangiferin < rutin < scopoletin < chlorogenic acid. Antioxidants are attributed for their beneficial role in age-related cognition decline. The proposed method provides an edge in terms of identification and quantification of antioxidant constituents in a multi-component system. This method may also provide application for identification of correct plant sources used in the name of Shankhpushpi in marketed ayurvedic formulation, food supplement, and extracts.
Antioxidant; cognition; controversial; separation; Shankhpushpi
Nutraceuticals are food or part of food that provides medical or health benefits including the prevention and/or treatment of a disease. Nutraceutical has advantage over the medicine because they avoid side effect, have naturally dietary supplement, etc. Nutraceutical; on the basis of their natural source, chemical grouping, categories into three key terms -nutrients, herbals, dietary supplements, dietary fiber, etc. The most rapidly growing segments of the industry were dietary supplements (19.5 percent per year) and natural/herbal products (11.6 percent per year). Global nutraceutical market is estimated as USD 117 billion. FDA regulated dietary supplements as foods to ensure that they were safe. In 2006, the Indian government passed Food Safety and Standard Act to regulate the nutraceutical industry. Herbal nutraceutical is used as a powerful instrument in maintaining health and to act against nutritionally induced acute and chronic diseases, thereby promoting optimal health, longevity, and quality of life.
Dietary supplement; global market; nutraceutical; regulation
Designing an ophthalmic drug delivery system is one of the most difficult challenges for the researchers. The anatomy and physiology of eye create barriers like blinking which leads to the poor retention time and penetration of drug moiety. Some conventional ocular drug delivery systems show shortcomings such as enhanced pre-corneal elimination, high variability in efficiency, and blurred vision. To overcome these problems, several novel drug delivery systems such as liposomes, nanoparticles, hydrogels, and in situ gels have been developed. In situ-forming hydrogels are liquid upon instillation and undergo phase transition in the ocular cul-de-sac to form viscoelastic gel and this provides a response to environmental changes. In the past few years, an impressive number of novel temperature, pH, and ion-induced in situ-forming systems have been reported for sustain ophthalmic drug delivery. Each system has its own advantages and drawbacks. Thus, a combination of two drug delivery systems, i.e., nanoparticles and in situ gel, has been developed which is known as nanoparticle laden in situ gel. This review describes every aspects of this novel formulation, which present the readers an exhaustive detail and might contribute to research and development.
Ion-activated in situ gel; in situ gel; ocular irritancy test; pH-based hydrogel; temperature sensitive in situ gel