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1.  Endovascular Management of Infective Intracranial Aneurysms with Acrylic Glue 
Interventional Neuroradiology  2009;15(4):443-447.
Cerebral mycotic aneurysms (MAs) also called infective aneurysms, are uncommon and are usually encountered in patients with infective endocarditis. These aneurysms often present with intracranial hemorrhage. MAs may resolve on treatment with antibiotics alone. However prognosis with medical management alone is unpredictable. Good prognosis with surgery has been reported for single accessible ruptured MAs. However surgery is associated with significant morbidity. Endovascular treatment of MAs along with appropriate antibiotics is emerging as an acceptable option for these patients.
We describe two cases of infective endocarditis complicated by ruptured MA treated successfully by liquid embolic glue material.
PMCID: PMC3299432  PMID: 20465872
mycotic aneurysm, infective endocarditis, endovascular treatment, liquid embolic glue material
2.  Safety and efficacy of oral ivabradine as a heart rate-reducing agent in patients undergoing CT coronary angiography 
The British Journal of Radiology  2012;85(1016):e424-e428.
To investigate the role of oral ivabradine as a heart rate reducing agent in patients undergoing CT coronary angiography (CTCA). Despite the routine use of β-blockers prior to CTCA studies, it is not uncommon to have patients with heart rates persistently above the target range of 65 bpm. Ivabradine is a selective inhibitor of the If current, which primarily contributes to sinus node pacemaker activity, and has no significant direct cardiovascular effects such as reduction of blood pressure, cardiac contractility or impairment of cardiac conduction.
We investigated 100 consecutive patients who had been referred for CTCA for the evaluation of suspected coronary artery disease (CAD). Patients were randomised to receive either of the following two pre-medication protocols: oral metorprolol or oral ivabradine.
Ivabradine was significantly more effective than metorprolol in lowering the heart rate; the mean percentage reduction in heart rate with ivabradine vs metorpolol was 23.89+6.95% vs 15.20+4.50%, respectively (p=0.0001). Metoprolol significantly lowered both systolic and diastolic blood pressure while ivabradine did not. The requirement of additional doses to achieve a target heart rate of <65 beats per min was also significantly more frequent with metoprolol.
Ivabradine is a potentially attractive alternative to currently used drugs for reduction of heart rate in patients undergoing CTCA.
PMCID: PMC3485546  PMID: 22815422
4.  Emerging & re-emerging infections in India: An overview 
The incidence of emerging infectious diseases in humans has increased within the recent past or threatens to increase in the near future. Over 30 new infectious agents have been detected worldwide in the last three decades; 60 per cent of these are of zoonotic origin. Developing countries such as India suffer disproportionately from the burden of infectious diseases given the confluence of existing environmental, socio-economic, and demographic factors. In the recent past, India has seen outbreaks of eight organisms of emerging and re-emerging diseases in various parts of the country, six of these are of zoonotic origin. Prevention and control of emerging infectious diseases will increasingly require the application of sophisticated epidemiologic and molecular biologic technologies, changes in human behaviour, a national policy on early detection of and rapid response to emerging infections and a plan of action. WHO has made several recommendations for national response mechanisms. Many of these are in various stages of implementation in India. However, for a country of size and population of India, the emerging infections remain a real and present danger. A meaningful response must approach the problem at the systems level. A comprehensive national strategy on infectious diseases cutting across all relevant sectors with emphasis on strengthened surveillance, rapid response, partnership building and research to guide public policy is needed.
PMCID: PMC3767269  PMID: 24056553
Avian influenza; chikungunya; control; emerging infections; India; Nipah virus; plague; prevention
5.  Angiosarcoma of the spleen presenting as spontaneous splenic rupture: A rare case report and review of the literature 
Angiosarcoma of the spleen is a rare malignancy of vascular origin with a high rate of metastasis and poor prognosis. We report one such rare case of spontaneous splenic rupture, along with a review of current literature.
A 30 year old man presented to our emergency services with severe abdominal pain, distension, hypotension and splenomegaly. Investigations revealed a marked anaemia, coagulopathy, severe lactic acidosis, and acute kidney injury. Imaging demonstrated splenomegaly with acute haemorrhage and lymphadenopathy. Laparotomy and splenectomy revealed piecemeal spleen and nodular omentum. The patient suffered an intra-operative cardiorespiratory arrest, and despite successful resuscitation, fatally arrested postoperatively in ICU. Histology revealed a primary splenic angiosarcoma with omental metastases.
Primary splenic angiosarcoma was first reported in 1879, with only 200 cases reported to date, largely as isolated case reports, with an annual incidence of 0.14–0.25 per million. With variable symptomatology and a potential to present with life-threatening complications, early diagnosis is paramount. CT scanning shows distinctive changes and is invaluable in disease assessment. Tissue diagnosis is often possible only after splenectomy. Spontaneous rupture carries the worst prognosis.
Primary splenic angiosarcoma is a rare and aggressive malignancy that often presents with metastatic disease, and largely carries a dismal prognosis. Definitive diagnosis is challenging, but imaging with CT scanning can show characteristic changes and establish any metastatic disease. With no established adjuvant therapy long term outlook remains poor even if treated successfully by surgery.
PMCID: PMC3741459  PMID: 23856255
Angiosarcoma; Spleen; Rupture
6.  Noninvasive Determination of 2-[18F]-Fluoroisonicotinic Acid Hydrazide Pharmacokinetics by Positron Emission Tomography in Mycobacterium tuberculosis-Infected Mice 
Antimicrobial Agents and Chemotherapy  2012;56(12):6284-6290.
Tuberculosis (TB) is a global pandemic requiring sustained therapy to facilitate curing and to prevent the emergence of drug resistance. There are few adequate tools to evaluate drug dynamics within infected tissues in vivo. In this report, we evaluated a fluorinated analog of isoniazid (INH), 2-[18F]fluoroisonicotinic acid hydrazide (2-[18F]-INH), as a probe for imaging Mycobacterium tuberculosis-infected mice by dynamic positron emission tomography (PET). We developed a tail vein catheter system to safely deliver drugs to M. tuberculosis aerosol-infected mice inside sealed biocontainment devices. Imaging was rapid and noninvasive, and it could simultaneously visualize multiple tissues. Dynamic PET imaging demonstrated that 2-[18F]-INH was extensively distributed and rapidly accumulated at the sites of infection, including necrotic pulmonary TB lesions. Compared to uninfected animals, M. tuberculosis-infected mice had a significantly higher PET signal within the lungs (P < 0.05) despite similar PET activity in the liver (P > 0.85), suggesting that 2-[18F]-INH accumulated at the site of the pulmonary infection. Furthermore, our data indicated that similar to INH, 2-[18F]-INH required specific activation and accumulated within the bacterium. Pathogen-specific metabolism makes positron-emitting INH analogs attractive candidates for development into imaging probes with the potential to both detect bacteria and yield pharmacokinetic data in situ. Since PET imaging is currently used clinically, this approach could be translated from preclinical studies to use in humans.
PMCID: PMC3497161  PMID: 23006755
7.  Interactions between the FTO and GNB3 Genes Contribute to Varied Clinical Phenotypes in Hypertension 
PLoS ONE  2013;8(5):e63934.
The genes FTO and GNB3 are implicated in essential hypertension but their interaction remains to be explored. This study investigates the role of interaction between the two genes in the pathophysiology of essential hypertension.
Methods/Principal Findings
In a case-control study comprising 750 controls and 550 patients, interaction between the polymorphisms of FTO and GNB3 was examined using multifactor dimensionality reduction (MDR). The influence of interaction on clinical phenotypes like systolic and diastolic blood pressure, mean arterial pressure and body mass index was also investigated. The 3-locus MDR model comprising FTO rs8050136C/A and GNB3 rs1129649T/C and rs5443C/T emerged as the best disease conferring model. Moreover, the interacted-genotypes having either 1, 2, 3, 4 or 5 risk alleles correlated with linearly increasing odds ratios of 1.91 (P = 0.027); 3.93 (P = 2.08E–06); 4.51 (P = 7.63E–07); 7.44 (P = 3.66E–08) and 11.57 (P = 1.18E–05), respectively, when compared with interacted-genotypes devoid of risk alleles. Furthermore, interactions among haplotypes of FTO (H1−9) and GNB3 (Ha-d) differed by >1.5-fold for protective-haplotypes, CTGGC+TC [H2+Ha] and CTGAC+TC [H4+Ha] (OR = 0.39, P = 0.003; OR = 0.22, P = 6.86E–05, respectively) and risk-haplotypes, AAAGC+CT [H3+Hc] and AAAGC+TT [H3+Hd] (OR = 2.91, P = 9.98E–06; OR = 2.50, P = 0.004, respectively) compared to individual haplotypes. Moreover, the effectiveness of gene-gene interaction was further corroborated with a 1.29-, 1.25- and 1.38-fold higher SBP, MAP and BMI, respectively, in patients having risk interacted-haplotype H3+Hc and 2.48-fold higher SBP having risk interacted-haplotype H3+Hd compared to individual haplotypes.
Interactions between genetic variants of FTO and GNB3 influence clinical parameters to augment hypertension.
PMCID: PMC3653800  PMID: 23691120
8.  Bioactivity Guided Fractionation of Leaves Extract of Nyctanthes arbor tristis (Harshringar) against P falciparum 
PLoS ONE  2012;7(12):e51714.
Nyctanthes arbor-tristis (Harshringar, Night Jasmine) has been traditionally used in Ayurveda, Unani and other systems of medicine in India. The juice of its leaves has been used by various tribal populations of India in treatment of fevers resembling malaria.
Aim of the study
This work reports the antiplasmodial activity guided fractionation of Harshringar leaves extract.
Crude ethanolic Harshringar leaves extract and its RPHPLC purified fractions were studied for antiplasmodial potency against 3D7 (CQ sensitive) and Dd2 (CQ resistant) strains of P.falciparum and subsequently subjected to bioassay guided fractionation using reverse phase chromatography to pursue the isolation of active fractions.
Principal Findings
Harshringar crude leaves extract and some of its RPHPLC purified fractions exhibited promising antiplasmodial potency against 3D7 and Dd2 strains of P.falciparum.
The present study has provided scientific validity to the traditional use of leaves extract of Harshringar against malaria leading to the conclusion that this plant holds promise with respect to antimalarial phytotherapy. This is the first scientific report of antiplasmodial activity of RPHPLC fractions of Harshringar leaves extract against P.falciparum strains.
PMCID: PMC3530506  PMID: 23300557
9.  Serum C-reactive protein and leptin for assessment of nutritional status in patients on maintenance hemodialysis 
Indian Journal of Nephrology  2012;22(6):419-423.
Nutrition is one of the key parameters in predicting morbidity and mortality in patients with end-stage renal disease (ESRD) on hemodialysis. Body weight, body mass index, and visceral protein levels (serum protein, albumin, prealbumin, and transferrin) have traditionally been used as markers for nutritional status. Serum leptin and C-reactive protein (CRP), have been recently added to the list of markers for nutritional status. This study was a comparative assessment of serum leptin and CRP for nutritional status in patients with ESRD on maintenance hemodialysis. A total of 40 patients with ESRD on maintenance hemodialysis and a similar number of age-, gender-, and BMI-matched healthy individuals were studies. Complete medical history was obtained and relevant clinical examination including anthropometry was carried out. All the individuals were subjected to routine investigations and special investigations (serum leptin and CRP). Data were analyzed using Student's t-test and correlation was found using Pearson's correlation coefficient. Mean value of serum leptin for the study group (1.44 ± 0.72 ng/ml) was found to be significantly higher than that of the control group (0.68 ± 0.55 ng/ml). In addition, we also observed a positive correlation between serum leptin and BMI (r = 0.350, P<0.05). For CRP, we observed that the study group (3.93 ± 1.20 mg/ml) had a significantly higher value vis-à-vis the control group (0.28 ± 0.24 mg/ml). However, CRP and BMI did not show a significant correlation. Based on the above observations, we conclude that serum leptin is a better biomarker than CRP for assessing nutritional status in patients with ESRD on maintenance hemodialysis.
PMCID: PMC3573482  PMID: 23440668
Body mass index; C-reactive protein; hemodialysis; malnutrition; serum leptin
10.  Association of the Myostatin Gene with Obesity, Abdominal Obesity and Low Lean Body Mass and in Non-Diabetic Asian Indians in North India 
PLoS ONE  2012;7(8):e40977.
To determine the association of the A55T and K153R polymorphisms of the Myostatin gene with obesity, abdominal obesity and lean body mass (LBM) in Asian Indians in north India.
Materials and Methods
A total of 335 subjects (238 men and 97 women) were assessed for anthropometry, % body fat (BF), LBM and biochemical parameters. Associations of Myostatin gene polymorphisms were evaluated with anthropometric, body composition and biochemical parameters. In A55T polymorphism, BMI (p = 0.04), suprailiac skinfold (p = 0.05), total skinfold (p = 0.008), %BF (p = 0.002) and total fat mass (p = 0.003) were highest and % LBM (p = 0.03) and total LBM (Kg) were lowest (p = 0.04) in subjects with Thr/Thr genotype as compared to other genotypes. Association analysis of K153R polymorphism showed that subjects with R/R genotype had significantly higher BMI (p = 0.05), waist circumference (p = 0.04), %BF (p = 0.04) and total fat mass (p = 0.03), and lower %LBM (p = 0.02) and total LBM [(Kg), (p = 0.04)] as compared to other genotypes. Using a multivariate logistic regression model after adjusting for age and sex, subjects with Thr/Thr genotype of A55T showed high risk for high %BF (OR, 3.92, 95% Cl: 2.61–12.41), truncal subcutaneous adiposity (OR, 2.9, 95% Cl: 1.57–6.60)] and low LBM (OR, 0.64, 95% CI: 0.33–0.89) whereas R/R genotype of K153R showed high risk of obesity (BMI; OR, 3.2, 95% CI: 1.2–12.9; %BF, OR, 3.6, 95% CI: 1.04–12.4), abdominal obesity (OR, 2.12, 95% CI: 2.71–14.23) and low LBM (OR, 0.61, 95% CI: 0.29–0.79).
We report that variants of Myostatin gene predispose to obesity, abdominal obesity and low lean body mass in Asian Indians in north India.
PMCID: PMC3423417  PMID: 22916099
11.  Giant cell glioblastoma in a child: A rare case report 
Asian Journal of Neurosurgery  2012;7(3):144-146.
Giant cell glioblastoma (GCG) is a subtype of Glioblastoma multiforme that is rare in incidence and distinct in features and histopathological examination. It is reported to have better prognosis than common glioblastomas. The incidence of GCG in children is even more rare. We report a case of GCG in a 10-year-old boy along with a review of the relevant literature focusing on the differentiating points from common glioblastoma.
PMCID: PMC3532762  PMID: 23293671
Giant cell glioblastoma; glioblastoma; pediatric
12.  Lumbosacral arachnoid cyst with tethered cord: A rare case report 
Arachnoid cysts are cerebrospinal fluid collections in the spine that can present with neurological symptoms or be discovered accidentally. Intradural location of such cysts especially in the lumbosacral region is relatively rare. The association of such cysts with other congenital anomalies such as tethered cord lends evidence to the developmental origin of arachnoid cysts. We report a case of lumbosacral arachnoid cyst with tethered cord in a 6-year-old male child and discuss the etiopathogenesis and management options.
PMCID: PMC3777317  PMID: 24082689
Arachnoid cyst; intradural; lumbosacral; syrinx
13.  Correlation of Adiponectin and Leptin with Insulin Resistance: A Pilot Study in Healthy North Indian Population 
The increasing incidence of obesity, leading to metabolic complications is now recognized as a major public-health problem. Insulin resistance is a central abnormality of the metabolic syndrome, or syndrome X, originally hypothesized by Reaven Insulin resistance is more strongly linked to intra abdominal fat than to fat in other depots. Adipose tissue secretes numerous factors (adipokines) known to markedly influence lipid and glucose/insulin metabolism, oxidative stress, and cardiovascular integrity. Some of these adipokines have been shown to directly or indirectly affect insulin sensitivity through modulation of insulin signaling and the molecules involved in glucose and lipid metabolism. A pilot study was conducted with 80 healthy subjects who were non diabetic, non hypertensive and having no family history of hypertension, the aim was to evaluate the correlation of adiponectin and leptin levels with obesity and insulin resistance markers in healthy north Indian adult population. Serum leptin, adiponectin and insulin was estimated by sandwich ELISA method. In our study, Leptin correlated significantly with BMI (P value of 0.0000), WC (P value = 0.007), and HC (P value = 0.000). leptin showed significant positive correlation with fasting insulin (P value 0.002), post prandial insulin (P value = 0.000) and HOMA-IR (P value = 0.002). Adiponectin showed significant positive correlation with triglycerides (P value = 0.038), strong negative correlation with HDL-cholesterol (P value = 0.017). Serum concentrations of leptin are associated with central body fat distribution. Insulin resistance and adiponectin is associated with dyslipidemia and these all disorders may ultimately lead to metabolic syndrome.
PMCID: PMC3107404  PMID: 22468049
Adiponectin; Leptin; Insulin resistance; Cytokines
14.  Optimization of process parameters for osmotic dehydration of papaya cubes 
Process temperature (30, 40 and 50 °C), syrup concentration (50, 60 and 70o Brix) and process time (4, 5 and 6 h) for osmotic dehydration of papaya (Carica papaya) cubes were optimized for the maximum water loss and optimum sugar gain by using response surface methodology. The peeled and pre-processed papaya cubes of 1 cm size were immersed in sugar syrup at constant temperature water bath having syrup to papaya cubes ratio of 4:1 (w/w). The cubes were removed from bath at pre-decided time, rinsed with water and weighed. Initial moisture content of papaya samples were 87.5–88.5% (wb), which was reduced to 67.6–81.1% after osmotic dehydration in various experiments showing mass reduction, water loss and sugar gain in the range of 20.6–36.4, 23.2–44.5 and 2.5–8.1%, respectively. The weight reduction, water loss and sugar gain data were statistically analyzed and regression equation of second order were found the best fit for all the experimental data. Maximum water loss of 28% with optimum sugar gain of 4% was predicted for the 60oBrix syrup concentration at 37 °C for syrup to fruit ratio as 4:1 in 4.25 h of osmotic dehydration.
PMCID: PMC3551066  PMID: 23572736
Papaya; Osmotic dehydration kinetics; Water loss; Sugar gain
15.  Novel Trichomonacidal Spermicides▿†‡ 
Metronidazole, the U.S. Food and Drug Administration-approved drug against trichomoniasis, is nonspermicidal and thus cannot offer pregnancy protection when used vaginally. Furthermore, increasing resistance of Trichomonas vaginalis to 5-nitro-imidazoles is a cause for serious concern. On the other hand, the vaginal spermicide nonoxynol-9 (N-9) does not protect against sexually transmitted diseases and HIV in clinical situations but may in fact increase their incidence due to its nonspecific, surfactant action. We therefore designed dually active, nonsurfactant molecules that were capable of killing Trichomonas vaginalis (both metronidazole-susceptible and -resistant strains) and irreversibly inactivating 100% human sperm at doses that were noncytotoxic to human cervical epithelial (HeLa) cells and vaginal microflora (lactobacilli) in vitro. Anaerobic energy metabolism, cell motility, and defense against reactive oxygen species, which are key to survival of both sperm and Trichomonas in the host after intravaginal inoculation, depend crucially on availability of free thiols. Consequently, molecules were designed with carbodithioic acid moiety as the major pharmacophore, and chemical variations were incorporated to provide high excess of reactive thiols for interacting with accessible thiols on sperm and Trichomonas. We report here the in vitro activities, structure-activity relationships, and safety profiles of these spermicidal antitrichomonas agents, the most promising of which was more effective than N-9 (the OTC spermicide) in inactivating human sperm and more efficacious than metronidazole in killing Trichomonas vaginalis (including metronidazole-resistant strain). It also significantly reduced the available free thiols on human sperm and inhibited the cytoadherence of Trichomonas on HeLa cells. Experimentally in vitro, the new compounds appeared to be safer than N-9 for vaginal use.
PMCID: PMC3165359  PMID: 21709091
16.  SREBP-2 1784 G/C Genotype is Associated with Non-Alcoholic Fatty Liver Disease in North Indians 
Disease markers  2011;31(6):371-377.
Background: Genetics of non-alcoholic fatty liver (NAFLD) in Asian Indians has been inadequately investigated. This study aims to determine the association of the 1784G > C polymorphism in the SREBP-2 gene with NAFLD in Asian Indians in north India.
Methods: In this study, (n = 335); 162 obese with NAFLD, 91 obese without NAFLD and 82 non-obese without NAFLD subjects were recruited. Abdominal ultrasound, clinical profile, anthropometry, metabolic profile, serum levels of alanine aminotransferase, aspartate aminotransferase, fasting insulin and high sensitivity C-reactive protein (hs-CRP) were analysed. Polymerase chain reaction and restriction fragment length polymorphism were used to identify individual genotypes, and the association of this polymorphism with clinical and biochemical parameters was assessed.
Results: The observed frequency of G allele was 0.73 and C allele was 0.27. Frequency of C/C genotype was higher in NAFLD as compared to obese and non-obese subjects (p = 0.003). In NAFLD subjects 57.4% were G/G homozygous, 31.5% G/C heterozygous and 11.1% were C/C homozygous. The SREBP-2 genotype frequencies deviated from the Hardy Weinberg Equilibrium (X2 = 6.39, p = 0.0114). Mean values of TG (p = 0.002), TC (p = 0.002), ALT (p = 0.04) and AST (p =0.03) levels were significantly higher in NAFLD subjects with G/C genotype as compared to G/G genotypes in obese and non-obese groups. Fasting insulin (p = 0.03), HOMA (p = 0.009) and hs-CRP levels were significantly higher in NAFLD subjects with G/C genotype as compared to obese and non obese subjects with G/G genotypes.
Conclusion: In this study, conducted for the first time in Asian Indians, SREBP-2 1784 G > C genotype was associated with NAFLD.
PMCID: PMC3826379  PMID: 22182810
Sterol regulatory element binding protein-2; Non-alcoholic fatty liver disease; Asian Indians; Alanine transaminase
17.  Involvement of Physical Parameters in Medium Improvement for Tannase Production by Aspergillus niger FETL FT3 in Submerged Fermentation 
Aspergillus niger FETL FT3, a local extracellular tannase producer strain that was isolated from one of dumping sites of tannin-rich barks of Rhizophora apiculata in Perak, Malaysia. This fungus was cultivated in 250 mL Erlenmeyer flask under submerged fermentation system. Various physical parameters were studied in order to maximize the tannase production. Maximal yield of tannase production, that is, 2.81 U per mL was obtained on the fourth day of cultivation when the submerged fermentation was carried out using liquid Czapek-Dox medium containing (percent; weight per volume) 0.25% NaNO3, 0.1% KH2PO4, 0.05% MgSO4 ·7H2O, 0.05% KCl, and 1.0% tannic acid. The physical parameters used initial medium pH of 6.0, incubation temperature of 30°C, agitation speed of 200 rpm and inoculums size of 6 × 106 spores/ ml. This research has showed that physical parameters were influenced the tannase production by the fungus with 156.4 percent increment.
PMCID: PMC3150781  PMID: 21826273
18.  A calcified conundrum 
The British Journal of Radiology  2010;83(990):535-537.
PMCID: PMC3473593  PMID: 20505035
19.  Studies on moisture sorption isotherms for osmotically dehydrated papaya cubes and verification of selected models 
The water desorption properties of osmotically dehydrated papaya cubes at various temperatures were studied by fitting experimental isotherms in Henderson, Oswin, Chen and Clayton and Kuhn equations having 2 parameters and Henderson and Oswin equations were modified to describe the temperature dependence of isotherm data. Oswin equation was useful to predict the equilibrium moisture content values for use in determining the effective moisture diffusion coefficient during subsequent air drying process.
PMCID: PMC3551034  PMID: 23572650
Papaya cubes; Desorption isotherms; Equilibrium moisture content; Diffusion coefficient; Osmotic dehydration; Air drying
20.  Pneumatocele formation in adult Escherichia coli pneumonia 
Annals of Thoracic Medicine  2011;6(2):101-102.
PMCID: PMC3081554  PMID: 21572702
21.  In-vitro Interaction of a Novel Immunosuppressant, FK 506, and Antacids 
The effect of selected antacids on the amount of FK 506 in solution in simulated gastric juice has been studied. FK 506 (2·5 mg) was incubated in 100 mL simulated gastric fluid (SGF) with the equivalent of 500 mg of various antacids. The addition of Mylanta and Tums resulted in 14 and 30% loss of FK 506, respectively, in 24 h; 98% loss was observed in 12 h in the presence of Mag-Ox; 100% loss was observed in the presence of magnesium oxide powder in 2 h. The loss of FK 506 from these solutions appears to be due to a pH mediated degradation of FK 506. The addition of aluminium hydroxide gel USP (Roxane) to the FK 506 solution resulted in a 35% loss within 2 min but no further loss was noted for 24 h, indicative of adsorption of FK 506. These results suggest that until additional in-vivo studies are carried out, it is prudent not to dose FK 506 and antacids at the same time to avoid potential interactions.
PMCID: PMC3022501  PMID: 1717676
22.  Development and Validation of a Reversed-phase HPLC Method for Simultaneous Determination of Aspirin, Atorvastatin Calcium and Clopidogrel Bisulphate in Capsules 
A simple, accurate, rapid and precise isocratic reversed-phase high-performance liquid chromatographic method has been developed and validated for simultaneous determination of aspirin, atorvastatin calcium and clopidogrel bisulphate in capsules. The chromatographic separation was carried out on an Inertsil ODS analytical column (150×4.6 mm; 5 μm) with a mixture of acetonitrile:phosphate buffer pH 3.0 adjusted with o-phosphoric acid (50:50, v/v) as mobile phase; at a flow rate of 1.2 ml/min. UV detection was performed at 235 nm. The retention times were 1.89, 6.6 and 19.8 min. for aspirin, atorvastatin calcium and clopidogrel bisulphate, respectively. Calibration plots were linear (r2>0.998) over the concentration range 5-30 μg/ml for atorvastatin calcium and 30-105 μg/ml for aspirin and clopidogrel bisulphate. The method was validated for accuracy, precision, specificity, linearity, and sensitivity. The proposed method was successfully used for quantitative analysis of capsules. No interference from any component of pharmaceutical dosage form was observed. Validation studies revealed that method is specific, rapid, reliable, and reproducible. The high recovery and low relative standard deviation confirm the suitability of the method for routine determination of aspirin, atorvastatin calcium and clopidogrel bisulphate in bulk drug and capsule dosage form.
PMCID: PMC3224406  PMID: 22131618
Aspirin; atorvastatin calcium; clopidogrel bisulphate; HPLC
23.  Osmo-air drying of aloe vera gel cubes 
Aloe vera (Aloe barbadensis Miller) cubes of 12.5 × 12.5 × 12.5 mm thick were osmosed for 4 h in sugar syrup of 30, 40 and 50°Brix concentration and temperatures of 30 and 50°C at constant syrup to fruit ratio of 5:1. Osmosed and unosmosed aloe vera samples were hot air dried at 50, 60, 70 and 80°C with constant air velocity of 1.5 m/s. The water loss, solid gain and convective drying behaviour were recorded during experiments. It was observed that water loss and solid gain ranged from 39.2 to 71.3 and 2.7 to 6.3%, respectively during osmo-drying. The moisture diffusivity varied from 2.9 to 8.0 × 10−9 m²/s and 2.7 to 4.6 × 10−9 m²/s during air drying of osmosed and unosmosed aloe vera samples, respectively. Drying air temperature and osmosis as pre-treatment affected the water loss, solid gain, diffusivity at −p ≤ 0.01
PMCID: PMC3022148  PMID: 21350589
Aloe vera; Osmosis; Hot-air drying; Moisture diffusivity; Water loss; Solid gain
24.  Osmo-air drying of aloe vera gel cubes 
Aloe vera (Aloe barbadensis Miller) cubes of 12.5 × 12.5 × 12.5 mm thick were osmosed for 4 h in sugar syrup of 30, 40 and 50°Brix concentration and temperatures of 30 and 50°C at constant syrup to fruit ratio of 5:1. Osmosed and unosmosed aloe vera samples were hot air dried at 50, 60, 70 and 80°C with constant air velocity of 1.5 m/s. The water loss, solid gain and convective drying behaviour were recorded during experiments. It was observed that water loss and solid gain ranged from 39.2 to 71.3 and 2.7 to 6.3%, respectively during osmo-drying. The moisture diffusivity varied from 2.9 to 8.0 × 10−9 m²/s and 2.7 to 4.6 × 10−9 m²/s during air drying of osmosed and unosmosed aloe vera samples, respectively. Drying air temperature and osmosis as pre-treatment affected the water loss, solid gain, diffusivity at −p ≤ 0.01
PMCID: PMC3022148  PMID: 21350589
Aloe vera; Osmosis; Hot-air drying; Moisture diffusivity; Water loss; Solid gain
25.  Design and Optimization of Floating Drug Delivery System of Acyclovir 
The purpose of the present work was to design and optimize floating drug delivery systems of acyclovir using psyllium husk and hydroxypropylmethylcellulose K4M as the polymers and sodium bicarbonate as a gas generating agent. The tablets were prepared by wet granulation method. A 32 full factorial design was used for optimization of drug release profile. The amount of psyllium husk (X1) and hydroxypropylmethylcellulose K4M (X2) were selected as independent variables. The times required for 50% (t50%) and 70% (t70%) drug dissolution were selected as dependent variables. All the designed nine batches of formulations were evaluated for hardness, friability, weight variation, drug content uniformity, swelling index, in vitro buoyancy, and in vitro drug release profile. All formulations had floating lag time below 3 min and constantly floated on dissolution medium for more than 24 h. Validity of the developed polynomial equation was verified by designing two check point formulations (C1 and C2). The closeness of predicted and observed values for t50% and t70% indicates validity of derived equations for the dependent variables. These studies indicated that the proper balance between psyllium husk and hydroxypropylmethylcellulose K4M can produce a drug dissolution profile similar to the predicted dissolution profile. The optimized formulations followed Higuchi's kinetics while the drug release mechanism was found to be anomalous type, controlled by diffusion through the swollen matrix.
PMCID: PMC3116305  PMID: 21694992
Acyclovir; factorial design; gastro retentive drug delivery; hydroxypropylmethylcellulose; psyllium husk

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