DEVELOPMENT AND OPTIMIZATION OF ORODISPERSIBLE TABLETS OF CARVEDILOL BY COMBINATION OF SUPER-DISINTEGRANTS ADDITION AND SUBLIMATION TECHNIQUES

Objective: Objective of the present research work was to prepare orodispersible tablets of carvedilol (CDL) for dysphagic patients.Methods: Carvedilol, an anti-hypertensive drug, was chosen as a model drug in this study. Orodispersible tablets of carvedilol were prepared using different super-disintegrating agents such as crospovidone, croscarmellose sodium and sodium starch glycolate at different concentrations. The best formulation was selected based on disintegration and dissolution profile that was further taken for sublimation studies using camphor, menthol and thymol. Drug-excipients interaction studies were carried out by fourier transform infra-red (FTIR) spectrophotometer with pure drug sample and optimized formulation.Results: The orodispersible tablet formulation having 4% croscarmellose sodium disintegrated in 92 sec. Hence this formulation was considered best formulation and taken further for sublimation studies. A formulation containing 10% w/w of menthol showed disintegration time of 16 sec with more than 96.64% drug release within 15 min. Menthol leaves the porous structure as it sublimates from the tablet. This might have contributed to the decrease in disintegration time. Hence, this formulation was considered optimized.Conclusion: From this study, it can be concluded that orodispersible tablets of carvedilol may prove to be more efficacious in the treatment of hypertension particularly in dysphagic patients

HIBISCUS ROSA SINENSIS LOADED SOLID LIPID NANOPARTICLES AND IN VIVO WOUND HEALING ACTIVITY IN WISTAR ALBINO RATS

Objective: The objective of the present research was to investigate the wound-healing potency of solid lipid nano particles of Hibiscus rosa sinensis extract. Crude herbal extracts and rudimentary formulations containing herbal extracts are good for demonstrating the feasibility of the concept; however, such formulations suffer with poor oral bioavailability and variability within groups of subjects. Converting herbal extracts into novel drug delivery systems may prove effective in addressing some of these problems. Methods: In the present study an attempt was made to develop Hibiscus rosa sinensis extract loaded solid lipid nanoparticles (HSLNs) using lipids glycerol monostearate (GMS) or beeswax. The prepared HSLNs were characterised for their size, surface charge and morphology. The optimized HSLNs were incorporated into Carbopol gel and tested for wound healing activity in male Wistar albino rats using excision wound model. Results: HSLNs of ~175 nm in size carrying negative charge were obtained with the optimised procedure using beeswax. The shape of the HSLNs was nearly spherical. The HSLNs (10 mg/ml) treated wounds healed much faster compared to raw crude extract and healing was comparable to marketed preparation. Conclusion: It is concluded that converting crude herbal extracts into SLNs can be an effective way to enhance the effectiveness of herbal extracts and their in vivo activity

DEVELOPMENT, CHARACTERIZATION AND EVALUATION OF SOFT ORAL EDIBLE GEL USING GELLAN GUM

Objective: The objective of present research work was to formulate and evaluate a novel oral edible gel dosage form using gellan gum as gelling agent and carvedilol as a model drug to ease the administration to dysphagic and geriatric patients. Methods: Oral edible gels were prepared using gelling agent low acetylated gellan gum and sodium citrate in different concentrations. The prepared edible gel formulations were evaluated for gelation time, appearance, texture, viscosity, pH, syneresis, drug-excipient compatibility studies by fourier transform infrared FTIR and percentage of drug release from the gel formulation. Results: Formulation containing gellan gum (0.4 % w/v) and sodium citrate (0.3 % w/v)) was found to be spoon thick†in consistency that is accepted for dysphagic patients as per national dysphagia diet task force. This formulation showed more than 95 % drug release within 12 min and found to be stable for 6 mo. All other parameters tested were optimal. Hence, this formulation was considered optimized. Conclusion: From this study, it can be concluded that the novel edible gel dosage form containing Carvedilol can be formulated and this dosage form may prove to be more efficacious in the treatment of hypertension in dysphagic patients

Homologous overexpression of hydrogenase and glycerol dehydrogenase in Clostridium pasteurianum to enhance hydrogen production from crude glycerol

This study reports engineering of a hypertransformable variant of C. pasteurianum for bioconversion of glycerol into hydrogen (H2). A functional glycerol-triggered hydrogen pathway was engineered based on two approaches: (1) increasing product yield by overexpression of immediate enzyme catalyzing H2 production, (2) increasing substrate uptake by overexpression of enzymes involved in glycerol utilization. The first strategy aimed at overexpression of hydA gene encoding hydrogenase, and the second one, through combination of overexpression of dhaD1 and dhaK genes encoding glycerol dehydrogenase and dihydroxyacetone kinase. These genetic manipulations resulted in two recombinant strains (hydA ++ /dhaD1K ++) capable of producing 97% H2 (v/v), with yields of 1.1 mol H2/mol glycerol in hydA overexpressed strain, and 0.93 mol H2/mol glycerol in dhaD1K overexpressed strain, which was 1.5 fold higher than wild type. Among two strains, dhaD1K ++ consumed more glycerol than hydA ++ which proves that overexpression of glycerol enzymes has enhanced glycerol intake rate

Sonochemical Synthesis of Cobalt Ferrite Nanoparticles

Cobalt ferrite being a hard magnetic material with high coercivity and moderate magnetization has found wide-spread applications. In this paper, we have reported the sonochemical synthesis of cobalt ferrite nanoparticles using metal acetate precursors. The ferrite synthesis occurs in three steps (hydrolysis of acetates, oxidation of hydroxides, and in situ microcalcination of metal oxides) that are facilitated by physical and chemical effects of cavitation bubbles. The physical and magnetic properties of the ferrite nano-particles thus synthesized have been found to be comparable with those reported in the literature using other synthesis techniques

Induction of fibroblast senescence generates a non-fibrogenic myofibroblast phenotype that differentially impacts on cancer prognosis

Cancer-associated fibroblasts (CAF) remain a poorly characterized, heterogeneous cell population. Here we characterized two previously described tumor-promoting CAF sub-types, smooth muscle actin (SMA)-positive myofibroblasts and senescent fibroblasts, identifying a novel link between the two

Single-pulse chemical shock tube for ignition delay measurements

We describe a single-pulse chemical shock tube CST2 established for measuring the reaction rate of chemical reactions and ignition delay for fuels at high temperature along with the procedure for its calibration. The suitability of the facility for measuring the ignition delay is demonstrated by measuring the ignition delay for the ethane-oxygen gas mixture in the temperature range 1250-1611 K by recording the ignition-induced pressure jump and emission from CH radical simultaneously. The results obtained in the present study compare well with the earlier reported values

MTN-001: Randomized Pharmacokinetic Cross-Over Study Comparing Tenofovir Vaginal Gel and Oral Tablets in Vaginal Tissue and Other Compartments

Background: Oral and vaginal preparations of tenofovir as pre-exposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) infection have demonstrated variable efficacy in men and women prompting assessment of variation in drug concentration as an explanation. Knowledge of tenofovir concentration and its active form, tenofovir diphosphate, at the putative vaginal and rectal site of action and its relationship to concentrations at multiple other anatomic locations may provide key information for both interpreting PrEP study outcomes and planning future PrEP drug development. Objective: MTN-001 was designed to directly compare oral to vaginal steady-state tenofovir pharmacokinetics in blood, vaginal tissue, and vaginal and rectal fluid in a paired cross-over design. Methods and Findings: We enrolled 144 HIV-uninfected women at 4 US and 3 African clinical research sites in an open label, 3-period crossover study of three different daily tenofovir regimens, each for 6 weeks (oral 300 mg tenofovir disoproxil fumarate, vaginal 1% tenofovir gel [40 mg], or both). Serum concentrations after vaginal dosing were 56-fold lower than after oral dosing (p<0.001). Vaginal tissue tenofovir diphosphate was quantifiable in ≥90% of women with vaginal dosing and only 19% of women with oral dosing. Vaginal tissue tenofovir diphosphate was ≥130-fold higher with vaginal compared to oral dosing (p<0.001). Rectal fluid tenofovir concentrations in vaginal dosing periods were higher than concentrations measured in the oral only dosing period (p<0.03). Conclusions: Compared to oral dosing, vaginal dosing achieved much lower serum concentrations and much higher vaginal tissue concentrations. Even allowing for 100-fold concentration differences due to poor adherence or less frequent prescribed dosing, vaginal dosing of tenofovir should provide higher active site concentrations and theoretically greater PrEP efficacy than oral dosing; randomized topical dosing PrEP trials to the contrary indicates that factors beyond tenofovir's antiviral effect substantially influence PrEP efficacy. Trial Registration: ClinicalTrials.gov NCT00592124

Gene expression analysis of TIL rich HPV-driven head and neck tumors reveals a distinct B-cell signature when compared to HPV independent tumors

Human papilloma virus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) has a better prognosis than it's HPV negative (HPV(-)) counterpart. This may be due to the higher numbers of tumor-infiltrating lymphocytes (TILs) in HPV positive (HPV(+)) tumors. RNA-Sequencing (RNA-Seq) was used to evaluate whether the differences in clinical behaviour simply reflect a numerical difference in TILs or whether there is a fundamental behavioural difference between TILs in these two settings. Thirty-nine HNSCC tumors were scored for TIL density by immunohistochemistry. After the removal of 16 TILlow tumors, RNA-Seq analysis was performed on 23 TILhigh/med tumors (HPV(+) n=10 and HPV(-) n=13). Using EdgeR, differentially expressed genes (DEG) were identified. Immune subset analysis was performed using Functional Analysis of Individual RNA-Seq/ Microarray Expression (FAIME) and immune gene RNA transcript count analysis. In total, 1,634 DEGs were identified, with a dominant immune signature observed in HPV(+) tumors. After normalizing the expression profiles to account for differences in B- and T-cell number, 437 significantly DEGs remained. A B-cell associated signature distinguished HPV(+) from HPV(-) tumors, and included the DEGs CD200, GGA2, ADAM28, STAG3, SPIB, VCAM1, BCL2 and ICOSLG; the immune signal relative to T-cells was qualitatively similar between TILs of both tumor cohorts. Our findings were validated and confirmed in two independent cohorts using TCGA data and tumor-infiltrating B-cells from additional HPV(+) HNSCC patients. A B-cell associated signal segregated tumors relative to HPV status. Our data suggests that the role of B-cells in the adaptive immune response to HPV(+) HNSCC requires re-assessment