Sunit Kumar Sahoo

Antibacterial activity of Hybanthus enneaspermus against selected urinary tract pathogens

Hybanthus enneaspermus Muell, belonging to family Violaceae, was investigated to evaluate in vitro antibacterial activity of aqueous, ethanolic, petroleum ether and chloroform extracts against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis and Staphylococcus aureus . The major urinary tract infection causing pathogens were tested by disc diffusion assay method, and the minimum inhibitory concentration was evaluated. Ethanol (95%) extract exhibited significant and broader spectrum of inhibition in comparison to aqueous, which showed moderate effect; chloroform and petroleum ether extract showed feeble activity at concentration of 300 mg/disc. An attempt has been made to compare the activity of extracts with standard antibiotics against selected urinary tract pathogens.

Microemulsion based topical hydrogel of sertaconazole: formulation, characterization and evaluation.

A microemulsion (ME) based hydrogel had studied as a topical delivery of sertaconazole (STZL) for effective eradication of cutaneous fungal infection. The existence of microemulsion region was investigated in pseudo-ternary phase diagrams and various ME formulations were prepared using oleic acid, Tween 80, propylene glycol and water. Hydrogel of STZL microemulsions (HSM) were prepared in Carbopol 940 (0.75%, w/w) and characterized. The prepared HSM and commercial cream of STZL were evaluated in vitro and ex vivo. The permeation rate of STZL from optimized formulation (HSM-4), composed with oleic acid (8.75%, w/w), tween 80 (33.35%, w/w), propylene glycol (33.35%, w/w) and water (24.55%, w/w) was observed higher in compare with other HSMs and commercial cream. HSM-4 was stable, had 3 times higher drug retention capacity in skin than commercial cream and did not caused any erythema or edema based on skin sensitivity study on rabbit. The average zone of inhibition of HSM-4 (23.54±0.72mm) was higher in compare with commercial cream (16.53±0.63mm) against Candida albicans which may be due to permeation enhancing effect of ME and skin retention effect of HSM. It is promising that the concentration of STZL used to treat cutaneous fungal infection could be decreased due to the high permeation and anti-fungal effect of STZL in HSM-4.

Effect of microemulsion in topical sertaconazole hydrogel: in vitro and in vivo study

Abstract Purpose: A topical microemulsion (ME)-based hydrogel was developed to enhance permeation of an antifungal drug, sertaconazole (STZL) for effective eradication of cutaneous fungal infection. Methods: Pseudo-ternary phase diagrams were used to determine the existence of MEs region. ME formulations were prepared with oleic acid, Tween 80, propylene glycol (PG) and water. Carbopol 940 (0.75% w/w) was used for preparation of hydrogel of STZL microemulsion (HSM) and characterized. The in vitro and in vivo evaluation of prepared HSM and commercial cream of STZL were compared. Results: The viscosity, average droplet size and pH of HSM were 154.23 ± 0.54 to 162.52 ± 0.21 Pas, 42.3–91.7 nm and 6.9–7.2 , respectively. Permeation rate of STZL from optimized formulation (HSM-4), composed with oleic acid (8.75 % w/w), Tween 80 (33.35% w/w), PG (33.35% w/w) and water (24.55% w/w) was observed higher in compare with other HSMs and commercial cream. HSM-4 was stable, three times higher drug retention capacity in skin than commercial cream and did not caused any erythema or edema based on skin sensitivity study on rabbit. The average zone of inhibition of HSM-4 (23.54 ± 0.72 mm) was higher in compare with commercial cream (16.53 ± 0.63 mm) against Candida albicans. Conclusion: The results of study showed that ME played a major role in permeation enhancing and skin retention effect of HSM and the concentration of STZL used for cutaneous fungal infection could be decreased by using ME based hydrogel preparation.

Mixed surfactant based (SNEDDS) self-nanoemulsifying drug delivery system presenting efavirenz for enhancement of oral bioavailability.

This study aims to develop a self-nanoemulsifying drug delivery system (SNEDDS) based on non-ionic surfactant mixtures to improve the oral bioavailability of efavirenz (EFZ) categorized as a class II according to the BCS, for HIV- therapy. The result of solubility studies of EFZ in various excipients utilized for construction of the pseudo ternary phase diagram containing surfactant mixtures. Surfactants in 1:1 combination are used with different co-surfactants in different ratio to delineate the area of monophasic region of the pseudo ternary phase diagram. Different accelerated physical stability studies and self-emulsification assessment were performed on the formulations. The formulations clearing the above studies are considered for percentage transmittance and turbidity analysis. The globule size distributions of post diluted SNEDDS having percentage transmittance above 90 were estimated. The TEM analysis of two optimized post diluted SNEDDS formulations further confirm the size in nanometric range (below 50nm). FT-IR studies showed the retention of the characteristic peaks of EFZ in the preconcentrate. The in vitro dissolution profile of SNEDDS established advantages of SNEDDS over plain drug as more than 80% drug was released within 30min in case of optimized SNEDDS while it was approximately 18.3% in the case of plain drug powder. Pharmacokinetic parameters were calculated after performing the in vivo studies of best optimized formulation in rats. The Pharmacokinetic data reveal a 2.63 fold increase in AUC(0-∞) in comparison to plain EFZ suspension. The designed delivery system showed the faith in generating an effective formulation of EFZ for HIV treatment.

Formulation and evaluation of gelatin micropellets of aceclofenac: Effect of process variables on encapsulation efficiency, particle size and drug release

In the present study aceclofenac-gelatin micropellets were prepared by the cross linking technique using gluteraldehyde as cross linking agent and characterized by X-ray diffractometry, differential scanning calorimetry and scanning electron microscopy. The effect of drug: polymer ratio, temperature of oil phase, amount of gluteraldehyde and stirring time was studied with respect to entrapment efficiency, micropellet size and drug release characteristics. Spherical micropellets having an entrapment efficiency of 57% to 97% were obtained. Differential scanning calorimetric analysis confirmed the absence of any drug-polymer interaction. The micromeritic studies of micropellets show improved flow property. The entrapment efficiency, micropellet size and drug release profile was altered significantly by changing various processing parameters.

Optimization of physical and nutritional parameters for hyaluronidase production by Streptococcus mitis

The effect of some physical and nutritional parameters were studied for the optimum production of extracellular enzyme hyaluronidase employing Streptococcus mitis MTCC*2695 by submerged fermentation. The effects of initial pH, incubation temperature and time, inoculum level and age of inoculum were studied. The maximum enzymatic activity was obtained with an initial pH 5.8, incubation temperature 37°, incubation time for 48 h and inoculum level 6% with inoculum age 24 h. The effect of different carbon and nitrogen sources and antibiotics were studied. The results indicated that sucrose and ammonium chloride showed the highest enzymatic activity among various carbon and nitrogen sources. Antibiotic clarithromycin showed strong inhibitory effect on hyaluronidase production.

Fabrication and evaluation of self-nanoemulsifying oil formulations (SNEOFs) of Efavirenz

Abstract The current work designed to fabricate and evaluate self-nanoemulsfying oil formulations (SNEOFs) of Efavirenz (Efz) a BCS class II drug with the objective of increasing its solubility as well as in vitro dissolution rate for improvisation of bioavailability. Preliminary screening of drug which includes solubility, emulsifying ability and ternary phase diagrams was carried out to fabricate SNEOFs. Various thermodynamic stability studies were exercised to find out the stable SNEOFs. Robustness to dilution, % transmittance and turbidity, droplet size analysis, TEM study, cloud point measurement, viscosity and refractive index were executed on the stable SNEOFs to characterize the delivery system. FTIR study was adopted for the compatibility of the additives with the drug. In vitro release profiles of SNEOFs compared with Efz, percent dissolution efficiency (DE) and dissolution half-life (t50) were evaluated. A low percent DE (30.12%) and high t50 was obtained for Efz whereas all SNEOFs showed a DE of greater than 78.48% and less than 9 min t50. The optimized SNEOFs (F8) demonstrated a significant (p < 0.05) increase in bioavailability over Efz. Thus the designed optimized delivery system could be instrumental in increasing aqueous solubility of Efz, improving its release performance and enhancement of oral absorption. Graphical Abstract

Liranaftate loaded Xanthan gum based hydrogel for topical delivery: Physical properties and ex-vivo permeability

A topical microemulsion (ME)-based hydrogel was developed to enhance permeation of an antifungal drug, liranaftate (LRFE) for effective eradication of cutaneous fungal infection. Pseudo-ternary phase diagrams were used to determine the existence of MEs region. ME formulations were prepared with Di-isopropyl adaptate, Cremophore-EL, Ethanol and distilled water. Xanthan Gum (1.5% w/w) was used for preparation of hydrogel of LRFE microemulsion (HLM) and characterized. The in-vitro and ex-vivo evaluation of prepared HLM and saturated drug solution were compared. The viscosity, average droplet size and pH of HLM were 142.30±0.42 to 165.15±0.21Pas, 52.53-93.40nm and 6.6-7.1, respectively. Permeation rate of LRFE from optimized formulation (HLM-3), composed with Di-isopropyl adaptate (4.5% w/w), Cremophor-EL (30% w/w), Ethanol (10% w/w) and water (52% w/w) was observed higher in compare with other HLMs and saturated drug solution. HLM-3 was stable, six times higher drug deposition capacity in skin than saturated drug solution and did not caused any erythema based on skin sensitivity study on rat. The average zone of inhibition of HLM-3 (25.52±0.26mm) was higher in compare with saturated drug solution (13.44±0.40mm) against Candida albicans.

Cefuroxime Axetil Loaded Gastroretentive Floating TabletsBased on Hydrophilic Polymers: Preparation and In Vitro Evaluation

The aim of this work was to study the formulation and in vitro characterization of hydro dynamically balanced floating matrix tablets using Cefuroxime axetil (CA) as model drug. Different excipients such as hydroxy propyl methyl cellulose (HPMC) K15M, E5LV (gelling agent), sodium bicarbonate (gas generating agent) and sodium lauryl sulfate (SLS) (solubility enhancer) were used in order to optimize the drug release profile as well as floating property. Decrease in release characteristics with high viscous polymer were observed due to increased gel strength, tortuosity and length of drug diffusion path. Significant difference (p<0.5) in release rate was found at different concentration of SLS. The release mechanisms were explored and explained with zero order, first order, Higuchi, Korsmeyer and Hixson-Crowell equations. The release rate, extent and mechanism were governed by the content of polymer. The polymer content and amount of floating agent significantly affected the time required for 50%of drug release (t50%), mean dissolution time (MDT), release rate constant, and diffusion exponent (n).Kinetic modeling of dissolution profile revealed that the drug release mechanism could range from diffusion controlled to case II transport, which was co-dominated by diffusion polymer erosion in the release mechanism.