A novel itraconazole bioadhesive film for vaginal delivery: design, optimization, and physicodynamic characterization.

The purpose of this work was to design and optimize a novel vaginal drug delivery system for more effective treatment against vaginal candidiasis. Itraconazole was formulated in bioadhesive film formulations that could be retained in the vagina for prolonged intervals. The polymeric films were prepared by solvent evaporation and optimized for various physicodynamic and aesthetic properties. In addition, percentage drug retained on vaginal mucosa was evaluated using a simulated dynamic vaginal system as function of time. A polymeric film containing 100 mg itraconazole per unit (2.5 cm x 2.5 cm) have been developed using generally regarded as safe listed excipients. The pH of vaginal film was found to be slightly acidic (4.90 +/- 0.04) in simulated vaginal fluid and alkaline (7.04 +/- 0.07) in water. The little moisture content (7.66 +/- 0.51% w/w) was present in the film, which helps them to remain stable and kept them from being completely dry and brittle. The mechanical properties, tensile strength, and percentage elongation at break (9.64 N/mm(2) and 67.56% for ITRF(65)) reveal that the formulations were found to be soft and tough. The films (ITRF(65)) contained solid dispersion of itraconazole (2.5)/hydroxypropyl cellulose (1)/polyethylene glycol 400 (0.5), which was found to be the optimal composition for a novel bioadhesive vaginal formulation, as they showed good peelability, relatively good swelling index, and moderate tensile strength and retained vaginal mucosa up to 8 h. Also, the film did not markedly affect normal vaginal flora (lactobacillus) and was noncytotoxic as indicated by the negligible decrease in cell viability.

A novel intravaginal delivery system for itraconazole: in vitro and in vivo evaluation.

The purpose of the present study was to formulate and systematically evaluate in vitro, ex vivo and in vivo performances of itraconazole containing bioadhesive vaginal film. We introduce here a novel intravaginal delivery system for itraconazole based on solid dispersion of itraconazole and hydroxypropyl methylcellulose E15 that improve drug solubility and produce bioadhesive system in presence of other ingredients. Solid dispersions of itraconazole were prepared with hydroxypropyl methylcellulose by a spray drying method and characterized by X-ray diffraction and differential scanning calorimetry. The film was prepared using a solvent evaporation technique. In the in vitro antimicrobial study, it was found that solid dispersion containing formulation improves antimicrobial action of itraconazole. From the ex vivo retention study, it was found that the bioadhesive polymers hold the film upto 7 hours on the vaginal mucosa. In vivo antifungal activity tested against Candida albicans vaginitis in female rats, was found to significantly improve the therapeutic benefit of the drug. At 6 days post-dose, the c.f.u. of Candida albicans was more than 10(3) fold decreased in film treated groups without affecting the morphology of vaginal mucosa. These studies suggested that bioadhesive vaginal film is a novel approach for delivery of itraconazole as topical drug delivery system for treating vaginal candidiasis.

Role of transglycosylation products in the expression of multiple xylanases in Myceliophthora sp. IMI 387099.

This study reports the regulation of multiple xylanases produced by Myceliophthora sp. IMI 387099. Fructose was found to positively regulate the expression of multiple xylanase when used as sole carbon source. The xylanases (EX(1 )and EX(2)) of acidic pI were expressed in the presence of simple sugars (glucose, arabinose, and xylose), whereas xylanase of both acidic as well as basic pI (EX(1,) EX(2,) EX(3), and EX(5)) were expressed in the presence of fructose, xylan, and combination of xylan and alcohol. The combination of fructose and xylan also led to expression of an additional xylanase (EX(4)). The positional isomer (iso-X4) was found to be the key transglycosylation product when cultures were grown in the presence of fructose and xylan. In the presence of alcohols, the higher expression of xylanase was ascribed to the synergistic effect of alkyl glycoside and other transglycosylation products present in the culture extracts.

Purification and characterization of beta-glucosidase from Melanocarpus sp. MTCC 3922

This study reports the purification and characterization of beta-glucosidase from a newly isolated thermophilic fungus, Melanocarpus sp. Microbial Type Culture Collection (MTCC) 3922. The molecular weight of beta-glucosidase was determined to be ~ 92 and 102 kDa with SDS PAGE and gel filtration, respectively, and pI of ~ 4.1. It was optimally active at 60 C and pH 6.0, though was stable at 50 C and pH 5.0 - 6.0. The presence of DTT, mercaptoethanol and metal ions such as Na+, K+, Ca2+, Mg2+and Zn2+ positively influenced the activity of beta-glucosidase but the activity was inhibited in the presence of CuSO4. beta-Glucosidase recognized pNP- beta-glucopyranoside (pNPG) as the preferred substrate, and showed very low affinity for pNP- beta-D-cellobioside. Km and Vmax for the hydrolysis of pNPG by beta-glucosidase was calculated as 3.3 mM and 43.68 ‘molmin-1mg protein-1, respectively and k cat was quantified as 4 x 10³ min-1. beta-Glucosidase activity was enhanced appreciably in the presence of alcohols (methanol and ethanol) moreover, purified beta-glucosidase showed putative transglycosylation activity that was positively catalyzed in presence of methanol as an acceptor molecule

Production of multiple xylanolytic and cellulolytic enzymes by thermophilic fungus Myceliophthora sp. IMI 387099.

This study reports the production of xylanolytic and cellulolytic enzymes by a thermophilic fungal isolate Myceliophthora sp. using a cheap medium containing rice straw and chemically defined basal medium under solid-state culture. A combination of one factor at a time approach followed by response surface methodology using Box-Behnken design of experiments resulted in 2.5, 1.25, 1.28 and 4.23 fold increase in xylanase, endoglucanase, beta-glucosidase and FPase activity, respectively. The zymograms developed against IEF gels showed that multiple isoforms of xylanase (5), endoglucanase (4) and beta-glucosidase (2) were produced under optimized culture conditions. Moreover, thiol containing serine proteases produced during the growth of the culture had no role in the post-translational modification of these xylanases.

Purification and characterization of two endoglucanases from Melanocarpus sp. MTCC 3922.

This study reports the purification and characterization of endoglucanases (EG I and EG II) from a newly isolated thermophilic fungus, Melanocarpus sp. MTCC 3922. The molecular weight of EG I and EG II as with SDS-PAGE and pI were approximately 40 and 50 kDa, and approximately 4.0 and 3.6, respectively. EG I and EG II were optimally active at 50 and 70 degrees C, and pH 6.0 and 5.0, respectively. EG I was active over a broad range of pH (5.0-7.0), whereas, loss of activity was observed as the temperature was increased from 50 to 80 degrees C. However, EG II was active over pH 4.0-6.0 and temperature 40-80 degrees C. The presence of mercaptoethanol and SDS inhibited the EG I activity but showed no negative effect on EG II. Both the endoglucanases showed higher activity against barley-beta-glucan as compared to CMC. Km values of EG I and EG II for barley-beta-glucan were lower than CMC. Turn over number (K(cat)) and catalytic efficiency (K(cat)/Km) values of both the endoglucanases were higher with barley-beta-glucan as substrate than CMC. EG I showed affinity for Avicel indicating the presence of cellulose binding domains (CBD) whereas, EG II was found to lack CBD.