Trametes versicolor (L.) Lloyd as a source of thermostable serine protease: production and characterization

Proteases are ubiquitously present and are among the largest groups of commercially important enzymes. Here, we investigated a wood-rot basidiomycete Trametes versicolor (L.) Lloyd [Syn. Coriolus versicolor (L.) Quél.; Polyporus versicolor (L.) Fr.] as a source of the enzyme serine protease, its production, and optimized to obtain a higher yield of the enzyme.. The significant variables with optimized values for maximum production of the enzyme were temperature (30?C), incubation time (120 h) and wheat bran (10 g). The yield increased by 30.76% by statistically optimizing the media. The optimized temperature and pH for the maximum protease activity was 50?C and pH 7.0, respectively. The enzyme was purified through ion exchange (using DEAE cellulose 52 resin) and gel filtration chromatography (using Superdex 200 column). The purified enzyme had a retention time of 7 min in RP-HPLC. The enzyme was stable at a broad range of temperature (30-60?C) and pH (5.0-8.0) with a half-life of 58.72 min, Vmax of 37.17 ?M min/mL and Km of 0.657 mg/mL. Its activity was enhanced by Na+, Ca2+, Mg2+ ions and SDS surfactant. These properties make this enzyme a valuable candidate for industrial applications

Application Of Central Composite Design For Citalopram Hydrogen Bromide Mouth Dissolving Films

Citalopram is an antidepressant used for treating major depressive disorder. In the current work Citalopram HBr is formulated as mouth dissolving film with enhanced drug dissolution. The Central Composite Design (CCD), employed to examine the effects of amount of HPMC E50 (A), amount of maltodextrin (B) and amount of glycerol (C) on response variables tensile strength, disintegration time and cumulative % drug release. 27 formulations prepared according to CCD and evaluated for physicochemical parameters and in vitro dissolution studies. Citalopram HBr mouth dissolving films formulated by employing solvent-casting method using HPMC E50, maltodextrin and glycerol, optimized for the effective dosage of superdisintegrants. The formulation CF21 with maximum tensile strength of 67.21±1.31 gm, least disintegration time of 9±1.60 sec and highest drug release of 98.41±1.81% is chosen optimal formulation with maximum content uniformity and folding endurance. It is evident from the above results that the developed formulation can be an innovative dosage form to improve the drug delivery, quick onset of action as well as improve patient compliance in the effective management of depression.

Medium optimization of protease production by Brevibacterium linens DSM 20158, using statistical approach

Various cultivation parameters were optimized for the production of extra cellular protease by Brevibacterium linens DSM 20158 grown in solid state fermentation conditions using statistical approach. The cultivation variables were screened by the Plackett-Burman design and four significant variables (soybean meal, wheat bran, (NH4)2SO4 and inoculum size were further optimized via central composite design (CCD) using a response surface methodological approach. Using the optimal factors (soybean meal 12.0g, wheat bran 8.50g, (NH4)2SO4) 0.45g and inoculum size 3.50%), the rate of protease production was found to be twofold higher in the optimized medium as compared to the unoptimized reference medium.

Optimized preparation of Silymarin Dropping Pill by a central composite design-response surface method / 中草药

Objective Using solid dispersion technique to prepare Silymarin Dropping Pill to accelerate dissolution and to improve bioavailability. A central composite design-response surface method was employed to select the optimum formulations. Methods Independent variables were Poloxamer 188 content and silymarin content, while dependent variables were disintegrating time and percent of silymarin dissoluted at a definite time. Linear, two and three order quadratic models were used to estimate the relationship between independent and dependent variables. Response surfaces were delineated according to best-fit mathematic models and optimum formulations were selected there from. Prediction was carried out through comparing the observed and predicted values. Results Three order quadratic equation was the best-fitted mathematic models to describe the relationship between dependent and independent variables, with a regression coefficient of 0.998. Bias between observed and predicted values of disintegrating time and dissolution percentage of optimum formulation dropping pill were negligible, indicating the high predictability of the fit models. Percent dissolution of Silymarin Dropping Pill at 60 min was 19 times as that of conventional tablets. Conclusion Dissolution speed of silymarin can be effectively improved through incorporating into dropping pills. It shows that the optimum mathematic model is highly predictive. The central composite design-response surface method can be fairly used in formulation screening.