Applying response surface methodology to optimize nimesulide permeation from topical formulation

Nimesulide is a non-steroidal anti-inflammatory drug that acts through selective inhibition of COX-2 enzyme. Poor bioavailability of this drug may leads to local toxicity at the site of aggregation and hinders reaching desired therapeutic effects. This study aimed at formulating and optimizing topically applied lotions of nimesulide using an experimental design approach, namely response surface methodology. The formulated lotions were evaluated for pH, viscosity, spreadability, homogeneity and in vitro permeation studies through rabbit skin using Franz diffusion cells. Data were fitted to linear, quadratic and cubic models and best fit model was selected to investigate the influence of permeation enhancers, namely propylene glycol and polyethylene glycol on percutaneous absorption of nimesulide from lotion formulations. The best fit quadratic model explained that the enhancer combination at equal levels significantly increased the flux and permeability coefficient. The model was validated by comparing the permeation profile of optimized formulations’ predicted and experimental response values, thus, endorsing the prognostic ability of response surface methodology

Formulation and evaluation of niosomes-based chlorpheniramine gel for the treatment of mild to moderate skin allergy

Purpose of present study was to develop eight formulations of chlorpheniramine (CPM) niosomes according to 23 factorial design, characterise on the basis of various evaluation tests, i.e. in vitro drug release, SEM, FTIR, TGA and release kinetics, optimise the eight formulation on the basis in vitro drug release data, formulate gel of optimised dispersion, and to perform in vivo and histopathological study using gel of optimised dispersion on rabbits. Here, N3 having low level of cholesterol and span-80 but high level of span-60(0.1:0.2:0.05) was selected as optimised dispersion of niosomes that showed highest drug release i.e. 88.25% at pH 6 over 24 h of study and followed Korsmeyers-Peppas release kinetics with Fickian diffusion mechanism. After application of statistic by Analysis of variance (ANOVA) with 3D surface plots construction, gel of optimised dispersion of CPM niosomes was formulated, and evaluated by tests for i.e. viscosity, Spreadability, Extrudibility, drug content, drug entrapment, stability, SEM, FTIR, TGA, in vitro drug release, in vivo drug release following first order kinetics and histopathological study. Niosomal gel of CPM ensured successful development using suitable combination of non-ionic surfactants, and effective loading of drug for targeted delivery of drug