Influence of different formulation variables on the performance of transdermal drug delivery system containing tizanidine hydrochloride: in vitro and ex vivo evaluations

The present study was aimed at preparation of transdermal patches of tizanidine HCl, evaluation of the effect of polymers on in vitro release pattern of the drug, and the effect of permeation enhancers on the penetration of the drug through the rabbit skin. Various proportions of hydrophilic (HPMC) and hydrophobic (Eudragit L-100) polymers were used with PEG 400 as film-forming agent, and Span 20 or DMSO as permeation enhancer. The formulations were assessed for physicochemical characteristics and in vitro drug release studies using USP paddle over disc method in phosphate buffered saline (pH 7.4) at 32.0±1°C. On the basis of in vitro studies and physicochemical evaluations, S03-A and S04-A were selected at Eudragit : HPMC ratios of 8 : 2 and 7 : 3, respectively, for further ex vivo analysis. The effects of different concentrations of Span 20 and DMSO were evaluated on excised rabbit skin using Franz diffusion cell. Cumulative drug permeation, flux, permeability coefficient, target flux, and enhancement ratio were calculated and compared with the control formulations. Kinetic models and Tukey's multiple comparison test were applied to evaluate the drug release patterns. Formulation SB03-PE containing Eudragit L-100:HPMC (7:3) with Span 20 (15% w/w) produced the highest enhancement in drug permeation, and followed zero order kinetic model with super case-II drug release mechanism.

Formulation and In-vitro Evaluation of Mucoadhesive Buccal Patches of Cyproheptadine Hydrochloride.

The goal of the present investigation was to design and evaluate mucoadhesive buccal patches of Cyproheptadine Hydrochloride (CPH) which is a sedating antihistamine with antimuscarinic, serotonin-antagonist, and calcium-channel blocking action. Buccal films were made with Hydroxy propylcellulose (HPC EF) and Hydroxy Propyl Methyl Cellulose (HPMC E15) as mucoadhesive polymers. Permeation of CPH was calculated ex vivo using porcine buccal membrane. The patches were evaluated for weight variation, thickness variation, surface pH, moisture absorption, in vitro residence time, mechanical properties, in vitro release, ex vivo permeation studies and drug content uniformity. The formulation F8 of HPMC E15 was found to give the better results and release of drug from the film followed Higuchi and Korsmeyer and Peppas models.