Development of matrix type transdermal Patches of Tizanidine HCl

Transdermal drug delivery system (TDDS) was designed to sustain the release and improve the bioavailability of drug and patient compliance. Among the various types of transdermal patches, matrix dispersion type systems disperse the drug in the solvent along with the polymers and solvent is allowed to evaporate forming a homogeneous drug-polymer matrix. Tizanidine Hydrochloride, an imidazoline derivative, is α2-adrenergic agonist and centrally acting myotonolytic skeletal muscle relaxant with a structure unrelated to other muscle relaxants. Tizanidine hydrochloride having lower bioavailability (40%) due to first pass metabolism by the liver. So, bioavailability can be increased by transdermal route. The object of the study was to develop Matrix Type Transdermal Patch of Tizanidine HCl. Transdermal patches were prepared by solvent evaporation method using Eudragit RS 100 and PVP polymers by incorporating Polyethylene Glycol and Propylene Glycol as plasticizer. Standard procedures were used to analyze the prepared films for various physicochemical parameters(weight variation, thickness uniformity, % moisture content, %moisture uptake, Folding Endurance and drug content). drug release (Franz diffusion cell) and skin irritation test. The drug and polymer compatibility was studied by DSC. Among all the formulations, the F1 prepared by using Eudragit RS 100 and PEG 400 as plasticizer is the better formulation for control release of drug up to 6 hrs of time. Results of the present study encouraged that the Tizanidine HCl with Eudragit RS 100 transdermal patch can be used as controlled drug delivery system and frequency of administration can be minimized. The kinetic models used were Zero order, First order Higuchi’s and Korsmeyer–Peppas model. Transdermal patches were successfully prepared for Tizanidine Hydrochloride and their evaluation suggested excellent quality and uniformity in patch characteristics. This can have potential applications in therapeutic area offering advantages in terms of reduced dosing frequency, improved patient compliance and bioavailability.

Keywords: Tizanidine Hydrochloride, Eudragit RS 100, Matrix type, polyvinylpyrrolidone, Transdermal patches