Formulation and evaluation of transdermal controlled drug delivery system of psychotropic drugs Buspirone hydrochloride and Trifluoperazine hydrochloride

Abstract

Psychiatric disorders frequently require chronic therapy and poor bioavailability of drugs and inadequate patient compliance often result in suboptimal therapeutic outcomes with conventional oral therapy This study evaluated the viability of a polymeric matrix type transdermal drug delivery system TDDS and a novel microparticle embedded polymeric matrix TDDS for two model psychotropic drug candidates buspirone HCl and trifluoperazine HCl to improve bioavailability and simplify the dosing regimen The polymers ethyl cellulose and PVP K30 were explored for developing matrix diffusion controlled TDDS The micro particle embedded matrix TDDS were formulated using chitosan and PVA Initially drug loaded spray dried chitosan microparticles were prepared which underwent extensive in vitro evaluations Microparticles with optimal drug loading and sustained release profiles were incorporated in microparticle embedded matrix patches The formulations demonstrated satisfactory physico chemical characteristics and a sustained in vitro drug release profiles The in vitro skin permeation study with permeation enhancer d limonene confirmed considerably increased drug permeation for the microparticle embedded matrix patches compared to matrix formulations The pharmacokinetic studies of optimized transdermal formulations on rabbits established significant enhancement of bioavailability for buspirone HCl AUC0 to 96 988 point 33 ng per ml hrs and trifluoperazine HCl AUC0 to 96 1252 point 95ng per ml hrs compared to oral solution Dermal irritation study confirmed the dermal safety of the formulations The accelerated stability study demonstrated that the formulations remained stable under accelerated storage conditions Hence it can be summarised that chitosan microparticle embedded matrix transdermal systems present a promising strategy to achieve a sustained plasma drug profile of the selected drugs and holds potential to enhance their bioavailability newline newline newline