Development and Characterization of Water-in-Oil Microemulsion for Transdermal Delivery of Eperisone Hydrochloride

Abstract

Background: Eperisone hydrochloride possesses short biological half-life due to first pass metabolism resulting in low bioavailability and short duration of response with toxic effects, ultimately limits its utilization for treatment of muscle spasm. Objective: In view of this background, current study was designed for the development of Eperisone hydrochloride-loaded microemulsion and Eperisone hydrochloride-loaded microemulsion based cream for topical delivery and compared it with conventional cream. Methods: Firstly, water-in-oil microemulsion was prepared by spontaneous emulsification method. The concentration of components was found out from existence of microemulsion region by constructing pseudoternary phase diagram. The oil was selected on the basis of drug solubility effect on the drug release, whereas surfactant and cosurfactant were screened on the basis of their efficiency to form microemulsion region. The influence of components on microemulsion formation, drug release capacity, permeation was studied by differential scanning calorimetry, X-ray diffraction, in-vitro release and ex-vivo drug permeation studies respectively. By using microemulsion, the cream was prepared for proving optimum structure for topical application. Microemulsion was evaluated for droplet size, zeta potential, pH, viscosity and conductivity. Besides the cream was characterized for pH, rheology and stability. Permeation of EPE from microemulsion across the rat skin was evaluated and compared with conventional cream. Results: The microemulsion consisting Isopropyl Myristrate/Water/Span 80:Tween 80 (50/8/42% by weight) possessed droplet size of 95.77nm, zeta potential of −5.23 mV with 7.25 pH and conductivity near to zero (<0.05mScm-1). Physical parameters of the cream were satisfactory, also 2.33-fold higher permeation and 1.57-fold higher release observed as compared to conventional cream. Conclusion: It can be concluded that Eperisone hydrochloride-loaded microemulsion and its cream is being effectively used for muscle spasticity by topical route.