Formulation and Evaluation of Transdermal Patches for Antianxiety Drug

Abstract

Aim: The aim of the present study was to design, develop, and evaluate a matrix-type transdermal formulation
containing buspirone hydrochloride (HCL) for treatment of anxiety with a goal to increase the bioavailability and
improve the patient compliance. Materials and Methods: In the present research work, the different concentrations
of hydroxypropyl methylcellulose (HPMC) E50, HPMC E15, and Eudragit RS100 were used in combination to
optimize the concentration of HPMC E15 and Eudragit RS100 in the formulation of transdermal patches. These
different ratios of hydrophilic and hydrophobic polymeric combinations plasticized with dibutyl phthalate by the
solvent evaporation technique. The prepared patches were evaluated for their physicochemical characteristics such
as thickness, weight and drug content uniformity, moisture content, moisture uptake and folding endurance, and
in vitro drug release studies. Optimized formulation was further evaluated by in vivo release study, drug-excipient
compatibility, and stability study. Results and Discussion: Effect of permeation enhancers such as oleic acid was
studied. The interference of the polymers was ruled out by Fourier transform infrared and ultraviolet-spectroscopic
methods. In vitro release studies of buspirone HCL-loaded patches in phosphate buffer (pH, 7.4) were performed
using a modified diffusion cell and showed first-order release rate. Skin studies for the transdermal patches were
assessed and were found to be free of irritation. In vivo drug release studies had shown release up to 24 h with the
release of 73.82% and it was correlated with in vitro studies. The patches were subjected to short-term stability
studies and were found stable. Conclusion: It is concluded from the present studies that the transdermal patches
of buspirone HCL were capable of exhibiting controlled release with the stability. Studies had shown promising
results, and there was a scope for further pharmacodynamic and pharmacokinetic evaluation.