Preparation of Bilayered Matrix Type of Transdermal Patches of a Classical Antihypertensive Drug: Assesment of Ex-vivo Permeation and in-vivo Pharmacokinetics

Abstract

Abstract Objective Felodipine (FD) is a calcium channel blocker used to treat hypertension and angina pectoris. Because of first-pass hepatic metabolism, it is less soluble, and its oral bioavailability is low (15%). To address the aforementioned drawbacks and maintain a consistent plasma concentration for optimal therapeutic efficacy, new methods, such as transdermal drug administration, must be developed. The goal of this study is to create bilayered transdermal films containing FD and test their efficacy using ex-vivo flux, and in-vivo pharmacokinetics studies. Methods Patches were made utilizing a solvent casting approach with both hydrophobic and hydrophilic polymers. The prepared films were thoroughly examined for ex-vivo permeation, and in-vivo pharmacokinetic tests on rabbits. The flux value for the formulation without the permeation enhancer (F4) was 14.585 g/cm2/h, but the flux increased in the formulation with the permeation enhancer lemongrass oil (F9) (1% v/v) was 30.4 g/cm2/h. In-vivo bioavailability findings in New Zealand white rabbits and blood samples were examined using HPLC and UV-visible spectrophotometer detector. Results When compared to FD with the transdermal patch system (F9) versus oral suspension administration, the bilayered transdermal films mean area under the curve values revealed an almost 1.2 times improvement in bioavailability (p < 0.05). Conclusion With a flux value of 30.4 g/cm2/h, the bilayered transdermal therapeutic system F9 containing lemongrass oil (1% v/v) as a permeation enhancer and a drug: polymer ratio (1:6) demonstrated good physicochemical and mechanical features. Formulation F9 may be deemed the best formulation for hypertension control based on above evaluation metrics.