Design and Evaluation of Buccal Patch Containing Combination of Hydrochlorothiazide and Lisinopril

Purpose: The objective of the present study was to formulate and evaluate buccal patches containing combination of lisinopril (LP) and hydrochlorothiazide (HCZ). Approach: Films were fabricated by solvent casting method, using combination of mucoadhesive polymers such as hydroxypropylmethyl cellulose (HPMC), hydroxypropyl cellulose (HPC), polyvinyl alcohol (PVA) and polyvinyl pyrolidone (PVP) and ethyl cellulose (EC) as backing layer. The patches were evaluated for physicochemical characteristics such as weight, thickness, surface pH, folding endurance, bioadhesive strength, swelling index, drug content, tensile strength, elongation at break, mucoadhesion time, in vitro and ex vivo drug permeation. Results: The IR spectra showed no interaction between drug and polymer. Physicochemical characteristics of all the samples were found to be satisfactory. Swelling of the films increased with increasing content of HPMC or HPC and PVP. Bioadhesive force, tensile strength, percentage elongation and mucoadhesion time increased with higher proportions of HPMC, HPC and PVA. In vitro drug release studies demonstrated slower release of both drugs in formulations with higher amount of HPMC, HPC and PVA. The in vitro drug release data of most formulations best fitted first order model, except for the formulations FA3 and FC. Ex vivo drug permeation studies of formulations through porcine buccal mucosa showed similar results as in vitro. Conclusion: Buccal delivery of this combination can resolve the drawbacks like incomplete absorption in the gut thereby possible improvement in bioavailability, apart from controlled release of the drugs.