Abstract
Purpose: To formulate and characterize tizanidine hydrochloride (TZN) and piroxicam (PRX)-loaded bilayer mucoadhesive buccal films with an intention to improve the bioavailability and patient compliance in pain management.Methods: Bilayer buccal films were prepared by solvent evaporation technique using hydroxypropyl methylcellulose (HPMC) 15cps and polyvinylpyrrolidone (PVP K30 as immediate release (IR) layer forming polymers and HPMC K15 M, PVP K 90 along with various muco adhesive polymers (Carbopol P934, sodium alginate, etc), as sustained release (SR) layer forming polymers. The prepared films werecharacterized for thickness, weight variation, folding endurance, surface pH, swelling index,mucoadhesive strength, in vitro residence time, in vitro drug release, ex vivo permeation and drug release kinetics.Results: The prepared films were of largely uniform thickness, weight and drug content. Moisture loss (%) and folding endurance were satisfactory. Surface pH was compatible with salivary fluid. Disintegration time was 85 s for F1 and 115 s for F2 of IR films. In vitro dissolution studies showed 99.12 ± 1.2 % (F1) and 90.36 ± 1.8 % (F2) were released in 45 min. Based on the above results, F1 was chosen as the optimum formulation to be combined with SR layer of TZN. Amongst the SR layers of TZN in vitro drug release. The findings show that of F2 was 98.38 ± 0.82 % and correlated with ex vivo release. Drug release followed zero order release kinetics and mechanism of drug release was non-Fickian type diffusion. In vitro residence time was greater than 5 h.Conclusion: The findings show that the bilayer buccal films demonstrate the dual impact of deliveringPRX instantly from the IR layer, with good controlled release and permeation of TZN from the SR layer, thus providing enhanced therapeutic efficacy, drug bioavailability and patient compliance.