Formulation & Effect of Polymers on Mucoadhesive Buccal Patch of Carvedilol Using Factorial Design

The study aim was concerned with formulation and in vitro evaluation of mucoadhesive buccal patch of carvedilol, which is extensively metabolized by liver. During last few years mucoadhesive dosage forms have promoted an area of drug delivery system that renders the treatment more effective and safe, not only for topical disorders but also for systemic problems. Therefore the present investigation is concerned with the development of the bucco-mucoadhesive patches, which were designed to prolong the buccal residence time, to increase penetration through buccal mucosa and thus increase the bioavailability. Various formulations were developed by using release rate controlling patches forming polymers like HPMC (K15, K4), HPC-L, Sodium alginate, PVP K30& Carbopol 934P in  alone & various combinations by solvent casting technique using plasticizer glycerol. For unidirectional release, backing layer prepared using ethyl cellulose 2.5%w/v dissolve in isopropyl alcohol and acetone. Glycerol used as a plasticizer was casted on the patches. The patches were evaluated for their thickness uniformity, folding endurance, weight uniformity, content uniformity, swelling behaviour, tensile strength, and surface pH, In vitro release studies, in vitro residence time, in vitro diffusion study. Patches exhibited drug release (diffusion) in the range of 75.69% to 96.53%. Kinetic models i.e. Higuchi, Korsemeyer-peppas, zero order were applied on data of diffusion release to explain release. The optimized formulation (F1) shows the zero order release.