Design, optimization, and evaluation of simvastatin bilayer buccal tablets using mucoadhesive polymers

Simvastatin Bucco adhesive bilayer tablets are the subject of this study's design, optimization, and assessment in order to improve the drug's bioavailability by preventing first-pass metabolism and enabling regulated drug release through the buccal mucosa. A common antihyperlipidemic drug, simvastatin, has a high hepatic first-pass metabolism, which results in limited oral bioavailability. A viable substitute is buccal medication administration, which permits direct absorption through the buccal mucosa into the systemic circulation. Simvastatin and mucoadhesive polymers like Hydroxypropyl Methylcellulose (HPMC K4M), Carbopol 934P, and Sodium Carboxymethyl Cellulose (NaCMC) were included in the mucoadhesive layer of the bilayer tablets. To enable unidirectional drug release, an impermeable backing layer made of ethylene cellulose was included. To maximize bio adhesive strength and drug release kinetics, six formulations (F1-F6) with different polymer ratios were created utilizing the direct compression method. Numerous pre- and post-compression tests were performed on the prepared tablets, including tests for hardness, thickness, friability, surface pH, swelling index, uniformity of drug content, mucoadhesive strength, and ex vivo residence time. Utilizing simulated salivary fluid (pH 6.8), in vitro drug release experiments were conducted. To comprehend the process of drug release, release kinetics were examined using mathematical models. F4 performed the best out of all the formulations, with excellent physicochemical characteristics, a sustained drug release over 8 hours (~85%), and a desired mucoadhesive strength (>20 g). The release data suggested a diffusion-controlled mechanism since it best matched the Korsmeyer-Peppas model. Simvastatin Bucco adhesive bilayer pills appear to be a promising approach for longer-lasting medication administration and enhanced systemic availability, according to the findings. This buccal technology has the potential to be used in the future to create lipid-lowering formulations that are more patient-friendly and have better therapeutic results.