Formulation and Evaluation of Furosemide Buccal Tablets using Carbopol and Chitosan Polymers

Abstract

Buccal formulations have been developed to allow prolonged localised therapy and enhanced systemic delivery. Buccal delivery systems refer to the administration of the drugs via the buccal mucosa. Furosemide is a potent loop diuretic drug, widely used in patients with oedema of various origins. The bioavailability of furosemide after oral administration is about 60% and dose quite variable (20–60mg) owing to the presence of an absorption window in the upper intestinal tract. The objective of the present study was to formulate buccal tablets of Furosemide using hydrophilic polymers chitosan and carbopol to elucidate the release kinetics of furosemide from the polymer. In the present study an attempt was made to develop the buccal tablets of furosemide. Furosemide buccal tablets were prepared by direct-compression method incorporating hydrophilic polymers such as Carbopol 934P, Chitosan, and Hydroxypropyl Methylcellulose (HPMC K4M) in various combinations and concentrations and coded as F1-F9. A total of nine formulations (F1–F9) were developed and subjected to thorough preformulation studies and Fourier-transform infrared spectroscopy (FTIR), which confirmed the compatibility of drug and excipients. The prepared tablets were evaluated for physical characteristics (weight variation, thickness, hardness, friability, and drug content), pH, swelling index and in vitro drug release. Among the formulations, F3, F8, and F9 exhibited optimal swelling properties due to higher concentrations of Carbopol. Drug release studies revealed that Carbopol significantly sustained drug release, whereas Chitosan-based formulations released the drug more rapidly. Drug release kinetics varied, with Weibull, Higuchi, and zero-order models providing the best fits depending on polymer composition and dissolution apparatus. The study concludes that combining Carbopol and Chitosan in appropriate ratios can produce effective buccal tablets with controlled drug release, enhanced mucoadhesion, and improved bioavailability of Furosemide. This formulation approach shows promise for enhancing patient compliance and therapeutic efficacy in clinical settings.