Design, development and evaluation of buccoadhesive drug delivery system for atorvastatin calcium

Abstract

The purpose of this research was to study mucoadhesive bilayer buccal tablets of Atorvastatin calcium using the bioadhesive polymers Carbopol 934P (CP), Sodium CMC, Hydroxy ethyl cellulose (HEC) and Sodium alginate (Na-alginate) along with ethyl cellulose as an impermeable backing layer. Nine different formulations of mucoadhesive buccal tablets of Atorvastatin calcium were prepared, which contain the polymers in various combinations. Tablets were prepared by direct compression method and characterized by swelling studies, % matrix erosion, surface pH, bioadhesive properties, in-vitro drug dissolution and in-vitro diffusion studies. All the formulations gave the satisfactory results in terms of bioadhesive performance, physical and mechanical properties and surface pH. The swelling index was proportional to CP content and inversely proportional to sodium CMC content. The surface pH of all tablets was found to be satisfactory, close to neutral pH; hence, buccal cavity irritation should not occur with these tablets. Drug release and drug diffusion from the tablets were depended on the ratio and type of the polymer used in the formulation. Tablets containing CP and Na-CMC in the ratio of 3:2 (F2) had the maximum percentage of in-vitro drug release without disintegration in 6 h. The mechanism of drug release was found to be non-Fickians diffusion and followed anomalous release. The formulation F2 was optimized based on good bioadhesive strength (19.0 ± 0.30 g) and sustained in-vitro drug permeation (85.68 ± 0.41% for 6 h). The chosen tablet containing 8 mg of Atorvastatin calcium performed 6 h sustained drug release with desired therapeutic concentration.