Design and development of atorvastatin calcium buccoadhesive bilayered devices for oral drug delivery

The present study comprises the development and evaluation of the buccoadhesive bilayer Atorvastatin calcium (ATC) tablet. ATC belongs to class of HMG Co-A reductase inhibitor which has low oral bioavailability (~ 14%) due to presystemic clearance in gastrointestinal (GI) mucosa and hepatic first-pass metabolism. The buccoadhesive systems overcome the challenges of first-pass metabolism and the side effects associated with GI drug delivery and enhance the bioavailability of various drugs. Formulated tablets were assessed for drug content, in vitro swelling index, matrix erosion, surface pH study, bioadhesion time, bioadhesive strength, in vitro drug release and in vitro diffusion study. It was observed that the use of a higher concentration of Carbopol 934P (CP) in formulation compared to the concentration of HPMC K-15(HPMC) in presence of Acacia enhances the in vitro swelling index and matrix erosion leading to more sustained drug release. Furthermore, mucoadhesive strength was greater in the case of combination of CP and acacia. Utilization of backing layer (BL) of ethylcellulose (EC) depicted reduced drug release, by virtue of unidirectional drug release. From the above investigation one can conclude that the utilization of this approach results in sustained drug release and enhanced mucoadhesive strength by altering the composition of polymers, as well as unidirectional drug release.