Biointerfacial phenomena of amlodipine buccomucosal tablets of HPMC matrix system containing polyacrylate polymer/β-cyclodextrin: Correlation of swelling and drug delivery performance

ABSTRACT

Objectives: This study focuses on the development of amlodipine bilayer buccal tablets of hydroxypropyl methylcellulose (HPMC) matrix system containing polyacrylate polymer (Carbopol^®)/β-cyclodextrin as the drug layer and ethylcellulose as the non-swellable backing layer, and their biointerfacial phenomena.

Methods: Tablets were evaluated for swelling, erosion and mucoadhesion using buccal mucosal tissue ex vivo. In vitro drug release and ex vivo drug transport across mucosal tissue were also performed in phosphate buffer (pH 6.8). The relationship of swelling with buccoadhesion and buccal permeation of various bilayer tablet formulations containing HPMC alone and in combination with Carbopol or drug-β-cyclodextrin complex has been prepared.

Results: Overall buccoadhesion of the tablet with combination of HPMC and Carbopol was increased significantly compared with that of HPMC alone. Presence of cyclodextrin did not change bioadhesion force and swelling behavior significantly. Ex vivo permeation was increased with the increase of HPMC proportion in other formulations as observed in in vitro dissolution.

Conclusion: Drug–cyclodextrin complexes in the tablet improved permeation due to its improved dissolution at the site of biointerface of tablet and buccomucosa. Correlations of ex vivo and in vitro data have been established to predict the buccomucosal permeation from the swelling index or drug release alone.

KEYWORDS:

• Bilayer tablet
• buccoadhesion
• buccomucosal permeation
• erosion
• ex vivo–in vitro correlation
• swelling

Acknowledgements

The authors are indebted to Dr. Manojranjan Nayak, President, Siksha ‘O’ Anusandhan University for providing all the facilities. We sincerely thank Dr. Reddy’s Laboratories for amlodipine besylate. Thanks are also given to the editor and anonymous reviewers for their valuable comments and suggestions.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.