Badam gum: a natural polymer in mucoadhesive drug delivery. Design,optimization, and biopharmaceutical evaluation of badam gum-based metoprolol succinate buccoadhesive tablets

Context: Applicability of natural polymers in pharmaceutical drug delivery.

Objective: The objective of the present investigation was to evaluate the applicability of badam gum (BG) obtained from Terminalia catappa LINN, belongs to the family combretaceae as a buccoadhesive polymer using metoprolol succinate as a model drug.

Methods: Tablets were prepared by wet granulation technique. Compression coating technique was employed for the preparation of unidirectional release buccal tablets using cellulose acetate as an impermeable backing layer.

Results: Muco/buccoadhesive properties of the BG were increased with the increase in the concentration of polymer which was evident form the detachment force measurement, ex vivo residence time, and swelling studies. MBG 2 was found to be the optimized formulation based on drug dissolution studies and bioadhesion studies. FTIR and DSC studies performed on the optimized formulation indicated no drug–polymer interaction. MBG 2 was found to be stable after accelerated stability testing for 6 months as per ICH guidelines. Pharmacokinetic studies of the optimized formulation were performed in six healthy human volunteers in comparison with that of the commercial extended release oral tablet GUDPRESS XL-25 by estimating pharmacokinetic parameters and mean residence time (MRT). It was found that there is a significant increase in the bioavailability of metoprolol succinate from BG formulation which was evident from the high AUC and MRT values compared with the commercial formulation.

Conclusion: The above results clearly indicated that badam gum can be used as a mucoadhesive polymer for buccal drug delivery.