Formulation and Evaluation of Cola acuminata Gum-based Mucoadhesive Sustained-release Matrix Tablets of Diclofenac Sodium

Objective: This study aimed to evaluate Cola acuminata gum (CAG) for the formulation of mucoadhesive sustained-release matrix tablets of diclofenac sodium. Methods: Different batches of granules containing CAG and 100 mg of DS in ratios 0.5:1, 1:1, 2:1, and 3:1 were prepared, compressed into tablets, and evaluated for mucoadhesive strength, swelling index, and drug release in SGF (pH 1.2) and SIF (pH 7.4). Results: Swelling indices and mucoadhesive strengths of the tablets were pH-dependent. Swelling indices of 56 ± 2.03 to 121 ± 2.19% and mucoadhesive strengths of 7.25 ± 1.45 to 15.43 ± 2.71 g/cm² obtained at pH 7.4 were significantly higher (p<0.05) than swelling indices of 25 ± 2.43 to 47 ± 3.15% and mucoadhesive strengths of 5.52 ± 0.76 to 9.22 ± 1.95 g/cm² obtained at pH 1.2. The percentage release of DS from the matrix tablets at pH 1.2 after 2 h (T2h) was insignificant. However, the percentage of drug release at pH 7.4 was significant for all the batches and dependent on the CAG concentration. The drug release was in the order of batches containing 3 g (80.44 ± 7.75) < 2 g (86.35 ± 5.65) < 1 g (90.08 ± 6.14) < 0.5 g (99.70 ± 3.90). The time for maximum drug release was 7 h (T7h) for CAG containing 0.5 g and 10 h (T10h) for other batches. Conclusion: This study showed that CAG could be useful for mucoadhesive sustained drug delivery.