An investigation of the direct compression properties of pre-gelatinized African bitter yam and cassava starches in acetylsalicylic acid tablet formulations

The direct compression ability of pre-gelatinized African bitter yam and cassava starches in acetylsalicylic acid tablet formulation was investigated. Starches from the African bitter yam and cassava tubers were extracted following standard procedures. The starch powders were subjected to some physicochemical evaluations and pre-gelatinized. Batches of acetylsalicylic acid granules and tablets were formulated with the native and pregelatinized forms of both the test and maize starches and microcrystalline cellulose at 5.0 and 10 %w/w by direct compression. Granules were evaluated for their flow properties and drug-excipient compatibility using DSC and FTIR while the tablets were investigated for their tablet parameters. The extracted starches were off-white to white in colour, insoluble in water, smooth in texture with particle sizes ranging from 5.0-10 μm that are oval to elliptical in shapes. The powders showed a swelling capacity ≤ 2.15, hydration capacity ≥ 1.20 and a moisture content ≤ 14.3 %. The granules exhibited good to fair flowability. Only tablets formulated with 10 %w/w of the pre-gelatinized starches and MCC met compendial requirements in their crushing strengths and friability. All the tablets disintegrated within 15 min with the pre-gelatinized cassava starches giving the shortest times of < 1.0 min. The 10 %w/w pre-gelatinized starches tablets compared favourably with MCC in their drug release profiles. Compatibility studies revealed no interaction between drug and excipients. The study show that the pre-gelatinized test starches compared favourably with MCC, a known direct compression excipient in their direct compression ability and drug release profiles especially at a concentration of 10 %w/w.