Impact of Thermal and Chemical Modifications on the Compression and Release Properties of Bambara Nut Starches in Directly Compressed Tablet Formulations

Chemical and physical modifications can be used to impart desired properties to native starches. The present study investigates the compaction, mechanical, and release properties of thermal and chemically modified starches from Bambara nuts in ibuprofen tablet formulations. The native starches extracted from Bambara nuts are modified to obtain the pregelatinized and carboxymethylated forms. Heckel, Kawakita, and Gurnham equations are used to analyze the compressional properties of the formulations. The crushing strength of the tablets are assessed while disintegration and dissolution times are used to evaluate the drug release properties of the tablets. Pregelatinized starch-containing formulations exhibited faster onset and carboxymethylated starch had a higher amount of plastic deformation during compression than formulations incorporating the native starch. An increase in the particle size of Bambara starch had a significant effect on the densification of the starches during die filling, particle rearrangement, fragmentation propensity, and elastic/plastic deformation. The crushing strength and dissolution times of the tablets improves on starch modification. Tablets from the pregelatinized starch had longer disintegration time when compared with carboxymethylated and native Bambara starches. Formulations incorporating carboxymethylated starch had the shortest disintegration time, longest dissolution, and highest crushing strength values. The compressional, mechanical, and release properties of directly compressed ibuprofen tablet formulations are improved with the incorporation of the modified starches. Carboxymethylation and pregelatinization may be used to develop native starches as pharmaceutical excipients in specific formulations.