modulating nimodipine crystallinity for enhancing dissolution: development of geriatric-friendly dosage form

Background: instant disintegration of oral disintegrating tablets (odts) provides a greater chance for buccal absorption, avoiding presystemic metabolism of nimodipine. in addition, odt can be easily dispersed in suitable liquid before delivery via nasogastric tube in critical care setting. methods: drop assisted co-grinding of nimodipine with glycine (at molar ratios 1:1, 1:2 and 1:3) or tartaric acid (at molar ratios 1:0.5, 1:1, 1:2, 1:3, and 1:4) was performed. solid state characterization and in vitro dissolution studies were employed. the optimized formulations were employed to prepare odts using suitable excipients. results: the prepared formulations improved drug dissolution compared to unprocessed and wet ground nimodipine. fourier–transform infrared spectroscopy, differential scanning calorimetry, powder x-ray diffraction and scanning electron microscopy suggested transformation of the crystalline structure after co-processing. this was due to salt formation in case of tartaric acid and the formation of new crystalline species/ size reduction in case of glycine. these changes were associated with dissolution enhancement. formulations with highest release efficiency (nimodipine and glycine with a molar ratio of 1:1 or nimodipine and tartaric acid at a molar ratio of 1:3) were successively incorporated in odts which showed fast liberation of nimodipine and dissolution efficiency values of 76 + 0.6% and 73.3 + 1.7% for the tablets containing glycine or tartaric acid respectively. conclusion: the study introduced a simple co-grinding approach for dissolution enhancement of nimodipine with high scaling up potential. the developed tablets will increase patient compliance with expected improved bioavailability.