|
Nimodipine is a water insoluble drug , low bioavailability , absorption unstable . In order to solve the above problems , the use of solid dispersion and micronized for the purpose a series of studies to improve the solubility and dissolution rate of the drug nimodipine , changing the state of presence of the drug to improve its solubility , thereby improving its bioavailability . Selected in the Development of a solid dispersion PEG4000, PEG6000, Poloxamer188 , PVP K30 , four kinds of the carrier , with a solvent - the melting method and the solvent prepared nimodipine solid dispersion preparation investigated by its dissolution , it is determined the solid dispersion formulation and preparation conditions: ethanol as the solvent, with PEG6000-Poloxamer188 as the carrier, the preparation was carried out with a solvent - melting method , drug - the ratio of the carrier to 1:3, the proportion of the two carriers 1:1. The cumulative dissolution rates , detection , solid dispersion within 2h 3.58 -fold increase compared to the bulk drugs . Recrystallization techniques , the micronized development of bulk drugs screened by examining the dissolution Preparation and prescription continuous phacoemulsification method for optimal prescription : in 250mL conical flask concentration of 1% PVP stabilizer aqueous solution 150mL, and placed in a 0 ° C ice water bath , slowly added dropwise to a speed of 1 mL / min under conditions of continuous ultrasound 25mL concentration of 0.03mol / L ethanol solution of nimodipine , standing after 2h centrifuged until completely separated , washed with distilled water , filtered and dried in oven thermostat , grinding, through a 120 mesh sieve . Micronized 2h cumulative dissolution rate 3.44 -fold increase compared to the bulk drugs . By X-ray diffraction scan of the solid dispersion and micronized quality inspection, the results show that : PEG6000 was and Poloxamer188 crystalline substance , so they no apparent suppression crystal made ??of solid dispersion , nimodipine part into molecular state , and the other part into a microcrystalline state dispersed in the carrier, the dissolution is improved ; nimodipine micronized crystalline state was still exist , due to its particle size becomes smaller , the powder specific surface area is increased , the dissolution is improved .
|