1983 Volume 103 Issue 6 Pages 690-695
In the previous paper, a new technique for particle size reduction of oxolinic acid (OA), a slightly soluble model drug having an acidic group in a molecule, by the crystallization through the neutralization of its alkaline solution in the presence of certain surfactant or polymer was described. The wet sieving method by the use of polycarbonate membrane filter for the evaluation of size reduction effect was also described. Various factors affecting the size reduction of OA were investigated in this paper. The results obtained were as follows ; manners of participation in various factors affecting the size reduction varied with OA concentration at crystallization, and in the case of 5 w/v% OA concentration, the influences of addition rate of hydrochloric acid solution, stirring rate, reaction temperature and concentration of hydrochloric acid were relatively low. Size reduction effects of various surfactants and polymers were investigated. All of them were effective, though differences were recognized in the extent of size reduction. It has been found that the establishment of optimal conditions to obtain the finest particles is enabled and moreover, there is a possibility to prepare the particle that have an optional particle size by regulating the various factors.
