1976 Volume 25 Issue 274 Pages 642-647
Sulfisomidine was agglomerated or encapsulated by spray-drying its aqueous slurry or ammonium solution containing various kinds of binder i. e. acacia, gelatin, carboxymethylcellulose, methylcellulose or polyvinylpyrrolidone. The spray-dried products prepared from the aqueous slurries were encapsulated, acquiring a smooth film. On the other hand the products from the ammonium solution were characterized by forming a porous agglomerating crust due to the drastic evaporation of ammonia from spray droplet and changing the crystalline form to the amorphous or disordered form which resulted in increasing the solubility. The dissolution rates of the disks of spray-dried particles were grouped into two cases, one with the increased rate and the other with the reduced, as compared with that of the untreated original particles. This dissolution behavior depended on the type of feeding liquid, whether aqueous slurry or ammonium solution, binder and solvent used. Irrespective of the kind of binder and solvent, the product from the ammonium solution showed a prolonged release behavior. The action of delaying the dissolution rate of methylcellulose and carboxymethylcellulose product was strongest among the spray-dried products. The rate process of the increased and the reduced dissolution was analyzed by“capillary dissolution”and diffusional“three film”model, respectively.