Development of hollow microspheres as floating controlled-release systems for cardiovascular drugs: Preparation and release characteristics

Citation
Ks. Soppimath et al., Development of hollow microspheres as floating controlled-release systems for cardiovascular drugs: Preparation and release characteristics, DRUG DEV IN, 27(6), 2001, pp. 507-515
Citations number
24
Categorie Soggetti
Pharmacology & Toxicology
Journal title
DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY
ISSN journal
03639045 → ACNP
Volume
27
Issue
6
Year of publication
2001
Pages
507 - 515
Database
ISI
SICI code
0363-9045(2001)27:6<507:DOHMAF>2.0.ZU;2-Y
Abstract
Hollow microspheres of cellulose acetate loaded with four cardiovascular dr ugs (nifedipine [NFD], nicardapine hydrochloride [NCD], verapamil hydrochlo ride [VRP], and dipyridamole [DIP]) were prepared by a novel solvent diffus ion-evaporation method. The oil-in-water emulsion prepared in an aqueous so lution of 0.05% poly(vinyl alcohol) medium with ethyl acetate, a water-solu ble and less toxic solvent, was used as the dispersing solvent. The yield o f the microspheres was up to 80%. The microspheres had smooth surfaces, wit h free-flowing and good-packing properties. Scanning electron microscopy (S EM) confirmed their hollow structures, with sizes in the range 489-350 mum. The microspheres tended to float over the gastric media for more than 12 h . The drug loaded in hollow microspheres was in an amorphous state, as conf irmed by differential scanning microscopy (DSC). The release of the drugs w as controlled for more than 8 h. The release kinetics followed different tr ansport mechanisms depending on the nature of the drug molecules.