Synthesis of hydroxyapatite hollow microspheres and their use in gastric retentive drug delivery systems
Date of Issue2007
School of Materials Science and Engineering
A totally erodible gastroretentive dosage form made of calcium alginate, sunflower oil and hydroxyapatite (HA) hollow microspheres (HMS) as the radiopacifer was developed. Porous thin-shelled HA HMSs in a ping-pong shape were successfully synthesized in a nozzle-reactor system with a thermosetting polymeric binder. The synthesis mechanism of HA HMSs was investigated in terms of solid content and rheological property of the starting slurry. Multiple-unit alginate floating dosage form was synthesized through an emulsion gelation process with the inclusion of sunflower oil and HA HMS radiopacifier. These beads were able to float continuously on the acidic medium for 24 hours, as well as control release both hydrophobic ibuprofen and hydrophilic niacinamide or metoclopramide HCl in consistency with the extended floatation time. HMS inclusion was found to able to enhance the niacinamide incorporation and further slow the release rate of ibuprofen. However, radiopacity was achieved at the cost of buoyancy because of disintegration of the HMSs. These beads are considered a promising oral control release dosage form for intragastric drug delivery.
Nanyang Technological University