title: In vitro delivery of dexamethasone using hydroxyapatite reservoirs.
abstract: Dexamethasone has been shown to stimulate bone nodule formation in vitro. A hydroxyapatite (HA) reservoir drug release device was designed to release dexamethasone in vitro. Two HA particle sizes (< 38 microns or 63-75 microns) were used to fabricate the reservoirs. Each HA reservoir was loaded with 2 mg of dexamethasone and suspended in 100 ml of 50% aqueous ethanol at 37 degrees C for a period of 28 days. The positive controls indicated a limited solubility of dexamethasone of 1.18 mg per 100 ml of 50% aqueous ethanol. Dexamethasone was not released from any of the HA reservoirs for the first 24 hours. The largest amount of dexamethasone (0.0137 microgram/microliter) was released from the 63-75 microns particle HA reservoirs. A significantly lesser amount (0.00855 microgram/microliter) of dexamethasone was released from the < 38 microns particle HA reservoirs. The results of this study suggest that a HA ceramic reservoir loaded with dexamethasone can be used to deliver dexamethasone over long periods of time.
authors.affiliation: Biology Department, University of Dayton, Ohio 45469-2320, USA.
authors.forename: W G
authors.initials: WG
authors.lastname: Billotte
authors.forename: P K
authors.initials: PK
authors.lastname: Bajpai
mesh_terms: D001672:Biocompatible Materials; D003907:Dexamethasone / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D017886:Durapatite; D005938:Glucocorticoids / Q000008:administration & dosage*
chemical_list: D001672:Biocompatible Materials; D005938:Glucocorticoids; D003907:Dexamethasone; D017886:Durapatite