title: Apatite as carrier for growth hormone: in vitro characterization of loading and release.
abstract: Previous studies concerning bone drug delivery systems have provided little data about the amount of drug loaded, one of the essential factors for determining the dose/effect relationship. To investigate this factor, an adsorption method involving a therapeutic agent was tested in vitro on an apatitic calcium phosphate (AP). One milligram of human growth hormone (hGH) was deposited onto 0.1, 0.15, and 0.2 g of AP powder over a period of 24 h at 37 degrees C. The amount of hGH loaded was determined by subtracting the dose recovered from that applied on AP. The results show that 1 g of AP absorbed 9.48 mg of hGH. From 0.1 and 0.15 g of hGH-loaded AP, hGH was released in vitro for 2 and 3 weeks, respectively, with a 50% time release (T1/2) at 30 h and 72 h, respectively, for the two quantities. The amount of drug loaded and the determined release kinetics were compatible with the action pattern of hGH, indicating that hGH-loaded calcium phosphate supports are suitable for bone-growth promotion.
authors.affiliation: Laboratoire de recherche sur les tissus calcifiés et les biomatériaux, Nantes, France.
authors.forename: J
authors.initials: J
authors.lastname: Guicheux
authors.forename: G
authors.initials: G
authors.lastname: Grimandi
authors.forename: M
authors.initials: M
authors.lastname: Trécant
authors.forename: A
authors.initials: A
authors.lastname: Faivre
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: G
authors.initials: G
authors.lastname: Daculsi
mesh_terms: D001031:Apatites; D016503:Drug Delivery Systems; D019382:Human Growth Hormone / Q000008:administration & dosage*; D006801:Humans
chemical_list: D001031:Apatites; D019382:Human Growth Hormone