title: Loading and release of doxycycline hyclate from strontium-substituted calcium phosphate cement.
abstract: Novel Sr-substituted calcium phosphate cement (CPC) loaded with doxycycline hyclate (DOXY-h) was employed to elucidate the effect of strontium substitution on antibiotic delivery. The cement was prepared using as reactants Sr-substituted beta-tricalcium phosphate (Sr-beta-TCP) and acidic monocalcium phosphate monohydrate. Two different methods were used to load DOXY-h: (i) the adsorption on CPC by incubating the set cement in drug-containing solutions; and (ii) the use of antibiotic solution as the cement liquid phase. The results revealed that the Sr-substituted cement efficiently adsorbs the antibiotic, which is attributed to an enhanced accessibility to the drug-binding sites within this CPC. DOXY-h desorption is influenced by the initial adsorbed amount and the cement matrix type. Furthermore, the fraction of drug released from CPCs set with DOXY-h solution was higher, and the release rate was faster for the CPC prepared with 26.7% Sr-beta-TCP. The analysis of releasing profiles points to Fickian diffusion as the mechanism responsible for antibiotic delivery. We can conclude that Sr substitution in secondary calcium phosphate cements improves their efficiency for DOXY-h adsorption and release. The antibiotic loading method provides a way to switch from rapid and complete to slower and prolonged drug release.
authors.affiliation: Departamento de Química-Física II, Facultad de Farmacia, UCM, 28040 Madrid, Spain. mkhresat@farm.ucm.es
authors.forename: M Hamdan
authors.initials: MH
authors.lastname: Alkhraisat
authors.forename: C
authors.initials: C
authors.lastname: Rueda
authors.forename: J
authors.initials: J
authors.lastname: Cabrejos-Azama
authors.forename: J
authors.initials: J
authors.lastname: Lucas-Aparicio
authors.forename: F Tamimi
authors.initials: FT
authors.lastname: Mariño
authors.forename: J
authors.initials: J
authors.lastname: Torres García-Denche
authors.forename: L Blanco
authors.initials: LB
authors.lastname: Jerez
authors.forename: U
authors.initials: U
authors.lastname: Gbureck
authors.forename: E Lopez
authors.initials: EL
authors.lastname: Cabarcos
mesh_terms: D000327:Adsorption / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002130:Calcium Phosphates / Q000737:chemistry*; D004318:Doxycycline / Q000031:analogs & derivatives* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D016062:Porosity / Q000187:drug effects; D016966:Porphyromonas gingivalis / Q000187:drug effects; D013324:Strontium / Q000737:chemistry*; D013696:Temperature; D013718:Tensile Strength / Q000187:drug effects; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate; D004318:Doxycycline; D013324:Strontium