title: Incorporation of tocopherol acetate-containing particles in acrylic bone cement.
abstract: Acrylic bone cement (BC) is used in orthopaedic surgery to anchor cemented prostheses to bone. Association of antioxidant molecules to BC may suppress reactive species injury which contributes to implant failure. Tocopherol acetate (ATA)-loaded polymethylmethacrylate (PMMA) particles (ATA(PMMA)) were prepared by single emulsion solvent evaporation technique and were incorporated into BC. An encapsulation efficiency of 84% (w/w) was obtained and drug release studies showed distinct ATA release profiles and mechanisms before and after particle incorporation into BC. Experimental data, analysed using first-order, Higuchi and Korsmeyer-Peppas models revealed that ATA was released from particles by a Fickian diffusion mechanism while a non-Fickian transport was observed upon particle incorporation in BC. There were no changes in the mechanical properties of BC specimens containing ATA(PMMA) particles, in contrast to what was observed when ATA was loaded directly into BC. Overall, ATA(PMMA) particles are potential carriers for the incorporation of an antioxidant drug into BC.
authors.affiliation: Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal. asimao@ff.ul.pt
authors.forename: A
authors.initials: A
authors.lastname: Bettencourt
authors.forename: H F
authors.initials: HF
authors.lastname: Florindo
authors.forename: I F S
authors.initials: IF
authors.lastname: Ferreira
authors.forename: A
authors.initials: A
authors.lastname: Matos
authors.forename: J
authors.initials: J
authors.lastname: Monteiro
authors.forename: C
authors.initials: C
authors.lastname: Neves
authors.forename: P
authors.initials: P
authors.lastname: Lopes
authors.forename: A
authors.initials: A
authors.lastname: Calado
authors.forename: M
authors.initials: M
authors.lastname: Castro
authors.forename: A J
authors.initials: AJ
authors.lastname: Almeida
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage*; D004339:Drug Compounding / Q000379:methods; D004655:Emulsions / Q000737:chemistry; D006244:Hardness; D010316:Particle Size; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D024505:Tocopherols / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D004655:Emulsions; D019904:Polymethyl Methacrylate; D024505:Tocopherols