title: Controlled release of a model antibacterial drug from a novel self-lubricating silicone biomaterial.
abstract: There is considerable interest in developing medical devices that provide controlled delivery of biologically active agents, for example, to reduce the incidence of device-related infection. Silicone elastomers are one of the commonest biomaterials used in medical device production. However, they have a relatively high coefficient of friction and the resulting lack of lubricity can cause pain and tissue damage on device insertion and removal. Novel silicone cross-linking agents have recently been reported that produce inherently 'self-lubricating' silicone elastomers with very low coefficients of friction. In this study, the model antibacterial drug metronidazole has been incorporated into these self-lubricating silicone elastomers to produce a novel bioactive biomaterial. The in vitro release characteristics of the bioactive component were evaluated as a function of cross-linker composition and drug loading. Although conventional matrix-type release kinetics were observed for metronidazole from the silicone systems, it was also observed that increasing the concentration of the cross-linking agent responsible for the lubricious character (tetra(oleyloxy)silane) relative to that of the standard non-lubricious cross-linking agent (tetrapropoxysilane) produced an increase in the metronidazole flux rate by up to 65% for a specified drug loading. The results highlight the potential for developing lubricious silicone medical devices with enhanced drug release characteristics.
authors.affiliation: School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: R K
authors.initials: RK
authors.lastname: Malcolm
authors.forename: S D
authors.initials: SD
authors.lastname: McCullagh
authors.forename: A D
authors.initials: AD
authors.lastname: Woolfson
authors.forename: S P
authors.initials: SP
authors.lastname: Gorman
authors.forename: D S
authors.initials: DS
authors.lastname: Jones
authors.forename: J
authors.initials: J
authors.lastname: Cuddy
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D003432:Cross-Linking Reagents / Q000737:chemistry; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004339:Drug Compounding; D005079:Excipients / Q000737:chemistry; D005233:Fatty Alcohols / Q000737:chemistry; D007700:Kinetics; D008795:Metronidazole / Q000008:administration & dosage / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012826:Silicone Elastomers / Q000737:chemistry*; D012995:Solubility
chemical_list: D000900:Anti-Bacterial Agents; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005079:Excipients; D005233:Fatty Alcohols; D012821:Silanes; D012826:Silicone Elastomers; C500353:tetra(oleyloxy)silane; D008795:Metronidazole