title: Design and in vitro evaluation of gentamicin-Eudragit microspheres intended for intra-ocular administration.
abstract: The conditions of preparation of gentamicin sulfate microspheres with high drug loading and a particle size less than 5 micro m, using a double-emulsion-solvent evaporation technique, intended for intra-ocular administration are described. The microspheres were prepared from poly methacrylate (Eudragit RS and RL) polymers cross-linked with polyvinyl alcohol. The parameters that improved the incorporation efficiency of gentamicin in the microspheres and controlled the particle size and surface morphology were investigated. Modifying the secondary aqueous phase by partially saturating it with various concentrations of either KCl or gentamicin increased the incorporation efficiency of the drug and affected the mean diameters of the microspheres. However, these characteristics were not altered when the initial drug loading was increased in the formulations. The modified gentamicin microspheres exhibited a smooth surface with an incorporation efficiency rate of 12.59% and a mean diameter of 4.06 micro m. The antimicrobial efficiency of gentamicin released from the modified particles against selected Gram-positive and -negative organisms including Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa confirmed that the entrapped gentamicin seemed to remain unaltered by the encapsulation process.
authors.affiliation: Department of Pharmaceutics, College of Pharmacy, King Saud University, PO Box 17221 Riyadh, 11484 Saudi Arabia. kassas_r@hotmail.com
authors.forename: R
authors.initials: R
authors.lastname: Al-Kassas
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000494:pharmacology; D004337:Drug Carriers / Q000737:chemistry; D004339:Drug Compounding / Q000379:methods; D016503:Drug Delivery Systems / Q000379:methods*; D004926:Escherichia coli / Q000187:drug effects; D005839:Gentamicins / Q000008:administration & dosage* / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008863:Microspheres; D009883:Ophthalmic Solutions; D010316:Particle Size; D011109:Polymethacrylic Acids / Q000737:chemistry; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D004337:Drug Carriers; D005839:Gentamicins; D009883:Ophthalmic Solutions; D011109:Polymethacrylic Acids; C038300:methylmethacrylate-methacrylic acid copolymer