title: An adaptable HPLC method for the analysis of frequently used antibiotics in ocular samples.
abstract: Four different antibiotics, delivered individually to rabbit eyes via hydrophilic intraocular lenses soaked in the drug solution prior to implantation, were measured in aqueous and vitreous humor samples from the eyes. To meet this analytical need, we developed a sensitive, high performance liquid chromatographic (HPLC) method for measuring the concentrations of moxifloxacin, gatifloxacin, linezolid, and cefuroxime in the ocular tissue. Separations were carried out on a LichroSpher RP-18 column, maintained at room temperature. The fluoroquinolones were eluted with a mobile phase consisting of 20% acetonitrile, in 0.1% trifluoroacetic acid (pH 3.0) with 30 mM tetrabutylammonium chloride. Linezolid and cefuroxime were eluted with 25% acetonitrile in 25 mM Na acetate buffer, pH 5.0. All elutions were isocratic. With ultraviolet detection, the lower limit of quantitation (LLOQ) for these compounds approached 1 ng (on-column injection). By using fluorescence detection, the LLOQ for the fluoroquinolones improved to 200 pg. The overall accuracy of the method was >or=90%. With minor modifications, the method was optimized for each of the agents, and the resulting analytical sensitivity made the method suitable for clinical investigations of the ocular penetration of these drugs.
authors.affiliation: Dept. of Ophthalmology, 7703 Floyd Curl Drive MS 6230, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
authors.forename: Lindsay T
authors.initials: LT
authors.lastname: Davis
authors.forename: Neeru
authors.initials: N
authors.lastname: Kumar
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Nijm
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Ulanski
authors.forename: Elmer Y
authors.initials: EY
authors.lastname: Tu
authors.forename: Richard G
authors.initials: RG
authors.lastname: Fiscella
authors.forename: Randal J
authors.initials: RJ
authors.lastname: Peterson
authors.forename: Randolph D
authors.initials: RD
authors.lastname: Glickman
mesh_terms: D000081:Acetamides / Q000032:analysis; D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D001372:Aza Compounds / Q000032:analysis; D002444:Cefuroxime / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003263:Contact Lenses, Hydrophilic; D005123:Eye / Q000737:chemistry; D024841:Fluoroquinolones / Q000032:analysis; D000077734:Gatifloxacin; D016014:Linear Models; D000069349:Linezolid; D000077266:Moxifloxacin; D023303:Oxazolidinones / Q000032:analysis; D011804:Quinolines / Q000032:analysis; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D014822:Vitreous Body / Q000737:chemistry*
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D023303:Oxazolidinones; D011804:Quinolines; D000069349:Linezolid; D000077734:Gatifloxacin; D002444:Cefuroxime; D000077266:Moxifloxacin