title: Determination of neomycin and oxytetracycline in the presence of their impurities in veterinary dosage forms by high-performance liquid chromatography/tandem mass spectrometry.
abstract: Two HPLC/MS/MS methods, one for determination of neomycin sulfate and the other for determination of oxytetracycline hydrochloride in the presence of their impurities, were developed and validated. Separations were achieved with gradient elution on a C18 column. All components were ionized by positive-ion electrospray and detected by multiple reaction monitoring. Calibration curves were linear, with correlation coefficients >0.99. Precision of the methods was confirmed by RSD values of 0.34 and 0.71% for neomycin and oxytetracycline, respectively. Recovery values of 101.5 and 101.0%, respectively, indicated adequate accuracy. Analysis time for neomycin was 24 min, with the retention time of the main compound at 10.1 min; for oxytetracycline, the analysis time was 18 min, with the main peak at 9.95 min. Longer retention times than expected were a consequence of the necessity of chromatographic separation of isomers with the same ion transition. All impurities defined in the pharmacopoeias were determined and their identities confirmed. The methods were tested for QC of veterinary dosage forms (commercial powders and injections containing these antibiotics).
authors.affiliation: DSP Chromatography, Bul. Zorana Dindića 166, 11 070 Belgrade, Serbia. katarina@dsp-c.co.rs
authors.forename: Katarina
authors.initials: K
authors.lastname: Vucićević-Prcetić
authors.forename: Robert
authors.initials: R
authors.lastname: Cservenák
authors.forename: Niko
authors.initials: N
authors.lastname: Radulović
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004304:Dosage Forms; D004340:Drug Contamination; D015394:Molecular Structure; D009355:Neomycin / Q000737:chemistry*; D010118:Oxytetracycline / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*; D019155:Veterinary Drugs / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D004304:Dosage Forms; D019155:Veterinary Drugs; D009355:Neomycin; D010118:Oxytetracycline