title: Validated stability-indicating densitometric thin-layer chromatography: application to stress degradation studies of minocycline.
abstract: A simple, stability-indicating high-performance thin-layer liquid chromatographic (HPTLC) method for analysis of minocycline was developed and validated. The densitometric analysis was carried out at 345 nm using methanol-acetonitrile-isopropyl alcohol-water (5:4:0.5:0.5, v/v/v/v) as mobile phase. The method employed TLC aluminium plates pre-coated with silica gel 60F-254 as the stationary phase. To achieve good result, plates were sprayed with a 10% (w/v) solution of disodium ethylene diaminetetraacetic acid (EDTA), the pH of which was adjusted to 9.0. Compact spots of minocycline were found at R(f) = 0.30+/-0.02. For proposed procedure, linearity (r = 0.9997), limit of detection (3.7 ng spot(-1)), recovery (99.23-100.16%), and precision (% R.S.D. < or = 0.364) was found to be satisfactory. The drug undergoes acidic and basic degradation, oxidation and photodegradation. All the peaks of degradation products were well resolved from the pure drug with significantly different R(f) values. The acidic and alkaline degradation kinetics of minocycline, evaluated using this method, is found to be of first order.
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Hamdard University, Hamdard Nagar, New Delhi 110062, India. jneelu78@yahoo.com
authors.forename: Nilu
authors.initials: N
authors.lastname: Jain
authors.forename: Gaurav Kumar
authors.initials: GK
authors.lastname: Jain
authors.forename: Farhan Jalees
authors.initials: FJ
authors.lastname: Ahmad
authors.forename: Roop Krishen
authors.initials: RK
authors.lastname: Khar
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002855:Chromatography, Thin Layer / Q000379:methods*; D003720:Densitometry / Q000379:methods*; D004340:Drug Contamination; D004355:Drug Stability; D007700:Kinetics; D008911:Minocycline / Q000032:analysis / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D035501:Uncertainty
chemical_list: D008911:Minocycline