Jain Nilu, Jain Gaurav Kumar, Ahmad Farhan Jalees, Khar Roop Krishen
Department of Pharmaceutics, Faculty of Pharmacy, Hamdard University, Hamdard Nagar, New Delhi 110062, India.
Anal Chim Acta. 2007 Sep 19;599(2):302-9. doi: 10.1016/j.aca.2007.08.020. Epub 2007 Aug 19.
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.
开发并验证了一种用于分析米诺环素的简单、稳定指示性高效薄层液相色谱（HPTLC）方法。使用甲醇 - 乙腈 - 异丙醇 - 水（5:4:0.5:0.5，v/v/v/v）作为流动相，在345 nm处进行密度测定分析。该方法采用预涂硅胶60F - 254的TLC铝板作为固定相。为了获得良好结果，用10%（w/v）乙二胺四乙酸二钠（EDTA）溶液喷雾板，将其pH值调至9.0。在R(f) = 0.30±0.02处发现米诺环素的斑点紧密。对于所提出的方法，线性（r = 0.9997）、检测限（3.7 ng spot⁻¹）、回收率（99.23 - 100.16%）和精密度（% R.S.D.≤0.364）令人满意。该药物会发生酸碱性降解、氧化和光降解。所有降解产物峰与纯药物峰均能很好地分离，R(f)值有显著差异。用该方法评估米诺环素的酸碱性降解动力学为一级。
