Determination of capsule and tablet of Minocycline hydrochloride and its related substances by HPLC

OBJECTIVE To establish a method for determining capsule and tablet of Minocycline hydrochloride and its related substances.METHODS An HPLC method was adopted with a C8 column.The mobile phase was 0.2 mol·L~-1 ammonium acetate -dimethyl formamide -tetrahydrofuran (600∶398∶2, containing 0.01 mol·L~-1 EDTA-2Na ), The wavelength for detection was set at 280 nm.RESULTS The standard curve of Minocycline hydrochloride was linear in the range of 0.1 to 2.0 mg·ml~-1(r=0.9999).The average recovery of capsule was 99.9% with RSD of 0.6%(n=9).The average recovery of tablet was 100.5% with RSD of 0.7%(n=9).CONCLUSION The method is accurate,highly specific and widely applicable . Through the investigation of the samples from the whole country,it is shown that the method developed in this study can be applicable to control the quality of products.