A rapid and sensitive high-performance liquid chromatographic method is described for simultaneous determination of isoniazid methanesulphonate (IHMS) and its metabolites, such as isoniazid (INH) and acetylisoniazid (AcINH) in rabbit blood. According to stability studies, IHMS was most stable at pH 3-5. After acidifying the blood to pH 5.0, a suitable amount of acetonitrile was added to the supernatant for extraction and niacinamide served as an internal standard. After evaporation, the residue was reconstituted with phosphate buffer and aliquots of this solution were separated on a reversed-phase phenyl column by a mobile phase consisting of 0.25 mM tetrabutylammonium phosphate as a paired-ion reagent. UV detection was performed at 280 nm. Under these conditions, the between-run coefficients of variation of IHMS, INH and AcINH from 1 to 25 μm/ml were 4.7 ± 2.5, 5.4 ± 1.0 and 5.1 ± 3.1%, respectively. Hence this sensitive, reproducible and accurate method was suitable for pharmacokinetic studies of IHMS.
|Number of pages||8|
|Journal||Journal of Chromatography B: Biomedical Sciences and Applications|
|Publication status||Published - 1989|
ASJC Scopus subject areas
- Clinical Biochemistry
- Molecular Medicine