HPTLC determination of isoniazid and acetylisoniazid in serum. Comparison with HPLC

The quantitative determination of isoniazid (INH) and its metabolite acetylisoniazid (AcINH) has been optimized, One-dimensional HPTLC was performed on silica gel plates with ethyl acetate-methanol, 70 + 30 (v/v) as mobile phase. Quantitation was performed by densitometry; nicotinamide was used as internal standard, Calibration curves were constructed and detection limits, precision, and repeatability for INH and AcINH established, The method has been compared with HPLC and satisfactory correlation found between the two techniques, The HPTLC method is sensitive and specific and has been used to quantify INH and AcINH in patient sera.