Assay of tipranavir capsules by a simple stability-indicating LC–UV method and cytotoxicity study of degraded samples

Abstract

Tipranavir (TPV) is a protease inhibitor (PI) specially recommended for treatment-experienced patients who are resistant to other PI drugs. It was approved by FDA in 2005, but, until now, it has not been included in any official compendia. The objective of this study is to develop and validate a simple LC–UV method to assay TPV capsules, and to study the cytotoxicity of TPV and degraded samples over the cell viability. The optimized conditions were C8 Phenomenex® column (Luna®, 150 mm × 4.6 mm, 5 µm); mobile phase composed by methanol, acetonitrile, and acidified water pH 3.5 (40:31:29); flow rate 1.0 mL min−1 and detection at 254 nm. The cytotoxic effects of non-degraded and degraded TPV samples were evaluated in 3T3 cells by means of MTT viability assay. The method was linear in the range of 10–100 µg mL−1 (r = 0.9999) and specific, even in the presence of degradation products and impurities. The method showed suitable accuracy (mean recovery 100.02%), precision (RSD < 1.10%), and a two-level full factorial design indicated the robustness of the method. The degraded samples exhibited cytotoxicity patterns similar to TPV under controlled conditions. The method developed is appropriate for quality control of TPV capsules and stability studies.