Análise farmacêutica de tibolona em cápsulas magistrais por cromatografia líquida de alta eficiência

Abstract

Tibolone is a drug with chemical structure derived from 19-nortestosterone and estrogenic, androgenic and progestogenic activities. Due to these characteristics, it has been used to treat menopausal symptoms related to estrogen deficiency in postmenopausal women and it has also been indicated for osteoporosis prevention. There is no official monograph for quantification and dissolution tests of tibolone capsules. Hence, the objective of this study was to develop, validate and apply a quick, selective, precise and stability indicating method by high performance liquid chromatography (HPLC) for determination of tibolone in capsules and an in vitro dissolution test for quantification of their release into the dissolution media. Three different commercial formulations were evaluated. The stability indicating assay was developed based on the drug stress study carried out under conditions like acid, alkaline, neutral, oxidative, thermal and UV light degradation. The separation was performed on a C18 reversed-phase column (250 mm x 4.0 mm; 5 µm particle size) with acetonitrile: water (60:40 v/v) as mobile phase at a flow rate of 1 mL/min with UV detection at 205 nm. The method validation presented acceptable limits for all parameters according to ICH and ANVISA. The proposed method was applied in tibolone capsules and showed satisfactory results in their quantitative analysis. In the tibolone capsules dissolution test the best profile was reached with 0,5 % sodium lauryl sulphate (SLS) in water as the dissolution media, paddle apparatus at 100 rpm and collection time at 45 minutes, where the percentage tibolone released was higher than 80% (Q = 75). The quantification was performed by HPLC at 205 nm. All validation parameters were considered satisfactory. Therefore, the developed methods are appropriate for quality control analysis, stability studies, dissolution tests and dissolution profile of capsules containing this drug.