Development of stability-indicating LC method assisted by Design of Experiment for fenticonazole cream analysis in presence of degradation product

Fenticonazole is an antifungal drug widely used in a cream formulation including as a generic medicine. Stability studies of fenticonazole in a cream formulation are very scarce. In this research, we intent to contribute to generic medicines quality control and provide reliable data seeking for insertion of fenticonazole monograph in official compendia. Therefore, in this work it was studied the behavior of fenticonazole under several conditions and developed a stability-indicating LC method to separate the degradation products and quantify the drug in presence of them, using the Design of Experiments (DoE) as tool to achieve robust and easy transferable method. Fenticonazole stability was evaluated under aqueous, alkaline (0.1 M NaOH), acidic (0.1 M HCL) and oxidative (3% v/v, H2O2) at ambient temperature and heating at 90°C, over 6 hours. The drug shows to be unstable under all stressed test conditions. It was completely degraded under acid medium with arising of degradation products. The robust and stability indicating LC method was validated. It is able to reveal the fenticonazole instability and to separate its degradation product with accuracy and precision (CV ˂ 2%) and without any placebo interferences.(AU)

Development and Validation of First Derivative Spectrophotometric Method for Quantification of Darunavir in Tablets.

Aims: Darunavir is widely used in HIV/AIDS therapy. It is a HIV protease inhibitor that has excellent efficacy against the virus. The aim of this study is to develop and validate an analytical method fast and free of interferences for determination of darunavir ethanolate as raw material and tablet dosage form. Methodology: As the formulation excipients show high interference in darunavir determination by a direct UV absorption measurement a derivative spectrophotometry was applied. A selective, easy and fast method was achieved employing simple and cheap instrumentation by using first-order derivative spectrophotometry. Results: The first-derivation of spectrum of the drug measured between 200 and 400 nm allowed identification of the analyte and showed absence of placebo interference. The assay was based on the absorbance at 276nm. The linear concentration range was established from 11 to 21 μg/mL. The intra-day and inter-day precision expressed as RSD was 0.06% and 3.75% respectively with mean recovery of 99.84%. Conclusion: The proposed analytical method is able to quantify darunavir as raw material and tablets and can be used routinely by any laboratory applying a spectrophotometer with a derivative accessory. The great difference of the method proposed here is that it proves to be free of placebo interferences as well as simple, fast and low cost.