Vicia faba, also known as “bakla” in Turkey, is a species of Fabaceae family that is widely grown in Africa and Asia. It is rich in levodopa, a medicinal substance used to treat Parkinson's disease. Levodopa produced by chemical synthesis is expensive and causes various side effects. Therefore, it is recommended to use natural levodopa sources to prevent possible side effects. A Central Composite Design technique has been used in this study to optimize levodopa extraction from Vicia faba. First, a single factor analysis examined 3 variables such as extraction temperature, extraction time, and concentration of acetic acid. The purpose of this study was to assess the effects of variables chosen on levodopa's extraction performance. By using variance and regression analyses, a second-order regression equation was determined as a predicted model. The value of R2 is 0.9882, which shows that the equation fits well. The best conditions are as follows: a temperature of 59.85 °C, an extraction time of 18.74 min, and an acetic acid content of 0.28%. Under optimum conditions, the maximum levodopa yield calculated from the predicted module was 4.53%. Extraction efficiency was determined as 4.54% experimentally under optimum conditions. A good relationship has been found between the experimental result and the predicted value.
Favipiravir (FVP), a pyrazine analog, has shown antiviral activity against a wide variety of viruses. It is considered to be worth further investigation as a potential candidate drug for COVID-19. It is not officially available in any pharmacopoeia. A rapid, simple, precise, accurate, and isocratic high performance liquid chromatography (HPLC) method has been developed for routine quality control of favipiravir in pharmaceutical formulations. Separation was carried out by C18 column. The mobile phase was a mixture of 50 mM potassium dihydrogen phosphate (pH 2.3) and acetonitrile (90:10, v/v) at a flow rate of 1 mL min−1. The ultraviolet (UV) detection and column temperature were 323 nm, and 30 °C, respectively. The run time was 15 min under these chromatographic conditions. Excellent linear relationship between peak area and favipiravir concentration in the range of 10–100 μg mL−1 has been observed (r2, 0.9999). Developed method has been found to be sensitive (limits of detection and quantification were 1.20 μg mL−1 and 3.60 μg mL−1, respectively), precise (the interday and intraday relative standard deviation (RSD) values for peak area and retention time were less than 0.4 and 0.2%, respectively), accurate (recovery, 99.19–100.17%), specific and robust (% RSD were less than 1.00, for system suitability parameters). Proposed method has been successfully applied for quantification of favipiravir in pharmaceutical formulations.
Authors:Serdar Gungor, Ibrahim Bulduk, Beyza Sultan Aydın, and Rahsan Ilikci Sagkan
Oseltamivir is an antiviral drug and is used in the treatment of all influenza viruses. It is the most effective antiviral option against all influenza viruses that can infect humans. UV and LC methods have been developed and validated according to ICH guidelines for various parameters like selectivity, linearity, accuracy, precision, LOD and LOQ, robustness for the quantitative determination of oseltamivir in pharmaceutical formulations. LC method has been performed using reverse phase technique on a C-18 column with a mobile phase consisting of 20 mM potassium dihydrogen phosphate solution and acetonitrile (60:40, v/v) at 25 °C. The mobile phase flow rate was 1.2 mL min−1. For the determination of oseltamivir, UV spectrum has been recorded between 200 and 800 nm using methanol as solvent and the wavelength of 215 nm has been selected. Both methods have demonstrated good linearity, precision and recovery. No spectral and chromatographic interferences from the capsule excipients were found in UV and LC methods. In both methods, correlation coefficients were greater than 0.999 within a concentration range of 10–60 mg mL−1 using UV and LC. Intra-day and inter-day precision with low relative standard deviation values were observed. The accuracy of these methods was within the range 99.85–100.17% for LC and from 99.26 to 100.70% for UV. Therefore UV and LC methods gave the most reliable outcomes for the determination of oseltamivir in pharmaceutical formulation.