University of Khartoum

Development of Stability – Indicating HPLC Method for the Determination of Methyldopa, Levodopa & Carbidopa in Bulk and Tablets Dosage Form

Development of Stability – Indicating HPLC Method for the Determination of Methyldopa, Levodopa & Carbidopa in Bulk and Tablets Dosage Form

Show full item record

Title: Development of Stability – Indicating HPLC Method for the Determination of Methyldopa, Levodopa & Carbidopa in Bulk and Tablets Dosage Form
Author: Mohammed, Osman Ahmed Osman
Abstract: Background Methyldopa, Levodopa and Carbidopa are three drugs with similar chemical structures and different pharmacological actions. This similarity made it difficult to distinguish between them in pharmaceutical analysis. Thus, development of selective methods for their routine analysis is highly needed. The current work aimed to develop and validate a selective HPLC method for the analysis of methyldopa, levodopa and carbidopa in bulk and pharmaceutical formulations. Methods Methyldopa, levodopa and carbidopa were dissolved in an appropriate diluent and chromatographic conditions were then optimized to separate the three drugs from their mixture. Linearity, accuracy, and precision were assessed to validate the developed method. The validated method was then applied for the analysis of the three drugs in bulk and pharmaceutical formulations and to study their stability under stress conditions. Furthermore the method was statistically compared with the official USP methods. Results Good resolution was achieved using the developed method. Constructed calibration curves were linear in the concentration ranges (25-250 μg/ml) and (2.5-25 μg/ml) for methyldopa, levodopa and carbidopa respectively with correlation coefficient not less than 0.999. The limit of detection (LOD) and limit of quantitation (LOQ) were (0.91 and 2.77) μg/ml for methyldopa, (3.77 and 11.44) μg/ml for levodopa and (0.98 and 2.96) μg/ml for carbidopa respectively. RSD% values were less than 2% which indicate the precision of the developed method. Comparison of the developed method with the official USP methods in terms of precision (using F test) and accuracy (using t test) showed that the developed method is precise (calculated F- value < tabulated one) for methyldopa and accurate (calculated t- value < tabulated one) for methyldopa and levodopa, while there was a significant difference (calculated F- value > tabulated one) in precision for levodopa and carbidopa and in accuracy (calculated t- value > tabulated one) for carbidopa. Stability studies showed that the three drugs solutions are unstable under heat and alkaline conditions. Methyldopa and carbidopa solutions were unstable under UV irradiation (254 nm), while levodopa and carbidopa solutions were unstable under UV irradiation (365 nm). Conclusion A selective, accurate and precise stability indicating HPLC method for analysis of methyldopa, levodopa and carbidopa in bulk and in their single or combined tablet formulations has been developed and validated in accordance with ICH guidelines. The developed method was found suitable for the routine analysis as well as for stability studies of these drugs.
URI: http://khartoumspace.uofk.edu/123456789/25614


Files in this item

Files Size Format View

This item appears in the following Collection(s)

Show full item record

Share

Search DSpace


Browse

My Account