DETERMINATION OF ALLAPININ CONTENT BY NON-AQUEOUS ACID-BASE TITRATION AND METHOD VALIDATION

417 Volume 5, Issue 10: Special Issue (EJAR) ISSN: 2181-2020 MPHAPP THE 6TH INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE “MODERN PHARMACEUTICS: ACTUAL PROBLEMS AND PROSPECTS” TASHKENT, OCTOBER 17, 2025 in-academy.uz DETERMINATION OF ALLAPININ CONTENT BY NON-AQUEOUS ACID-BASE TITRATION AND METHOD VALIDATION Mirzabdullayeva N.Sh. Ubaydullayev Q.A. Tashkent Pharmaceutical Institute, Tashkent, Republic of Uzbekistan e-mail: [email protected], tel: (99)395-56-12 https://doi.org/10.5281/zenodo.17341154 Relevance: Allapinin is an antiarrhythmic drug that blocks sodium channels in the heart due to the presence of lappaconitine. As an antiarrhythmic drug belonging to the diterpene alkaloid group, assessing the quality parameters of Allapinin, studying its properties, and comparatively evaluating quality control methods are essential. Another important task is to assess the validation parameters of the quantitative determination method of Allapinin. Purpose of the Study: To evaluate the method for determining the quantitative content of Allapinin using validation parameters. Methods: The content of Allapinin was determined by non-aqueous acid-base titration, and the obtained results were validated. Results: Several modern analytical methods were used to determine the content of Allapinin. One of them is acid-base titration with 0.1% perchloric acid. Salts that are poorly or practically insoluble in water, or that possess weak acidic or basic properties, are analyzed by acid-base titration using non-aqueous solvents. Weak electrolytes (acids or bases) are substances with a dissociation constant Kd < 10⁻⁸, i.e., with pKa > 8. The method was based on non-aqueous titration using perchloric acid (HClO₄) solution in glacial acetic acid, with crystal violet as an indicator. This method is used for the quantitative analysis of organic bases that are soluble in acetic acid and react with perchloric acid. The substance under study is dissolved in acetic acid and titrated with perchloric acid solution. The change in the color of the solution from violet to blue indicates the endpoint of titration. Knowing the volume of perchloric acid solution consumed for titration, the content of the analyzed base can be calculated. During the development of this method, it was determined that the most suitable solvent for dissolving a 200 mg sample of Allapinin is glacial acetic acid. Validation of the analytical method is the process of experimentally confirming the suitability of the method for its intended purpose. This ensures the reliability and reproducibility of the results, which is of critical importance in the quality control of pharmaceutical substances and finished products. According to the requirements of the European Pharmacopoeia, the working range for validation of quantitative determination methods for substances and medicinal products should cover 80–120% of the nominal content. Within this range, the linearity, accuracy, and precision of the method must be demonstrated. Conclusion: According to the validation results, the method for determining Allapinin content demonstrated specificity, as the use of glacial acetic acid did not introduce interfering substances into the titration results. The linearity data showed a correlation coefficient of 0.9993, which exceeds the minimum acceptance criterion (≥ 0.990). Accuracy was within 99.0% – 101.0%. These results confirm full compliance with validation requirements. Precision testing yielded a coefficient of variation of 0.47%, and intra-laboratory precision was 0.56%, both not exceeding the ≤ 2% acceptance limit. Based on these results, non-aqueous acid-base titration using 0.05 M perchloric acid solution was successfully applied for the quantitative determination of Allapinin. Validation outcomes confirm that this analytical method is suitable for determining the content of Allapinin.