A METHODOLOGICAL APPROACH TO DESIGNING EXPERIMENTS WHEN DEALING WITH IDENTIFICATION TESTS FOR MEDICINAL PRODUCT COMPONENTS (AS ILLUSTRATED BY ASCORBIC ACID)

The need for identification  testing of active substances or excipients in multi-component medicinal products,  including the use of qualitative tests, calls for research substantiating the choice of tests and test conditions  with due regard to interference  effects caused by other components  of medicinal products and the amount of the sample used. The aim of the study was to develop a methodological approach to designing experiments while selecting qualitative reactions for identification testing of a medicinal product component based on the results of studies investigating the possibility of using known qualitative tests (as illustrated by ascorbic acid in a multi-component product — 0.4 mg of ascorbic acid per 100 mg of the vial contents)  with due regard to interference on the part of other medicinal product components and the amount of the sample used. Material and methods: the study focused on a multi-component medicinal product — lyophilisate for solution for intravenous and intramuscular  injections containing an antiinflammatory active substance and ascorbic acid as a stabilizing agent (antioxidant). The analysis of literature sources helped to determine qualitative tests that were assessed for potential use for identification testing of ascorbic acid as a component of the analysed medicinal product. The study involved experimental testing of the qualitative reactions based on acidic and reducing properties of ascorbic acid. Results: it was demonstrated that several well-known qualitative tests could be used for identification  testing of ascorbic acid as a component of the analysed medicinal product,  namely, the reaction of ferrous ascorbate formation  and the reaction of silver nitrate reduction to metallic silver after preliminary separation of ascorbic acid from the other medicinal product components, as well as the reaction of Prussian blue formation,  iodine test and reaction with a potassium permanganate solution, which do not require additional sample preparation.  It is not practicable to use the reaction with a methylene blue solution and the Fehling’s reagent reaction for this particular medicinal product,  since their results are feeble. Conclusions: the analysis of the multi-component medicinal product helped to develop a methodological  approach to choosing qualitative reactions for identification testing of one of the medicinal product’s components  (e.g., ascorbic acid). The suggested algorithm includes the choice of reactions, determination of their sensitivity and applicability for a particular medicinal product, analysis of the other components’ effects on the results of the chemical reaction,  and the need for additional sample preparation.  The whole complex of the studies performed helped to determine qualitative reactions and optimal conditions for identification testing of the analysed substance.

1. The State pharmacopoeia of the Russian Federation. 13th ed. V. 1–3. Moscow; 2015 (In Russ.)

2. Avdeeva ZhI, Soldatov AA, Alpatova NA, Kiselevsky MV, Lysikova SL, Bondarev VP, et al. Recombinant granulocyte colony stimulating factor biosimilars. Quality assessment. BIOpreparaty. Profilaktika, diagnostika, lechenie = BIOpreparations. Prevention, Diagnosis, Treatment. 2015;(1):4–14 (In Russ.)

3. Hima V, Rubesh Kumar S, Duganath N, Devanna N. Quantization of ascorbic acid in ayurvedic amla capsule by various analytical techniques. Der Pharma Chemica. 2013;5(3):8–17.

4. Neuberger S, Jooß K, Flottmann D, Scriba G, Neusüß C. Raman spectroscopy and capillary zone electrophoresis for the analysis of degradation processes in commercial effervescent tablets containing acetylsalicylic acid and ascorbic acid. J Pharm Biomed Anal. 2017;134:122–9. https://doi.org/10.1016/j.jpba.2016.11.020

5. Shanawany AE, Neugebaur M, El-Sadek M, Rucker G. HPLC method for quantitative determination of ascorbic acid, phenylephrine, paracetamol and caffeine mixture. Indian J Pharm Sci. 1990;52(4):182–5.

6. Goodpaster JV, Keto RO. Identification of ascorbic acid and its degradation products in black powder substitutes. J Forensic Sci. 2004;49(3):523–8.

7. Sadamasu Y, Morikawa M, Sakamaki N, Monma K, Kobayashi C. Quantitative analysis of L-ascorbic acid and erythorbic acid in foods by HPLC, and confirmation method by LC-MS/MS. Shokuhin Eiseigaku Zasshi. 2018;59(1):11–7 (In Jap.). https://doi.org/10.3358/shokueishi.59.11

8. The State pharmacopoeia of the Russian Federation. 12th ed. Part 1. Moscow: Scientific Centre for Expert Evaluation of Medicinal Products; 2007 (In Russ.)

9. European Pharmacopoeia online. European Directorate for the Quality of Medicines. Available from: http://online.edqm.eu

10. United States Pharmacopeia. 39th ed. 2016. Available from: http://www.uspnf.com/uspnf

11. Pogodina LI. Analysis of multicomponent dosage forms. Minsk: Vysheyshaya shkola; 1985 (In Russ.)

12. Feigl F. Spot tests in organic analysis. Moscow: Goskhimizdat; 1962 (In Russ.)