PhD Scientific Days 2025

Pharmaceutical Sciences and Health Technologies II.

Separation of Tolperisone and its Degradation Products by a Dual Cyclodextrin Capillary Electrophoresis System to Elucidate their Possible Role in Allergic Adverse Effects

Name of the presenter

Ignáth Zsuzsanna

Institute/workplace of the presenter

Semmelweis Egyetem

Authors

Ms. Zsuzsanna Ignáth¹

1: Semmelweis Egyetem

Text of the abstract

Introduction: Tolperisone is a centrally acting muscle relaxant that has been used for the treatment of post-stroke spasticity and low back pain. The clinical safety of tolperisone has been recently reassessed due to rare but severe allergic reactions that are known to occur during its use. It has been suggested that the reactive degradation products of tolperisone may be responsible for these hypersensitivity reactions.
Aims: The objective of this study was to identify the major degradants of tolperisone, examine their presence in pharmaceutical products and investigate their possible role in the allergic effect of tolperisone preparations. For this purpose, a capillary electrophoresis UV detection (CE-UV) method was developed for the separation of tolperisone enantiomers as well as their most common degradation products.
Methods: Measurements were carried out using silica capillaries in a lithium acetate (25 mM LiAc) buffer. Proper separation of analytes was achieved by a dual cyclodextrin system containing beta-cyclodextrin (BCD) and carboxymethyl-beta-cyclodextrin (CMBCD). The molecules were detected based on their UV absorption.
Results: A CE-UV method was developed and validated for separation of known tolperisone degradants, 2-methyl-1-(4-methylphenyl)prop-2-en-1-ol (MMP) and 1-(4-methylphenyl)propan-1-one (MMPO) in the presence of high concentrations of tolperisone. MMP was identified as the main degradant in forced degradation tests of the active pharmaceutical ingredient. Next, the presence of impurities was examined in two tolperisone preparations by different Hungarian manufacturers past their date of expiry. Differences in MMP content have been found, highlighting the role of formulation in their stability. High reactivity of MMP was also demonstrated as rapid and almost complete adduct formation with cysteine was found. This degradation product thus might be responsible for the allergic adverse effects of tolperisone even when it is present in trace amounts in tablets by readily reacting with peptides in vivo.
Conclusion: A dual cyclodextrin CE method was developed for the detection and quantification of the most common degradants of tolperisone. The difference in MMP content of pills suggests that the selection of appropriate excipients can prevent the formation of this potentially allergenic degradation product.
Funding: EKÖP-2024-147