Forced degradation study of thiocolchicoside: Characterization of its degradation products

Dipartimento di Scienze Chimiche, Alimentari, Farmaceutiche e Farmacologiche and Drug and Food Biotechnology Centre, Università degli Studi del Piemonte Orientale Amedeo Avogadro, Largo Donegani 2, 28100 Novara, Italy.
Journal of pharmaceutical and biomedical analysis (Impact Factor: 2.83). 03/2012; 61:215-23. DOI: 10.1016/j.jpba.2011.12.008
Source: PubMed

ABSTRACT Thiocolchicoside (TCC, N-[1,2-dimethoxy-10-methylsulphanyl-9-oxo-3-(3,4,5-trihydroxy-6-hydroxymethyl-tetrahydropyran-2-yloxy)-5,6,7,9-tetrahydro-benzo[a]heptalen-7-yl]-acetamide) was subjected to hydrolytic, oxidative, and photolytic stresses. TCC underwent degradation in acidic, basic, and oxidative conditions, while it was stable toward other stress conditions. The degradation products (DPs) were detected and their separation was achieved on a SGE Wakosil C18RS 5μm (250*4.6 mm; SGE) column employing a gradient LC-MS method for a total time of analysis of 18 min. The mass fragmentation pathways of both thiocolchicoside and its degradation products were established using LC-MS experiments assigning the structures to the DPs. In particular, five DPs were identified as: D1SO (N-[1,2-dimethoxy-10-methylsulphoxide-9-oxo-3-(3,4,5-trihydroxy-6-hydroxymethyl-tetrahydropyran-2-yloxy)-5,6,7,9-tetrahydro-benzo[a]heptalen-7-yl]-acetamide), D1SO(2) (N-[1,2-dimethoxy-10-methylsulphone-9-oxo-3-(3,4,5-trihydroxy-6-hydroxymethyl-tetrahydropyran-2-yloxy)-5,6,7,9-tetrahydro-benzo[a]heptalen-7-yl]-acetamide), D2 ([1,2-dimethoxy-10-methylsulphanyl-9-oxo-3-(3,4,5-trihydroxy-6-hydroxymethyl-tetrahydropyran-2-yloxy)-5,6,7,9-tetrahydro-benzo[a]heptalen-7-yl]-amine), D3 (N-[1,2-dimethoxy-3-hydroxy-10-methylsulphanyl-9-oxo-5,6,7,9-tetrahydro-benzo[a]heptalen-7-yl]-acetamide or 3-O-demethylthiocolchicine), D4 ([1,2-dimethoxy-3-hydroxy-10-methylsulphanyl-9-oxo-5,6,7,9-tetrahydro-benzo[a]heptalen-7-yl]-amine or N-deacetyl-3-O-demethylthiocochicine). Moreover, the structures of DPs were confirmed by synthesis of the reference standards which were fully characterized by MS, NMR, IR analyses. Finally a comprehensive degradation scheme of TCC was proposed allowing to outline D1SO and D3 as the indicators of its stability for oxidative and hydrolytic stress conditions.

  • [Show abstract] [Hide abstract]
    ABSTRACT: A forced degradation study is an essential step in the design of a regulatory compliant stability program for both drug substances and products, and was formalized as a regulatory requirement in ICH Guideline Q1A in 1993. It has since been extended to generic drugs. We provide an update on world-wide regulatory requirements. Also, we list all possible benefits of forced degradation studies to assess the stability of drugs and products. We discuss the kind of forced degradation study likely to meet regulatory expectations. We include the knowledge gained from these studies within the Quality by Design paradigm.
    TrAC Trends in Analytical Chemistry 09/2013; 49:71–88. DOI:10.1016/j.trac.2013.05.006 · 6.61 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Current standards and regulations demand the pharmaceutical industry not only to produce highly pure drug substances, but to achieve a thorough understanding of the impurities accompanying their manufactured drug substances and products. These challenges have become important goals of process chemistry and have steadily stimulated the search of impurities after accelerated or forced degradation procedures. As a result, impurity profiling is one of the most attractive, active and relevant fields of modern pharmaceutical analysis. This activity includes the identification, structural elucidation and quantitative determination of impurities and degradation products in bulk drugs and their pharmaceutical formulations. Nuclear magnetic resonance (NMR) spectroscopy has evolved into an irreplaceable approach for pharmaceutical quality assessment, currently playing a critical role in unequivocal structure identification as well as structural confirmation (qualitative detection), enabling the understanding of the underlying mechanisms of the formation of process and/or degradation impurities. NMR is able to provide qualitative information without the need of standards of the unknown compounds and multiple components can be quantified in a complex sample without previous separation. When coupled to separative techniques, the resulting hyphenated methodologies enhance the analytical power of this spectroscopy to previously unknown levels. As a result, and by enabling the implementation of rational decisions regarding the identity and level of impurities, NMR contributes to the goal of making better and safer medicines. Herein are discussed the applications of NMR spectroscopy and its hyphenated derivate techniques to the study of a wide range pharmaceutical impurities. Details on the advantages and disadvantages of the methodology and well as specific challenges with regards to the different analytical problems are also presented.
    Journal of Pharmaceutical and Biomedical Analysis 04/2014; DOI:10.1016/j.jpba.2014.04.016 · 2.83 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A new stability-indicating reversed-phase high-performance thin-layer chromatographic (RP-HPTLC) method for densitometric analysis of thiocolchicoside was developed and validated. The chromatograms were developed using aluminum plates pre-coated with silica gel 60 RP-18 F254S as a stationary phase and methanol : water (70 : 30 v/v) as a mobile phase. The compact band for thiocolchicoside was observed at R f value of 0.60 ± 0.02 at an absorption wavelength of 377 nm. The linear regression data for the calibration plots (r (2) = 0.9984) was found with respect to peak area in the concentration range of 100-600 ng per band. The limit of detection (LOD) and limit of quantification (LOQ) were 9.77 ng and 29.63 ng, respectively. The drug was exposed to acidic and alkaline hydrolysis, oxidation, photo degradation, and dry heat conditions. The peaks of degradation products were well-resolved from the peak of the standard drug with significantly different R f values. Statistical analysis proved that the established RP-HPTLC method is reproducible, selective, and accurate for the determination of thiocolchicoside in its formulations. The method can effectively separate the drug from its degradation products, and it can be considered as stability-indicating assay.
    09/2013; 2013:142628. DOI:10.1155/2013/142628

Full-text (2 Sources)

Available from
May 28, 2014