Desenvolvimento e validação do método de quantificação por HPLC, de Maleato de Dexclorfeniramina e Betametasona em xarope e de seus produtos de degradação

Abstract

A assurance of drug stability is a vital element in ensuring therapeutic efficacy and safety throughout the validity period. In this context, a specific and reliable analytical method becomes indispensable for monitoring the stability of the pharmaceutical product under analysis. Therefore, in the study, an analytical method was developed using High-Performance Liquid Chromatography (HPLC), which allows for a precise assessment of the active components in the syrup, as well as the identification and quantification of any impurities that may arise during the manufacturing, storage, or transportation of the medication. After the development tests, the chromatographic parameters for validation were defined. The YMC Triart C18 ExRS chromatographic column (250 mm x 4.6 mm, 3.0 µm) was used at a temperature of 45 ºC. The system employs a gradient elution with a mixture of diethylamine at concentrations of 0.02 % and 0.15 %, in a combination of purified water and acetonitrile. The flow rate of the mobile phase for the assay method was 1.0 mL min-1 in a 20 minute analytical run and 0.9 mL min-1 in a 90 minute run for the degradation product method, both with detection at 254 nm. The analytical method validation was conducted in accordance with National Health Surveillance Agency (ANVISA) RDC 166/2017, in harmony with Internacional Conference on Harmonization (ICH) guidelines. The assay method proved to be precise, accurate, and linear in the concentration range of 40.0 to 60.0 µg mL-1 for betamethasone and 320,0 to 480,0 µg mL-1 for exchlorpheniramine maleate. For the degradation product method, it was within the disregard limit range of 0.1 % (0.05 µg mL-1) to 0.6 % (0.3 µg mL-1) for unspecific impurities related to betamethasone and from 0.1 % (0.4 µg mL-1) to 0.24 % (0.96 µg mL-1) for unspecific impurities of dexchlorpheniramine maleate. In selectivity, the behavior of molecules of dexchlorpheniramine maleate and betamethasone under degradation conditions (acidic hydrolysis, basic hydrolysis, oxidative degradation, metal ions, temperature, humidity, and photolysis) was elucidated with the purpose of assessing the susceptibility of these molecules to degradation. Additionally, in the product degradation method, it was demonstrated the capability to separate specific impurities A, B, C, D, E, F, G, H, I, and J of betamethasone, as well as the impurity pheniramine originating from dexchlorpheniramine.