Stability of vancomycin hydrochloride employed in antimicrobial seal solutions of central intravenous catheters

Abstract Objective: to verify the stability of vancomycin hydrochloride in antimicrobial seal solutions with and without association of heparin sodium according to temperature and association time. Method: an experimental study designed for the analysis of hydrogenionic potential and concentration by means of high-efficiency liquid chromatography of vancomycin hydrochloride (n=06) and vancomycin hydrochloride and heparin sodium (n=06). The solutions studied were submitted to absence of light, as well as to 22°C and 37°C. Analyses in triplicate (n=192) were performed at the initial moment (T0) and three (T3), eight (T8) and 24 hours (T24) after preparation. The data were submitted to analysis of variance (p≤0.05). Results: concentration of the antimicrobial at 22°C presented a reduction (T0-T8) and a subsequent increase (T24); hydrogenionic potential decreased significantly over time. At 37°C, the concentration increased up to T3 and decreased at T24, with a reduction of hydrogenionic potential up to 24 hours. Concentration of the vancomycin hydrochloride and heparin sodium solutions varied with a reduction at 22°C, accompanied by increased hydrogenionic potential. Precipitate formation was observed by visual inspection of the vancomycin hydrochloride-heparin sodium association (T3). Conclusion: pharmacological stability of vancomycin hydrochloride (5 mg/mL) and physical incompatibility with heparin sodium (100 IU/mL) were evidenced after three hours of association in the antimicrobial seal solutions studied. Resumo Objetivo: verificar a estabilidade do cloridrato de vancomicina em soluções de selo antimicrobiano sem e com associação de heparina sódica segundo a temperatura e tempo de associação. Método: estudo experimental delineado para análise de potencial hidrogeniônico e concentração por cromatografia líquida de alta eficiência de soluções de cloridrato de vancomicina (n=06) e cloridrato de vancomicina e heparina sódica (n=06). Submeteram-se as soluções estudadas à ausência de luz, 22°C e 37°C. Análises em triplicadas (n=192) ocorreram no momento inicial (T0), três (T3), oito (T8) e 24 horas (T24) após preparo. Os dados foram submetidos à análise de variância (p≤0,05). Resultados: a concentração do antimicrobiano a 22°C apresentou redução (T0-T8) e posterior elevação (T24); o potencial hidrogeniônico diminuiu significativamente ao longo do tempo. Em 37°C a concentração aumentou em até T3 e reduziu em T24, com redução de potencial hidrogeniônico até 24