Estudo da cinética de degradação de alguns medicamentos

Abstract

In the People's Republic of Mozambique, due to transport problems, lack of conditions at the peripheral level and delays in warehouses » there is a significant deterioration of medicines • That is why it is imperative to know their stability in the climatic conditions of our country. problem of conservation of medicines it is necessary to study stability in order to know the resistance of medicines to the action of certain physical factors. In this work, the study of the accelerated stability of Benzylpenicilne with Procaine, Chloramphenicol and Chlorthalidone is carried out. The influences of temperature and humidity are mainly studied, which are key factors that affect the stability of medicines. The kinetic results obtained are significant, and testify that. some drugs have great stability (Chloramphenicol) and do not need special care. Others, such as penicillin are easily degraded and the time it takes for the active ingredient to reach the minimum acceptable value, called t90, because the concentration must be 90% of that stated on the label, it is about 60 days for the suspension formulation and 90 days for the powder form at a temperature of 30°C. The study of the influence of moisture demonstrates that the degradation rate constant of Chlorthalidone increases with increasing moisture. The t90 for Chlorthalidone at a temperature of 30°c and 00% relative humidity, considering these elements as normal conditions in the Mozambican climate, is about 227 days. A modified version of the spectrophotometric method of analysis of Chloroquine recommended by the American Pharmacopoeia is also proposed. A statistical analysis of the results is carried out, comparing different parameters. Because the standard deviation of the modified method is smaller compared to the American Pharmacopoeia method, the modified version is considered to be more accurate. Comparison of the other parameters reveals that this method is more accurate (TRADUÇÃO NOSSA)