Estudo termoanalítico da compatibilidade fármaco – excipiente da fluoxetina com alguns excipientes utilizados na obtenção de formas farmacêuticas sólidas.

Abstract

For the development of a stable and bioavailable pharmaceutical form, it is necessary to know the physical and chemical properties of the drug and excipients alone and when combined. This study for each formulation is thus termed a pre-formulation study. The drug and the excipients used must be compatible with each other to generate a stable, efficient, attractive, easy to administer and secure. As some drugs have physicochemical compatibility and special features should be selected excipients that most suit them. Several related to the application of thermogravimetry (TG) and differential (DSC) characterization scanning calorimetry, assessment of purity, pharmaceutical formulation compatibility, identification of polymorphism Thermal stability and decomposition studies of drugs and drugs are described in the literature. TG is used to measure the weight variation as a function of temperature under a controlled atmosphere heating program. For pharmaceutical purposes, its use is described in the characterization, determination of purity and moisture, identification of polymorphism in evaluating the stability of drugs and medicines and kinetic studies of degradation. It is understood as a chemical incompatibility between substances in this type of study, the existence of any interaction between them, due to heating, which gives rise to changes in the chemical structure of the substance measured, either by decomposition of the parent molecule or by forming a new chemical species. In this study, thermal analysis techniques TG and DTG were used to investigate the compatibility between fluoxetine and the excipients used for the production of tablets and capsules, namely, corn starch, magnesium stearate, lactose and talc. The results of this study, together with data in the literature about the use of these excipients, point to a possible incompatibility between fluoxetine and excipients magnesium stearate and lactose. However, only the data obtained by TG / DTG are not sufficient to prove the incompatibility. Combining the data obtained in this study, the information from the literature about the use of these excipients together to fluoxetine, discourages the use with these last two excipients. It is evident that the use of thermal analysis techniques in the pharmaceutical area should be encouraged and always used in combination with other techniques.