Avaliação da estabilidade de formulações líquidas orais de sulfadiazina obtidas a partir de comprimidos

Abstract

Sulfadiazine (SDZ) is one of the drugs used for the treatment of congenital toxoplasmosis, however the only commercially available oral formulation is the tablet (500 mg). One of the strategies to solve this problem is through the transformation of pharmaceutical forms. Thus, the present work aimed to prepare and evaluate the physical, chemical and microbiological stability of extemporaneous suspensions of SDZ (100 mg / mL) using tablets (FURP-Sulfadiazine). The suspension vehicles used were: A - 85% simple syrup and 1% (w/v) methylcellulose; and B - sorbitol 70%. Stability was evaluated during days 0, 7, 14 and 30 under storage at controlled temperatures of 5 °C ± 3 °C and 22.5 °C ± 2.5 °C. The physical characteristics analyzed were the organoleptic characteristics, the pH, the particle size and the viscosity. The concentration of SDZ was determined by a method developed and validated using ultra-high performance liquid chromatography (CLUE). Microbiological attributes of non-sterile pharmaceutical forms were also evaluated by adding p-aminobenzoic acid to the culture media in order to neutralize the antimicrobial activity of SDZ. pH and viscosity showed significant differences on study days. The particle size distribution was constant up to 14 days of study for both formulations. However, only the SDZ A suspension presented reliable results within the pharmacopoeial limits, probably influenced by the solubility of the active substance at different pH, particle sedimentation and viscosity reduction. In addition, during the study no microbial contamination was observed. Based on the results, it can be concluded that SDZ A suspension at room temperature is stable for 14 days and is a viable alternative for the pediatric treatment of congenital toxoplasmosis.