Stability of extemporaneous sulfadiazine oral suspensions from commercially available tablets for treatment of congenital toxoplasmosis.

OBJECTIVES: To determine the physicochemical and microbiological stability of sulfadiazine suspensions (100 mg/mL) in simple syrup (A) and sorbitol (B) formulations prepared from commercially available tablets. METHODS: An ultra-performance liquid chromatographic assay was developed and validated to determine the chemical stability of sulfadiazine. Three samples were prepared and stored at 5 and 25 °C and assayed at 0, 7, 14 and 30 days. Physical parameters (appearance, pH, particle size and viscosity) were also monitored. Microbiological examination was performed through the suitable counting method. RESULTS: The formulations presented a sulfadiazine concentration of around 95% at the beginning at both temperatures. There was some variation in pH, viscosity and particle size distribution over time. The samples met the pharmacopoeia criteria of microbiological quality over 30 days, but only sulfadiazine formulated in syrup stored at 25 °C was suitable for use after one week. CONCLUSION: The sulfadiazine suspension in simple syrup was chosen as the most suitable formulation because it demonstrated stability for 14 days at room temperature, providing an alternative liquid dosage form of sulfadiazine for congenital toxoplasmosis treatment.

OBJECTIFS: Déterminer la stabilité physicochimique et microbiologique de suspensions de sulfadiazine (100 mg/mL) dans des formulations de sirop simple (A) et de sorbitol (B) préparées à partir de comprimés disponibles dans le commerce. MÉTHODES: Un test de chromatographie liquide ultra-performante a été développé et validé pour déterminer la stabilité chimique de la sulfadiazine. Trois échantillons ont été préparés et stockés à 5 ºC et à 25 ºC et analysés à 0, 7, 14 et 30 jours. Les paramètres physiques (apparence, pH, granulométrie et viscosité) ont également été contrôlés. Un examen microbiologique a été effectué par la méthode de comptage appropriée. RÉSULTATS: Les formulations présentaient une concentration en sulfadiazine d'environ 95% au début aux deux températures. Il y avait une certaine variation du pH, de la viscosité et de la distribution de la taille des particules au fil du temps. Les échantillons répondaient aux critères de pharmacopée pour la qualité microbiologique aprè 30 jours, mais seule la sulfadiazine formulée dans du sirop conservé à 25 ºC pouvait être utilisée après une semaine. CONCLUSION: La suspension de sulfadiazine dans un sirop simple a été choisie comme la formulation la plus appropriée car elle a démontré une stabilité à 14 jours à température ambiante, fournissant une forme galénique liquide alternative de sulfadiazine pour le traitement de la toxoplasmose congénitale.

Development and Validation of HPLC-DAD and UHPLC-DAD Methods for the Simultaneous Determination of Guanylhydrazone Derivatives Employing a Factorial Design.

Guanylhydrazones are molecules with great pharmacological potential in various therapeutic areas, including antitumoral activity. Factorial design is an excellent tool in the optimization of a chromatographic method, because it is possible quickly change factors such as temperature, mobile phase composition, mobile phase pH, column length, among others to establish the optimal conditions of analysis. The aim of the present work was to develop and validate a HPLC and UHPLC methods for the simultaneous determination of guanylhydrazones with anticancer activity employing experimental design. Precise, exact, linear and robust HPLC and UHPLC methods were developed and validated for the simultaneous quantification of the guanylhydrazones LQM10, LQM14, and LQM17. The UHPLC method was more economic, with a four times less solvent consumption, and 20 times less injection volume, what allowed better column performance. Comparing the empirical approach employed in the HPLC method development to the DoE approach employed in the UHPLC method development, we can conclude that the factorial design made the method development faster, more practical and rational. This resulted in methods that can be employed in the analysis, evaluation and quality control of these new synthetic guanylhydrazones.