Compatibilidad química del piracetam determinada por calorimetría diferencial de barrido / Chemical compatibility of piracetam determined by differential scanning calorimetry

Introducción: en la primera etapa de preformulación de un medicamento se seleccionan los excipientes y es importante la realización de los estudios de compatibilidad química entre el ingrediente activo farmacéutico (IFA) y excipientes. Una de las técnicas más rápidas para realizar dichos estudios es la Calorimetría diferencial de barrido (DSC), y como técnica complementaria la Termogravimetría (TG). Objetivo: empleando DSC y TG, se realiza un estudio de compatibilidad química entre IFA y excipientes preseleccionados, para comprobar la existencia o no de interacción química. Métodos: el equipo empleado fue el TA3000Mettler, aco­plado a la celda DSC20 y al horno TG50. El IFA utilizado fue Piracetam, y los excipientes: Kollidon VA 64, Estearato de magnesio, Celulosa microcristalina, Polietilenglicol 20 000 y Aerosil. Dichos excipientes se caracterizaron por DSC al igual que el IFA, al cual se le detectó la transición física de fusión. Para el estudio de compatibilidad se prepararon mezclas físicas binarias en una relación de concentración 1:1 Resultados: la figura 1 muestra la detección del punto de fusión por DSC del IFA. Se obtuvieron dos transiciones endotérmicas, comprobándose por TG cuál era la de fusión. La figura 2 muestra los termogramas de las mezclas formadas entre IFA y excipientes. Conclusiones: no se detectó aparición de nuevos picos, por lo que se infiere que no hay incompatibilidad química entre las sustancias estudiadas y se recomienda el uso de los excipientes para el desarrollo de la formulación farmacéutica

Introduction: the first phase of the drug preformulation comprises the selection of excipients and the conduction of studies on chemical compatibility between pharmacologically active ingredient and the excipients. One of the quickest techniques is the differential scanning calorimetry and the supplementary technique called thermogravimetic analysis. Objective: to conduct a chemical compatibility study of the pharmacologically active ingredient and of the preselected excipients by using differential scanning calorimentry (DSC) and thermogravimetric analysis (TG), in order to confirm the chemical interaction between them. Methods: this study used the thermal analysis equipment TA 3000 Mettler, coupled with the DSC 20 cell and the TG50 oven. The pharmacologically active ingredient was Piracetam and the excipients were Aerosil Kollidon VA64, magnesium stearate, microcrystalline cellulose, Polyethylene glycol 20 000. The differential scanning calorimetry characterized the excipients and the pharmacologically active ingredient as well, whose physical fusion transition was determined. Some binary physical mixtures with a concentration ratio of 1:1 were prepared to study compatibility. Results: figure 1 showed the pharmacologically active ingredient´s fusion point detection. Two endothermal transitions were determined as well as the fusion transition by the TG equipment. Figure 2 showed the thermograms of mixtures between pharmacologically active ingredient and excipients. Conclusions: the occurrence of new peaks was bit detected, so it was inferred from this study that there was no chemical incompatibility between the studied substances, and the excipients are recommended for the development of the final pharmaceutical formulation

Prolonged-release solid dispersions of ibuprofen.

Ibuprofen (IB) is one of the most important non-steroidal anti-inflammatory drugs used in the treatment of inflammatory chronic diseases. This drug presents, in the pure state, poor physical and mechanical characteristics and their use in solid dosage forms needs the addition of excipients which improve these properties. The selection of the best excipients and the suitable pharmaceutical dosage form to carry ibuprofen are very important for the industrial success of this drug. Thus, in this work, solid dispersions of ibuprofen in cethyl alcohol (SD CA), stearic acid (SD SA) and hydrogenated castor oil (SD HCO) were prepared in order to improve physical and mechanical characteristics of this drug. Physical mixtures with the same composition of solid dispersions were also prepared. Solid dispersions of ibuprofen with stearic acid and hydrogenated castor oil showed better flow characteristics than pure ibuprofen and the respective physical mixtures. Gelatin capsules filled with solid dispersions were submitted to dissolution tests in order to study the influence of the prepared systems in the release profiles of ibuprofen. Prolonged-release of ibuprofen was achieved with the solid dispersions prepared with the different types of excipients.

Enhancement of dissolution rate of etoricoxib through solid dispersion technique.

Etoricoxib, a non-steroidal anti-inflammatory drug, is used to Osteoarthritis, Rheumatoid arthritis and Acute Gouty arthritis. Etoricoxib is practically insoluble in water; hence present study was carried out to enhance dissolution properties of Etoricoxib through the preparation of Solid Dispersions using PEG 6000 as carrier at various proportions by using different techniques like Physical mixtures, Kneading Method and Solvent Evaporation Method. The drug release profile was studied in 0.1N HCl containing 1 % SLS. U.V. Spectrophotometric method was selected for assay as well as in-vitro dissolution studies at 234nm.All the solid dispersions exhibited superior dissolution than pure drug. The drug dissolution studies followed first order kinetics. Solvent evaporation method was found to be superior to other methods.