Thermal analysis study of solid dispersions hydrochlorothiazide

Solid dispersions (SD) are used as a technological strategy to increase the aqueous dissolution rate of poorly soluble active pharmaceutical ingredients, such as hydrochlorothiazide (HCTZ), an antihypertensive used frequently in medical clinics. The aim of this study was to characterize solid dispersions of HCTZ obtained with different processing adjuvants, using the DSC, TG, XRPD, FTIR and SEM techniques, and to evaluate the influence of carriers used in biopharmaceutical performance by analyzing dissolution efficiency. The SDs were obtained using the solvent method, and spray drying was used as the drying technique. The carriers used PEG 1500, sodium lauryl sulfate and PVP K30. The calorimetric analysis and XRPD showed amorphous behavior to SDs that used hydrophilic polymer as a carrier, and thermogravimetric analysis showed maintaining thermal stability of the HCTZ for most dispersions. FTIR detected intermolecular interactions of hydrogen bonds, while SEM showed the formation of microparticles with a tendency to sphericity. Acquired morphology associated with amorphization contributed to the increase in dissolution efficiency of dispersions, being that this SD (HCTZ/PVP K30) showed the best increase in dissolution. We therefore concluded that the analytical techniques used were of fundamental importance to the characterization of pharmaceutical products developed as to their physicochemical properties and the prescience of the oral bioavailability of HCTZ.