Obtenção de dados de solubilidade de lactose em misturas de água e isopropanol

Abstract

Lactose is the main carbohidrate contained in milk, being therefore very important for the food industry and presenting a lot of applicability also in the pharmaceutical industry. Recent studies consider feasible the use of crystallized lactose under controlled conditions, by using an anti-solvent. Those types of crystals are excelent as excipients for drugs administration via the respiratory tract, for the treatment of respiratory diseases. Therefore, this work aims to study experimentally the solubility of lactose in water and isopropyl alcohol solutions. It were used solutions with mass concentrations from 0 to 100% of isopropyl alcohol in water, varying this concentration 10 by 10%, at temperatures of 25, 30, 35 and 40°C, at standard and constant atmospheric pressure. The procedure was performed in jacketed glass equilibrium cells, connected to a water heater source. Lactose solubilization took place under agitation for two hours, followed by rest for another two hours. Sampling was performed, and samples were quantified by gravimetry. The results were compared with the literature and models were proposed to predict the solubility of lactose as a function of temperature and concentration of isopropyl alcohol in the solvent. It was concluded that higher temperatures increases the solubility of lactose, and higher concentrations of alcohol decreases the solubility.