Influence of spray drying manufacturing parameters on quality of losartan potassium microspheres

A general aim of the research was to develop a technology of manufacturing microspheres with losartan potassium as an active substance, and Eudragit L30D55 as a matrix with the use of spray drying technique. During the first step of the study, optimal values of parameters in spray drying process were established (i.e., operating temperature, peristaltic pump performance, aspiration value). Those values have a crucial effect on morphological parameters, and the size and homogeneity of received particles. In the obtained microspheres, the activity of excipients, which modify morphological properties of microspheres, were tested. Additionally, we studied the impact of the type and amount of plasticizer, as well as the amount of an adopted polymer in proportion to dry matter of losartan potassium, on quality of final product. Triethyl citrate and citric acid, plasticizers tested in reported studies, were also verified. A detailed study of the influence of both plasticizers on the qualities of microspheres containing losartan potassium on Eudragit L30D55 matrix indicated a positive influence of triethyl citrate and a negative influence of citric acid on morphological properties, shape and size of particles. The application of optimal parameters of spray drying and triethyl citrate as a plasticizer in the amount of 10 to 15% allows to obtain microspheres from 1.27 to 7.24 μm.