Scale-up of the preparation process of solid lipid nanospheres. Part I

An apparatus was designed to prepare solid lipid nanospheres (SLN), potenti al colloidal therapeutic system obtained by dispersing a warm oil-in-water (o/w) microemulsion in cold water. The apparatus, consisting mainly of a th ermostated aluminium chamber and a pneumatic piston, permitted to disperse through a needle up to 100 ml of warm microemulsion and to vary the tempera ture, the dispersing rate and the drop size of the warm o/w microemulsion. Experimental design was applied to study the effect of four experimental fa ctors, such as chamber temperature, piston pressure, needle gauge and volum e of dispersing water, on average diameter and polydispersity index of SLN and on dispersing time of microemulsion (the time required for the microemu lsion to drip completely from the apparatus). The results showed that tempe rature and pressure play the most important roles depending on the needle g auge used. In particular, the smallest SLN were obtained using high tempera ture and pressure values and a small needle gauge. (C) 2000 Elsevier Scienc e B.V. All rights reserved.