A variety of factors were evaluated in order to establish the characteristics of the liposomes obtained with a high-pressure homogenizer (Microfluidizer 110S). The experimental mean diameter of the liposomes and the width of their size distribution were correlated to surfaces calculated from the responses obtained by the combination of two groups of factors. First, the inlet pressure of the homogenizer, the times that the samples were processed (cycles) and the bulk ionic strength. Second, the phospholipid (P) and ethanol concentrations. The variation of the entrapped liposome volume upon the pressure and cycles was also studied. All the calculated surfaces are statistically significant and have a low S.E. of estimate. Mean liposome diameter decreases with increasing inlet pressure, number of cycles and ethanol concentration, and increases raising ionic strength. No P concentration effect was observed. The variation of the entrapped volume of liposomes upon the cycles and pressure has a similar behavior to the diameter. Within the studied variable range, microfluidization does not increase the P oxidation index, nor does it significantly alter the P concentration. © 2001 Elsevier Science B.V.
|Journal||International Journal of Pharmaceutics|
|Publication status||Published - 1 Feb 2001|
- Experimental design
- High-pressure homogenization
- Statistical optimization