Isolation of a relatively pure outer membrane fraction of Moraxella nonliquefaciens and a comparison of its characteristics with the cytoplasmic membrane-containing material

Cell envelope fractions of Moraxella nonliquefaciens were isolated by a slight modification of Osborn's method. Two main membrane fractions were characterized chemically and morphologically. The density of the fraction containing cytoplasmic membrane material was 1.17 to 1.18 g cm-3 compared with 1.24 to 1.27 g cm-3 for the outer membrane fraction. Lipopolysaccharide was detected almost exclusively in the outer membrane fraction and sodium dodecyl sulphate polyacrylamide gel electrophoresis of this fraction revealed one dominant protein band with an apparent molecular weight of 45 000. Cross-contamination of the fractions was estimated to be about 10%, as calculated on the basis of the lipopolysaccharide fatty acid 3-hydroxydodecanoic acid and on the relative activities of D-lactate dehydrogenase and succinate dehydrogenase.     

Study of load capacity of Avicel PH-200 and Cellactose, two direct compression excipients, using experimental design

The load capacity of two excipients, a large particle size grade of microcrystalline cellulose (Avicel™ PH-200) and a coprocessed material composed of lactose and pulverized cellulose (Cellactose™) was determined using a model mix with Dipyrone (metamizol sodium) and experiments planned by design of experiments. A multiple-regression model was proposed, and as a result, a new parameter, called specific load capacity S_LC was obtained. This constant can be determined for other excipients and drugs; it depends only on the excipient and the drug used.