Abstract
The effect of added substance (S) and pH (P) of the vehicle, and temperature (T) and period (M) of preservation on the change of mean diameter of suspended particles was investigated with a sulfadiazine suspension, and the following conclusions were drawn : 1) The distribution of particle size was logarithmic normal throughout the determinations, the same as in the starting material. 2) As a result of factorial analysis of the mean diameter, main effects P, T, and M were highly significant and interaction P×T was significant. 3) The same result was obtained on the analysis of standard deviation. 4) A highly significant negative correlation was found between the mean diameter and standard deviation. 5) As observed in this study, it may be considered that there is a maximum to the increase of particle size and the tendency is represented as follows : [numerical formula] where e is the factor promoting the change of mean diameter d, and k, A, B, and I are constants which are expected to be influenced by physical and chemical properties of the material used, the vehicle, and other conditions.
