Abstract A procedure has been developed for the determination of the thickness of the wall sections of hard gelatin capsules. A chlorine-36 source was mounted in the tip of a stainless steel capsule dipping pin and was used to observe the differences in thickness of the wall sections. Twelve series (replications) of 25 determinations each were performed. The measurements taken included the weight, area, calculated weight per unit area, thickness in inches using a micrometer, and beta count rate. The count rates were plotted against the corresponding weight per unit area (mg./cm.2) and thickness (in.). Regression curves were prepared using least squares calculations. A t test was used to compare the individual slopes of the regression curves with the mean slope. The applicability of this method of determining the thickness of wall sections of hard gelatin capsules is discussed.

A study has been made of six common types of emulsification equipment normally encountered in pilot plant experimentation or small-scale manufacturing. Mineral oil and cod liver oil emulsions were prepared. The evaluation of the emulsion products involved measurements of particle size distribution, rate of creaming, and viscosity. The particle size distribution studies and the rate of creaming evaluation clearly differentiated the equipment studied. It was shown that the emulsions processed with a homogenizer usually produced samples with a smaller average particle size and a lower rate of creaming under the conditions of the study. The data of this study were subjected to statistical evaluation which indicated that both the emulsifying agent and the processing equipment used significantly affect emulsion quality. A significant interaction between equipment and emulsifying agents was also shown.