Uniformity of Weight of Single-Dose Preparations

Weigh individually 20 units selected at random or, for single dose preparations in individual containers, the contents of 20 units, and calculate the average weight. Not more than two of the individual weights deviate from the average weight by more than the percentage shown in the table and none deviates by more than twice that percentage.

For capsules

Weigh an intact capsule. Open it without losing any part of the shell and remove the contents as completely as possible. For soft gelatin capsules, wash the shell with a suitable solvent and keep aside until the odor of the solvent is not perceptible. Weigh the shell. The difference between the weighings gives the weight of the contents. Repeat the procedure with another 19 capsules.

For powders for parenteral use

Remove any adhering labels from a container and wash and dry the outside. Open the container and immediately weigh it along with the contents. Empty it as completely as possible by gentle tapping, rinse it with water and then with ethanol. Dry at 100° to 105° for one hour, or if the nature of the contents does not permit drying at this temperature, dry at a lower temperature to constant weight. Cool in a desiccator and weigh. The difference in the weighings gives the weight of the contents of the container. Repeat the procedure with another 19 containers.