Weigh individually twenty units taken at random or, for single-dose preparations presented in individual containers the contents of twenty units, and determine the average mass.
Not more than two of the individual masses deviate from the average mass by more than the percentage deviation shown in table 1 and none deviates by more than twice that percentage.
Powders for parenteral use:
Remove any paper labels from a container and wash and dry the outside.
Open the container and without delay weigh the container and its contents.
Empty the container as completely as possible by gentle tapping, rinse it if necessary with water R and alcohol R and dry at 100 °C to 105 °C for 1 h.
If the nature of the container precludes heating at this temperature, dry at a lower temperature to constant mass.
Allow to cool in a desiccator and weigh.
The mass of the contents is the difference between the weighing.
Repeat the procedure with another 19 containers.
Uniformity of weight (mass) of delivered doses from multi-dose containers:
The following test is intended for oral dosage forms such as granules, powders for oral use and liquids for oral use, which are supplied in multi-dose containers fitted with an integral measuring device.
Weigh individually twenty doses taken at random from one or more containers with the integral measuring device.
Determine the individual and average weights (masses).
Not more than two of the individual weights (masses) deviate from the average weight (mass) by more than 10% and none deviates by more than 20%.