General Test Procedure Loss on drying

Purpose
1. This procedure is applicable to all incoming Raw materials, In-process and Finished products.
Apparatus
1. Hot air oven/vacuum oven
2. calibrated thermometer
3. Calibrated Balance
Reagents
1. None
Procedure
1. Weigh a glass stoppered, shallow weighing bottle that has been dried under the same conditions to be

employed in the determination. Transfer to the bottle the quantity of the sample specified in the

individual monograph, cover it and accurately weigh the bottle and the contents. Distribute the

sample as evenly as practicable by gentle sidewise shaking to a depth not exceeding 10 mm. Place the

loaded bottle in the drying chamber (oven or desiccators) as directed in the monograph, remove the

stopper and leave it also in the chamber. Dry the sample to constant weight or for the specified time

and at the temperature indicated in the monograph. After drying is completed, open the drying

Chamber, close the bottle promptly and allow it to cool to room temperature (where applicable) in a

desiccators before weighing. Weigh the bottle and the contents.

Conditions of Loss on drying:

(a) In a desiccators : The drying is carried out over phosphorus pentaoxide at atmospheric pressure and at room temperature.

(b) In vacuum : The drying is carried out over phosphorus pentoxide at a pressure 1.5 to 2.5 kPa at room temperature.

(c) In vacuum : Within a specified temperature range: The drying is carried out phosphorus pentoxide at a pressure of 1.5 to 2.5 kPa temperature range specified in the monograph.

(d) In an oven : Within a specified temperature range: The drying is carried out in an Oven within the temperature range specified in the monograph.

(e) Under high vacuum: The drying is carried out over phosphorus pentoxide at a pressure no exceeding 0.1kPa at the temperature prescribed in the monograph.