Determination of loss on drying of effervescent tablets

The effervescent tablet loss-on-drying determination method refers to taking the test product, mixing it evenly (if it is a larger crystal, it should be quickly mashed into small particles below 2mm), taking about 1g or the weight specified under each category, and placing In a flat weighing bottle dried to a constant weight under the same conditions as the test product, accurately weigh it. Unless otherwise specified, dry to a constant weight at 105°C. Calculate the loss on drying of the test product from the lost weight and the sample volume.

When the test product is dry, it should be spread flat in a flat weighing bottle, and the thickness should not exceed 5mm. If it is a loose substance, the thickness should not exceed 10mm. When it is placed in an oven or desiccator for drying, the bottle cap should be removed and weighed Next to the bottle, or half open the bottle cap to dry; when taking out, the weighing bottle must be capped. The test product dried in the oven should be taken out and placed in a desiccator to cool, and then weighed.

If the test product melts if it does not reach the specified drying temperature, unless otherwise specified, the test product should be dried at a temperature of 5-10℃ lower than the melting temperature until most of the water is removed, and then the specified conditions dry. Biological products should be dried at a lower temperature until most of the water is removed, and then dried according to the specified conditions.

When using a vacuum dryer (usually at room temperature) or a constant temperature and vacuum dryer (the temperature should be set according to the regulations under each item. For biological products, the temperature is 60°C unless otherwise specified), unless otherwise specified, The pressure should be below 2.67kPa (20mmHg). The commonly used desiccant in the dryer is phosphorus pentoxide, anhydrous calcium chloride or silica gel; the commonly used desiccant in the constant temperature and reduced pressure dryer is phosphorus pentoxide. The desiccant should be replaced in time to keep it in an effective state.