Loss on drying tests in pharmaceuticals

Loss on drying is described as the weight loss as a percentage of w / w resulting from volatile substances and water of any type that can be removed under specific conditions. This test is done with a mixture of substances. If the substance to be analyzed is in the form of large particles, the sizes must be reduced by rapid grinding to a powder. The test is to determine the water content and volatile substance in a sample that is exposed to heat. Loss on drying is a technique that has been used by many pharmaceutical products. There are different methods to perform this test and the technician chooses the most suitable one based on the substance being tested.

To perform the test, do the following:

Weigh a shallow weigh bottle that has been dried under the same conditions that will be used in the determination.

Transfer the amount of sample specified in the individual monograph to the dry bottle.

Cover the bottle and weigh yourself accurately along with its contents.

Distribute the sample evenly by gently shaking sideways to a depth not exceeding 10 mm.

Dry the substance by placing the bottle in the drying chamber.

· Remove the cap and leave it in the chamber.

Dry the sample until it has a constant weight.

Open the drying chamber and close the bottle quickly and allow it to cool to room temperature.

Weigh the bottle and its contents.

The temperature to which the substance to be analyzed must be exposed is always specified and must not be exceeded in order not to obtain incorrect results. Each substance has its specific heat level.

The loss on drying test in pharmaceuticals is a technique for removing water and other volatile impurities from a well-mixed substance sample. the amount of heat applied to the substance depends on time and temperature.

The total moisture content of pharmaceuticals can contain both free and bound water.

Where impurities are present, the loss in drying level will be greater compared to the water content.

Sometimes the loss on drying level can be much less compared to the water content, as some water molecules may not be removed by heating as in other methods of determining loss on drying. To calculate the percent loss on drying, the method is shown below.

Percentage LOD = Percentage of water content – Percentage of water molecules in the API

The type of substance that is being used must be known, the prescription must be known exactly to determine how the experiment is carried out. For the hydrated substance, the equivalent weight of the anhydrous content must be calculated before exposing it to heat. In case moisture is specified on the certificate, the pharmacy before the substance is used in the loss on drying experiment.

Conclution

Loss on drying has been used in many pharmaceutical companies to determine drug concentration. These experiments are also used to perform tests to determine substances in moisture. This experiment requires a lot of care and enthusiasm to find real results. Weight should be measured with non-faulty devices to ensure accurate hold. During heating, it should be done to the end to make sure that there is water left.