Research on the Hygroscopicity of MCC sand MCC Co-processed Excipients

There is no official method individually applicable to studying the hygroscopicity of excipients. Here, the research has been carried out with reference to the guidelines for the testing of drugs for hygroscopicity in Volume IV of Chinese Pharmacopoeia 2015, which describes the concept of drug hygroscopicity and defines the hygroscopic weight gain as follows:

The hygroscopicity of a drug refers to the property of the substance to absorb moisture in certain temperature and humidity conditions. The test samples are solid APIs that meet drug specifications, and the test results can be taken as a reference for selecting the suitable drug packaging and storage conditions.

Deliquescence: the process of forming a solution after absorbing adequate moisture.

Highly hygroscopic: hygroscopic weight gain rate is no less than 15%.

Hygroscopic: hygroscopic weight gain rate is between 2% and 15%.

Slightly hygroscopic: hygroscopic weight gain rate is between 0.2% and 2%.

Not or practically not hygroscopic: hygroscopic weight gain rate is less than 0.2%. 

As a matter of fact, the hygroscopicity of APIs or excipients is not just used for selecting appropriate packaging and storage conditions. Their hygroscopicity can also affect the results of certain test items of the product itself. For example, a highly hygroscopic excipient may lead to deviations in the viscosity and moisture test results after absorbing moisture; in actual manufacturing, if the temperature and humidity are not set properly based on the hygroscopicity of APIs and excipients, exposing APIs and excipients to a highly humid environment will greatly affect water-sensitive APIs, and thus affect the product quality.

In this trial, the above guidelines have been taken as the reference to establish the trial protocol for studying the hygroscopicity of MCCs and MCC co-processed excipients manufactured by Topchain. The results are shown below. Leave a message at the background to get the complete trial protocol. 

Research on Hygroscopicity

→Test conditions

Temperature: 25℃±1℃

Relative humidity: 80%±2%

→Test results

Fig. 1 Data about Hygroscopic Weight Gain Rates of Test Samples

→Test conclusion

According to the test data, the hygroscopic weight gain rates of model samples used for the test were all less than 15% but no less than 2%. Judging from Chinese Pharmacopoeia 2015, the test samples are hygroscopic. 

Research under Production Conditions

→Simulated production environment

Temperature: 25℃±1℃

Relative humidity: 55%±2%

Test basis: literature 

→Test results 

Table 2 Data about Hygroscopic Weight Gain Rates of Test Samples

Fig. 1 Hygroscopic Weight Gain Rate-Time Curve

→Test conclusions

1. Under the test condition (temperature: 25±1℃, relative humidity: 55±2%), the test samples reached the hygroscopic equilibrium in approximately 8 hours; 

2. The 24-hour hygroscopic weight gain rate of every test sample was less than 3.50%, and the rate of both TC302 and TMT934 was lower than 2%, indicating slightly hygroscopic under this condition. 

3. The test results show that controlling the environmental humidity could effectively reduce the hygroscopic weight gain rate of MCC and MCC co-processed excipients.