Moisture Penetration

Many studies have been conducted on predicting the role of packaging in moisture adsorption by dosage forms. Adsorption of moisture by tablets contained in polypropylene films was successfully modeled from storage temperature and the difference in water vapor pressure between the inside and outside ofthe packaging, as shown in Fig. 188.733 Similarly, the moisture adsorption of moisture by cloxazolam tablets through press through packaging (PTP) composed of polyvinyl chloride and on aluminum film under nonisothermal conditions was predicted from the moisture permeability coefficient of the packaging as well as from temperature and humidity conditions inside and outside the packaging.734

Figure 188. Prediction of moisture adsorption by tablets in polypropylene films (25°C and 75% RH). Number of tablets placed in a permeability cup: □, 3; x, 6; A, 9;Ot 112. Lines represent predicted sorption curves. (Reproduced from Ref. 733 with permission.)

Figure 188. Prediction of moisture adsorption by tablets in polypropylene films (25°C and 75% RH). Number of tablets placed in a permeability cup: □, 3; x, 6; A, 9;Ot 112. Lines represent predicted sorption curves. (Reproduced from Ref. 733 with permission.)

Chemical and physical degradation of packaged dosage forms caused by moisture adsorption has been predicted from the moisture permeability of the packaging. For example, strength changes of lactose-corn starch tablets in strip packaging (SP) and PTP,735 discoloration of sugar-coated tablets of ascorbic acid,736,737 and hydrolysis of aspirin aluminum tablets in PTP and glass bottles738 were predicted using the moisture permeability coefficient of the packaging.

Desiccants are often used to eliminate moisture in packaging when the moisture resistance of the packaging itself is not sufficient to prevent exposure. The utility of desiccants has been assessed based on a sorption-desorption moisture transfer model.739

Continue reading here: Adsorption onto and Absorption into Containers and Transfer of Container Components into Pharmaceuticals

Was this article helpful?

0 0