A soft gel’s elastic properties and resistance to force depends on the degree of moisture in the gelatin-and will thus indicate moisture content.
A white paper on testing soft gel capsules has been published by Dr. Schleuniger Pharmatron (Manchester, NH), a firm specialized in hardness testing solutions for tablets. According to the company, hardness tests can help determine moisture content, as well as soft gel strength and seam strength.
“Using hardness testing as a means to determine moisture content in the soft gel production environment has been accepted by the industry as an efficient and accurate replacement for traditional methods, which are more time consuming and complex,” states white paper author Bradford Klements, the company’s product and application specialist. “As well as moisture, the overall integrity and strength of a soft gel can also be quickly measured.”
For instance, says Klements, as hardness tests apply force to a soft gel, the gelatin of the outer shell is required to stretch. A soft gel’s elastic properties and resistance to force depends on the degree of moisture in the gelatin-and will thus indicate moisture content. Additionally, hardness tests can be used to test soft gel strength and the strength of a soft gel’s seams.
The company says that tests described in the white paper can help quicken testing times and save costs.