Rupture Test: A Quick and Easy Way to Avoid Soft Gel Capsule Failure

Although the FDA has yet to endorse the rupture test as an alternative to dissolution or disintegration testing, it has gained popularity among manufacturers of soft gel capsules. The rupture test, a form of hardness testing, is a quick and easy way for qualifying and quantifying the film strength, which is also the bursting strength of a soft gelatin capsule. A recent study to investigate differences between the rupture test and the disintegration test using soft-shell capsules revealed that both tests are comparable and equally sensitive in detecting simulated production deficiencies that cause non-conforming film strength.

As the product-to-market timeline for new pharmaceutical formulations becomes tighter, it is essential to efficiently quantify the critical properties of soft gel capsules that affect product performance. There are several ways to perform a rupture test on soft gel capsule with a Texture Analyzer, an instrument that can cause materials to deform in compression or tension. (Figure 1) One such method uses a 2 mm cylinder probe (Figure 2) to penetrate into the test sample until rupture. The TA-CJ Fixture (Figure 3) is used to secure the soft gel capsule in place for the rupture test. A single compression test on the soft gel capsule detects and measures the weakness in a gelatin film or seal; this test therefore simulates circumstances whereby a capsule may burst during manufacturing, packaging or handling. It can also quantify the elasticity of the gel capsule shell by measuring its deformation at peak load. The Texture Analyzer gives quality control the necessary tool to guarantee compliance with R&D performance specifications.