Dissolution Testing and Rheological Characterization of Medicated Chewing Gums
Dissolution testing of Medicated Chewing Gums
Emmace offers dissolution testing of medicated chewing gums as an analytical service to clients on a CRO basis. The testing is performed according to European Pharmacopeia 2.9.25, using Apparatus B (the only equipment commercially available). We can implement HPLC-based assay methods developed and provided by the client, but we also offer development of an assay method if this is not available. The analytical test protocol is always planned together with the client.
The chewing gum equipment is meant to simulate the chewing of a human jaw. The medicated gums are placed in a phosphate buffer or simulated saliva that is heated to 37 degrees Celcius. A piston chews the gum in the buffer by pressing it and exerting a shearing force at its bottom position. Different total chewing time, chewing frequency and shearing angle can be used. At certain time points, samples of the buffer with the dissolved or partly dissolved chewing gum, are taken out for quantification. Dissolution testing will yield the amount of substance that has been dissolved during the chewing process.
In addition to the well-known dissolution profile curves (amount vs time) we also offer measurement of the rheological properties of the chewing gum during the dissolution testing. These measurements are possible because of two built-in sensors; one sensor is measuring the force to press together the “jaws” and the other sensor is measuring the torque forces when the “jaws” are shearing the gum.
These rheological data can be used as a useful fingerprint and indication of the “chewing feeling” of a gum, whether it is perceived by the consumer as soft and wet or as hard and compact. This information is an important input to formulators so that the desired chewing feeling for the consumer can be achieved.
