Alger Salt received bachelor’s and master’s degrees in analytical chemistry from East Carolina University. He is employed by GSK at Research Triangle Park, NC in a role to provide and support platforms for automated tablet testing. Connect with Alger on LinkedIn at http://www.linkedin.com/pub/alger-salt/1/109/850
Three speakers presented on three very different and very interesting topics at the mini-symposium Emerging Dissolution Technologies during the 2013 AAPS Annual Meeting and Exposition. Xujin Liu’s presentation on in vitro dissolution imaging discussed the use of low-field nuclear magnetic resonance (NMR), fourier transform infrared spectroscopy (FTIR), and ultraviolet (UV) imaging of the dissolution process. Imaging technologies can provide “another set of eyes” to better enable dissolution scientists to understand and characterize the release mechanisms of drugs from dosage forms. These technologies are typically used in systems that employ flow-through, as opposed to stirred, media. Raman spectroscopy could also be employed for characterizing drug precipitation processes from both dosage forms and different forms of active pharmaceutical ingredients. NMR is used to monitor the ingress of water into the dosage form. FTIR can be used for drug-specific imaging of solids during the dissolution test. UV imaging is generally used to monitor the movement and concentration of a dissolved drug.
Matt Burke spoke about a device that can be installed on a conventional dissolution apparatus that allows it to mimic the peristaltic action within the gastrointestinal tract. Case studies were presented that showed superior in-vitro in-vivo correlation results when compared to work done using the same apparatus without the peristaltic device. This was shown for both modified release and at least one immediate release formulation. The device can be adjusted to operate in ways that make it more relevant to the more dominant peristalsis observed in the fed state or likewise in the fasted state. The device will soon be commercially available.
Anette Mullertz presented results of work done using the Dynamic Gastric Model. Acid secretion from the stomach wall and the slow rate of mixing causes a significant variation of pH in the fed stomach, which makes it difficult to simulate with conventional dissolution test conditions and equipment. The stomach enzyme lipase can affect dissolution of products that contain lipids, but this is usually omitted from simulated gastric fluids. The Dynamic Gastric Model provides these and other conditions not available with conventional dissolution test equipment. Superior correlations were demonstrated in case studies versus those obtained with conventional in vitro dissolution tests. The device itself is not commercially available but a service is provided whereby samples can be processed with the Dynamic Gastric Model on a contract basis.
These technologies provide capabilities that were not available a few years ago. Spectroscopic imaging allows us to see and better understand dissolution release mechanisms. The DGM provides a much more diverse set of conditions for the dosage form to be exposed to within the stomach. The peristaltic dissolution device yields better correlation with in vivo data. These scientific contributions combine to yield better understanding of developmental formulations that ultimately will yield safer and more effective medicines.