Although aqueous buffers alone cannot be expected to fulfill all the requirements of biorelevant media, buffers will likely continue to play a central role in controlling the pH of complex formulations simulating biological fluids (3,9). The use of biorelevant dissolution media to forecast in vivo drug performance has been reviewed (9). This minireview focuses on the physicochemical factors related to buffers used in these media and not the biorelevant dissolution media, per se. This mini-review is based on a survey of the literature associated with buffers in general
ABSTRACTThis literature review focuses on the physicochemical properties of buffers used in biorelevant media for in vitro dissolution testing. Because biorelevant dissolution systems have been previously reviewed, this review is primarily related to the buffers used in biorelevant media and not the media, per se. It is based on a survey of the literature in areas including analytical chemistry; biochemistry; clinical, solution, and physical chemistry; dissolution science and technology; pharmaceutical sciences; simulated biological fluids; and buffer-related articles from the National Institute of Standards and Technology with the intent of identifying challenges in formulating buffered biorelevant dissolution media and also identifying general attributes that are useful in selecting a buffer for a particular dissolution application. Other topics include: (1) key physicochemical properties of buffers that affect experimental conditions and dissolution results; (2) buffer compatibility with a diverse array of ingredients found in biorelevant media; and (3) the potential to supplement the library of traditional buffers used for in vitro dissolution testing with zwitterionic buffers that were designed for biological application.