Physicochemical Properties of Buffers Used in Simulated Biological Fluids with Potential Application for In Vitro Dissolution Testing: A Mini-review

Abstract

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.

Buffer solutions in drug formulation and processing: How pKa values depend on temperature, pressure and ionic strength

“…Regulation of pH is often essential, e.g., biological and biochemical processes are controlled by proton transfer (Fukada and Takahashi, 1998). Energy production in mitochondria by reduction of NAD + to NADH is one example of a biological process governed by proton transfer, and many biochemical studies are performed under pH-buffered conditions (Fukada and Takahashi, 1998;Karow et al, 2013;Mauger, 2017). pH is also an important factor in drug formulation and processing, as the pH facilitates folding and unfolding of proteins, chemical degradation and solubility of drug compounds (Babic et al, 2007;O'Brien et al, 2012;Stoll and Blanchard, 1990).…”

Comparison of Efavirenz Release in Biorelevant Dissolution Media Using Manual Sampling and In Situ UV Fiber Optic System

“…In the present study, f 2 was used only as a comparison criterion since this is the most compendium-recommended method (28). (5). Such interference might also be one explanation for statistical differences in EFV release in similar biorelevant media (i.e., FeSSIF and FeSSIF-V2).…”

“…As an alternative, it is of great interest to the scientific community and drug manufacturers to use biorelevant dissolution media that mimic the GI tract physiological conditions and, in most cases, use surfactants that are present in human intestinal fluids such as sodium taurocholate and phosphatidylcholine to simulate bile salts and phospholipids, respectively (4). These media can be adjusted for pH, osmolarity, superficial tension, and other physicochemical properties to simulate conditions in specific segments of the GI tract, which allows a drug solubility enhancement (5,6).…”

Chemical Stability of Metal‐organic Frameworks for Applications in Drug Delivery

“…Therefore, solutions containing various ions and molecules (including proteins) at concentrations found in the body are usually preferred [35] . Additionally, to maintain the pH value, these solutions are most of the time buffered [36] . An overview on common solutions used to simulate body conditions is given in Table 1.…”