Plasma proteins and cellular membranes

Plasma proteins and cellular membranes constitute the fundamental biological matrices that govern the pharmacokinetics and distribution of nearly all systemic drugs. Plasma proteins, primarily albumin and alpha-1-acid glycoprotein, serve as high-capacity, low-affinity reservoirs that regulate the concentration of free, pharmacologically active drug in the bloodstream (StatPearls, 2023). Cellular membranes, composed of organized phospholipid bilayers, act as the gatekeepers for intracellular drug delivery and are the site of action for many membrane-active agents (Nature Reviews Molecular Cell Biology, 2020). Although these are not specific therapeutic targets in the classical sense, their physical and chemical properties determine a drug's volume of distribution and half-life (Journal of Pharmaceutical Sciences, 2010). Interactions at these sites are critical for understanding drug-drug interactions, particularly when drugs compete for the same protein binding sites, potentially leading to toxic surges in free drug levels (Pharmacological Reviews, 2001). Consequently, characterizing these interactions is a prerequisite for successful drug design and clinical dosing strategies.

Other names

Blood proteinsCellular lipid bilayersPlasma-membrane interfaceNon-specific binding sites

Non-specific reversible binding to plasma proteins and partitioning into or modulation of cellular lipid bilayers.