Cations therapeutic interference

Conditions for the LAL reaction with endotoxin require pH neutrality and optimum levels of sodium and divalent cations. A uniform temperature of 37°C optimizes the rate of reaction. Most therapeutic drug products require dilution with LAL reagent water (LRW) before testing to avoid interference, which is recognized by improper recovery of the positive product control (PPC). Inhibition is a failure to recover the PPC, whereas enhancement is high recovery of the PPC. Cooper has described ways to identify the concentration of a substance, which is chemically compatible with the BET, and to validate the BET with drug products and excipients. 

ESI has also increased the, until recently limited, investigations of the interactions of rare earth cations with biologically relevant molecules, for example, amino acids (AAs), peptides, and other biomolecules, by ion chemistry methods. These elements are not as important as many others in biological processes, but both the toxicity, through interference with the activity of Ca, and the potential therapeutic uses of these cations are attracting more attention. Curiously, the biocoordination behavior of uranyl and other actinide cations, which could reveal specific molecular interactions involved in transport and chemical toxicity, is relatively tmexplored, including via MS/gas-phase approaches. 

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