Penicillin drugs such as Penicillin G and Penicillin V can be hydrolyzed to form penicilloic acid during storage or transportation due to various reasons including the following:  (1) the temperature is too high; (2)  the solution  pH is not optimal for stabilization; or (3) the sample contains lactamase.  The hydrolyzed penicillin drug molecule is thermodynamically more stable than the non-hydrolyzed one but completely inactive.

Penicillin Drug Stability Test Kit (Catalog number PST100): for penicillin concentration measurement and stability test

The Penicillin Drug Stability Test Kit (Catalog number PST100) provides a reagent that quickly detects the hydrolyzed form of penicillin drugs including the commonly used Penicillin G and Penicillin V. The reagent, Dye PST, interacts with alpha-amino acids which are the hydrolysis products of penicillin drugs and generates fluorescence at 535 nm with excitation wavelength at 485 nm.  The background signal with the non-hydrolyzed penicillin drugs is very low.

The kit can be used to measure penicillin drug concentrations and detect hydrolysis of penicillin drugs.  It can also be used to detect the lactamase activity using penicillin as a substrate.