Stability studies enzymatic degradation

The degradation of agrochemicals during storage may result from a variety of factors such as acidic and alkaline hydrolysis, enzymatic action, etc. It is recommended that a preliminary stability study be performed for the chemical in the environmental sample. If the chemical is stable under acidic conditions, for example, samples can be stored after acidification with hydrochloric or phosphoric acid. 

Some of recent papers by Ratner et al. [63, 64] revealed that there are significant differences in the surface chemistry of Biomer lots. The surface of some lots was dominated by poly(diisopropylaminoethyl methacrylate) (DPAEMA or DIPAM), a high molecular weight UV stabilizer, which was absent from some older lots [65]. Ratner et al. carried out comparative studies on in vitro enzymatic and oxidative degradation of two lots of Biomer, BSU 001 and BSP 067. Lot BSU 001 contains both DPAEMA and an antioxidant, Santowhite powder, while BSP 067 contains only the antioxidant. It was found that DPAEMA retarded the enzymatic degradation process, but accelerated oxidative degradation. 

Although many studies have been reported on the stabilization of drugs against enzymatic degradation in vivo, such as the protection of peptides from metabolism by modifying the N-terminal with an ethyl group,512 this topic will not be covered here. 

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