Storage stability studies

Application of ICH Stability Study Storage Conditions to Approved Applications... 

A program for stability assessment may include storage at accelerated, long-term, and, if applicable, intermediate stability study storage conditions (refer to IV.G of the ICH Q1A Guidance and Section II.A). Stability samples should be stored in the bulk storage container equivalent (e.g., same composition and type of container, closure, and liner, but smaller in size). 

Calvo C. and Salvador A., Use of natural colorants in food gels inflnence of composition of gels on their colour and study of their stability during storage. Food... 

Storage stability studies for carfentrazone-ethyl compounds on crop matrices have shown a pattern of stability for at least 7-24 months, depending on the study program or the maximum sample storage interval for the study. Carfentrazone-ethyl was not stable in field corn starch, potato tuber and bovine kidney. The residue results indicated that a significant portion of carfentrazone-ethyl was converted to C-Cl-PAc in these matrices however, the total amount of carfentrazone-ethyl and C-Cl-PAc accounted for the original spiking level. Since both carfentrazone-ethyl and C-Cl-PAc were determined in these stability studies, the instability of carfentrazone-ethyl was not of any concern. 

Storage stability studies for sulfentrazone compounds on crop matrices showed a pattern of stability for at least 3-38 months, depending on the study program or the maximum sample storage interval for the study. 

In many cases, there is difficulty in preserving residues in samples after collection and prior to pesticide analysis which coincides with a rapid further degradation and mineralization of the pesticide residues under most environmental conditions. Storage stability studies and studies on the reactivity of sample collection equipment in addition to field quality assurance procedures can help address some of these questions. Concerns are accentuated for compounds that have short half-lives in the environment but still have high acute toxicity. 

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. 

Monsanto. 1981. Stability study of natural sediments samples preserved by frozen storage with attachment. Monsanto Company, St. Louis, MO. 

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