Metabolic stability has a profound influence on therapeutic efficacy and toxicity. The majority of drugs are biotransformed by metabolic enzymes into more polar molecules that are readily excreted. Rapid metabolism lowers drug exposure at the therapeutic target. Microsomes are sub-cellular liver fractions containing phase I enzymes and are the most commonly used reagent for determining stability as most drugs undergo CYP-mediated metabolism.
Microsome and S9 stability assay data sheet
