Microsomal Stability Assay
Creative Animodel is a leading biotech company specializing in offering a set of services for extensive drug metabolism and pharmacokinetic capabilities. We provide liver microsomal stability study to investigate in vitro intrinsic clearance of new drug candidates or identify metabolites formed. We guarantee our clients consistent and high-quality data with cost-efficiency that come from a highly automated approach.
What Is Liver Microsome?
The liver is regarded as the major site of drug metabolism in humans and animals. Approximately 60% of marketed drugs are eliminated via hepatic mediated metabolism. Thus, it is important to understand hepatic modification of new drug entries in early stages. Microsomes are subcellular fractions and can easily be prepared from the liver of animals and human donors by ultracentrifugation. Liver microsomes contain all cytochrome P450 (CYPs) isozymes and other membrane-bound drug metabolizing enzymes, including flavin monooxygenase (FMO) and uridine diphosphate-glucuronosyl transferases (UGTs), which are responsible for the metabolism of majority of drugs. And the enzymatic activities can be quite stable during prolonged storage of the microsomes. Therefore, liver microsomes are well characterized and are the most frequently-used form of in vitro models of hepatic clearance studies, especially since they are easily adaptable to high throughput screens.
Figure 1. Liver microsomes are useful in vitro model for metabolism studies.
Standard Conditions of Microsomal Stability Assay
Creative Animodel provides stability assay in liver microsomes obtained from human and various animal species including but not restricted to primate, pig, dog, rabbit, rat and mouse. Test compounds are incubated in microsomal suspensions at 37℃ in duplicate. We also provide Phase I or combined Phase I/Phase II assay to determine both Phase I and Phase II metabolism by utilizing cofactors NADPH and UDPGA. After incubation, the supernatant is collected by centrifugation, and the disappearance of parent compound is investigated by LC-MS/MS analysis at five-time points over 60 minutes (0, 15, 30, 45 and 60 min). Data output consists of mean intrinsic clearance and half-life measurements.
Figure 2. Human microsomal stability data from Creative Animodel (red) and literature (blue). Data from in-house laboratory are shown as mean ± standard deviation.
Creative Animodel provides a wide variety of in vitro metabolic stability studies to predict in vivo intrinsic clearance or identify metabolites formed in a fast and cost-efficient manner. In support of understanding the metabolic stability of compounds early in discovery, our mission is to help our clients reduce the potential for drug candidates to fail in development as a result of pharmacokinetic reasons.
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2. Baranczewski P, et al. Introduction to in vitro estimation of metabolic stability and drug interactions of new chemical entities in drug discovery and development. Pharmacol Rep. 2006, 58(4):453-72.
3. Fonsi M, et al. High-throughput microsomal stability assay for screening new chemical entities in drug discovery. J Biomol Screen. 2008, 13(9):862-9.