Examination of the Utility of the High Throughput In Vitro Metabolic Stability Assay to Estimate In Vivo Clearance in the Mouse

Abstract

Abstract:In vitro determination of metabolic stability is routinely used to assess the overall metabolic liability of compounds and for prioritization for in vivo studies. If in vitro metabolic stability data could be used to reliably predict in vivo clearance (CL), it would add significant value in the selection of compounds for in vivo pharmacokinetic and pharmacology studies. We have evaluated the utility of our in vitro metabolic stability screening assay to estimate in vivo CL in the mouse. The in vitro mouse clearances (CL in vitro ) of 146 structurally diverse compounds with metabolic stabilities > 30 %, were compared to mouse in vivo CL data. Approximately 45 % of the compounds showed agreement between in vivo CL and predicted CL in vitro within a 2-fold error criteria. The correlation appeared worse when correction for the extent of incorporation of plasma protein binding or both plasma and S9 bindings (i.e. ~14 % and~ 28 % agreement, respectively). Classification of the compounds into three groups based on in vivo CL (<30 mL/min/kg, 30-70 mL/min/kg, and >70 mL/min/kg) did not show any improvement between in vivo CL and predicted CL in vitro . The percentage of compounds falling within the 2-fold error criteria for low CL, moderate CL and high CL groups were 54, 31 and 24 %, respectively. In conclusion, our analysis suggests that in vitro metabolic stability data, as routinely obtained in early ADME screening protocols, does not demonstrate a strong correlation with or predictivity for, absolute in vivo CL in the mouse.

Physicochemical Characterization of Mitragyna speciosa Alkaloid Extract and Mitragynine using In Vitro High Throughput Assays

“…Hepatic clearance is the major drug clearance mechanism in the human body. The usual practice in the pharmaceutical industry is that, for compounds with low metabolic stability (<30%), it is not advisable for it to be carried further into in vivo studies [33]. Drugs which are highly metabolized will have short half-life (T 1/2 ) and low bioavailability.…”

“…Compounds with low metabolism are not considered to be disadvantageous in early drug development since the dosing frequency is less, thereby minimizing the potential toxicity. However, it is important to understand that variations in pharmacokinetics do exist between animal species and this will affect the prediction of the rate of metabolism in humans [33]. Hence, studies using human liver microsomes will be more directly related to the clinical development, whereas, rodent metabolism are useful in early drug discovery, particularly to design protocols for animal models.…”

Biotransformation of 4‐fluoro‐N‐(1‐{2‐[(propan‐2‐yl)phenoxy]ethyl}‐8‐azabicyclo[3.2.1]octan‐3‐yl)‐benzenesulfonamide, a novel potent 5‐HT7 receptor antagonist with antidepressant‐like and anxiolytic properties: In vitro and in silico approach

“…Next, CL int,micr was scaled to whole liver dimensions to calculate the intrinsic clearance (CL int ). Finally, human hepatic clearance (CL H ) was calculated without consideration of plasma protein binding …”

In Vitro and In Vivo Pharmacokinetics of Aminoalkylated Diarylpropanes NP085 and NP102

“…The in vivo hepatic clearance (CL H ) was estimated according to the "restrictive well-stirred liver" model (15). The in vivo hepatic clearance (CL H ) is expressed as:…”