In Vitro
In addition to in vivo studies, Ricerca provides a complete package of in vitro studies to characterize your drug candidate's intrinsic metabolic behavior and to help predict a compound’s disposition in humans. When required, our experienced synthetic chemistry team can also supply radiolabeled drug substances for these studies. Among the key in vitro assays provided by Ricerca are:
Cytotoxicity
A cytotoxicity assay is a cost-effective tool to quickly help predict overt toxicity and sort out likely failures before a compound is entered into the costly development process. Ricerca's in vitro cytotoxicity assays use a selection of cell lines tailored to specific drug leads to identify and evaluate qualified lead compounds.
Solubility
Aqueous solubility is an important determinant of the bioavailability and usefulness of a drug candidate. Nephelometry (light scattering) is an accepted technique to rapidly determine the apparent solubility of a large number of lead compounds.
Permeability
The intestinal permeability of compounds intended for oral administration plays an important role in selecting candidates for drug development; ranking a series of lead compounds in order of absorption potential facilitates compound selection. Ricerca uses a comparison of apparent permeability through Caco-2 or MDCK monolayer cultures (Artusson and Borchardt, Pharm. Res. 1997, 14, 1655-1657). These models are also useful for understanding absorption issues in compounds further advanced in development, especially those involved with active transport mechanisms.
Metabolic stability
The metabolic stability of a drug candidate is vital to determining its potential for human use and selecting appropriate animal models for preclinical development. The metabolism of the drug in the body, the half-life of the drug in the body and whether it forms metabolites are all important parameters to prepare rationale drug development strategies.
Ricerca's metabolic stability assays are designed to quickly determine whether a compound is metabolized by hepatic drug metabolizing enzymes. Adding time points to the assay allows the determination of the metabolic rate, and this, coupled with permeability data, can help identify compounds with unacceptable pharmacokinetic properties. Ricerca can also perform in vivo PK studies, medicinal chemistry, radiolabel synthesis, LC-MS/MS, and metabolite studies to confirm bioavailability and clearance predictions and identify metabolites.
Protein binding
The degree of binding of a compound to plasma proteins can provide important indications about its efficacy, selected safety liabilities, and potential for drug-drug interactions. Ricerca utilizes ultrafiltration centrifugation to quickly determine plasma protein binding.
CYP450 Inhibition/Induction
The potential for drug-drug interactions are determined, in part, by a new drug entity’s ability to inhibit or induce cytochrome P450 (CYP) isozymes. Carrying out these assays during the discovery phase is a cost-effective means of eliminating leads with low potential for success.
Interspecies comparison
The interspecies comparison study is conducted to highlight potential metabolic differences between species and to aid in the selection of the best species to conduct subsequent in vivo toxicology and pharmacokinetic studies.
Metabolite identification
Ricerca conducts on-site metabolite and standards synthesis, including radiolabeled compounds. Sophisticated analytical tools employed by experienced metabolism chemists will facilitate structure modifications and help to design appropriate toxicokinetic and pharmacokinetic studies.