When we at Assay Depot say that we help with pharmaceutical outsourcing, what types of services are we helping CROs deliver to researchers? Our site is currently broken down into five key disciplines: Biology, Chemistry, DMPK, Pharmacology, and Toxicology. Common services involved in academic and pharmaceutical research are found in these five disciplines. This blog post will attempt to help identify the primary areas in drug discovery and development in the context of service categories and disciplines on Assay Depot. Each section contains links to suggested services for the relevant stage of drug development.

Drug development is an umbrella term for the research, development, and commercialization of a treatment for a disease. The three big steps are Research, Drug Discovery, and Drug Development.



The Research phase can be conducted in academia, small biotechnology companies, or large pharmaceuticals. The goal of this phase is to identify a cause for a specific disease. The process of accurately determining a cause requires a wide range of services, particularly in our Biology Discipline. Studies tend to investigate genomics or proteomics, thus requiring Molecular Profiling, Protein Services, DNA Services, or Cell-Based Assays. Animal studies are often required to verify any findings in vivo. Pharmacology provides services and CROs in almost all key research areas, from the heavily researched Oncology models to the less-funded but also important Ophthalmic Models. 



DNA Services

Cell Based Assays

Protein Services

Molecular Profiling


Drug Discovery

Target Identification

After adequate research and results are found, drug discovery begins (assuming you have the funding for it!).  Using the results of the research, a target for your drug needs to be identified, expressed, and validated. It is useful to develop assays throughout the process to ease replication of experimentation in the future.

Target Identification

Target Gene Expression

Target Validation

Drug Target Assays

Assay Development


Libraries and Screening

With the disease target in mind, the next steps require finding a potential drug that can reliably act on the target. Libraries of possible drug candidates are assembled and tested for efficacy on the target.  Leads may derive from natural products and synthetic chemistry. Virtual screening offers a powerful method of filtering out compounds for libraries based on criteria of choice before starting actual screening tests. High Throughput Screening quickly determines “hits” (or active compounds) from compound libraries that will eventually convert to leads.

High Throughput Screening

Natural Product Screening

Activity Based Libraries

HTS Library Suppliers

Custom Libraries

Library Design

Virtual Screening


Lead Optimization and ADME

After performing hit-to-lead screening, the leads require optimization and tweaking before they become a drug. Medicinal chemistry optimizes the structure, function, and biology of the drug. Chemical properties, compound integrity, and structural chemistry services are valuable in creating an effective test drug.

The lead now has to be tested for absorption, distribution, metabolism, and excretion (ADME) in animals. Pharmacokinetics and pharmacodynamics (PK PD) elucidate physicochemical properties and mechanisms of action. Cytochrome P450 analysis identifies complications and further information about the drug candidate. The final step includes any additional toxicity testing to verify the safety of drug before drug formulation.

Compound Integrity

Chemical Properties

Structural Chemistry

PK PD Analysis

In Vivo PK Services

Cytochrome P450 Services

Toxicology Testing


Drug Development 

The drug is now ready for formulation and preclinical testing. The drug is evaluated for toxicity, absorption/permeability, and pharmacology.  The most effective compound is the final candidate and must be prepared for submission. Issues, such as scaling, materials, and pricing, are now taken into greater consideration. This process development is vital to determining the fate of the drug in the pharmaceutical market.

Before entering clinical trials, CMC (chemistry manufacturing and controls) documentation describing the drug, its manufacturing, and other critical information is submitted to the FDA. The Investigational New Drug (IND) application also submitted at the end of preclinical trials and indicates beginning of clinical trials.  The Drug Development portion of Assay Depot contains services for clinical research, commercialization, quality assurance, quality control, CMC, and regulatory affairs.

Drug Formulation




Process Development

Drug Development

Chemistry Manufacturing and Controls

Can’t find the services you want? Let us know!


Source: Eckstein, J. Drug Discovery Tutorial. Alzheimer Research Forum.