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Small Molecule Solutions

Discover promising small molecule compounds, refine their efficacy and safety properties, and prepare them for IND and NDA submission with WuXi AppTec. With our fully integrated program addressing the bioanalytical, DMPK, and toxicology testing needs of your candidate, we can accelerate your development process to bring novel small molecule drugs to market.

Small Molecules Tested by WuXi AppTec Lab Testing Division

IND Enabling Packages

In Vitro Studies per Year

In Vivo Studies per Year

Comprehensive Small Molecule
Preclinical Testing

We combine speed, expertise, and quality to deliver world-class small molecule testing—so you can deliver small molecule therapeutics that address unmet needs.


Leverage an end-to-end platform of drug metabolism and pharmacokinetic services, from discovery through clinical, including in vitro and in vivo ADME solutions for small molecules.


Get a fit-for-purpose bioanalytical strategy for your small molecule development program designed to establish and execute the right assays for a successful regulatory submission.


Accelerate your small molecule program to the next level of development with a full-service toxicology department that provides the highest quality safety assessment data.


We support efficient, flexible, and high quality solutions for small molecule development, from preclinical to commercial lifecycle management.


Get validated discovery assays, including in vitro assays and in vivo disease models in cardiovascular, CNS, respiratory, metabolic, and infectious diseases.

Regulatory Affairs

Make global filings for your small molecule convenient, efficient, and cost-effective across US FDA, NMPA, and EMA with our extensive regulatory submission support.

End-to-End Preclinical Services

WuXi AppTec has a well-established small molecule platform from discovery to IND-enabling studies to NDA submission, including capabilities in DMPK/ADME, bioanalysis, safety assessment, pharmacology, and Chemistry, Manufacturing and Controls (CMC).

Global Partner & Network

WuXi AppTec is a global provider of preclinical small molecule solutions. With state-of-the-art facilities and experts across the US, Europe and China, we have decades of experience operating within diverse regulatory environments and delivering tailored testing solutions that advance small molecules through discovery and development.

Regulatory Expertise

We help you navigate the complex world of small molecule regulatory standards, bringing deep technical expertise enriched by constant interaction with regulatory authorities. This knowledge and detail are then translated into actionable, forward-looking testing strategies that meet stringent requirements and enable smooth progression from testing to regulatory approval.

Frequently Asked Questions

What are small molecule drugs in the context of preclinical testing?

In preclinical testing, small molecule drugs refer to compounds with relatively low molecular weights (typically < 900 Daltons) that are designed to interact with specific targets within the body to produce a therapeutic effect. These drugs are typically synthesized chemically and are characterized by their size, usually consisting of a few hundred atoms or less.

How are small molecules different from large molecules?

Small molecule drugs are distinct from larger biological molecules like proteins or nucleic acids in terms of their size and composition. They often have advantages in terms of manufacturing, stability, and oral bioavailability, which make them attractive candidates for drug development.

How are small molecule drugs selected for preclinical testing?

Small molecule drugs are selected for preclinical testing based on the identification and validation of molecular targets associated with a disease. Compounds are screened to find those that interact with the target, followed by lead optimization to enhance their properties. Preclinical studies in animal models evaluate efficacy, pharmacokinetics, and toxicity. Risk assessments identify and mitigate safety concerns.

Why is preclinical testing important for small molecules?

During preclinical studies, researchers investigate the pharmacological properties, efficacy, safety, and other characteristics of small molecule drugs to assess their potential for further development and eventual clinical testing in humans.

What are the objectives of preclinical testing for small molecule drugs?

The objectives of preclinical testing for small molecule drugs are to ensure safety, assess efficacy, optimize dosing, and support the selection and advancement of promising candidates for clinical development.

What types of preclinical studies are conducted for small molecule drugs?

Preclinical studies for small molecule drugs encompass crucial assessments in DMPK, bioanalysis, and toxicology. DMPK studies use both in vitro and in vivo models to elucidate the drug’s absorption, distribution, metabolism, and excretion properties, providing invaluable insights into its behavior in the body and potential interactions. Bioanalytical studies quantitatively measure drug concentrations and metabolites in biological samples, facilitating the establishment of pharmacokinetic profiles and aiding in dose selection. Toxicology evaluations are instrumental in identifying potential adverse effects on various organ systems, ensuring human safety during subsequent clinical trials. Together, these preclinical studies furnish indispensable data that guide further development and inform regulatory submissions for small molecule drugs

How are the pharmacokinetics of small molecule drugs evaluated in preclinical testing?

In preclinical testing, the pharmacokinetics of small molecule drugs are evaluated through a combination of in vitro and in vivo models. These preclinical pharmacokinetic studies are essential for understanding the absorption, distribution, metabolism, and excretion properties of the drugs. By providing crucial insights into these processes, these studies help optimize dosing regimens, predict human pharmacokinetics, and guide decision-making for further development in clinical trials.

What safety assessments are conducted during preclinical testing of small molecule drugs?

Preclinical testing of small molecule drugs involves various safety assessments to evaluate potential adverse effects, including acute and chronic toxicity studies, genotoxicity and carcinogenicity evaluations, reproductive toxicity assessments, and studies on cardiovascular and central nervous system safety. These assessments help identify and mitigate risks associated with the drug candidate to ensure the safety of human subjects in subsequent clinical trials.

What efficacy studies are performed during preclinical testing small molecules?

Efficacy studies during preclinical testing of small molecules include in vitro assays to assess target interaction, in vivo disease models to evaluate therapeutic effects, pharmacodynamic studies to confirm mechanisms, and biomarker analysis to measure drug response.

How are the results of preclinical testing used to inform clinical development decisions?

The results of preclinical testing inform clinical development decisions for small molecule drugs by guiding candidate selection, dose determination, and safety assessment for clinical trials. These data help establish the potential efficacy and safety profile of the drug candidates, influencing regulatory submissions, trial design, and investment decisions.

What regulatory guidelines govern preclinical testing of small molecule drugs?

Preclinical testing of small molecule drugs is governed by regulatory guidelines established by agencies such as Food and Drug Administration (FDA) in the United States, European Medicines Agency (EMA) in Europe, National Medical Products Administration (NMPA) in China, and similar regulatory bodies worldwide.

What are the common challenges in preclinical testing of small molecule drugs?

Common challenges in preclinical testing of small molecule drugs include difficulty in accurately predicting human responses from animal models, translating effective doses to human trials, selecting appropriate models, ensuring safety, and interpreting complex data.

How long does preclinical testing typically take for small molecule drugs before advancing to clinical trials?

Preclinical testing for small molecule drugs typically takes around 1 to 3 years before advancing to clinical trials. However, the duration can vary depending on factors such as the complexity of the drug candidate, the extent of preclinical studies required, regulatory requirements, and the availability of resources.

What considerations should be taken into account for selecting preclinical testing solutions for small molecules?

When selecting preclinical testing solutions for small molecules, it is important to prioritize providers with both scientific expertise and extensive project management experience, acting as your extended team. Look for providers capable of delivering flexible, customized solutions tailored to your specific needs and timelines. Evaluate the availability of specialized assays, relevant animal models, and comprehensive services covering safety, pharmacokinetics, and pharmacodynamics assessments. Regulatory compliance is paramount, as is the delivery of high-quality data and robust reporting, facilitating informed decision-making throughout the development process of small molecule therapeutics.

What strategies are employed to enhance the bioavailability and stability of small molecule drugs in preclinical studies?

Common strategies employed to enhance the bioavailability and stability of small molecule drugs during preclinical studies include optimizing drug formulations, designing prodrugs, reducing particle size, utilizing advanced drug delivery systems, co-crystallization techniques, pH adjustment, and forming inclusion complexes. These approaches aim to improve drug solubility, absorption, and protection from degradation, ensuring effective preclinical testing and potential clinical translation.

What are some examples of small molecule therapeutics that have undergone successful preclinical testing?

With our extensive experience and expertise in preclinical research and development, WuXi AppTec has evaluated millions of small molecules across diverse therapeutic areas. Our comprehensive portfolio of services, including specialized assays, relevant animal models, and comprehensive safety, pharmacokinetics, and pharmacodynamics assessments, has enabled us to identify promising candidates and advance them through preclinical testing with demonstrated efficacy and safety profiles.

Let’s Talk About Your Small Molecule

Have questions? Need specific assays? Talk to an expert today about your small molecule program.