Why Are Synthetic Small Molecule APIs Commonly Used in Healthcare?

The pharmaceutical industry is vast. It relies on various compounds for developing drugs. Active pharmaceutical ingredients (APIs) are an essential component of pharmaceuticals. They enable the drug to be effective, allowing it to treat a wide range of health conditions.

There are three main types of APIs. These include biologics, peptides, and small molecules. In this blog post, we explain to you what synthetic small molecule APIs are and how they are made. We also shed light on the key metrics and growth drivers of the synthetic small molecule API market. Let’s dive in!

What Are Synthetic Small Molecule APIs?

Small molecule APIs are an important element of traditional drug manufacturing. These molecules are chemical compounds having low molecular weight. Their weight is usually less than 900 Daltons. Small molecule APIs are usually manufactured using chemical synthesis. This is in contrast to biologics that are obtained using fermentation processes and living cells. The synthetic nature of small molecule APIs makes them more stable and improves their affordability. It’s also easy to scale the production of synthetic small molecule APIs.

After synthesis and purification, these molecules are added to the drug formulation. Here, they become the active component that treats the disease. Some of the drugs using APIs are listed below:

• Painkillers: Painkillers are widely used for treating pain and inflammation. Examples include ibuprofen and aspirin.
• Antibiotics: Antibiotics target bacterial infections in the body. Examples of small molecule antibiotics available in the antibiotics market are penicillin and amoxicillin.
• Cholesterol Medications: Statins such as atorvastatin are used for managing high levels of cholesterol and lowering the risk of heart disease.

What Is the Synthetic Small Molecule API Market Outlook?

Our latest analysis reveals that the synthetic small molecule API market is expected to grow at a steady rate. The market stood at USD 184.24 billion in 2024. It is anticipated to account for a CAGR of 5.40% between 2025 to 2024.

The market for these APIs is primarily driven by their numerous applications in the healthcare industry. In addition, increased demand for generic drugs is also having a favorable impact on the synthetic small molecule API market growth.

What Are Key Characteristics of Small Molecule Drugs?

Size and Structure: The size of small molecule drugs is typically between 0.1 and 1 kDa. The small size helps improve GI absorption into the bloodstream. As such, these drugs are suitable for oral use.

Composition: Small molecule APIs are often crystalline and hydrophobic. So, they can bypass lipid-rich cell membranes and have their therapeutic effects.

Synthesis: Chemical reactions are generally used for synthesizing small molecules. This helps improve the scalability and affordability of these drugs.

Action Mechanism: The targeting of specific enzymes and proteins by small molecules allows for the precise modulation of biochemical pathways.

Administration: The administration of small molecule drugs is typically done using oral routes. This helps improve patient compliance and accessibility.

Immunogenicity: The small size means these drugs typically have low immunogenicity. So, the chances of triggering an adverse immune response are low.

Metabolism and Excretion: The metabolism of small molecule drugs typically takes place within the liver. Their elimination is done through the kidneys. They follow the standard pathways of excretion.

Stability and Storage: The ability of these drugs to stay stable at room temperature helps simplify packaging, labeling, and distribution.

How Are Synthetic Small Molecule APIs Manufactured?

The manufacturing and distribution of small molecule APIs is complex and highly regulated. There are several steps involved in the making of these molecules. They include:

Chemical Synthesis

The process of making small molecule APIs starts with designing a synthetic pathway. The pathway is basically a set of chemical reactions that assemble the target molecule from the starting materials. The intricate nature of small molecules necessitates multiple steps. The use of solvents enables specific reactions. The addition of catalysts may be done to improve the speed of the process.

Purification

The synthesis of the molecule gives a crude mixture that contains the desired product. But it contains impurities and side-products as well. The removal of these impurities needs to be done to ensure that the drug is safe for the patient. Crystallization and distillation are commonly used methods for purification.

Characterization and Testing

Ensuring purity isn’t enough. Manufacturers also need to confirm whether the resulting compound is the correct molecule and has the required structure. Analytical tools available in the nuclear magnetic resonance spectroscopy market are used for the same. These analytical methods ensure that the product is consistent across every batch.

Formulation

Direct administration of purified API usually can’t be done. Excipients are added to the API to transform it into a useful medicine. Excipients are inactive ingredients that help improve the stability and absorption of the drug. APIs are formulated into various forms based on the therapeutic need. They can be formulated as tablets, capsules, injectables, and topical preparations.

Quality Control and Regulatory Compliance

There are stringent international standards in place for each manufacturing stage. APIs must meet the approval of regulatory authorities before they make their way to the market. Extensive testing by quality control teams is carried out to ensure that the API is consistent across the batch. Testing also ensures that the API remains stable while it’s being stored and distributed.

Which Therapeutic Areas Need API?

Oncology

Cancer is characterized by high complexity. Small molecules have been pivotal in the advancement of targeted therapies for cancer. These molecules can be designed to inhibit specific enzymes or receptors that cause the tumor to grow.

Cardiology

Cardiovascular diseases account for a major portion of all the deaths globally. Small molecules help a great deal in prevention and treatment. The use of statins lowers the levels of cholesterol and reduces the risk of heart attacks. Using beta-blockers, it’s possible to regulate blood pressure and improve the functioning of the heart.

Neurology and Psychiatry

Unique challenges are presented by the nervous system and brain when developing drugs. Small molecules have helped in solving some of these challenges by modulating neurological pathways. The use of antidepressants enables the management of food disorders. Seizures are prevented by antiepileptic drugs as they stabilize neural activity.

To Conclude

Small molecule APIs are essential for the manufacturing of several commonly used drugs. The low molecular weight of these APIs means that they can easily penetrate cell membranes. Drugs containing these APIs are also easy to administer and have high oral bioavailability. The use of innovative methods by key players in the synthetic small molecule API market is reducing the time and cost needed to produce APIs.