Classification of active pharmaceutical ingredients

1. Source-based Classification:

   1. Synthetic APIs: These are chemically synthesized in laboratories using various organic chemistry techniques. Synthetic APIs offer precise control over their chemical composition and are often more cost-effective to produce compared to other sources.

   2. Natural APIs: These are extracted or isolated from natural sources such as plants, animals, or microorganisms. Natural APIs can exhibit complex chemical structures and may offer potential therapeutic benefits due to their natural origins.

2. Chemical Structure-based Classification:

   1. Small Molecule APIs: These are characterized by their relatively low molecular weight and simple chemical structures. Small molecule APIs are often orally bioavailable and can target intracellular processes.

   2. Biologic APIs: These are large, complex molecules derived from living organisms or produced using biotechnology methods. Biologic APIs include proteins, peptides, antibodies, and nucleic acids. They require specialized manufacturing processes and are typically administered via injection.

3. Therapeutic Use-based Classification:

   1. Oncology APIs: These APIs are specifically used in the treatment of cancer. They may inhibit tumor growth, promote apoptosis (cell death), or target specific molecular pathways involved in cancer progression.

   2. Cardiovascular APIs: These APIs are designed to manage cardiovascular conditions such as hypertension, heart failure, or arrhythmias. They can regulate blood pressure, improve cardiac function, or modulate heart rhythm.

   3. Central Nervous System (CNS) APIs: These APIs affect the brain and nervous system, addressing conditions like depression, anxiety, epilepsy, or neurodegenerative disorders. They can modulate neurotransmitter levels or regulate neuronal activity.

   4. Anti-inflammatory APIs: These APIs target inflammation and immune responses associated with conditions like arthritis, asthma, or autoimmune diseases. They can alleviate pain, reduce inflammation, or suppress immune reactions.

   5. Anti-infective APIs: These APIs combat microbial infections, including antibiotics, antivirals, antifungals, and antiparasitic drugs. They inhibit the growth or kill microorganisms responsible for infections.

These classification systems help researchers, manufacturers, and healthcare professionals understand the characteristics, properties, and therapeutic applications of APIs. By categorizing APIs based on their source, chemical structure, and therapeutic use, it becomes easier to develop targeted drug formulations and ensure their safe and effective use in clinical practice.