In the pharmaceutical industry, Isoniazid (INH) 300 mg is a foundational first-line antitubercular agent. As a pharmacist, I view this 300 mg strength as the gold standard daily dose for adults in both the treatment of active disease and the prevention of latent infection. It is a highly specific “narrow-spectrum” antibiotic, targeting only mycobacteria.

Primary Clinical Uses

• Active Tuberculosis (TB): Used as a core component of the standard four-drug regimen (alongside Rifampicin, Pyrazinamide, and Ethambutol) to treat pulmonary and extra-pulmonary TB.

• Latent Tuberculosis Infection (LTBI): Prescribed as monotherapy (usually 300 mg daily for 6–9 months) to prevent the progression of latent TB to active disease in high-risk individuals.

• Prophylaxis: Given to individuals who have been in close contact with patients having active TB, regardless of their skin test results.

Mechanism of Action

Isoniazid is a prodrug that must be activated by the bacterial enzyme KatG (a catalase-peroxidase).

Inhibition of Mycolic Acid Synthesis: Once activated, it binds to and inhibits the enzyme InhA (enoyl-ACP reductase).

Cell Wall Disruption: This blockade prevents the synthesis of mycolic acids, which are the essential long-chain fatty acids that make up the “waxy” protective cell wall of Mycobacterium tuberculosis.

Bactericidal Effect: For actively dividing bacteria, this loss of cell wall integrity is lethal, making INH highly bactericidal.

The Manufacturer’s Perspective: Formulation & Export

From a manufacturing and global trade standpoint, Isoniazid 300 mg is a high-volume “Essential Medicine” with specific technical requirements:

• Fixed-Dose Combinations (FDCs): While we manufacture 300 mg single-drug tablets, the global export market (especially via the Global Drug Facility – GDF) heavily favors FDCs like Rifampicin + Isoniazid (150mg/75mg or 300mg/150mg). For your digital platform, showcasing these FDCs is key to attracting B2B buyers.

• API Purity & Hydrazine Monitoring: During synthesis and storage, INH can degrade into hydrazine, a toxic impurity. As a WHO-GMP firm, we maintain strict assay controls to ensure hydrazine levels remain well below pharmacopeial limits.

• Stability for Tropical Export: INH is sensitive to moisture and light. We utilize Alu-Alu or high-grade PVC/PVDC blister packaging to ensure a 36-month shelf life for export to Zone IVb regions (Africa, SE Asia, and CIS countries).

• Pharmacovigilance (Vitamin B6): It is industry standard to recommend co-administration with Pyridoxine (Vitamin B6) to prevent peripheral neuropathy, a common side effect of INH. We often market these as a bundle or a “combipack.”