Rifampicin

Also known as: Rifadin, Rimactane, Rifocin, R-Cin, Rimpin

CAS Number: 13292-46-1

Rifamycin antibiotic — cornerstone of anti-tuberculosis therapy

Pharmacopeia Standards

USPBPIPEP

Mechanism of Action

Semi-synthetic rifamycin that inhibits bacterial DNA-dependent RNA polymerase (beta subunit, rpoB gene product) by binding the catalytic center, blocking mRNA chain initiation. Bactericidal. Resistance emerges rapidly with monotherapy (single-step mutations in rpoB). Potent inducer of CYP450 enzymes and P-glycoprotein — major drug interactions with antiretrovirals, warfarin, oral contraceptives, and many other drugs. Turns body fluids orange-red (harmless).

Technical Specifications

Generic / INN Name	Rifampicin
CAS Registry Number	13292-46-1
Molecular Formula	C43H58N4O12
Molecular Weight	822.94 g/mol
Typical Purity	97.0–103.0%
Storage Conditions	Store below 25°C, dry, protected from light
Shelf Life	36 months from date of manufacture
Category	Rifamycins

Specifications are indicative and intended for sourcing reference only. Always confirm against the supplier's Certificate of Analysis and the applicable pharmacopeial monograph before issuing a purchase specification.

Typical Applications

Anti-tuberculosis therapy (first-line component of all active TB regimens: HRZE/HRE), MDR-TB where susceptibility confirmed, leprosy (multidrug therapy: rifampicin + dapsone + clofazimine), non-tuberculous mycobacterial infections, Staphylococcal biofilm infections (prosthetic joint/valve — always in combination), H. influenzae and N. meningitidis prophylaxis (close contacts of meningococcal disease), Legionella (combination).