Rofecoxib API is a synthetic, selective cyclooxygenase-2 (COX-2) inhibitor belonging to the coxib class of non-steroidal anti-inflammatory drugs (NSAIDs). It was developed as an anti-inflammatory, analgesic and antipyretic active pharmaceutical ingredient.
Rofecoxib is chemically identified as 4-[4-(methylsulfonyl)phenyl]-3-phenyl-2(5H)-furanone. FDA substance records identify Rofecoxib under CAS 162011-90-7, molecular formula C17H14O4S, and molecular weight 314.36 g/mol.
Rofecoxib is a small-molecule pharmaceutical API characterized by its selective inhibition of COX-2. By reducing COX-2-mediated prostaglandin synthesis, the compound has anti-inflammatory, analgesic and antipyretic pharmacological effects.
The API is reported as a white to off-white to light-yellow powder. It is practically insoluble in water and has limited solubility in several organic solvents.
Rofecoxib contains a substituted furanone ring, phenyl group and methylsulfone functionality. The API has the molecular formula C17H14O4S and molecular weight 314.36 g/mol.
Rofecoxib is an anhydrous crystalline material, and polymorphic-form control can be relevant to pharmaceutical development. Published drug-substance work has specifically characterized Form A using XRPD and thermal analysis.
Rofecoxib was developed for the management of pain and inflammation associated with conditions such as osteoarthritis and rheumatoid arthritis and was also used for acute pain and other inflammatory conditions.
Its pharmacological activity is associated with selective COX-2 inhibition, distinguishing it mechanistically from conventional non-selective NSAIDs.
Regulatory note: Rofecoxib-containing Vioxx products were withdrawn from the U.S. market because of cardiovascular safety concerns. Therefore, Rofecoxib should not be described as a currently marketed U.S. therapeutic product.
Rofecoxib API can be characterized using a combination of chromatographic, spectroscopic and solid-state analytical techniques.
Typical quality-control testing includes HPLC/UHPLC assay and related substances, FTIR identity, water determination by Karl Fischer, residual-solvent testing by GC, residue on ignition, XRPD for crystalline form and particle-size characterization where applicable.
Published drug-substance specifications use UHPLC for assay and impurities, FTIR/UHPLC for identification, Karl Fischer for water and XRPD for polymorphic-form confirmation.
Rofecoxib API manufacturing requires controlled synthesis, purification and crystallization to achieve consistent chemical purity and physical properties. Particular attention can be given to related substances, residual solvents, water content and crystalline form.
Quality-focused API production should be supported by validated analytical procedures and batch-specific quality documentation.
Rofecoxib should be packed in suitable well-closed, moisture-protective pharmaceutical packaging that protects the API from environmental contamination and humidity.
Published drug-substance stability work used double HDPE bags inside an HDPE drum for Rofecoxib drug substance. This is a reported packaging configuration, not a universal pharmacopoeial requirement.
Storage conditions should follow the validated stability data for the specific API batch and packaging configuration.
Typical documentation for Rofecoxib API can include:
Rofecoxib is a well-characterized small-molecule COX-2 inhibitor with established analytical methods and extensive pharmaceutical-development history. Its defined molecular structure, crystalline nature and documented analytical profile make control of assay, impurities, residual solvents, water content and solid form important aspects of API quality.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.10% |
| Individual Impurity | NMT 0.50% |
| Total Impurities | NMT 1.0% |