Catalog No.S3043 Synonyms: MK-0966

For research use only.

Rofecoxib (MK-0966) is a COX-2 inhibitor with IC50 of 18 nM.

Rofecoxib  Chemical Structure

CAS No. 162011-90-7

Selleck's Rofecoxib has been cited by 1 Publication

Purity & Quality Control

Choose Selective COX Inhibitors

Other COX Products

Biological Activity

Description Rofecoxib (MK-0966) is a COX-2 inhibitor with IC50 of 18 nM.
COX-2 [1]
18 nM
In vitro

Rofecoxib inhibits the COX-2-dependent production of PGE2 in human osteosarcoma cells with an IC50 of 26 nM. Rofecoxib is a time-dependent inhibitor of purified human recombinant COX-2 with an IC50 of 0.34 μM. Rofecoxib causes inhibition of purified human COX-1 in a non-time-dependent manner. In a human whole blood assay, Rofecoxib selectively inhibits lipopolysaccharide-induced, COX-2-derived PGE2 synthesis with an IC50 value of 0.53 μM compared with an IC50 value of 18.8 μM for the inhibition of COX-1-derived thromboxane B2 synthesis after blood coagulation. [1] Rofecoxib moderately inhibits phenacetin O-deethylation with an IC50 of 23 μM. And a 30-minute preincubation with microsomes and NADPH considerably increases the inhibitory effect of Rofecoxib with an IC50 of 4.2 μM. Inactivation of CYP1A2 by rofecoxib requires NADPH, and is characterized by a K i of 4.8 μM. [2]

Cell Data
Cell Lines Assay Type Concentration Incubation Time Formulation Activity Description PMID
J774 NVjReGZoTnWwY4Tpc44h[XO|YYm= M3LhVWlvKH[rdILvJIlvcGmkaYTvdpkh[WO2aY\peJkh[WejaX7zeEBRem:|dHHncIFv\GmwIFevTEB{gW62aHHz[UAzKGmwIH31dolv\SCMN{e0JINmdGy|LDDJR|UxRTBwMEGyJO69VQ>? M3vL[VE2QDV5MUS5
In vivo Rofecoxib potently inhibits carrageenan-induced paw edema, carrageenan-induced paw hyperalgesia, lipopolysaccharide-induced pyresis with IC50 of 1.5 mg/kg, 1.0 mg/kg and 0.24 mg/kg, respectively. Rofecoxib also blocks adjuvant-induced arthritis with an IC50 of 0.74 mg/kg/day. Rofecoxib also has a protective effect on adjuvant-induced destruction of cartilage and bone structures in rats. [1] Oral administration of rofecoxib decreases portal pressure in rats that are treated with CCl4 for 8 weeks. In addition, rofecoxib administration reduces the number of activated HSCs and to downregulate hepatic protein levels of three detected types of collagen, laminin, VEGF and CTGF in CCl4-treated rats. [3]

Protocol (from reference)

Kinase Assay:[1]
  • In vitro biochemical and pharmacological assaysinhibition studies with recombinant human COX-1 and COX-2:

    Microsomal preparations of recombinant human COX-1 and COX-2 are prepared from a vaccinia virus-COS-7 cell expression system. Recombinant human COX-1 and COX-2 are expressed in baculovirus-Sf9 cells, and enzymes are purified. Enzymatic activity is monitored continuously by either a fluorescence assay measuring the appearance of the oxidized form of the reducing agent cosubstrate homovanillic acid or by oxygen consumption. The HPLC assay for the assessment of inhibition of purified COX-1 by Rofecoxib with 0.1 μM arachidonic acid substrate concentration, the determination of the stoichiometry of the complex between COX-2 and Rofecoxib, the dissociation rate constant of the enzyme-inhibitor complex by recovery of enzymatic activity, and the recovery of intact Rofecoxib from that complex are all performed as described previously. The solvent system for the HPLC analysis of Rofecoxib is 15:85 MeOH/aqueous potassium phosphate (1 g/liter), with elution by a linear gradient of 15 to 75% MeOH over 25 minutes with detection at 275 nm on a Novapak C18 column.

Cell Research:[1]
  • Cell lines: Human osteosarcoma cell line and human lymphoma U937 cells
  • Concentrations: 0.5 μM, 8 μM
  • Incubation Time: 15 minutes
  • Method: The human osteosarcoma cell line has been shown to selectively express COX-2 by reverse transcription-polymerase chain reaction and immunoblot analysis, whereas undifferentiated human lymphoma U937 cells selectively express COX-1. The production of PGE2 by these cells after arachidonic acid challenge is used as an index of cellular COX-2 and COX-1 activity, respectively. Rofecoxib is preincubated for 5 to 15 minutes with the cells under serum-free conditions [Hanks' balanced salt solution (HBSS)] before a 10-minutes stimulation with 10 μM arachidonic acid and measurement of PGE2 production. COX activity in each cell line is defined as the difference in PGE2 concentrations in samples incubated in the presence or absence of arachidonic acid.
Animal Research:[1]
  • Animal Models: Rat adjuvant-induced arthritis (AIA) model
  • Dosages: 0.1 mg/kg/day, 0.3 mg/kg/day, 1.0 mg/kg/day, and 3.0 mg/kg/day
  • Administration: p.o.

Solubility (25°C)

In vitro

DMSO 63 mg/mL
(200.4 mM)
Water Insoluble
Ethanol Insoluble

In vivo

Add solvents to the product individually and in order
(Data is from Selleck tests instead of citations):
30% PEG400+0.5% Tween80+5% propylene glycol
For best results, use promptly after mixing.

30 mg/mL

Chemical Information

Molecular Weight 314.36


CAS No. 162011-90-7
Storage 3 years -20°C powder
2 years -80°C in solvent
Smiles CS(=O)(=O)C1=CC=C(C=C1)C2=C(C(=O)OC2)C3=CC=CC=C3

In vivo Formulation Calculator (Clear solution)

Step 1: Enter information below (Recommended: An additional animal making an allowance for loss during the experiment)

mg/kg g μL

Step 2: Enter the in vivo formulation (This is only the calculator, not formulation. Please contact us first if there is no in vivo formulation at the solubility Section.)

% DMSO % % Tween 80 % ddH2O

Calculation results:

Working concentration: mg/ml;

Method for preparing DMSO master liquid: mg drug pre-dissolved in μL DMSO ( Master liquid concentration mg/mL, Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug. )

Method for preparing in vivo formulation: Take μL DMSO master liquid, next addμL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O, mix and clarify.

Method for preparing in vivo formulation: Take μL DMSO master liquid, next add μL Corn oil, mix and clarify.

Note: 1. Please make sure the liquid is clear before adding the next solvent.
2. Be sure to add the solvent(s) in order. You must ensure that the solution obtained, in the previous addition, is a clear solution before proceeding to add the next solvent. Physical methods such
as vortex, ultrasound or hot water bath can be used to aid dissolving.

Molarity Calculator

Mass Concentration Volume Molecular Weight

Clinical Trial Information

NCT Number Recruitment Interventions Conditions Sponsor/Collaborators Start Date Phases
NCT00637988 Completed Drug: Esomeprazole|Drug: Aspirin|Drug: Rofecoxib Barrett''s Esophagus AstraZeneca April 2002 Phase 4
NCT00038389 Terminated Drug: Vioxx Glioma|Brain Neoplasms M.D. Anderson Cancer Center October 2001 Phase 1

(data from, updated on 2022-01-17)

Tech Support

Answers to questions you may have can be found in the inhibitor handling instructions. Topics include how to prepare stock solutions, how to store inhibitors, and issues that need special attention for cell-based assays and animal experiments.

Handling Instructions

Tel: +1-832-582-8158 Ext:3
If you have any other enquiries, please leave a message.

* Indicates a Required Field

Please enter your name.
Please enter your email. Please enter a valid email address.
Please write something to us.
Tags: buy Rofecoxib | Rofecoxib supplier | purchase Rofecoxib | Rofecoxib cost | Rofecoxib manufacturer | order Rofecoxib | Rofecoxib distributor