Naproxen Sodium

Catalog No.S1626 Synonyms: RS-3650

For research use only.

Naproxen Sodium (RS-3650) is a COX inhibitor for COX-1 and COX-2 with IC50 of 8.7 μM and 5.2 μM, respectively.

Naproxen Sodium Chemical Structure

CAS No. 26159-34-2

Selleck's Naproxen Sodium has been cited by 2 Publications

Purity & Quality Control

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Biological Activity

Description Naproxen Sodium (RS-3650) is a COX inhibitor for COX-1 and COX-2 with IC50 of 8.7 μM and 5.2 μM, respectively.
Features Displays approximately equipotent inhibitory selectivity for COX-1 and COX-2 in intact cells.
COX-2 [1] COX-1 [1]
5.2 μM 8.7 μM
In vitro

Naproxen is approximately equipotent inhibitor of COX-1 and COX-2 in intact cells with IC50 of 2.2 μg/mL and 1.3 μg/mL, respectively. [1] Naproxen decreases the in vitro LPS-induced PGE2 and TXB2 production in rats and humans with IC50 of 30.7 μM and 79.5 μM for PGE2 inhibition, 72.4 μM and 48.3 μM for TXB2 inhibition, respectively. [2] Naproxen produces concentration-related inhibition of TXB2 production from human platelets and LPS-induced TXB2 production from human mononuclear cells with plC50 values (-log concentration inhibiting TXB2 by 50%) of 5.7 and 6.4, respectively, and exhibits slightly inhibitory selectivity for constitutive and induced COX-2 with IC50 COX-1/IC50 COX-2 of 6.3. [3] Only high concentration of Naproxen can significantly induce apoptosis at 48 hours in HCA-7 colon cancer cells with IC50 of 1.45 mM. [4]

In vivo Administration of Naproxen reduces the LPS-induced PGE2 and TXB2 production in vivo in rats with IC50 values of 12.8 μM and 5.9 μM, respectively, which represents that Naproxen is a nonselective COX inhibitor with the log IC50 ratio (COX-2/COX-1) of 0.34. [2] Naproxen displays IC50 of 27 μM for analgesia in a rat model with carrageenan-induced arthritis and IC50 of 40 μM for antipyretics in a yeast-induced fever rat model, while exhibits inhibition of PGE2 with IC50 of 13 μM and TXB2 with IC50 of 5 μM. [5]

Protocol (from reference)

Kinase Assay:[1]
  • COX-1 and COX-2 activities in intact cells:

    For the determination of COX-1 and COX-2 inhibition, bovine aortic endothelial cells (BAEC) are incubated for 30 minutes with Naproxen (0.1 ng/mL to 1 mg/mL), and cultured J774.2 macrophages are treated with endotoxin at 1 μg/mL for 12 hours to induce COX-2 followed by incubated for 30 minutes with Naproxen (0.1 ng/mL to 1 mg/mL), respectively. Arachidonic acid (30 μM) is then added, and the cells are incubated for a further 15 minutes at 37 °C. The medium is then removed, and radioimmunoassay is used to measure the formation of 6-keto-PGF1α, PGE2, thromboxane B2, or PGF for the assessment of IC50 for COX-1 and COX-2.

Cell Research:[4]
  • Cell lines: Human colon cancer HCA-7 cell lines
  • Concentrations: Dissolved in culture medium, final concentration ~20 mM
  • Incubation Time: 24 and 48 hours
  • Method: Cells are exposed to Naproxen for 24 and 48 hours, respectively. At the end of incubation, cells are harvested by trypsinization, stained with trypan blue solution (0.04% wt/vol) and counted in a Neubauer haemocytometer chamber for the determination of cell viability.
Animal Research:[2]
  • Animal Models: Male Sprague-Dawley rats
  • Dosages: 2.5, 10 or 25 mg/kg
  • Administration: Intravenously (i.v.) infusion or intraperitoneal (i.p.) injection

Solubility (25°C)

In vitro

Water 50 mg/mL
(198.22 mM)
DMSO 3 mg/mL
(11.89 mM)
Ethanol Insoluble

Chemical Information

Molecular Weight 252.24


CAS No. 26159-34-2
Storage 3 years -20°C powder
2 years -80°C in solvent
Smiles CC(C1=CC2=C(C=C1)C=C(C=C2)OC)C(=O)[O-].[Na+]

In vivo Formulation Calculator (Clear solution)

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

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Molarity Calculator

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Clinical Trial Information

NCT Number Recruitment Interventions Conditions Sponsor/Collaborators Start Date Phases
NCT05026320 Recruiting Drug: Naproxen gel|Drug: Diclofenac gel|Drug: Placebo gel Soft Tissue Injury Bayer|Deutsche Sporthochschule Köln August 8 2021 Phase 2
NCT04145518 Recruiting Drug: Naproxen Sodium Dysmenorrhea (Disorder)|Dysmenorrhea Primary|Dysmenorrhea Secondary|Endometrial Diseases|Leiomyoma|Fibroid Uterus NorthShore University HealthSystem|National Institutes of Health (NIH)|Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) October 25 2019 Phase 4

(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

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