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Pharmaceutical Secondary Standard; Certified Reference Material

NAP, (S)-(+)-2-(6-Methoxy-2-naphthyl)propionic acid
Linear Formula:
CAS Number:
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Quality Level


certified reference material
pharmaceutical secondary standard


current certificate can be downloaded


HPLC: suitable
gas chromatography (GC): suitable


152-154 °C (lit.)


pharmaceutical (small molecule)



pharmacopeia traceability

traceable to BP 435
traceable to PhEur N0250000
traceable to USP 1457301

storage temp.


SMILES string




InChI key


Gene Information

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General description

Pharmaceutical secondary standards for application in quality control, provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards.
Naproxen belongs to the class of arylacetic acids and is used as a non-steroidal anti-inflammatory drug (NSAID). It is useful for the management of pain, inflammation and stiffness. It is also used in the treatment of rheumatoid arthritis and other painful musculoskeletal disorders.


These Secondary Standards are qualified as Certified Reference Materials. These are suitable for use in several analytical applications including but not limited to pharma release testing, pharma method development for qualitative and quantitative analyses, food and beverage quality control testing, and other calibration requirements.
Naproxen may be used as a pharmaceutical reference standard for the determination of the analyte in pharmaceutical formulations by high performance liquid chromatography (HPLC) technique.

Biochem/physiol Actions

Non-selective cyclooxygenase (COX-1 and COX-2) inhibitor.

Analysis Note

These secondary standards offer multi-traceability to the USP, EP (PhEur) and BP primary standards, where they are available.

Other Notes

This Certified Reference Material (CRM) is produced and certified in accordance with ISO 17034 and ISO/IEC 17025. All information regarding the use of this CRM can be found on the certificate of analysis.


To see an example of a Certificate of Analysis for this material enter LRAA8968 in the slot below. This is an example certificate only and may not be the lot that you receive.


Exclamation markHealth hazard

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Hazard Classifications

Acute Tox. 4 Oral - Eye Irrit. 2 - Repr. 2 - Skin Irrit. 2 - STOT SE 3

Target Organs

Respiratory system

Storage Class Code

11 - Combustible Solids



Certificate of Analysis

Certificate of Origin

Simultaneous determination of naproxen, ketoprofen and phenol red in samples from rat intestinal permeability studies: HPLC method development and validation
Zakeri-Milani P, et al.
Journal of Pharmaceutical and Biomedical Analysis, 39(3-4), 624-630 (2005)
High performance liquid chromatography with photo diode array for separation and analysis of naproxen and esomeprazole in presence of their chiral impurities: enantiomeric purity determination in tablets
Ragab MAA and Eman I
Journal of Chromatography A, 1497, 110-117 (2017)
J Rossat et al.
Clinical pharmacology and therapeutics, 66(1), 76-84 (1999-08-03)
To compare the renal hemodynamic and tubular effects of celecoxib, a selective inhibitor of cyclooxygenase-2 (COX-2) to those of naproxen, a nonselective inhibitor of cyclooxygenases in salt-depleted subjects. Forty subjects were randomized into four parallel groups to receive 200 mg
J Sieper et al.
Annals of the rheumatic diseases, 73(1), 101-107 (2013-05-23)
To assess whether combination therapy with infliximab (IFX) plus nonsteroidal anti-inflammatory drugs (NSAIDs) is superior to NSAID monotherapy for reaching Assessment of SpondyloArthritis international Society (ASAS) partial remission in patients with early, active axial spondyloarthritis (SpA) who were naïve to
J I Schwartz et al.
Clinical pharmacology and therapeutics, 72(1), 50-61 (2002-08-02)
This study compared directly the renal effects of two selective cyclooxygenase (COX)-2 inhibitors (rofecoxib and celecoxib) with naproxen (dual COX-1/COX-2 inhibitor) and placebo in healthy elderly subjects on a sodium-replete diet. A total of 67 elderly subjects stabilized in the

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