Contents Naproxen

The permeabilities of the acid examples rise with increasing phospholipid content, up to 20% lipid, with rank ordering preserved. Naproxen and ketoprofen... 

The permeabilities of the acid examples rise with increasing phospholipid content, up to 20% lipid, with rank ordering preserved (data not shown). Naproxen and ketoprofen show the most dramatic increases in going from 2% to 10% lipid membranes - somewhat higher in soy than in egg. Piroxicam shows less... 

Calculate the percentage of stated content for naproxen and aspirin. 

Claire Bombardier, Loren Laine, et al., Comparison of Upper Gastrointestinal Toxicity of Rofecoxib and Naproxen in Patients with Rheumatoid Arthritis. VIGOR Study Group, New England Journal of Medicine 343, no. 21, November 23, 2000, pp. 1,520-1,528. Also available online. URL http //content.nejm.org/ cgi/content/full/343/21/1520. Downloaded April 15, 2009. 

Research was undertaken to develop a controlled release tablet of naproxen using ethylcellulose and both methods of wet granulation and solid dispersion were compared for effectiveness. Naproxen level was kept constant at 16% while ethylcellulose content was varied from 6% to 28% in the formulations. While both methods were successful at producing formulations with drug release profiles of at least 12 hours, the amount of ethylcellulose required to prepare such formulations was 33% less using the solid dispersion method. While none of the formulations released 100% of the drug, a cumulative 88% of naproxen was released from the solid dispersion formulation, compared with 84% from the wet granulation formulation (50). 

All HPMC samples had similar viscosity, except batch 7 which is outside USP specifications (75-140% of the nominal value 15000). Methoxyl contents are uniformly high and three batches fall outside the USP specifications 19-24%. Hydroxypropyl contents, although within the specified limits (4-10%), vary relatively more than methoxyl contents, with batch 5 showing the lowest value. When measuring the release of the drug naproxen from compressed matrix tablets, the authors observed in vitro a strong dependence of the release rate (expressed in h ° s ) on the hydroxypropyl content of the HPMC (Fig. 1). 

Fig. 1. Influence of HPMC 2208 hydro-xypropyl content on naproxen release from matrix tablets [19]...

Van den Mooter, G. Sam3m, C. Kinget, R. The relation between swelling properties euid enzymatic degradation of azo pol3Tners designed for colon-specific drug delivery. Pharm.Res., 1994,11, 1737-1741 [naproxen (IS) rat cecal content release medium]... 

Naproxen contents in sugar coated tablets was determined by fluorescence (30) spectrophotometry. Naproxen tablets with their sugar-coating removed, were powdered and a sample equivalent to about 25 mg of naproxen was dissolved in 5 ml of 1% NaOH and diluted with H2O. A 0.5 ml portion of the supernatant solution was mixed with 1 ml of 1M-HCI and dilute to 100 ml with H2O and the fluorescence of the solution was measured at 356 nm (excitation at 274 nm) vs. 0.01 M-HCl. Recovery was 99.5% with a coeff. of variation of 0.8%... 

Pour the contents of the filter flasks into a 125-mL separatory funnel. The upper organic layer contains toluene and the tert-butyl ester of naproxen. Remove the lower aqueous layer from the separatory funnel and discard it. Pour the toluene layer remaining in the funnel from the top of the separatory funnel into an Erlen-meyer flask. 

Add 4 mL of trifluoroacetic acid (careful, toxic) to the crude tert-butyl ester of naproxen contained in the round-bottom flask. Add a stir bar and heat the contents with stirring on a hot plate in an open flask at 130°C for Vi hour (check the internal temperature of the mixture with a thermometer). After Vi hour, cool the flask to room temperature, and add 20 mL water and 20 mL methylene chloride (dichloromethane). 

Dosing is generally based on naproxen content 200, 500 mg naproxen = 220, 550 mg naproxen sodium. 

The content of naproxen in Naproxen tablets (Hasco-Lek S. A., Poland, and Polfarmex, Poland) can be determined with the obtained electrodes with an error of 2% and high precision of 3%. 

The accuracy obtained from the determination of naproxen in a real sample (Naprosyne )was also assessed using the diamond electrode. The declared amount of naproxen in Naprosyne is 500 mg. From this study, a value of 498 mg (mean - RSD of 1.4%) was obtained, which is in close agreement with the stated content. The analysis exhibited a mean recovery of 99.7% and a relative standard deviation of 2.15%, indicating adequate precision and accuracy for this electrode. This result also indicates that the excipients are electrochemically inactive and have no interference effects on the analysis of naproxen. 

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