mwu.mukogawa-u.ac.jp

A uniformly sized molecularly imprinted polymer (MIP) for (S)-naproxen has been prepared by a multi-step swelling and polymerization method using 4-vinylpyridine (4-VPY) and ethylene glycol dimethacrylate (EDMA) as a functional monomer and cross-linker, respectively. We optimized the preparation method of the MIP by changing the molar amounts of the template molecule and functional monomer. Further, we examined the effects of organic modifier type, column temperature and flow-rate on the retentivity and enantioselectivity for naproxen using a mixture of phosphate buffer and organic modifier (acetonitrile, ethanol and 2-propanol) as an eluent. When the amounts of (S)-naproxen, 4-VPY and EDMA used were 4, 6 and 25 mmol, respectively, the enantioselectivity and resolution for naproxen were good despite the shorter retention. When acetonitrile was used as an organic modifier, the highest column efficiency was obtained for the separation of naproxen enantiomers. With regard to the effects of column temperature and flow-rate, the column performance was improved by elevating a column temperature and decreasing a flow-rate.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11354156&dopt=Abstract Naproxen Naprosyn
[PubMed - as supplied by publisher]

mwu.mukogawa-u.ac.jp

A uniformly sized molecularly imprinted polymer (MIP) for (S)-naproxen has been prepared by a multi-step swelling and polymerization method using 4-vinylpyridine (4-VPY) and ethylene glycol dimethacrylate (EDMA) as a functional monomer and cross-linker, respectively. We optimized the preparation method of the MIP by changing the molar amounts of the template molecule and functional monomer. Further, we examined the effects of organic modifier type, column temperature and flow-rate on the retentivity and enantioselectivity for naproxen using a mixture of phosphate buffer and organic modifier (acetonitrile, ethanol and 2-propanol) as an eluent. When the amounts of (S)-naproxen, 4-VPY and EDMA used were 4, 6 and 25 mmol, respectively, the enantioselectivity and resolution for naproxen were good despite the shorter retention. When acetonitrile was used as an organic modifier, the highest column efficiency was obtained for the separation of naproxen enantiomers. With regard to the effects of column temperature and flow-rate, the column performance was improved by elevating a column temperature and decreasing a flow-rate.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11355806&dopt=Abstract Naproxen Naprosyn





J Pharm Biomed Anal. 2001 Jul;25(5-6):881-91.
Determination of ibuprofen and naproxen in tablets.

Sadecka J, Cakrt M, Hercegova A, Polonsky J, Skacani I.

Department of Analytical Chemistry, Faculty of Chemical Technology, Slovak University of Technology, Radlinskeho 9, SK-812 37, Bratislava, Slovak Republic.

Ibuprofen and naproxen have been quantified in tablets by capillary isotachophoresis. Hydrochloric acid (10 mmol/l) adjusted with creatinine to pH 5.0 plus 0.1% polyvinylpyrrolidone was used as the leading electrolyte and 10 mmol/l 4-morpholineethanesulfonic acid as the terminating electrolyte. Linearity was observed from 40.0 to 200.0 mg/l of ibuprofen (naproxen), with a coefficient of determination (r2) of 0.999. Good quantitation was obtained in short analysis time. The isotachophoretic results were compared with those obtained by the fluorescence spectrometry. Experimental parameters for ibuprofen were: lambdaEX=224 nm and lambdaEM=290 nm. Experimental parameters for naproxen were: lambdaEX=230 nm and lambdaEM=355 nm. The calibration plot was found to be linear in the range 0.4-2.4 mg/l for ibuprofen and 5.0-20.0 microg/l for naproxen. The minimal sample pretreatment and relatively low running cost make isotachophoresis a good alternative to existing methods.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11377071&dopt=Abstract Naproxen Naprosyn





J Chromatogr A. 2001 May 4;916(1-2):207-14.
Isotachophoretic determination of naproxen in the presence of its metabolite in human serum.

Cakrt M, Hercegova A, Lesko J, Polonsky J, Sadecka J, Skacani I.

Department of Analytical Chemistry, Faculty of Chemical Technology, Slovak University of Technology, Bratislava, Slovak Republic.

An isotachophoretic method with conductivity detection was developed to determine naproxen in the presence of its metabolite 6-O-desmethylnaproxen in human serum. The leading electrolyte contained 10 mM hydrochloric acid, beta-alanine, pH 4.0 and 0.1% methylhydroxypropylcellulose. The terminating electrolyte was 10 mM 2-(N-morpholino)ethanesulfonic acid-tris(hydroxymethyl)aminomethane, pH 6.9, containing 20% (v/v) of ethanol. Naproxen was determined in serum supernatant after simple deproteination of the sample with ethanol. The isotachophoretic results were compared with those obtained by synchronous fluorescence spectrometry.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11382293&dopt=Abstract Naproxen Naprosyn





J Biochem Biophys Methods. 2001 May 28;48(3):247-56.
Stereoselective synthesis of (S)-(+)-Naproxen catalyzed by carboxyl esterase in a multicompartment electrolyzer.

Cretich M, Chiari M, Carrea G.

Institute of Biocatalysis and Molecular Recognition, CNR, Via Mario Bianco, 9, 20131, Milan, Italy.

The stereoselective hydrolysis of racemic 2-substituted propionates, catalyzed by carboxyl esterase, provides a cost-competitive route to produce the optically pure, anti-inflammatory drug Naproxen. In the present work, we describe the application of the multicompartment electrolyzer reactor (ME) for the stereoselective hydrolysis of a racemic Naproxen ester, (R,S)-ethoxyethyl-[2-(6-methoxy-2-naphtyl)]propionate, catalyzed by a carboxyl esterase.The enzyme was trapped in a reactor chamber, delimited by two isoelectric membranes encompassing the pI value of the enzyme, together with the neutral substrate. After 90 min, a conversion of 45% was obtained with an enantiomeric excess of 84%. The reaction product, (S)-(+)-Naproxen, was electrophoretically removed in continuous from the reaction chamber and collected in a contiguous, more acidic chamber, separated from the enzyme and from the unreacted substrate. Moreover, at the end of the reaction, it was possible to recover the enzyme from the reactor and use it again.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11384761&dopt=Abstract Naproxen Naprosyn





Drug Dev Ind Pharm. 2001 Apr;27(4):287-96.
Naproxen particle design using porous starch.

Nagata K, Okamoto H, Danjo K.

Faculty of Pharmacy, Meijo University, Nagoya, Japan.

Naproxen (Nap) was embedded in porous starch by preferential grinding, and we examined the physicochemical properties of these particles, including pore diameter, pore volume, and dissolution of naproxen. Porous starch (PS) particles made by preferential grinding with a Mechanofusion system had a higher content of naproxen than those made using the Mechanomill as determined using a mercury porosimeter. Neither sample showed any significant changes in crystallization state of naproxen in particles as determined by powder X-ray diffraction and differential scanning calorimetry (DSC). No interactions occurred between naproxen and porous starch due to preferential grinding as determined by powder X-ray diffraction and DSC. The dissolution rate of drug from particles prepared by preferential grinding was faster than that from physical mixtures.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11411896&dopt=Abstract Naproxen Naprosyn





Analyst. 2001 Jun;126(6):917-22.
Determination of naproxen in pharmaceutical preparations by room-temperature phosphorescence. A comparative study of several organized media.

Arancibia JA, Escandar GM.

Departamento de Quimica Analitica, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRL Rosario, Argentina.

Different methods for the determination of naproxen by room-temperature phosphorescence (RTP) using organized media such as cyclodextrins (beta-CD and gamma-CD) and micelles (Triton X-100 and sodium dodecyl sulfate) are reported. The inclusion complexes formed between both beta- and gamma-cyclodextrins and naproxen were previously investigated at both acid and basic pH by spectrofluorimetry. In both cases, 1:1 guest-host stoichiometries were established and the corresponding association constants were calculated. Different systems were examined with the purpose of obtaining phosphorescent emission from naproxen solutions, and the best signals were obtained when naproxen was in the presence of beta-CD-cyclohexane-Tl(I), gamma-CD-1,3-dibromopropane, Triton X-100-Tl(I) and SDS-Tl(I), respectively. In all cases, sodium sulfite was used as deoxygenator. The use of an inorganic compound (thallium nitrate) as a heavy-atom source in a cyclodextrin system represents a novel finding. Surface response optimization approaches were carried out to optimize the chemical variables which have an influence on the RTP emission of naproxen. Based on the results obtained, univariate RTP calibration methods for the determination of the analyte in pharmaceutical preparations were satisfactorily developed. In one case, the standard additions method was applied to a mixture of naproxen and the antibiotic tetracycline.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11445962&dopt=Abstract Naproxen Naprosyn