Monitoring ibuprofen enantiomers released from polymeric systems.
Two methacrylic derivatives of ibuprofen (N-[4-[2-(4-isobutylphenyl)propionyloxy]phenyl] methacrylamide (MAI) and 2-[(4-isobutylphenyl)propionyloxy]ethyl methacrylate (MEI)) were used together with 2-hydroxyethyl methacrylate (HEMA) to synthesize four polymeric materials: two hydrophobic homopolymers, PMAI and PMEI, and two hydrophilic copolymers containing 70% (w/w) HEMA, MAI-HEMA 30 and MEI-HEMA 30. The enantiomeric determination of R- and S-IBU released from these four systems has been carried out by capillary electrophoresis. Release of R- and S-IBU was monitored during in vitro assays done at 37 degrees C at pH 7.4 and 10 in buffered solutions and rat plasma. There is a hydrolytical activation in plasma and at pH 10 compared to pH 7.4; moreover, the release rate from the copolymers is much higher than from the homopolymers as a consequence of the greater hydrophilic character. A slight excess of the S-enantiomer of IBU is observed in all the experiments, being more relevant at higher release rates, i.e. copolymers at pH 10.
Instituto de Fermentaciones Industriales (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain.
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Simó
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Gallardo
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Parejo
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San Román
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Barbas
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Cifuentes
D000818:Animals; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D019075:Electrophoresis, Capillary; D006863:Hydrogen-Ion Concentration; D007052:Ibuprofen / Q000737:chemistry*; D066298:In Vitro Techniques; D008297:Male; D008689:Methacrylates / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D013237:Stereoisomerism; D013997:Time Factors
C472506:2-((4-isobutylphenyl)propionyloxy)ethyl methacrylate; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D008689:Methacrylates; C104743:N-(4-(2-(4-isobutylphenyl)propionyloxy)phenyl)methacrylamide; D011108:Polymers; C005044:hydroxyethyl methacrylate; D007052:Ibuprofen