Ibuprofen solution

Sample preparation Condition an Analytichem AASP propylbenzenesulfonic acid (SCX) SPE cartridge with isopropanol at 4 mL/min for 1.5 min and with mobile phase at 4 mL/min for 2 min. 100 p-L Ibuprofen solution in dichloromethane + 100 pL 500 pg/mL... 

Sample preparation Condition an Analytichem AASP propylbenzenesulfonic add (SCX) SPE cartridge with isopropanol at 4 mL/min for 1.5 min and with mobile phase at 4 mL/min for 2 min. 100 fjiL Ibuprofen solution in dichloromethane + 100 iL 500 jig(mL 2-phenylpropionic acid in dichloromethane + 200 jI< 100 mM triethylamine in dichloromethane + 100 j,L 60 mM ethyl chloroformate, vortex for 15 s, let stand for 15 min, add 100 p.L 500 mM p-anisidine in dichloromethane, vortex for 15 s, let stand for 5 min, add 600 p.L isopropanol hexane 10 90, vortex for 15 s, add a 25 (lL aliquot to the SPE cartridge, elute the contents of the SPE cartridge onto the analytical column with mobile phase, after 2.43 min remove the SPE cartridge from the circuit, elute the analytical column with mobile phase and monitor the efduent from the column. 

Electropherograms of a urine sample (8 ml) spiked with non-steroidal anti-inflammatory drugs (10 p-g/ml each) after direct CE analysis (b) and at-line SPE-CE (c). Peak identification is as follows I, ibuprofen N, naproxen K, ketoprofen P, flurbiprofen. Reprinted from Journal of Chromatography, 6 719, J. R. Veraait et al., At-line solid-phase exti action for capillary electrophoresis application to negatively charged solutes, pp. 199-208, copyright 1998, with permission from Elsevier Science. 

Encapsulation of small drugs in M S has also been demonstrated by a similar strategy [68]. In that work, the MS spheres were loaded with ibuprofen and then encapsulated within eight layers of PAH and PSS on the particle surface to cap the mesopore openings [68]. The encapsulated drug molecules were subsequently released from the MS particles under the influence of solution pH and salt concentration. 

Part of the sample was soaked in a solution of ibuprofen in pentane (33 mg/ml) for 2 hours at room temperature, before being immersed in 30 ml of stirred SBF kept at 37°C (referred to as MCM-41-IBU). The remaining aliquot, used as reference, was soaked directly in SBF (MCM-41-REF). 

Changes in the releasing properties of MCM-41 spheres loaded with ibuprofen are not ascribable either to the morphology, as SEM pictures show the same spherical shape before and after the contact with the SBF solution, or to structural phenomena, because XRD patterns are the same even after 170 hours of contact with SBF. 

The sample tube of the polarimeter is rinsed with the drug solution (2.5% w/v) and filled up with the same solution. The end glass-windows are closed properly. The angle of rotation of ibuprofen is now measured at 19.5° to 20.5°, using the D-line of polarized sodium light. Take at least five measurements and determine the mean value. 

Osmolarity of perfusate solution The buffer osmolarity should be standardised to facilitate estimation of Peff values. Generally adjusted to physiological conditions of 290 mOsm/kg. (70 mM phosphate buffer) with 5.4 mM potassium chloride, 48 mM sodium chloride, 35 mM mannitol, and 10 mM D-glucose. Lane et al. [131] demonstrated the effect of hypersomolar perfusion on Tapp of ibuprofen in the in situ rat gut technique. Hypersomolar solutions tended to decrease Peff values, attributable to a reversed solvent drag effect. 

Pharmaceutical grade ibuprofen, pseudoephedrine HCl, chlorpheniramine maleate, nipagen and syrup preparation were kindly supplied by Berko tlag Sanayi A. , Istanbul. 0.03 M H PO and KH PO solutions were prepared with analytical grade chemicals and milliQ water. HPLC grade acetoiutrile was used. 

Standard drag stock solutions (5,000 ppm for ibuprofen and 1,000 ppm for other drags) were prepared in water-acetoiutrile (50 50). 

Appropriate amount of stock solutions were mixed and diluted with water-acetonitrile (50 50) to obtain the final concentration of 1,000, 150, 10 and 50 ppm for ibuprofen, pseudoephedrine HCl, chlorpheniramine maleate and nipagen. 

The immobilized lipase (0.1 g) in pH 7 phosphate buffer (25 mL) was added to 25 mL (20 mM) of ester stock solution in a 250 mL Erlenmeyer flask (reaction flask). The reaction flask was incubated in an incubator shaker at 40 °C with the agitation speed set to 200 rpm. Samples from the organic phase and aqueous phase were withdrawn at 24 h intervals over a 5-day reaction period. The samples collected were filtered using 0.45 pm nylon filter and injected into the HPLC system to determine the rate of resolution by monitoring both substrate ((/ ,5)-2-ethoxyethyl ibuprofen ester) and product (5-ibuprofen acid concentration). 

To isooctane (25 mL) was added (7 ,5)-ibuprofen ester (0.27 g, 40 mM), 0.5 m sodium hydroxide (25 mL) and immobilized lipase (0.2 g). The reaction medium consisted of two layers of solution, namely ibuprofen ester in isooctane and aqueous NaOH, where the reaction only occurred at the interface between these two layers. The mixture was agitated in an orbital shaker at constant temperature of 45 °C and at 200 rpm. 

Scaiano and coworkers designed the two new photoremovable protecting groups 27 and 28, based on ketoprofen 25. Photolysis of 27 in aqueous solutions releases ibuprofen in quantum yields of 0.75 (Scheme 19). Furthermore, the rate constant for the release of ibuprofen from 27 was measured to be 5 x 10 s Thus, 27 can release ibuprofen both rapidly and in high quantum yields. 

Dissolve sucrose, Kollidon 90 F and sodium citrate in about 40 ml of water, suspend Kollidon CL-M and ibuprofen in this solution by stirring and add the rest of water. 

Dissolve Lutrol F 68 and the preservative in water II and ibuprofene in Cremophor RH 40 (I). Add the solution II slowly to the ibuprofene-Cremophor RH 40 mixture I whilst stirring. 

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