Enantiospecific disposition of pranoprofen in beagle dogs and rats

Enantioseparation of six profenoid drugs by capillary electrophoresis with bovine serum albumin-modified gold nanoparticles as quasi-stationary phases

Profenoid drugs are a kind of common non-steroidal anti-inflammatory drugs and their chiral enantiomers often have huge differences in pharmacological activities. In this work, a novel chiral separation system by capillary electrophoresis (CE) was constructed using gold nanoparticles (AuNPs) functionalized with bovine serum albumin (BSA) as a quasi-stationary phase (QSP), and the enantioseparation of six profenoid drugs was efficiently accomplished. Under optimal chromatographic conditions, the enantioseparation performance of the AuNP@BSA-based chiral separation system was greatly improved compared with that of free BSA (Resolutions, Ibuprofen: 0.89 → 8.15; Ketoprofen: 0 → 10.02; Flurbiprofen:0.56 → 9.83; Indoprofen: 0.88 → 13.83; Fenoprofen: 0 → 15.21; Pyranoprofen: 0.59 → 5.34). Such high Rs are exciting and satisfying and it is in the leading position in the reported papers. Finally, through molecular docking, it was also found that the difference in binding energy between BSA and enantiomers was closely related to the resolutions of CE systems, revealing the chiral selection mechanism of BSA. This work significantly improves the CE chiral separation performance through a simple strategy, providing a simple and efficient idea for the chiral separation method.

Differential anti-inflammatory and analgesic effects by enantiomers of zaltoprofen in rodents

In the present study, we investigated the effect of zaltoprofen enantiomers on inflammation and pain and compared their effect with racemic zaltoprofen. S(+)-zaltoprofen potently inhibited the inflammatory response in carrageenan-induced paw edema model, whereas R(-)-zaltoprofen did not. Moreover, the anti-inflammatory effect of S(+)-zaltoprofen was stronger than that of racemic zaltoprofen, suggesting that S(+)-zaltoprofen is an active component of racemic zaltoprofen in terms of anti-inflammatory activity. In contrast, the results of acetic acid-induced writhing model demonstrated that no significant analgesic effect was observed by racemic zaltoprofen and zaltoprofen enantiomers at doses used in carrageenan-induced paw edema model. However, racemic zaltoprofen and zaltoprofen enantiomers all exerted an analgesic effect at higher doses, which is inconsistent with the result of carrageenan-induced paw edema model. Gastric ulcers induced by racemic zaltoprofen and zaltoprofen enantiomers were minimal. Taken together, these results suggest that S(+)-zaltoprofen is a potent and active anti-inflammatory component of racemic zaltoprofen, but both S(+)-zaltoprofen and R(-)-zaltoprofen might seem to contribute to the analgesic effect of racemic zaltoprofen.

Chiral pharmacokinetics of zaltoprofen in rats by HPLC with solid-phase extraction

We investigated the pharmacokinetic profile of (R)- and (S)-zaltoprofen (ZPF) in rats using rapid and selective liquid chromatography with solid-phase extraction (SPE). The ZPF enantiomers were extracted from a small volume of plasma (0.2 mL) by means of SPE using cartridges and were analyzed on a Chiralcel OJ-H (4.6 mm × 150 mm, 5 μm) column with ultraviolet detection at 244 nm. The lower limit of quantification of the ZPF enantiomers in plasma was 0.1μg/mL. The validated method was successfully applied to chiral pharmacokinetic studies of oral administration of racemic ZPF to rats. (S)-ZPF showed significantly higher AUC, T(max), and C(max) and a longer half-life than (R)-ZPF, indicating higher bioavailability of the (S)-isomer. A total of 8 samples (about 12% of the total number of samples) were selected for incurred sample reanalysis (ISR). The % difference between the re-assay concentrations and the original concentrations were all less than 15% of their mean values and met the acceptance criteria for ISR.

Biosynthesis and stereoselective analysis of (-)- and (+)-zaltoprofen glucuronide in rat hepatic microsomes and its application to the kinetic analysis

Zaltoprofen, available commercially as a racemic mixture, is a propionic acid derivative of non-steroidal anti-inflammatory drugs (NSAIDs). Firstly, (+)- and (-)-zaltoprofen glucuronide was biosynthesized and purified. Then a simple and rapid RP-HPLC analysis method for direct determination of (+)- and (-)-zaltoprofen glucuronide in rat hepatic microsomes was developed and validated. The calibration curves of (+)- and (-)-zaltoprofen glucuronide both showed good linearity in the concentration range from 0.15 to 31.13 μM. The lower limit of quantification was 0.15 μM. Finally, this method was used to investigate the enantioselectivity of zaltoprofen glucuronidation in rat hepatic microsomes. The kinetics of zaltoprofen glucuronidation in rat hepatic microsomes for 40 min incubation fit the Michaelis-Menten model. Kinetic analysis indicated that (-)-zaltoprofen had a higher glucuronidation rate in rat liver microsome than that of (+)-zaltoprofen. The catalyzing efficiency (V(max)/K(m)) ratio of (+)-zaltoprofen to (-)-enantiomer is 0.8 times in rat liver microsomes.

Enantioselective Pharmacokinetics of Ibuprofen and Involved Mechanisms

Although dexibuprofen (S-ibuprofen) was marketed in Austria and Switzerland, the racemate at various formulations is still extensively used worldwide, and there are no indications that the racemate will be replaced by the single enantiomer. Thus, elucidation of the characteristics and involved mechanisms of the chiral pharmacokinetics of racemic ibuprofen is of special importance for the understanding of the pharmacological and toxicological consequences, and for prediction of the clinically potential drug interactions and influence of the pathological states. Stereoselective pharmacokinetics and metabolism are common features for chiral nonsteroidal antiinflammatory drugs (NSAIDs) and especially for 2-arylpropionic acid derivatives characterized with a chiral center adjacent to the carboxyl group. Although the enantioselective pharmacokinetic characteristics of different NSAIDs should be treated case by case, they share similar mechanisms underlying the protein binding, metabolism and chiral inversion. Ibuprofen was the most extensively researched drug in terms of chiral characteristics and mechanisms. Therefore, elucidation of the mechanisms derived from research on ibuprofen may provide better understanding and prediction of other chiral drugs. This article attempts to elucidate the chiral pharmacokinetics and involved mechanisms of ibuprofen in comparison with other NSAIDs based on recent developments. Topics on history of ibuprofen, enantioselective analysis method, absorption, protein binding, conventional metabolism, metabolic chiral inversion, gene polymorphism, and biochemical developments were included. It is worth mentioning that some underlying biochemical mechanisms, especially for the metabolic chiral inversion and ethnic differences still remain to be seen. Further research is required to develop human-resourced researching model and to provide more evidence concerning the site of inversion, species variation, CYP450 gene polymorphisms, and biochemical mechanisms.