Determination of oxaceprol in rat plasma by LC–MS/MS and its application in a pharmacokinetic study

Development and characterization of oxaceprol-loaded poly-lactide-co-glycolide nanoparticles for the treatment of osteoarthritis

Oxaceprol is well-defined therapeutic agent as an atypical inhibitor of inflammation in osteoarthritis. In the present study, we aimed to develop and characterize oxaceprol-loaded poly-lactide-co-glycolide (PLGA) nanoparticles for intra-articular administration in osteoarthritis. PLGA nanoparticles were prepared by double-emulsion solvent evaporation method. Meanwhile, a straightforward and generally applicable high performance liquid chromatography method was developed, and validated for the first time for the quantification of oxaceprol. To examine the drug carrying capacity of nanoparticles, varying amount of oxaceprol was entrapped into a constant amount of polymer matrix. Moreover, the efficacy of drug amount on nanoparticle characteristics such as particle size, zeta potential, morphology, drug entrapment, and in vitro drug release was investigated. Nanoparticle sizes were between 229 and 509 nm for different amount of oxaceprol with spherical smooth morphology. Encapsulation efficiency ranged between 39.73 and 63.83% by decreasing oxaceprol amount. The results of Fourier transform infrared and DSC showed absence of interaction between oxaceprol and PLGA. The in vitro drug release from these nanoparticles showed a sustained release of oxaceprol over 30 days. According to cell culture studies, oxaceprol-loaded nanoparticles had no cytotoxicity with high biocompatibility. This study was the first step of developing an intra-articular system in the treatment of osteoarthritis for the controlled release of oxaceprol. Our findings showed that these nanoparticles can be beneficial for an effective treatment of osteoarthritis avoiding side effects associated with oral administration.

Development of a hydrophilic interaction chromatography-UPLC assay to determine trigonelline in rat plasma and its application in a pharmacokinetic study

AIM

Trigonelline (Tr) is the second most abundant alkaloid in coffee beans. This study developed an assay combining hydrophilic interaction chromatography with ultra performance liquid chromatography (HILIC-UPLC) for the quantification of Tr in rat plasma to determine its pharmacokinetic behavior.

METHODS

After the administration of Tr by gavage as well as intravenous injection and that of methanol extract of coffee beans (MECB) orally, blood samples from the experimental rats were analyzed using the HILIC-UPLC assay. Pharmacokinetic parameters were determined using the standard non-compartmental method and calculated using Practical Pharmacokinetic Program Version 87/97.

RESULTS

The HILIC-UPLC assay was validated with the linear range of 0.12-100 μg·mL(-1) and a lower limit of quantitation of 0.12 μg·mL(-1). Its accuracy, precision, recovery, and stability were within acceptable limits. The AUC(0-∞) (where AUC is the area under the plasma concentration-time curve) values were determined to be (4 066.83 ± 1 244.41) and (3 544.29 ± 908.80) min·μg·mL(-1) after Tr was orally and intravenously administered, respectively. It was (4 566.75 ± 1 435.64) min·μg·mL(-1) after MECB was orally administered. The absolute bioavailability of Tr alone reached 57.37%, whereas that of Tr in MECB was 64.42%. The relative bioavailability of the alkaloid was 112.29%.

CONCLUSIONS

The HILIC-UPLC assay for Tr determination is simple and accurate, and also exhibits good reproducibility. The bioavailability of stand-alone Tr and that of Tr in MECB were both good. Tr alone and that in MECB orally administered did not exhibit any significant difference.

UPLC-MS/MS determination and pharmacokinetic study of 26-OH-panaxadiol in rat plasma

Dammar-20S, 25R-epoxy-3β, 12β, 26-triol (26-OH-panaxadiol), the new sapogenin product of the oxidative cyclization of protopanaxadiol from ginseng, exhibits a significant pharmacological effect as an anti-tumor agent. A sensitive and rapid analytical method based on ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) was initially developed for the detection of 26-OH-panaxadiol in rat plasma. Pre-treatment of the sample obtained from the plasma involved a single protein precipitation step using methanol. 26-OH-panaxadiol and an internal standard (IS), tanshinone II A, were separated on a Waters ACQUITY UPLC BEH C₁₈ analytical column (50 mm × 2.1 mm, 1.7 μm) using acetonitrile-0.1% formic acid in water (80 : 20, v/v) as the mobile phase, at a flow rate of 0.3 mL min^-1. Chromatography of the 26-OH-panaxadiol and IS was performed within 3 minutes. Detection was performed through positive ion electrospray ionization (ESI⁺) in multiple reaction monitoring (MRM) mode. The assay was linear over the concentration range of 1-1000 ng mL^-1 (r > 0.9960). The limit of detection (LOD) and the lower limit of quantification (LLOQ) were 0.3 ng mL^-1 and 1.0 ng mL^-1, respectively. The intra- and inter-day deviations (expressed as relative standard deviation, RSD) were ≤4.8% and ≤8.5%, respectively, and the accuracy (expressed as relative error, RE) was in the range of 4.5% to 5.3%. The recoveries of 26-OH-panaxadiol and IS were 91.2% and 98.7%, respectively, and the matrix effects were satisfactory in all of the biological matrices examined. This fully validated method was successfully applied to the pharmacokinetic study of rats after a single initial intragastric administration of 15 mg kg^-1 26-OH-panaxadiol. The main pharmaco-kinetic parameters: T_max (the time to peak), C_max (the concentration to peak), and t_1/2 (the biological half life) were 3.08 ± 1.24 h, 2833.86 ± 1246.08 μg L^-1, 5.14 ± 1.01 h, respectively.

Determination of Pseudoginsengenin DQ in rat plasma by UPLC-MS/MS and application of the method in a pharmacokinetic study

Pseudoginsengenin DQ (pseudoginsengenin of diol derivatives quest, PDQ), the product of the oxidative cyclization of protopanaxadiol, exhibits a significant pharmacological effect as an antiarrhythmic agent. A sensitive and rapid analytical method based on ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) was initially developed for the detection of PDQ in rat plasma. Pre-treatment of the sample obtained from the plasma involved a single protein precipitation step, using methanol. PDQ and an internal standard (IS), physcion, were separated on a Waters ACQUITY UPLC BEH C18 analytical column (50mm×2.1mm, 1.7μm) using acetonitrile-0.1% formic acid in water (70:30, v/v) as the mobile phase, at a flow rate of 0.3mL/min. Chromatography of the PDQ and IS was performed within 3min. Detection was performed through positive ion electrospray ionization (ESI(+)) in multiple reaction-monitoring (MRM) mode. The assay was linear over the concentration range of 5-1000ng/mL (r>0.9980). The limit of detection (LOD) and the lower limit of quantification (LLOQ) were 0.5ng/mL and 5.0ng/mL, respectively. The intra- and inter-day deviations (expressed as relative standard deviation, RSD) were ≤9.5% and ≤1.7%, respectively, and the accuracy (expressed as relative error, RE) was in the range of -1.1 to 2.7%. The recoveries of PDQ and IS were 95.2% and 100.7%, respectively, and the matrix effects were satisfactory in all of the biological matrices examined. This fully validated method was successfully applied to the pharmacokinetic study of rats after a single initial intragastric administration of 15mg/kg PDQ. The main pharmacokinetic parameters: Tmax (the time to peak), Cmax (the concentration to peak), and t1/2 (the biological half time) were 4.0±0.0h, 3265.12±700.26ng/mL, 5.97±0.43h, respectively.