LC-MS/MS quantitation of plasma progesterone in cattle

LC-MS/MS Method for Rapid Quantification of Progesterone in Rabbit Plasma and Its Application in a Pharmacokinetic Study of the Transdermal Formulation

A rapid and effective method using QuEChERS-based sample preparation procedure and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis has been developed and validated to determine progesterone in rabbit plasma. The analyte was extracted from plasma by acetonitrile with phase partitioning by a mixture of magnesium sulfate and sodium chloride. The supernatant was then directly injected into LC-MS/MS in a positive electrospray ionization mode and quantified using progesterone-d9 as the internal standard. The method linearity was in the range from 1 ng/mL (LOQ) to 200 ng/mL. Method recovery was from 86.0% to 103%, and repeatability was lower than 5.5%. The plasma sample was stable for 12 weeks stored at 18 ± 2°C. This method was applied to quantify progesterone in rabbit plasma in a pharmacokinetic study of two transdermal formulations: a reference drug and a eutectic-hydrogel system. The data indicate that the eutectic-hydrogel system's bioavailability was 1.5 times better than that of the reference drug, and the transdermal system is a potential drug delivery system for progesterone.

Evaluation of two chemiluminescent assays compared with radioimmunoassay for serum progesterone measurement in bitches

Serum progesterone (sP4) measurement is commonly used to determine the optimal time for mating in bitches, and to diagnose reproduction-related abnormalities. Radioimmunoassay (RIA) is the gold standard assay, but is becoming less available, and has several practical disadvantages. Chemiluminescence immunoassays (CLIA) are commonly used in human medicine for sP4 measurement, and are becoming more available in veterinary medicine. Our objective was to compare the sP4 results obtained by RIA and two CLIA systems (Immulite-Siemens [IS-CLIA] and Elecsys-Roche [ER-CLIA]) in the same sera in 60 client-owned healthy bitches at different estrous cycle stages. The agreement between the two CLIAs and RIA was examined using the Passing-Bablok regression and Bland Altman plots. Comparing sP4 concentrations measured by the IS-CLIA to the RIA yielded an intercept of 0.16 ng/mL (95% confidence interval [95%CI], 0.03-0.25) with a slope of 0.45 (95%CI, 0.44-0.47) and a median difference of -2.10 ng/mL (P < 0.0001) that was strongly correlated to the average of measurements (r = -0.97; P < 0.0001). Comparing sP4 concentrations measured by the ER-CLIA to the RIA yielded an intercept of -0.23 ng/mL (95%CI, -0.56 to -0.09) with a slope of 1.06 (95%CI, 1.00-1.12) and a median difference of -0.09 ng/mL (P = 0.9), that was weakly correlated to the average of measurements (r = 0.34; P = 0.018). The performance of the ER-CLIA was similar to the RIA, while the IS-CLIA showed significantly different results compared to the RIA. Our study supports the conclusion that sP4 results generated by the ER-CLIA can be used interchangeably with RIA results for clinical purposes, while IS-CLIA results require adjustment to RIA results for clinical practice.

Rapid simultaneous determination of 160 drugs in urine and blood of livestock and poultry by ultra-high-performance liquid chromatography-tandem mass spectrometry

In order to address the specific question of food safety in livestock and poultry, it is imperative to monitor veterinary drugs at every moment in the process of livestock and poultry breeding. Thus, multi-residue analysis of a wide variety of drugs using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) has become a tool of critical significance, especially for veterinary drug monitoring programs. A total of 160 compounds, belonging to 17 different families of veterinary drugs, were investigated in the urine and blood of livestock and poultry. Drug samples were extracted using a slightly acidic acetonitrile solution. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) preparation method, combined with dispersive solid phase extraction (d-SPE) was compared with the approach of solid phase extraction (SPE). In the end, the QuEChERS extraction procedure was selected to reduce matrix effects and efficiently extract target veterinary drugs, and d-SPE was applied as a cleanup step. Electrospray ionization coupled with positive dynamic multiple reaction monitoring (dMRM) was utilized for the analysis of 160 different drugs in a single chromatographic run of 24 min. The efficiency of this method was evaluated using 7 matrices (pig blood, cattle blood, sheep blood, chicken blood, pig urine, cattle urine, and sheep urine). Good linearity was obtained for the analytes in a concentration range of 1-100 ng/mL, with correlation coefficients higher than 0.990. Most of the 160 drugs studied gave estimated limits of detection (LOQs) of 1 ng/mL, with some LOQs reaching as much as 5 ng/mL. The mean recoveries at four spike-in levels of 1, 5, 10, and 50 ng/mL, ranged from 60% to 120%. The intra-day precision measurements had coefficients of variation (n = 6) <15%, and the inter-day precision measurements were below 25%. Our method was applied in real samples and proved to be adequate for routine analysis. The proposed method proved to be simple, rapid and reliable for monitoring 160 drugs in the urine and blood of livestock and poultry, and can also be used for food safety monitoring.

Total glycosides of Paeony shows Neuroprotective effects against Semen Strychni-induced neurotoxicity by recovering secretion of hormones and improving brain energy metabolism

In this study, we investigated the protective effect of total glycosides of paeony against Semen Strychni-induced neurotoxicity and discussed some probably mechanisms. Levels of estrone, estradiol, estriol and growth hormone in male rats' serum were determined by ELISA, levels of ATP and substances associated with energy metabolism in rats' brain were determined by HPLC and levels of progesterone was determined by a UPLC-MS/MS method. The results showed that neurotoxicity induced by Semen Strychni could cause a significant decrease (p < 0.05, compare to the blank group) in secretion of estrogens and GH and disorder brain energy metabolism at the same time. While, rats with total glycosides of paeony pre-protection (orally administrated with total glycosides of paeony for 15 days before administrating Semen Strychni extract) showed a much better condition in the secretion of hormones and brain energy metabolism, and showed no significant changes in most of those associated substances when comparing to the blank group. Our study indicated that total glycosides of paeony have neuroprotective effects on Semen Strychni-induced neurotoxicity. It could recover the disordered hormone secretion and improve the brain energy metabolism. Total glycosides of paeony is potential to be further used in clinic to protect against neurotoxicity induced by other reasons.

Injectable Sustained-Release Depots of PLGA Microspheres for Insoluble Drugs Prepared by hot-Melt Extrusion

PURPOSE

Progesterone (PRG) was selected as a model drug to develop a long-acting injection system for poorly water-soluble drugs.

METHODS

Microspheres with high density-low porosity were prepared by hot-melt extrusion (HME) combined with wet-milling as the representative formulation, and a microcrystal suspension was also studied as a comparison. The morphology, particle size and distribution, polymorphism, drug distribution, density and porosity were characterized by scanning electron microscopy, laser diffraction particle size analyzer, power X-ray diffraction and DSC respectively. The in vivo performance of the different formulations within 7 days after intramuscular injection was evaluated in male SD rats.

RESULTS

The drug-loading rate of the microspheres could be as high as 40%. The average initial burst release of the microspheres (PLGA lactide:glycolide = 75:25) was only 6.7% much lower than that of the microsuspension (25.7%) and a sustained release was exhibited for at least 7 days. The release mechanism was speculated to be as follows. The microspheres are a drug depot with drug microcrystals in the PLGA matrix which is a layer by layer honeycomb structure.

CONCLUSIONS

Microspheres prepared by HME combined with wet-milling could achieve a long-term sustained release effect as a novel long-acting formulation strategy.

Method Validation for Progesterone Determination in Poly(methyl methacrylate) Nanoparticles Synthesized via Miniemulsion Polymerization

Exogenous progesterone has several applications in human health and in veterinary medicine, especially in fixed-time artificial insemination protocol. Progesterone nanoencapsulation in biocompatible polymers, such as poly(methyl methacrylate) (PMMA), is an alternative to substitute silicone-based release device traditionally used for estrus control. Progesterone concentration inside the nanoparticles must be precisely known; for that reason, a validation methodology must be applied to ensure reliable results, suitable for nanoparticles application. In this work, an UV-Vis spectrophotometric method was validated for the determination of progesterone in PMMA nanoparticles synthesized by miniemulsion polymerization. Chloroform was used as solvent, showing selectivity to the encapsulated drug and the components of the polymeric matrix did not influence progesterone recovery. Detection and quantitation limits (DL and QL) obtained were 0.32 and 0.96 mg·L−1, respectively, and precision tests (between different analysts and equipment) indicated acceptable Relative Standard Deviations (RSD < 5%). Miniemulsion polymerization reactions were carried out producing two different morphologies: nanospheres (NS) and nanocapsules (NC), with average intensity diameters (Dz) of 150–200 nm and 240–300 nm, respectively. Polymerization gravimetric conversions obtained for both cases were higher than 95% and encapsulation efficiencies greater than 69% and 90% for the nanospheres and nanocapsules, respectively.

Laboratory and Clinical Evaluation of a Feia Method for Canine Serum Progesterone Assay

The evaluation of progesterone (P4) concentration is a valuable tool in assessing physiological reproductive events and reproductive disorders in bitches. A reliable and rapid (preferable, point of care) determination of P4 is advisable in most cases. Aims of this study were to evaluate a fluorescence enzyme immunoassay (FEIA) for canine serum P4 concentration by (i) the agreement with liquid chromatography-tandem mass spectrometry (LC/MS/MS), (ii) the association with vaginal cytology and (iii) the accuracy in the prediction of the parturition date calculated from the estimated day of ovulation. Serum samples were collected from client-owned bitches presented between 2011 and 2014 for the evaluation of their oestrous cycle, pregnancy or reproductive disorders. The agreement between FEIA and LC/MS/MS, evaluated on 19 samples, was statistically significant (R(2) = 95.7%, p < 0.001), although FEIA showed significantly higher values than LC/MS/MS (p < 0.05). In the different phases of oestrous cycle, as determined by vaginal cytology, P4 concentrations (by FEIA) were statistically different (p < 0.05): anoestrus (n = 7) 0.38 ± 0.14 ng/ml, proestrus (n = 14) 1.04 ± 0.67 ng/ml and oestrus (n = 72) 6.8 ± 7.26 ng/ml. Mean pregnancy length from the estimated day of ovulation was 62.9 ± 1.8 days. In 13 of 22 (59.1%), 19 of 22 (86.3%) and 21 of 22 (95.5%) bitches pregnancy lasted 63 ± 1, 63 ± 2 and 63 ± 3 days, respectively. Three pregnancies were outside the 61-65 days range (60, 60 and 67 days). In conclusion, the FEIA method employed can be considered reliable and, in association with vaginal cytology, effective in evaluating the canine oestrous cycle.