A randomized, double-blind, placebo-controlled, phase IIa, clinical study on investigating the efficacy and safety of SPH3127 tablet in patients with essential hypertension.

Around 70% of patients diagnosed with hypertension exhibit increased levels of renin. SPH3127, an inventive renin inhibitor, has shown favorable tolerability and sustained pharmacodynamic inhibitory impact on plasma renin activity (PRA) during previous phase I trials. This phase II study was conducted to investigate the efficacy and safety of SPH3127 in patients with essential hypertension. This study was conducted in patients with mild to moderate essential hypertension, utilizing a randomized, double-blind, placebo-controlled design. The patients were administered either tablet of SPH3127 at doses of 50 mg, 100 mg, or 200 mg, or a placebo. A total of 122 patients were included in the study, with 121 patients included in the full analysis set. Among these patients, there were 30 individuals in each subgroup receiving different dosage regimens of SPH3127, and 31 patients in the placebo group. The reductions in mean sitting diastolic blood pressure (msDBP) after 8 weeks compared to baseline were 5.7 ± 9.5, 8.6 ± 8.8, and 3.8 ± 10.6 mmHg in the SPH3127 50-, 100-, and 200 mg groups, respectively. In the placebo group, the reduction was 3.1 ± 8.4 mmHg. The corresponding reductions in mean sitting systolic blood pressure (msSBP) were 11.8 ± 13.0, 13.8 ± 11.2, 11.1 ± 13.1, and 7.7 ± 9.7 mmHg in each respective group. SPH3127 is a promising drug for the treatment of patients with essential hypertension. The recommended dosage is 100 mg daily.Clinical trial registration: This study was registered in ClinicalTrials.gov (NCT03756103).

Simultaneous determination of three triterpenes in rat plasma by LC-MS/MS and its application to a pharmacokinetic study of Rhizoma Alismatis extract.

We have developed a sensitive and specific LC-MS/MS method for the simultaneous determination of alisol A (A), alisol A 23-acetate (A23) and alisol A 24-acetate (A24), the major active components in Rhizoma Alismatis extract (RAE), in rat plasma. In brief, plasma samples were extracted by methyl tert-butyl ether and chromatographically separated by using a C18 column. A tandem mass spectrometric detection with an electrospray ionization (ESI) interface was conducted via multiple reaction monitoring (MRM) under positive ionization mode. This method was validated for specificity, linearity, accuracy (within ±15.4%), intra- and inter-day precision (CV<11.4%) over the concentration range of 25-5000ng/mL for A, and 5-1000ng/mL for both A23 and A24. The significantly lower detection limit was determined as 25ng/mL for A, 5ng/mL for A23 and A24. This validated method of ours was then used to study the pharmacokinetics of RAE in rat. The elimination half-lives (t1/2) of A, A23 and A24 was determined as 0.75, 0.83 and 0.82h respectively after intravenous injection, and the oral absolute bioavailability of A, A23 and A24 was 43.1±18.1%, 6.3±1.5% and 7.9±1.2%. This new determination method of us for alisols is proven to very useful to study the pharmacological activities of RAE in future.

Normal-phase liquid chromatography coupled with electrospray ionization mass spectrometry for chiral separation and quantification of clevudine and its enantiomer in human plasma.

A new, simple and enantioselective normal-phase liquid chromatography-mass spectrometry method was presented for the quantification of clevudine and its enantiomer in human plasma. A C18 cartridge was used in this method to extract the enantiomers in 200µL plasma followed by a chiral separation on a cellulose-based LC column with mobile phase consisted of hexane, methanol and ethanol (62:28:10, V/V/V). The eluate was directed to a mass spectrometry through an electrospray ionization interface. A transition of m/z 261.0 to m/z 126.8 was used for monitoring of clevudine and its enantiomer. This method showed good linearity (R>0.997), precision (<9.6%) and accuracy (within 95.48-105.9%) within a range of 10-1000ng/mL for the enantiomers and has been applied to the pharmacokinetics study of clevudine capsules in human plasma.

Simultaneous determination of ipratropium and salbutamol in rat plasma by LC-MS/MS and its application to a pharmacokinetic study.

A novel, sensitive and specific LC-MS/MS method with silica-based solid-phase extraction was developed for simultaneous determination of ipratropium (IPR) and salbutamol (SAL) in rat plasma. Chromatographic separation was achieved on a Shiseido Capcell Pak CR column (SCX:C(18)=1:4, 150 mm × 2.0 mm, 5 µm) with a mobile phase consisting of methanol/water (85:15, v/v) containing 20 mmol/L ammonium formate and 0.1% formic acid at a flow rate of 0.3 mL/min. A tandem mass spectrometric detection with an electrospray ionization (ESI) interface was conducted via multiple reaction monitoring (MRM) under positive ionization mode. This method was validated in terms of specificity, linearity, accuracy (within ±115.4%), intra- and inter-day precision (<11.4%) over the concentration range of 8-1612 pg/mL for IPR and 50-10,000 pg/mL for SAL. In addition, stability and matrix effects of IPR and SAL in plasma were evaluated. This method has been successfully applied to the pharmacokinetic study of compound ipratropium bromide aerosol mainly containing ipratropium bromide (IB) and salbutamol sulphate (SS) after inhalation in rats.

Simultaneous determination of lamivudine, stavudine and nevirapine in human plasma by LC-MS/MS and its application to pharmacokinetic study in clinic.

A new high-throughput LC-MS/MS method for the simultaneous determination of lamivudine (3TC), stavudine (d4T) and nevirapine (NVP) in human plasma is presented, with zidovudine as an internal standard. The analytes were extracted from plasma by protein precipitation and only 150 microL plasma was needed. Chromatographic separation was achieved on a Shiseido C(8) column (150 x 2.0 mm, 5 microm) with a total run time of 6 min. A tandem mass spectrometric detection was conducted using multiple reaction monitoring under positive ionization mode with an electrospray ionization interface. The method was developed and validated over the concentration range of 25-5000 ng/mL for 3TC and NVP and 20-4000 ng/mL for d4T. The method was validated in terms of intra- and inter-day precision (< or = 8.6%), accuracy (within +/- 8.4%), linearity and specificity. The method has been successfully applied to the pharmacokinetic study of a combination treatment of 300 mg lamivudine, 30 mg stavudine and 200 mg nevirapine in 22 healthy male volunteers under fasting conditions.

[Simultaneous determination of gestodene, etonogestrel and ethinylestradiol in plasma by LC-MS/MS following derivatization].

To establish a sensitive and specific method for simultaneous determination of gestodene, etonogestrel and ethinylestradiol in plasma by LC-MS/MS, plasma samples were extracted and derivatized before injection. An ESI ion source was used and operated in the positive ion mode with multiple reaction monitoring (MRM). Norgestrel was chosen as internal standard and performed on a C18 (100 mm x 2.1 mm, 5 microm) column. The concentrations of gestodene, etonogestrel and ethinylestradiol were measured, using step-gradient mobile phase and step-gradient flow rate. The method was validated over the concentration range of 0.1-20 ng x mL(-1) for gestodene and etonogestrel and 0.01-2 ng x mL(-1) for ethinylestradiol, and showed excellent linearity. The intra- and inter-assay accuracy and precision were below 10.0% and recovery was 93.6%-110.9% over the three concentration levels evaluated. The method was applied in pharmacokinetic study of the compound gestodene patch and the compound etonogestrel patch in rabbits. The LC-MS/MS method was selective, accurate and sensitive, especially the LOQ were 100 pg x mL(-1) for gestodene and etonogestrel and 10 pg x mL(-1) for ethinylestradiol. The method was successfully applied in pharmacokinetic study for contraceptives.

Determination of norelgestromin in rabbit plasma by LC-MS/MS and its application to the pharmacokinetic study of ORTHO EVRA.

A simple, sensitive and rapid method is presented for the determination of norelgestromin using LC-MS/MS, interfaced via an electrospray ionization (ESI) probe, operating in the positive ion mode with multiple reaction monitoring (MRM). The method was developed and validated over the concentration range of 0.05-20 ng/ml, and showed excellent linearity. The intra- and inter-assay accuracy error and precision were ranging from -2.3% to 6.0% of nominal values and 2.2% to 7.8% over the three concentration levels evaluated. The concentration of formic acid in mobile phase was optimized to achieve satisfactory injection reproducibility and sensitivity, and sample preparation was optimized, with only 1.6 ml organic solvents used in performing the liquid-liquid extraction. The method has been successfully applied to a pharmacokinetic study of the ORTHO EVRA patch in rabbits.

Simultaneous determination of ginkgolides A, B, C and bilobalide in plasma by LC-MS/MS and its application to the pharmacokinetic study of Ginkgo biloba extract in rats.

A new liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of ginkgolides (includes ginkgolide C for the first time) and bilobalide in plasma is presented. Ketoprofen was used as an internal standard, and sample pre-treatment consisted of a liquid-liquid extraction. Chromatographic separation was achieved on a 5 microm Shiseido C8 column (150 mm x 2.0 mm i.d., particle size 5 microm) with a mobile phase consisting of methanol/ 6 mM ammonium acetate (60/40, v/v) at a flow rate of 0.3 ml/min. A tandem mass spectrometric detection was conducted using multiple reaction monitoring (MRM) under negative ionization mode with an atmospheric pressure chemical ionization (APCI) interface. The method was validated in terms of intra- and inter-day precision (<12.7%), accuracy (within +/- 7.0%), linearity, specificity and stability. In addition, matrix effects of ginkgolides and bilobalide in plasma were evaluated in different reconstitution solvents. Smaller matrix effects were observed for reconstitution solvents containing less organic solvent. The method has been successfully applied to a pharmacokinetic study of Ginkgo biloba extract in rats after intravenous administration. This is the first report of pharmacokinetic data for ginkgolide C.

Simultaneous determination of metformin and glipizide in human plasma by liquid chromatography-tandem mass spectrometry.

A method has been developed for the simultaneous quantification of metformin (I) and glipizide (II) in human plasma. It is based on high-performance liquid chromatography with electrospray ionization tandem mass (LC-ESI-MS/MS) spectrometric detection in positive ionization mode. Phenformin (III) and gliclazide (IV) were used as internal standards for I and II, respectively. The MS/MS detection was performed in multiple reaction monitoring (MRM) mode. The precursor-product ion combinations of m/z 130 --> 71, 446 --> 321, 206 --> 60 and 324 --> 127 were used to quantify I, II, III and IV, respectively. This method was validated in the concentration ranges of 0.02-4 microg/mL for I and 0.004-0.8 microg/mL for II. It was utilized to support a clinical pharmacokinetic study after single dose oral administration of a combination of I and II.