Pharmacokinetics of ginkgolide B-lyophilized nanoparticles after intravenous injection in rats using liquid chromatography-tandem mass spectrometry

RATIONALE

Ginkgolide B (GB) performs diverse pharmacological activities but has poor water solubility. The currently available GB injections have a short half-life and are lethal when injected rapidly. We prepared GB-lyophilized nanoparticles (GB-NPs) using a new nonsurfactant polysaccharide polymer, ZY-010, as its carrier to regulate the release of GB in vivo. Here, the pharmacokinetics (PK) of GB-NPs after intravenous injection in rats was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

METHODS

The samples were separated on an Agilent Eclipse XDB-C 18 column (2.1 × 50 mm, 1.85 μm) maintained at 30°C. The MS/MS transitions of GB and glibenclamide as the internal standard (IS) were set at m/z 423.1 → 367.1 and m/z 492.1 → 367.0, respectively. The standard curve of GB content was constructed, and the specificity, sensitivity, precision, and extraction recovery of LC-MS/MS analysis were assessed. The main PK parameters were analyzed using DAS (Drug And Statistics for Windows) software, version 2.0.

RESULTS

The retention time of GB and IS at elution was 2.77 and 4.75 min, respectively. An excellent linear response across the concentration range of 0.001-100 μg/ml was achieved (r = 0.9997). The relative standard deviation value of precision was less than 10%. The total extraction recovery was above 80.76 ± 2.08%. The main PK parameters for the GB-NPs were as follows: t_1/2  = 69.32 h, AUC_{(0 → ∞)}  = 188 312.97 ± 143 312.41 μg/L h, CL = 0.03 ± 0.02 L/h/kg, and V = 0.09 ± 0.05 L/kg. The t_1/2 of the GB-NPs was significantly longer than that of GB solution, and AUC_{(0 → ∞)} of GB-NPs was about 1.4 times that of GB solution. The PK data demonstrated that the blood concentration of GB in rats conformed to a three-compartment model in both GB solution and GB-NPs.

CONCLUSION

A rapid and accurate LC-MS/MS method was established for the determination of GB-NPs in rats. GB-NPs exhibited a sustained-release behavior in vivo compared with GB solution.

Enhanced anti-amnestic effect of donepezil by Ginkgo biloba extract (EGb 761) via further improvement in pro-cholinergic and antioxidative activities

ETHNOPHARMACOLOGICAL RELEVANCE

EGb 761 is a standardized dry extract of Ginkgo biloba L. leaves traditionally used by Eastern Asia and has been associated with beneficial effects on neurodegeneration disorders, including Alzheimer's disease.

AIM OF THE STUDY

Since beneficial interactions between EGb 761 and donepezil have been observed in previous clinical studies, the current study was proposed aiming to further explore related mechanisms from both pharmacokinetics and pharmacodynamics aspects.

MATERIALS AND METHODS

Pharmacodynamic interactions were studied in scopolamine-induced cognitive impairment rats received two-weeks treatment of vehicle, EGb 761 and/or donepezil by the Morris water maze test and ex vivo evaluation of biomarkers of cholinergic transmission and oxidative stress in rat brain. In the meantime, pharmacokinetic profiles of donepezil and bilobalide were obtained and compared among all treatment groups. In addition, impact of the bioavailable EGb 761 components on donepezil brain penetration was evaluated with the hCMEC/D3 cell monolayer model.

RESULTS

Scopolamine-induced rats with co-treatment of EGb 761 and donepezil had significantly improved cognitive function in the Morris water maze test with increased brain levels of superoxide dismutase and decreased brain levels of acetylcholinesterase and malondialdehyde than that with treatment of only EGb 761 or donepezil. Despite such beneficial pharmacodynamics outcomes, the two-week co-treatment of EGb 761 and donepezil did not alter the plasma pharmacokinetics and brain uptake of donepezil or bilobalide, which was further verified in the hCMEC/D3 monolayer model.

CONCLUSION

Co-administration of EGb 761 and donepezil exerted better anti-amnestic effect via further enhanced pro-cholinergic and antioxidative effects of EGb 761 or donepezil in scopolamine-induced cognitive impairment rat without alteration in their systemic/brain exposure.

Influence of organic anion transporter 1/3 on the pharmacokinetics and renal excretion of ginkgolides and bilobalide

ETHNOPHARMACOLOGICAL RELEVANCE

The major terpene lactones of ginkgo biloba extract (GBE) include ginkgolide A, B, C and bilobalide are used for the protection of cardiovascular, cerebrovascular and neurodegenerative diseases. Terpene lactones are orally bioavailable and predominantly eliminated via the renal pathway. However, information on the transporters involved in the pharmacokinetics (PK) and renal excretion of terpene lactones is limited.

AIM OF THE STUDY

The objective of this study is to assess the role of OAT1/3 which are important transporters in the human kidney in the PK and renal excretion ginkgolide A, B, C and bilobalide.

MATERIALS AND METHODS

Uptake of ginkgolide A, B, C and bilobalide in Madin-Darby Canine Kidney (MDCK) and human embryonic kidney 293 (HEK293) cells overexpressing OAT1 or OAT3, respectively were studied. To verify the result from in vitro cell models, the studies on PK, kidney accumulation and urinary excretion of ginkgolide A, B, C and bilobalide were carried out in rats.

RESULTS

The result showed that ginkgolide A, B, C and bilobalide are low-affinity substrates of OAT1/3. Following co-administration with probenecid, a typical inhibitor of OAT1/3, the rat plasma concentrations of ginkgolide A, B, C and bilobalide increased significantly. AUC showed a significant increase in the probenecid-treated rats compared to control rats (893.48 vs. 1123.85, 314.91 vs. 505.74, and 2724.97 vs. 3096.40 μg/L*h for ginkgolide A, B and bilobalide, respectively), while the clearance of these compounds significantly decreased. The accumulation of ginkgolide A, B and bilobalide in the kidney of the probenecid-treated rats was reduced by 1.8, 2.4, and 1.5-fold, respectively; further reducing the cumulative urinary recovery of these compounds.

CONCLUSION

The findings indicated that ginkgolide A, B and bilobalide are excreted via OAT1/3-mediated transport in the kidney and OAT1/3 inhibitor significantly influence the PK ginkgolides and bilobalide.

[Absolute bioavailability of ginkgolide compounds in rats]

To investigate the pharmacokinetic characteristics and absolute bioavailability of ginkgolide A (GA), ginkgolide B (GB) and bilobalide (BB) in rats. In this experiment, a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/ MS) method was established to determine the plasma concentrations of GA, GB and BB in rats after rats were administrated with the three drugs through ig and iv respectively. The main pharmacokinetic parameters and absolute bioavailability of three ginkgolide compounds were obtained by using pharmacokinetic software DAS 2. 0. After the inject of GA, GB and BB, the results showed Cmax at (513.9 ± 116.9), (701.3 ± 76.0), (5,255.6 ± 476.8) µg · L(-1) and AUC0.24h of (960.9 ± 268.5), (779.5 ± 140.6), (7,409.3 ± 1,181.1) µg · h · L(-1), respectively; after the oral administration, the results showed Cmax at (522.9 ± 39.9), (146.8 ± 31.6), (2,711.9 ± 588.9) µg · L(-1) and AUC0-24 h of (1,760.4 ± 300.7), (636.6 ± 180.3), (16,651.4 ± 1,306.5) µg · h · L(-1), respectively. The absolute bioavailability of GA, GB and BB in rats was (61.1 ± 10.4)%, (27.2 ± 7.7)%, (56.2 ± 4.4)%, respectively. The method established in this experiment has a good specificity and sensitivity and so can be used to study the pharmacokinetics and absolute bioavailability of GA, GB and BB in rats.

Urinary excretion of ginkgolide terpene lactones following acute consumption of Ginkgo biloba extract

Urinary biomarkers of plant food supplement (PFS) exposure/intake represent an accurate, objective tool for determining PFS consumption in humans with applications ranging from epidemiology to subject compliance in clinical trials. Ginkgo biloba remains one of the worlds most popular PFS, yet few studies have investigated the uptake and metabolism of its primary unique bioactives: the terpene lactones. To this end, we conducted a dual-dose, acute crossover intervention using G. biloba supplements in healthy participants (n = 12). Pooled 24-H urine samples were analyzed by triple quadrupole LC-MS-MS. We observed that bilobalide and ginkgolides A and B were passed into urine intact and in a dose-dependent manner. Low levels of intact ginkgolides C and J were also excreted. To our knowledge, this is the first study to report intact ginkgolide J in urine following oral consumption of ginkgo supplements and is also the first to account for excreted terpene lactones as a proportion of dose.

The pharmacokinetics and conversion of the lactone to the carboxylate forms of ginkgolide B in rat plasma

Ginkgolide B consists of three lactone groups, which may undergo hydrolysis, and lead to the rings opening in aqueous solution with different pHs. From mechanisms of pharmacological activity in vivo, the lactone appears to be the active form of the drug. Pharmacokinetics of lactone form (GB-lac) and the total of the lactone and carboxylate form (GB-tot) of ginkgolide B were investigated after intravenous administration of a dose of 4 mg/kg ginkgolide B. The rate of lactone hydrolysis was also studied in plasma in vitro. After intravenous administration, ginkgolide B in the original form was converted to its carboxylate form under simulated physiological conditions. The AUC0 - ∞ of GB-lac constituted 63.5 ± 17.4% of the AUC0 - ∞ of GB-tot. The ratio of average cumulation of excretion of lactone to carboxylate reached approximately 1 to 1 in urine. From the equilibrium of lactone hydrolysis in rat plasma in vitro, the k obs was - 0.0176 min(- 1) and t 1/2 was 39.38 min. In conclusion, the equilibrium existed between lactone of ginkgolide B and its carboxylate form in vivo at physiological pH, which suggested that more attention should be focused on the original and the ionization forms of ginkgolide B and the conversion of the lactone into carboxylate in vivo.

[Study on pharmacokinetics of ginkgolide B injection in Beagle dogs]

OBJECTIVE

To study the pharmacokinetics of ginkgolide B injection in Beagle dogs.

METHODS

Determined the serum concentration of ginkgolide B by LC-MS and calculated its parameter of pharmacokinetics via DAS 2.0 software.

RESULTS

After intravenous drips of 0.62, 2.07 and 10.35 mg/kg ginkgolide B, parameters of pharmacokinetics of ginkgolide B were as follows: Tmax were 0.444, 1, 1 h; Cmax were 0.764, 3.024, 11.013 mg/L; AUC(0-1) were 1.007, 3.644, 16.646 mg x h/Lo.

CONCLUSION

Ginkgolide B has two compartment model in Beagle dogs.

[Study on the pharmacokinetics of ginkgolide B for injection in rats]

OBJECTIVE

To study the pharmacokinetics of ginkgolide B for injection in rats.

METHODS

The serum concentration of ginkgolide B was determined by LC-MS and calculate its parameter of pharmacokinetics via DAS2.0 software.

RESULTS

After intravenous of 0.75, 3.75 and 14.0 mg/kg ginkgolide B, parameters of pharmacokinetics of ginkgolide B were: Tmax were all (0.083 +/- 0) h, Cmax were (422.312 +/- 14.203), (1608.467 +/- 226.677), (1987.036 +/- 237.202) microg/L, AUC0-1 were (533.833 +/- 114.943), (1786.029 +/- 137.066), (1943.44 +/- 415.892) microg x h/L.

CONCLUSION

Ginkgolide B has three compartment model in rats.

Pharmacokinetics, tissue distribution, excretion, and metabolism of a new cardioprotective agent 10-O-dimethylaminoethylginkgolide B in rats

The plasma pharmacokinetics, tissue distribution, excretion, and metabolism of 10-O-dimethylaminoethylginkgolide B (XQ-1H), a protective agent against cardiovascular accident for its potential anti-platelet-activating factor activity, were investigated in rats. Plasma profiles were obtained after intravenous administration of 4, 8, 16, and 32 mg/kg of XQ-1H. There was a gender difference in the pharmacokinetics of XQ-1H. The elimination half-life of XQ-1H was 209.55, 200.81, 236.95, and 269.78 min in female rats and was 139.63, 173.83, 191.28, and 228.0 min in male rats at doses of 4, 8, 16, and 32 mg/kg, respectively. At four dose levels, female rats have higher values for area under the curve (AUC) than male rats. XQ-1H had linear pharmacokinetic characteristics in rats within the dose ranges tested. The volume of distribution in rats ranged from 6.05 to 15.09 l/kg. XQ-1H showed an extensive distribution into multiple tissues and reached its maximal concentration in all tissues at 10 min post-dose. About 80% of XQ-1H was mainly converted to its hydrolyzed and demethylated metabolites in vivo, and the elimination of unchanged compound was minor ( < 20%) in rats.

[Pharmacokinetics of ginkgolides sustained-release tablet]

OBJECTIVE

To study the pharmacokinetics and bioavailability of ginkgolides sustained-release tablet and conventional tablet in Beagle dogs.

METHOD

The concentrations of ginkgolides in plasma were determined by LC-MS. The main pharmacokinetic parameters of ginkgolides sustained-release tablet and conventional tablet in vivo were obtained using Pharmacokinetic software DAS 2.0.

RESULT

The C(max) of grinkgolide A in ginkgolide sustained-release tablet and conventional tablet were 443.51, 1 039.30 microg x L(-1), respecitvely. t(max) were 2.92, 1.08 h, respectively. AUC(0-12h) were 1 808.21, 2 041.37 h x microg(-1) x L(-1), respectively. MRT were 5.18, 3.18 h, respectively. The relative bioavailability of ginkgolides A was 88.58%. The C(max) of ginkgolide B in ginkgolide sustained-release tablet and conventional tablet were 407.13, 547.38 microg x L(-1), respectively. t(max) were 2.92, 1.08 h, respectively. AUC(01-12 h) were 1 987.31, 1 748.04 h x microg(-1) x L(-1), respectively. MRT were 6.05, 4.98 h, respectively. The relative bioavailability of ginkgolides B was 113.69%.

CONCLUSION

The ginkgolides sustained-release tablets have good sustained release characteristics and are bioequivalent to the reference formulation.

Plasma and brain levels of terpene trilactones in rats after an oral single dose of standardized Ginkgo biloba extract EGb 761®

Several studies indicate that the terpene trilactones (TTL) of EGb 761® are responsible for most of its pharmacological action in the brain . Therefore, we investigated the ability of the TTL to cross the blood brain barrier in rats after a single oral administration (600 mg/kg) of EGb 761® and compared it with the plasma levels. In addition, we checked the pharmacokinetic characteristics of an application of EGb 761® against a similar amount of pure substances. For this purpose, we developed a sensitive HPLC-(APCI)-MS method for the determination of the Ginkgo biloba TTL (ginkgolide A [GA], B [GB], C [GC] and bilobalide [Bb]) in plasma as well as in brain tissue. The following animal study shows that the oral application of 600 mg/kg EGb 761® results in significant GA, GB, and Bb concentrations in plasma as well as in the CNS of the rodents, while the GC concentration was below the detection limit of the analytical method in both matrices. GA, GB, and Bb brain concentrations showed a rapid increase up to 55 ng/g, 40 ng/g, and 98 ng/g with no difference of the characteristic after extract or pure substance application. Regarding the plasma levels, significant higher C(max) and AUC values were detected after application of the extract EGb 761®. These results allow for the first time a discussion of pharmacological effects with the knowledge of the pharmacokinetic behavior of the TTL in target tissues.

[Preparation and quality evaluation of ginkgolide B-loaded self microemulsifying drug delivery system]

OBJECTIVE

To prepare ginkgolide B-loaded self microemulsifying drug delivery system (SMEDDS) and evaluate its quality.

METHOD

The solubility of ginkgolide B in different oil, surfactant and co-surfactant were measured by HPLC-ESI-MS. The GB-SMEDDS formulation was optimized by the self emulsifying efficiency of various combinations of oil and mix-surfactant evaluated by using pseudo-temary phase diagram. The preliminary stability of GB-SEMEDDS was evaluated by the variety of loading rate of GB and dispersed medium. The morphology, the particle size and the formulation stability were evaluated after diluting by 0.1 mol x L(-1) HCl.

RESULT

The blank self microemulsified system was composed of ethyl oleate-( cremophor EL-lecithin-ethanol, 4: 1:2) (40: 60), the loading dosage was 2.5%. Little influence of GB and emulsified medium was observed on the stability of GB-SEMDDS. After diluted with 0.1 mol x L(-1) HCl, the morphology of the microemulsion was homogeneous small spherical drops observed under electro-microscope. The particle size was (41.6 +/- 1.11) nm, the self microemulsifing time was around 2 min. The formulation was stable within 8 h, without significant changes in particle size and separation of drugs.

CONCLUSION

GB-SMEDDS is easy to prepare and its quality is stable. The solubility of GB was significantly improved by SMEDDS.

[Preparation and transdermal diffusion of flexible nanoliposomes of ginkgolide B]

OBJECTIVE

To prepare flexible nanoliposomes of Ginkgolid B (GB) and study the transdermal diffusion law.

METHOD

Flexible nanoliposomes of GB were prepared by film dispersion method, and the shape and particle size of nanoliposomes were analyzed. GB permeation tests in vitro through the skin of rats were performed in modified Franz diffusion cell. The accumulated permeation amounts of GB alcoholic solution, flexible nanoliposomes of GB and ordinary nanoliposomes of GB were compared.

RESULT

The average encapsulation percentage, the particle size, and the Zata potential of the flexible nanoliposomes were (89.52 +/- 1.76)%, and was (208.3 +/- 25.49) nm, and was -49.2 mV, respectively. The accumulated permeation amount of flexible nanoliposomes in 8 hours was 189.97 microg x cm(-2), and its transdermal permeability in 8 hours was 23.75 microg x cm(-2) x h(-1).

CONCLUSION

The encapsulation percentage of the flexible nanoliposomes is good,and the stability of the GB nanoliposomes is fine. Flexible nanoliposomes can significantly enhance the diffusion rate of GB through the skin of rats.

[Preparation of the oral self-microemulsifying drug delivery system of GBE50]

To prepare the oral self-microemulsifying drug delivery system (SMEDDS) of GBE50, balance solubility method was used to screen emulsifier and assistant emulsifier; a pseudo-tamary phase diagram was used to prepare microemulsion; and orthogonal design was used to optimize formulation. Self-microemulsifying efficiency, dissolution, stability and pharmacokinetics of the preparation were studied. As a result, GBE50-SMEDDS of IPM, Cremophor EL, 1,2-propanediol and GBE50 could be self emulsified to form stable microemulsion with particle diameter between 20 and 50 nm when emulsifying with water. Its self-microemulsifying efficiency and dissolution are quick with good stability and it has a higher bioavailability than market existing agents Xingling particles. GBE50-SMEDDS is stable and effective.

[Effect of cyclosporine A on the pharmacokinetics of ginkgolide B in rats]

The paper is aimed to investigate the effect of cyclosporine A (CyA) on the pharmacokinetics of ginkgolide B (GB) in rats, and to look for the mechanism of the changes in pharmacokinetic behaviors of GB. GB concentration in plasma, brain homogenate and urine samples of rats was determined by LC-MS. Effects of CyA on plasma levels, brain distributions as well as urinary excretions after intravenous administration of GB were evaluated. CyA co administrated intravenously at 10 mg kg(-1) or 20 mg kg(-1) significantly increased AUC(0-360 min) (P < 0.01) and decreased total CL of GB in rats. While co administrated CYP3A inhibitor itraconazole (ICZ) has no appreciable effect on the pharmacokinetic behavior of GB. CyA increased the brain uptake of GB in a dose-dependent manner. The brain distribution of GB was significantly increased at 5 min by different doses of CyA (P < 0.001), while at 20 and 60 min only high dose of CyA could significantly increase the levels of GB in the brain (P < 0.01 and P < 0.001). Different P-gp inhibitors CyA or verapamil (VER) or digoxin (DGX) decreased the urinary GB excretion, the urinary excretion of GB in 0-8 h were about 34.8% (P < 0.001), 59.4% (P < 0.001) and 79.7% (P < 0.05) of the control, separately. No appreciable effect of ICZ was observed on urinary excretion of GB. Coadministration of P-gp inhibitors CyA could significantly increase the plasma level, accelerate the brain distribution and decrease the urinary excretion of GB.

Pharmacokinetics of the ginkgo B following intravenous administration of ginkgo B emulsion in rats

Ginkgo B (GB) is an extract from the leaves of Ginkgo biloba, used in the treatment of dementia, cerebral insufficiency or related cognitive decline. In this paper, the main features of the pharmacokinetics of GB emulsion in rats were reviewed and the binding rate of GB to rat plasma and human plasma protein were investigated meanwhile. The concentrations of GB in plasma, tissue, and excretion of rats after i.v. administration of GB were measured using HPLC-ESI-MS. The metabolite was qualitated by LC-MS/MS. Intravenously administered GB was eliminated in a biphasic manner with a prominent initial phase (half-life of 0.3 h) followed by a slower terminal phase (half-life of 1.5 h). After i.v. 4, 12 and 36 mg/kg GB emulsion, the pharmacokinetic parameters from a two compartment model analysis of plasma samples were AUC(0-tau) (microg x min/ml): 53.7, 165.5 and 649.7; CL (l/min/kg): 0.07, 0.07 and 0.05; V(C) (l/kg): 2.27, 3.27 and 2.76, respectively. Peak concentrations generally occurred at 10 min except brain and fat. Tissue concentration then declined by several-fold during 6 h although still present in most tissues at 6 h. Single intravenous dose was mainly excreted in the urine (40-50%), feces contained less than 30%. The binding rate to rat plasma was little higher than to human plasma, but the difference was negligible. Some metabolites were found in urine and bile through qualitative analysis on the urine and bile by LC-MS/MS.