Pharmacokinetics of amosulalol,an α, β-adrenoceptor blocker,in rats,dogs and monkeys

1. The pharmacokinetics of an α,β-adrenoceptor blocker, amosulalol hydrochloride, were studied after i.v. and oral administration to rats, dogs and monkeys.

2. After an i.v. dose (1 mg/kg), the plasma concentration-time curve fitted a two-compartment open model with terminal half-lives of 2-5 h in rats, 21 h in dogs and 1-8 h in monkeys. The order of plasma clearances for amosulalol was: rats > dogs > monkeys.

3. After oral administration, the maximum plasma concentration was obtained at 0-5-1 h in rats (10-100mg/kg) and dogs (3-30mg/kg), and at l-7-2-7h in monkeys (3-10 mg/kg). A linear relationship between the area under the plasma concentration-time curve and dose administered was obtained for all three species. The systemic availabilities of the drug in rats, dogs and monkeys were 22-31%, 51-59% and 57-66%, respectively.

4. After repeated oral administration (10 mg/kg) to dogs for 15 days, the pharmaco-kinetic parameters did not differ significantly from those on the first day.     

Development of noncytotoxic PLGA nanoparticles to improve the effect of a new inhibitor of p53–MDM2 interaction

One possible approach to overcome solubility complications and enhance the biological activity of drugs is their incorporation into drug delivery systems. Within this scope, several nanosphere and nanocapsule formulations of a new inhibitor of p53–MDM2 interaction (xanthone 1) were developed and their physicochemical properties analyzed. Through the investigation of the effect of several empty nanoparticles on the growth of MCF-7 cells, it was possible to observe that four out of five formulations were cytotoxic and that some correlations between the toxic potential of these polymeric nanoparticles and their properties/composition could be extrapolated. One empty formulation of nanocapsules developed by emulsification/solvent evaporation and containing PLGA, PVA and Mygliol^® 812 was found to be noncytotoxic to this cell line. The corresponding compound 1-loaded nanocapsules showed an incorporation efficiency of 77% and revealed to be more potent than the free drug against cell growth inhibition, which may be related to the enhancement in its intracellular delivery. In an integrative study, the intracellular uptake of nanocapsules was confirmed using fluorescent 6-coumarin and well as compound 1 release from nanocapsules. Overall, it was possible to enhance the effect of the hit inhibitor of p53–MDM2 interaction through the development of suitable noncytotoxic polymeric nanoparticles.     

Study of the in vitro–in vivo correlation of Danshensu and protocatechuic aldehyde in a two-step release system

A two-step release system (TSRS) for the compound Danshen, which has drug-release behavior that is in accordance with the circadian rhythms of cardiovascular disease, was developed by combining an effervescent osmotic pump tablet and a pulsed-released tablet into one hard capsule by our lab. An in vivo study indicated that after oral administration of TSRS, two peaks of the plasma concentration of both Danshensu (DS) and protocatechuic aldehyde (PA) were observed, which suggested that the drug plasma concentration–time curve could meet the requirements for chronotherapy of cardiovascular disease after the bed-time administration of such a device. High performance liquid chromatography using an ultraviolet (UV) detector was used to simultaneously determine the concentrations of DS and PA in plasma. This method was simple, convenient, and appropriate for the quality control of DS and PA. A linear correlation model was established based on the percent absorbant data and percent in vitro dissolution data. Because the drugs were released from the device in an osmotic pressure-dependent manner and absorbed rapidly, a reasonable linear regression relationship was observed between the in vitro and in vivo performances. The current study highlights the potential use of such a device for chronopharmaceutical drug delivery.     

Disposition and metabolism of amosulalol hydrochloride,a new combined α- and β-adrenoceptor blocking agent,in rats,dogs and monkeys

1. The disposition and metabolism of amosulalol hydrochloride, a combined α- and β-adrenoceptor blocking agent, were studied in rats, dogs and monkeys.

2. After oral administration of [¹⁴C]amosulalol hydrochloride, the plasma concentration of radioactivity reached a maximum at 05 to 1 h in all species and declined with half-lives of about 2 h in both rats and monkeys, and of about 4 h in dogs. The ratios of unchanged drug to total radioactivity in the rat and dog plasma were 8 and 43% at 05 h after administration, respectively. The radioactivity in the rat tissues was high in the liver, kidney, blood and pancreas after oral administration.

3. Following oral dosage, the urinary excretion of radioactivity was 26-34% of the dose in rats, 45% in dogs and 46% in monkeys in 48 h. The biliary excretion after oral dosage amounted to 66% and 41% in rats and dogs, respectively.

4. Six metabolites were isolated and identified from the urine of rats and dogs. They were derived from one or two of the following pathways: I, hydroxylation of the 2-methyl group of the methylbenzenesulphonamide ring; II, demethylation of the o-methoxy group of the methoxyphenoxy ring; III, hydroxylation at the 4 or 5 position of the methoxy-phenoxy ring; IV, oxidative cleavage of the C—N bond yielding o-methoxyphenoxy acetic acid. Moreover, some metabolites were metabolized to glucuronide or sulphate.     

Clinical disposition,metabolism and in vitro drug–drug interaction properties of omadacycline

1.?Absorption, distribution, metabolism, transport and elimination properties of omadacycline, an aminomethylcycline antibiotic, were investigated in vitro and in a study in healthy male subjects.

2.?Omadacycline was metabolically stable in human liver microsomes and hepatocytes and did not inhibit or induce any of the nine cytochrome P450 or five transporters tested. Omadacycline was a substrate of P-glycoprotein, but not of the other transporters.

3.?Omadacycline metabolic stability was confirmed in six healthy male subjects who received a single 300?mg oral dose of [¹⁴C]-omadacycline (36.6 μCi). Absorption was rapid with peak radioactivity (～610 ngEq/mL) between 1–4?h in plasma or blood. The AUC_last of plasma radioactivity (only quantifiable to 8?h due to low radioactivity) was 3096 ngEq?h/mL and apparent terminal half-life was 11.1?h. Unchanged omadacycline reached peak plasma concentrations (～563?ng/mL) between 1–4?h. Apparent plasma half-life was 17.6?h with biphasic elimination. Plasma exposure (AUC_inf) averaged 9418?ng?h/mL, with high clearance (CL/F, 32.8?L/h) and volume of distribution (Vz/F 828?L). No plasma metabolites were observed.

4.?Radioactivity recovery of the administered dose in excreta was complete (>95%); renal and fecal elimination were 14.4% and 81.1%, respectively. No metabolites were observed in urine or feces, only the omadacycline C4-epimer.     

Pharmacokinetics of muraglitazar (BMS-298585), a dual peroxisome proliferator-activated receptors (PPAR) α and γ activator,in mice,rats, dogs,and monkeys

The pharmacokinetic parameters of muraglitazar, a novel dual-activator of the peroxisome proliferator-activated receptors (PPAR)?α?and γ, were determined in mice, rats, dogs, and monkeys after intravenous and oral administration. In the mouse, rat, and monkey the absolute oral bioavailability of muraglitazar ranged from 64 to 88%, and in the dog oral bioavailability was approximately 18%. The systemic clearance values of muraglitazar in the mouse, rat, dog, and cynomolgus monkey were 1.2, 3.0, 12.3 and 1.2?ml min^?1?kg^?1, respectively. The terminal elimination half-life was 2.4?h in dogs and 7.3?h in rats. The terminal elimination half-life could not be determined in the mouse and monkey because the sampling interval did not adequately cover the terminal elimination phase. Muraglitazar appears to be distributed outside of the vasculature, with the steady-state volume of distribution being approximately twofold that of the vascular volume in rats and dogs, and approximately twofold that of the total body water in mice. The systemic plasma clearance of muraglitazar in humans was predicted to be approximately 12–14?ml?min^?1?kg^?1 based on allometry or by scaling of in vitro clearance parameters. Overall, the pharmacokinetic parameters of muraglitazar in preclinical species were acceptable for the advancement of the compound as a clinical candidate.     

Effects of p,p′-DDE on the mRNA and protein expressions of vimentin,N-cadherin and FSHR in rats testes: An in vivo and in vitro study

To elucidate the mechanism underlying the testicular effects of 1,1-dichloro-2,2bis(p-chlorophenyl)ethylene (p,p′-DDE), the expressions of vimentin, neural cadherin and follicle-stimulating hormone receptor mRNA and proteins were measured in vivo and in vitro. Sprague-Dawley rats were dosed with p,p′-DDE at 0, 20, 60 and 100 mg/kg every other day by intraperitoneal injection for 10 days, and Sertoli cells were treated with p,p′-DDE (0, 10, 30, and 50 μM) for 24 h. Results indicated that the survival rate of Sertoli cells was decreased with increasing doses of p,p′-DDE. In vitro and in vivo studies, p,p′-DDE could increase the expression of neural cadherin, follicle-stimulating hormone receptor mRNA, while decrease the levels of vimentin, neural cadherin and follicle-stimulating hormone receptor proteins. Moreover, immunohistochemistry analysis revealed that the protein expressions of vimentin, neural cadherin and follicle-stimulating hormone receptor in pubertal rat testes were disrupted by treatment with p,p′-DDE. Taken together, these results suggested that p,p′-DDE exposure could induce testicular toxicity through the changes of the mRNA and protein expressions of vimentin, neural cadherin and follicle-stimulating hormone receptor in vitro and in vivo.     

Combination of α-glucosidase inhibitor and ribavirin for the treatment of dengue virus infection in vitro and in vivo

Cellular α-glucosidases I and II are enzymes that sequentially trim the three terminal glucoses in the N-linked oligosaccharides of viral envelope glycoproteins. This process is essential for the proper folding of viral glycoproteins and subsequent assembly of many enveloped viruses, including dengue virus (DENV). Imino sugars are substrate mimics of α-glucosidases I and II. In this report, we show that two oxygenated alkyl imino sugar derivatives, CM-9-78 and CM-10-18, are potent inhibitors of both α-glucosidases I and II in vitro and in treated animals, and efficiently inhibit DENV infection of cultured human cells. Pharmacokinetic studies reveal that both compounds are well tolerated at doses up to 100mg/kg in rats and have favorable pharmacokinetic properties and bioavailability in mice. Moreover, we showed that oral administration of either CM-9-78 or CM-10-18 reduces the peak viremia of DENV in mice. Interestingly, while treatment of DENV infected mice with ribavirin alone did not reduce the viremia, combination therapy of ribavirin with sub-effective dose of CM-10-18 demonstrated a significantly enhanced antiviral activity, as indicated by a profound reduction of the viremia. Our findings thus suggest that combination therapy of two broad-spectrum antiviral agents may provide a practically useful approach for the treatment of DENV infection.     

Pharmacokinetics and blood-brain barrier penetration of a novel salidroside derivative pOBz in rats北大核心CSCD

Aim To develop a ultra-high performance liquid chromatography electrospray-ionization tandem mass spectrometry ( UPLC-MS/MS ) method for the simultaneous determination of salidroside derivative pOBz in rat plasma and brain tissue, and to study the pharmacokinetic profile and penetration of the blood-brain barrier in rats after a single dose intravenous administration of pOBz. Methods SD rats were administered pOBz at a dose of 50 mg • kg -1via tail vein, and plasma and brain tissue samples were collected at different time points. UPLC-MS/MS method was used to determine the concentration of pOBz in plasma and brain tissue. The plasma concentration-time curve was fitted by DAS 2. 1. 1 software to calculate the pharmacokinetic parameters of pOBz. Results The linear regression equation of pOBz in plasma was: Y = 0.062 3X + 0.024 8 , r2=0.999, and the linear range was 0. 2 ~ 200 mg • L-1; the linearity regression equation in brain homogenate was : Y = 0.065 1X + 0.0317 , r2= 0.997, and the linear range was 0.2 ~ 200 mg • L -1. The half-life T1/2 of pOBz in plasma was 1.03 h,the area under the drug-time curve AUC0_twas 198.4 h • mg • L -1the mean residence time MRT0_twas 0.87 h, and the clearance rate CL was 0. 246 L • h-1• kg-1. 5 min after administration, pOBz could be detected in brain tissue at a concentration of 1.21 mg • L-1; it was not completely eliminated 3 h after administration. Conclusions The UPLC-MS/MS method is accurate and applicable for the pharmacokinetic study of pOBz in plasma and brain homogenate. pOBz can penetrate the blood-brain barrier and exert pharmacological effects in central nervous system. © 2023 Publication Centre of Anhui Medical University. All rights reserved.     

Generic sustained release tablets of trimetazidine hydrochloride: Preparation and in vitro–in vivo correlation studies

The aim of the current work was to develop generic sustained-release tablets containing 35 mg trimetazidine dihydrochloride and to establish an in vitro–in vivo correlation that could predict the bioavailability. The marketed sustained release tablet (Vastarel MR) used as reference, a sustained-release matrix tablet was prepared using hydroxypropyl methylcellulose (HPMC) as matrix by wet granulation and the in vitro dissolution profiles of the self-made tablets were determined in four different dissolution media (0.1 M HCl, pH 4.5 PBS, pH 6.8 PBS and water). A higher similarity between prepared tablets and Vastarel MR was established, with similarity factor (f₂) ranging from 60 to 75 in the four media. The in vivo pharmacokinetics was studied in six healthy beagles. Compared with Vastarel MR, the C_max of self-made tablets was slightly decreased, while the T_max and MRT_0–t were slightly prolonged, but with no significant difference (P > 0.05). The average of relative bioavailability (F) was 102.52% based on AUC_0–t. For log-transformed AUC_0–t and C_max, the upper confidence limit on the appropriate criterion is <0, indicating these two formulations were population bioequivalent. The in vivo–in vitro correlation coefficient obtained from point-to-point analysis of self-made tablets was 0.9720. In conclusion, the prepared tablets were bioequivalent to the marketed tablets, according to both the in vitro release rate and extent of absorption, and a good in vivo–in vitro correlation was established for the self-made tablets that indicated in vitro dissolution tests could be used as a surrogate for bioavailability studies.     

Evaluation of drug–drug interaction between henagliflozin,a novel sodium-glucose co-transporter 2 inhibitor,and metformin in healthy Chinese males

1.?Henagliflozin is a novel sodium-glucose transporter 2 inhibitor and presents a complementary therapy to metformin for patients with T2DM due to its insulin-independent mechanism of action. This study evaluated the potential pharmacokinetic drug-drug interaction between henagliflozin and metformin in healthy Chinese male subjects.

2.?In open-label, single-center, single-arm, two-period, three-treatment self-control study, 12 subjects received 25?mg henagliflozin, 1000?mg metformin or the combination. Lack of PK interaction was defined as the ratio of geometric means and 90% confidence interval (CI) for combination: monotherapy being within the range of 0.80-1.25.

3.?Co-administration of henagliflozin with metformin had no effect on henagliflozin area under the plasma concentration-time curve (AUC_0–24) (GRM: 1.08; CI: 1.05, 1.10) and peak plasma concentration (C_max) (GRM: 0.99; CI: 0.92, 1.07). Reciprocally, co-administration of metformin with henagliflozin had no clinically significant on metformin AUC_0–24 (GRM: 1.09, CI: 1.02, 1.16) although there was an 11% increase in metformin C_max (GRM 1.12; CI 1.02, 1.23). All monotherapies and combination therapy were well tolerated.

4.?Henagliflozin can be co-administered with metformin without dose adjustment of either drug.     

Biotransformation and in vitro assessment of metabolism-associated drug–drug interaction for CRx-102, a novel combination drug candidate

CRx-102 is an oral synergistic combination drug which contains the cardiovascular agent, dipyridamole (DP) and a very low dose of the glucocorticoid, prednisolone (PRED). CRx-102 works through a novel mechanism of action in which DP selectively amplifies the anti-inflammatory activity of PRED without replicating its side effects. CRx-102 is in clinical trials for the treatment of osteoarthritis. Here we delineate the in vitro metabolism and explore the potential for a drug–drug interaction between the active agents in CRx-102. Our study using human hepatocyte suspensions showed that both DP and PRED were metabolized by CYP3A4 isozymes, resulting in the formation of diverse arrays of both oxidative and oxidative-reduced metabolites. Within phase 1 biotransformation, CYP3A4 was one of the pathways responsible for the metabolism of PRED, while phase 2 biotransformation played a significant role in the metabolism of DP. Glucuronidation of DP was substantial and was catalyzed by many UGT members, specifically those in the UGT1A subfamily. Based on the tandem mass (MS/MS) product ion spectra (PIS) acquired, the major metabolites of both agents, namely, monooxygenated, mono-N-deethanolaminated, dehydrogenated and O-glucuronidated metabolites of DP and the monooxygenated (e.g., 6-hydroxyl), dehydrogenated (prednisone) and reduced (20-hydroxyl) metabolites of PRED, were identified and elucidated. The affinities for DP biotransformation, including CYP3A4-mediated oxidative pathways and UGT-mediated O-glucuronidation, appeared high (K_m < 10 μM), as compared with the modest affinities of PRED biotransformation catalyzed by CYP3A4 (K_m ∼ 40–170 μM). DP, but not PRED, exerted a minimal inhibitory effect on the drug-metabolizing CYP isoforms, including CYP3A4, which was determined using a panel of CYP isoform-preferred substrate activities in pooled human liver microsomal (HLM) preparations and microsomal preparations containing the recombinant enzymes (K_i ∼ 2–12 μM). Using the DP maximal plasma concentration (C_max) observed in the clinic and a predictive mathematical model for metabolism-associated drug–drug interaction (DDI), we have demonstrated that there is little likelihood of a pharmacokinetic interaction between the two active agents in CRx-102.     

In vitro profiling of the metabolism and drug–drug interaction of tofogliflozin,a potent and highly specific sodium-glucose co-transporter 2 inhibitor,using human liver microsomes,human hepatocytes,and recombinant human CYP

Abstract

1. The metabolism and drug–drug interaction (DDI) risk of tofogliflozin, a potent and highly specific sodium-glucose co-transporter 2 inhibitor, were evaluated by in vitro studies using human liver microsomes, human hepatocytes, and recombinant human CYPs.

2. The main metabolite of tofogliflozin was the carboxylated derivative (M1) in human hepatocytes, which was the same as in vivo. The metabolic pathway of tofogliflozin to M1 was considered to be as follows: first, tofogliflozin was catalyzed to the primary hydroxylated derivative (M4) by CYP2C18, CYP4A11 and CYP4F3B, then M4 was oxidized to M1.

3. Tofogliflozin had no induction potential on CYP1A2 and CYP3A4. Neither tofogliflozin nor M1 had inhibition potential on CYPs, with the exception of a weak CYP2C19 inhibition by M1.

4. Not only are multiple metabolic enzymes involved in the tofogliflozin metabolism, but the drug is also excreted into urine after oral administration, indicating that tofogliflozin is eliminated through multiple pathways. Thus, the exposure of tofogliflozin would not be significantly altered by DDI caused by any co-administered drugs. Also, tofogliflozin seems not to cause significant DDI of co-administered drugs because tofogliflozin has no CYP induction or inhibition potency, and the main metabolite M1 has no clinically relevant CYP inhibition potency.     

Preparation,optimization and in vitro–in vivo investigation for capsules of the choline salt of febuxostat

The objective of the present study was to exhibit the enhanced water-solubility and in vivo oral absorption when febuxostat (FXT) became the salt formation of choline. The formation of the choline salt of febuxostat was confirmed by X-ray powder diffraction, infrared spectroscopy analysis and differential scanning calorimetry. The direct filling method was used to develop a capsule formulation. Cellactose 80 was used as the filler due to its good fluidity, while cross-linked polyvinylpyrrolidone (PVPP) and magnesium stearate (MS) were used as the disintegrant and lubricant, respectively. Then the in vitro release of the formulation was carried out in five different dissolution media including HCl solution (pH 1.2), acetate buffer (pH 4.5), phosphate buffer (pH 6.8 and pH 7.2) and water. Evident improvement of release for choline febuxostat (CXT) was presented in water while the dissolution degree was decreased for CXT in the medium of phosphate buffer (pH 6.8) in comparison with FXT. Furthermore, the pharmacokinetics of CXT was studied in rats using UPLC-MS/MS compared with FXT. The data acquired illustrated that AUC_0-24h of CXT and FXT were 22,245.96 ± 7342.92 µg⋅h/l and 12,249.70 ± 2024.04 µg⋅h/l, respectively. The relative bioavailability of CXT to FXT was about 181.6% and the P value of AUC_0-24h was less than 0.05. It showed significant difference between the two drugs after oral administration. In conclusion, the water-solubility and oral bioavailability were both improved remarkably for the choline salt of febuxostat and choline salinization was proved an effective way to increase the in vivo absorption for FXT.     

Metabolic fate of sipoglitazar, a novel oral PPAR agonist with activities for PPAR-γ, -α and -δ, in rats and monkeys and comparison with humans in vitro

Sipoglitazar is a novel anti-diabetic agent with triple agonistic activities on the human peroxisome proliferator-activated receptors, hPPAR-γ, -α, and -δ. The bioavailability for sipoglitazar was 95.0% and 72.6% in rats and monkeys respectively and sipoglitazar is hardly subject to first pass metabolism in either species. Following oral administration of [1?C]sipoglitazar to rats, sipoglitazar and its metabolites were distributed to the rat tissues with relatively high concentrations in the liver and also to the target tissue, the adipose tissue. The major component was sipoglitazar in the plasma of rats and monkeys. In rats, sipoglitazar was mainly excreted into the feces via biliary excretion as sipoglitazar-G, while the major component was M-I-G in the urine and M-I in the feces of monkeys. In hepatocytes, the metabolism was not extensively advanced in rats and the main metabolites were M-I and sipoglitazar-G in humans, similar to the metabolic profile in monkeys. There was no metabolite specific for humans in vitro. In conclusion, the formation of M-I, M-I-G and sipoglitazar-G is considered to be crucial and sipoglitazar is presumed to be cleared primarily by oxidation and glucuronidation in humans, when examined in vivo and in vitro.     

In vitro and in vivo characterization of PF-04418948, a novel, potent and selective prostaglandin EP₂ receptor antagonist

BACKGROUND AND PURPOSE

Studies of the role of the prostaglandin EP₂ receptor) have been limited by the availability of potent and selective antagonist tools. Here we describe the in vitro/in vivo pharmacological characterization of a novel EP₂ receptor antagonist, PF-04418948 (1-(4-fluorobenzoyl)-3-{[(6-methoxy-2-naphthyl)oxy]methyl} azetidine-3-carboxylic acid).

EXPERIMENTAL APPROACH

Functional antagonist potency was assessed in cell-based systems expressing human EP₂ receptors and native tissue preparations from human, dog and mouse. The selectivity of PF-04418948 was assessed against related receptors and a panel of GPCRs, ion channels and enzymes. The ability of PF-04418948 to pharmacologically block EP₂ receptor function in vivo was tested in rats.

KEY RESULTS

PF-04418948 inhibited prostaglandin E₂ (PGE₂)-induced increase in cAMP in cells expressing EP₂ receptors with a functional K_B value of 1.8 nM. In human myometrium, PF-04418948 produced a parallel, rightward shift of the butaprost-induced inhibition of the contractions induced by electrical field stimulation with an apparent K_B of 5.4 nM. In dog bronchiole and mouse trachea, PF-04418948 produced parallel rightward shifts of the PGE₂-induced relaxation curve with a K_B of 2.5 nM and an apparent K_B of 1.3 nM respectively. Reversal of the PGE₂-induced relaxation in the mouse trachea by PF-04418948 produced an IC₅₀ value of 2.7 nM. Given orally, PF-04418948 attenuated the butaprost-induced cutaneous blood flow response in rats. PF-04418948 was selective for EP₂ receptors over homologous and unrelated receptors, enzymes and channels.

CONCLUSIONS AND IMPLICATIONS

PF-04418948 is an orally active, potent and selective surmountable EP₂ receptor antagonist that should aid further elaboration of EP₂ receptor function.

LINKED ARTICLE

This article is commented on by Birrell and Nials, pp. 1845–1846 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2011.01494.x