Yanhua Ding

Synthesis, characterization and biological activity of a niobium-substituted-heteropolytungstate on hepatitis B virus.

n Abstractn n To synthesise and characterize the polyoxometalate Cs2K4Na[SiW9Nb3O40]·H2O 1 for its anti-hepatitis B virus (HBV) properties by using the HepG2.2.15 cell. The methylthiazol tetrazolium assay was used to evaluate the growth inhibitory effect of Compound 1 on HepG2.2.15 cell. By using ELISA and real-time PCR, respectively, the presence of extracellular hepatitis B surface antigen (HBsAg), e antigen (HBeAg), and HBV DNA were measured. The levels of intracellular HBV DNA and mRNA were determined by using Southern blot or reverse-transcription-PCR, respectively. Intracellular distribution of antigen were measured by Western blot. A 1995μmol/L concentration of the commercially-available hepatitis B drug, adefovir dipivoxil (ADV), was required to achieve 50% cytotoxicity against cultured cells (CC50) by day nine; in contrast, only 1747μmol/L of Compound 1 was required for the same result. Treatment of HepG2.2.15 cells with Compound 1 effectively suppress the secretion of HBV antigens and HBV DNA in a dose-dependent and time-dependent manner. IC50 values were determined to be 80μmol/L for HBsAg, 75μmol/L for HBeAg and 3.72μmol/L for supernatant HBV DNA at day nine post-exposure, as opposed to 266, 296, 30.09μmol/L, respectively, for ADV. Intracellular HBV DNA, mRNA and antigen were also found to be decreased by Compound 1. The same dose of ADV yielded a significantly less robust inhibitory effect. Compound 1 can clear HBV from hepatic cells and may represent a therapeutic agent to treat HBV infection.n n

Antiviral effects of three novel derivatives of adefovir on the replication of hepatitis B virus

Nucleoside/tide analogs are now widely used for treatment of chronic hepatitis B (CHB). However, available nucleoside/tide analogs for treatment of CHB usually have limited therapeutic effect and potential adverse effects on CHB patients. We evaluated the anti-HBV effects of three novel derivatives (compounds 1, 4, and 8) of adefovir on the replication of hepatitis B virus (HBV) and determined their cytotoxicity. The effects of those compounds on the replication of human HBV in the HepG2 2.2.15 cell line and duck HBV in infected ducks were characterized by measuring the extracellular and intracellular HBV DNA using the quantitative real-time PCR and Southern blot assays. Their cytotoxicities against HepG2 cells were evaluated by MTT and measuring the contents of mitochondrial DNA using the dot blot assay. We found that all of the compounds inhibited the production of HBV in a dose-dependent manner, similar to that of adefovir dipivoxil. Furthermore, treatment with any of the compounds reduced significantly the replication of DHBV in ducks, accompanied by a significant reduction of inflammation in the livers, and the compound 1 appeared to be a fast-acting and long-lasting anti-DHBV reagent. Importantly, all of the compounds showed little cytotoxicity against HepG2 cells, even at a concentration of 1xa0mM. Collectively, those novel derivatives of adefovir had potent anti-HBV activity with little adverse effect and may be therapeutic candidates for potential clinical studies.

Bioequivalence and Pharmacokinetic Profiles of Agomelatine 25-mg Tablets in Healthy Chinese Subjects: A Four-Way Replicate Crossover Study Demonstrating High Intra- and Inter-individual Variations

The present study was designed to assess the bioequivalence of two agomelatine formulations (25-mg tablets) in healthy Chinese male subjects. This single-dose, open-label, randomized, four-way replicate study with a 1-week washout period was conducted in 60 healthy Chinese male volunteers under fasting conditions. Blood samples were collected over a 12-h period after a single dose of the 25-mg agomelatine test (T) formulation or a reference (R) formulation, and the drug concentrations were assayed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Pharmacokinetic parameters were calculated using a non-compartmental model. Bioequivalence between the formulations was assessed. Tolerability and safety were monitored by physical examination, electrocardiogram (12-lead ECG), clinical laboratory tests, and adverse events (AEs). A total of 56 out of 60 subjects completed the study. No AEs were observed. The values of maximum plasma concentration (Cmax), maximum concentration (Tmax), area under curve (AUC)0-t and t1/2 were 12.032u2009ng/mL, 0.658u2009h, 12.637u2009ng·h/mL, and 0.813u2009h, respectively, for the test formulation, and 10.891u2009ng/mL, 0.709u2009h, 11.572u2009ng·h/mL, and 0.96u2009h, respectively, for the reference formulation. The intra-individual variability of Cmax and AUC0-t were 78.3 and 61.8%, respectively. The inter-individual coefficients of variance (CVs) of Cmax and AUC0-t were approximately 100%. The 90% confidence intervals for the ratio of means for the log-transformed Cmax (97.7-124.9%), AUC0-t (98.2-118%), and AUC0-∞ (97.8-117.2%) were within the guideline range of bioequivalence (80-125%). The test and reference formulations of agomelatine met the regulatory criteria for bioequivalence of the Chinese Food and Drug Administration. Significant intra-individual and inter-individual variations were found.

Tolerability, pharmacokinetics and antiviral activity of rHSA/IFNα2a for the treatment of chronic hepatitis B infection

Aims A recombinant human serum albumin‐interferon alpha2a fusion protein (rHSA/IFN&agr;2a) is expected to extend the half‐life of IFN&agr;2a. This study aims to evaluate the tolerability, safety and efficacy of rHSA/IFN&agr;2a. Methods This is an open, randomized, positive control, multiple‐dose ascending Phase Ib study. A panel of 32 treatment naïve and non‐cirrhotic chronic hepatitis B patients were divided into four cohorts, and each received 600, 750 or 900 &mgr;g of rHSA/IFN&agr;2a or 180 &mgr;g of PEG‐IFN&agr;2a for 3 months. Tolerability, pharmacokinetics and antiviral responses were assessed. Results Thirty‐one of 32 enrolled patients completed the treatment study. The rHSA/IFN&agr;2a treatment was better tolerated than the PEG‐IFN&agr;2a 180 &mgr;g treatment, as evidenced by blood cell counts and higher serum albumin levels. Half‐life (t1/2) of rHSA/IFN&agr;2a was estimated to be 120–140 h, and is potentially suitable for a dosing interval of 2 weeks or longer. Pharmacokinetics of the last dose between rHSA/IFN&agr;2a 750 &mgr;g and PEG‐IFN&agr;2a 180 &mgr;g, with the exception of t1/2, was comparable, and a similar kinetics of inhibiting HBV DNA replication was observed in both groups. Mean reductions in serum HBV DNA levels after treatment were −1.32, −2.13, −1.10 and −2.48 log10 IU/ml in the 600, 750 and 900 &mgr;g rHSA/IFN&agr;2a groups and PEG‐IFN&agr;2a group, respectively. Conclusions The rHSA/IFN&agr;2a treatment was well tolerated and can be administered biweekly. Similar efficacy in inhibiting HBV replication was observed in both PEG‐IFN&agr;2a and rHSA/IFN&agr;2a 750 &mgr;g groups.

Pharmacokinetics, Pharmacodynamics, and Tolerability of Single and Multiple Doses of Trandolapril, an Effective Angiotensin-Converting Enzyme Inhibitor, in Healthy Chinese Subjects

Trandolapril is the pro-drug of trandolaprilat, a non-sulfhydryl angiotensin-converting enzyme inhibitor. This study was designed to assess the pharmacokinetics (PK), pharmacodynamics (PD), and tolerability of single and multiple doses of trandolapril in healthy Chinese subjects. Healthy subjects (six men and six women) were randomized into a single-dose, 3xa0×xa03 crossover study (1–2–4xa0mg, 2–4–1xa0mg, and 4–1–2xa0mg), and a multiple-dose study (2xa0mg/day, 6xa0days). Serial blood and urine samples were collected after drug administration and analyzed using a validated LC–MS/MS method, and the trandolapril and trandolaprilat PK parameters were obtained. PD was evaluated by the changes in blood pressure and heart rates after dosing. Tolerability was assessed by monitoring adverse events, vital signs, ECGs, and changes in laboratory tests. In the single-dose study, trandolapril was absorbed rapidly, and peak plasma levels (Cmax, 1.57, 3.77, and 7.99xa0ng/mL) and AUCs (1.89, 3.46, and 6.47xa0ng/mL) were dose-dependent. The AUC0–∞ of trandolaprilat was dose-dependent, but in a non-linear fashion. The cumulative urine excretion of trandolapril and trandolaprilat was 5.51, 6.20, and 7.41xa0% for three doses, respectively. In the multiple-dose study, steady-state pharmacokinetics was observed; there was no trandolapril accumulation, but there was mild trandolaprilat accumulation (Rxa0=xa01.67). Trandolapril was well tolerated. The most pronounced reductions in blood pressure were observed at 8xa0h after administration, which was later than Tmax. No orthostatic hypotension occurred. The pharmacokinetics and pharmacodynamics following single and multiple oral doses trandolapril in healthy Chinese subjects are similar to those observed in non-Chinese healthy subjects.

Pharmacokinetics and safety profiles of novel diethylstilbestrol orally dissolving film in comparison with diethylstilbestrol capsules in healthy Chinese male subjects.

OBJECTIVEnWe compared the pharmacokinetic (PK) profiles of diethylstilbestrol orally dissolving film (DES ODF) and DES-capsule as well as assessing the safety, local tolerability, taste, and disintegration time of DES ODF.nnnMATERIALS AND METHODSnTwelve healthy male volunteers receiving a single administration of 2.0 mg of DES ODF or DES-capsule were included in the study. The tolerability, taste, and time to dissolution of DES ODF were assessed after dosing. Safety assessments included adverse events, hematology and biochemistry tests, urinalysis, vital signs, and electrocardiography.nnnRESULTSnThe PK parameters of DES ODF were all greater than those of DEScapsule. The Cmax values were 5.64 ± 1.1 and 3.4 ± 1.93 ng/mL for DES ODF and DES-capsule, respectively. Assessment of bioequivalence was based on the 90% CIs of the treatment ratios of the log-transformed Cmax, AUC0-t, and AUC0-∞ (DES ODF to DES-capsule), with the mean values being 1.93 (141 - 264), 1.24 (98 - 156), and 1.59 (121 - 207), respectively, indicating that DES ODF had a significantly high bioavailability. The mean DES ODF disintegration time was 14 ± 5 minutes. DES ODF was well tolerated and no serious adverse events or clinically relevant changes were observed.nnnCONCLUSIONSnThe DES ODF is well tolerated and better absorbed in comparison with DES-capsule.

Inhibition of HCV 5'-NTR and core expression by a small hairpin RNA delivered by a histone gene carrier, HPhA.

siRNA (small interfering RNA) interference represents an exciting new technology that could have therapeutic applications for the treatment of viral infections. However, a major challenge in the use of siRNA as a therapeutic agent is the development of a suitable delivery system. We demonstrated that a new non-viral transgene carrier, recombinant archaeal histone from the hyperthermophile Pyrococcus horikoshii OT3 (HPhA), can transfect short hairpin RNA (shRNA) expressing plasmids into HL-7702 cells to inhibit the expression of HCV 5NTR and Core protein and mRNA. Plasmids Psilencirle transfected by HPhA inhibited the expression of HCV 5-NTR and Core protein and mRNA in HL-7702 cells. The transfection efficiency of HPhA in HL-7702 cells was not affected by 10% fetal calf serum (FCS). HPhA exhibited effects of transfection without apparent toxicity, and with high affinity for DNA. This suggests that HPhA may be useful for RNAi-based gene therapy in vivo.

Single-Dose Pharmacokinetic Properties, Bioavailability, and Tolerability of Two Lamivudine 100-mg Tablet Formulations: A Randomized Crossover Study in Healthy Chinese Male Subjects

BACKGROUNDnLamivudine is used in the treatment of HIV and chronic hepatitis B (HBV) infections. Since 1999, at least 2 million Chinese HBV patients have been treated with lamivudine, but there are limited studies on the pharmacokinetics and safety of the drug in Chinese populations.nnnOBJECTIVEnThis study was designed to assess the bioequivalence of a newly developed lamivudine tablet (test drug) and a branded lamivudine tablet (reference drug) in healthy Chinese male volunteers.nnnMETHODSnA single-center, single-dose, randomized, open-label, 2-period crossover study was conducted in 28 healthy Chinese male volunteers. Blood samples were collected up to 24 hours after the administration of oral lamivudine 100 mg in each period. Plasma lamivudine concentrations were analyzed by a validated LC-MS/MS method. Pharmacokinetic and bioavailability parameters were calculated. Adverse events (AEs) were recorded.nnnRESULTSnThere were no significant differences in mean (SD) pharmacokinetic parameters between the test and reference drugs, including Cmax (1239 [328.9] ng/mL vs 1176 [341.5] ng/mL), AUC0-t (4096 [599.1] ng · h/mL vs 4064 [678.2] ng · h/mL), and AUC0-∞ (4200 [607.7] ng · h/mL vs 4162 [672.2] ng · h/mL). The geometric mean test/reference ratios (90% CI) calculated for the log-transformed parameters were Cmax, 1.06 (96.21-116.90); AUC0-t, 1.01 (96.53-105.39); and AUC0-∞, 1.01 (96.81-105.16), all of which were within the acceptance limits for bioequivalence. No serious AEs were reported, and all mild AEs were recovered quickly without treatment.nnnCONCLUSIONnThese findings suggest that the test formulation of lamivudine 100 mg meets the FDA regulatory standards for bioequivalence with the reference formulation. Both formulations were well tolerated.

Association of immune response parameters with virological response in hepatitis C virus patients treated with pegylated consensus interferon.

BACKGROUNDnA new, potent, long lasting recombinant interferon variant (pegylated consensus interferon, PEGCIFN) was expressed by Escherichia coli. The aim of this study was to test safety and antiviral activity of the new type of interferon in adults with hepatitis C virus (HCV) infection and to determine the relationship between immune response markers and virological response.nnnMETHODn40 naive HCV patients (1 : 1 : 1 : 1) were injected subcutaneously with PEG-CIFN 1.0, 1.5, 2.0 μg/kg and peginterferon-α 180 μg once per week for 12 weeks. Serum HCV RNA, cytokines, chemokines levels were tested, and clinical data were collected at this course.nnnRESULTSnPEG-CIFN is safety/tolerability. The serum HCV RNA levels were markedly decreased after therapy. 20% (2/10), 70% (7/10), 70% (7/10), and 60% (6/10) exhibited early virologic responses (EVR (+)) during PEGCIFN 1.0, 1.5, and 2.0 μg/kg treatment and peginterferon-α 180 μg treatment, respectively. Interleukin-4, interferon induced protein 10 (IP-10), and macrophage inflammatory protein 1β (MIP-1β) levels were lower, and granulocyte colony-stimulating factor levels were higher in EVR (+) than in the group not having an EVR (EVR (-)) (p < 0.05) after PEG-CIFN treatment. IP-10 and MIP-1β levels were associated with HCV RNA values, alanine aminotransferase, and aspartate aminotransferase levels after PEG-CIFN treatment.nnnCONCLUSIONnPEGCIFN was well tolerated and effective at inhibiting HCV RNA, which is associated with changes in markers of immune response. PEG-CIFN 1.5 μg/kg has been selected for further hepatitis C clinical development.

Single- and multiple-dose pharmacokinetics and tolerability of limaprost in healthy Chinese subjects.

Background and ObjectivesLimaprost, a prostaglandin E1 analogue, is used to treat various symptoms in patients with ischemic diseases. The present study was designed to determine the pharmacokinetics and tolerability of single and multiple oral doses of limaprost 5xa0μg tablets in healthy Chinese subjects.MethodsSingle and multiple doses of 5-μg limaprost were orally administered to 12 healthy Chinese subjects. There was a 2-week washout period between single and multiple dosing. Blood samples were collected at various times. Indomethacin and aspirin were added to the blood samples to inhibit the endogenous release of prostaglandins during the sample processing. Plasma limaprost was measured by a two-dimensional liquid chromatography-tandem mass spectrometry method.ResultsAfter single dosing, limaprost was rapidly absorbed (time to reach maximum plasma concentration [tmax]xa0=xa022.50xa0min) and eliminated (elimination half-life [t½]xa0=xa021.70xa0min), with the maximum plasma concentration (Cmax) being 2.56xa0pg/mL and area under the concentration-time curve (AUC) from time 0 to the last quantifiable time point (AUC0–t) being 70.68xa0pg·min/mL. There were significant inter-individual variations in the AUCs for both single- and multiple-dose regimens. The values of Cmax, AUC,t½ and tmax were not statistically different between single and multiple dosing. The accumulation factor R was 0.609xa0±xa00.432 (Rxa0<xa01), indicating that there was no accumulation after multiple dosing. There were no statistically significant differences in pharmacokinetic parameters for both single and multiple dosing between female and male subjects. The drug was well tolerated, with no severe adverse events being observed.ConclusionsLimaprost is rapidly absorbed after oral administration and is rapidly eliminated, with no accumulation after multiple dosing. The drug is well tolerated and no serious adverse events occurred.