Seigo Iwakawa

Kobe Pharmaceutical University, Kōbe-shi, Hyogo-ken, Japan

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Publications (22)50.15 Total impact

  • Article: [Cooperation of medical and pharmaceutical sciences between private and national universities to educate professionals in the fields of drug development and rational pharmacotherapy].
    Seigo Iwakawa
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    ABSTRACT: Cooperation in education and research in medical and pharmaceutical sciences between Kobe Pharmaceutical University and Kobe University was started in 2008 for training professionals in drug development and rational pharmacotherapy. Initially, we started a two-year pharmacy residency program. Our pharmacy residents can attend lectures at our universities, and they also help pharmacist preceptors educate undergraduate pharmacy students in practical training. As curricula for cooperative education of pharmacy, nursing and medical students, we developed two new elective subjects (early exposure to clinical training for first year students and IPW (inter-professional work) seminar for fifth year pharmacy students) to learn about the roles of health care professionals in a medical team. Cooperative research between faculty members and graduate students is also in progress. For faculty and staff developments, invited lectures by clinical pharmacy and medical professors from the United States on the clinical education system in pharmacy and medicine in the United States have been held. This systematic cooperation will contribute to the promotion of a new curriculum for inter-professional education in the health-science fields.
    YAKUGAKU ZASSHI 01/2012; 132(1):3-5. · 0.37 Impact Factor
  • Article: Different involvement of DNA methylation and histone deacetylation in the expression of solute-carrier transporters in 4 colon cancer cell lines.
    Mika Ikehata, Kumiko Ueda, Seigo Iwakawa
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    ABSTRACT: The purpose of this study on the involvement of epigenetic control of the expression of solute carrier (SLC) transporters by DNA methylation and histone deacetylation in 4 colon cancer cells is to find the epigenetic control mechanisms of drug transporters in colon cancers. Human colon cancer cell lines (HCT116, HT29, SW48, SW480) were treated with 5-aza-2'-deoxycytidine (DAC), as a DNA methyltransferase inhibitor, followed by trichostatin A (TSA), as a histone deacetylase inhibitor. The mRNA expression and DNA methylation of several SLC transporters were analyzed by real-time polymerase chain reaction (PCR) and methylation-specific PCR, respectively. Among 12 SLC transporters possessing cytosine-phosphate-guanine (CpG) islands, thiamine transporter 2 (THTR2) (SLC19A3) gene showed a correlation between its mRNA expression level and DNA methylation status. TSA treatment increased histone H3 acetylation of THTR2 promoter region in all 4 colon cancer cell lines examined. HCT116 and SW48 cells showed a lack of THTR2 mRNA expression and methylation of its promoter, and DAC treatment induced its re-expression. In addition, the co-treatment with DAC and TSA increased THTR2 mRNA expression more markedly than DAC treatment in HCT116 and SW48 cells. In HT29 and SW480 cells that showed little methylation of THTR2 promoter, TSA treatment induced THTR2 mRNA expression markedly, but DAC treatment did not. In the 4 colon cancer cells examined, THTR2 mRNA expression is down-regulated by DNA methylation and/or histone deacetylation.
    Biological & Pharmaceutical Bulletin 01/2012; 35(3):301-7. · 1.66 Impact Factor
  • Article: Hydrogen-deuterium (h-d) exchange reaction of warfarin in D(2)O solution.
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    ABSTRACT: To prove the presence of a hydrogen-deuterium (H-D) exchange reaction, (1)H- and (13)C-NMR spectra of warfarin were measured in solvents containing D(2)O and H(2)O. In D(2)O or D(2)O/dimethyl sulfoxide (DMSO)-d(6) solvent, signal pattern changes were observed on H12 and H11 as well as 14 methyl protons over time while no changes were observed on H(2)O or H(2)O/DMSO-d(6) solvent. The observed changes in the solvents containing D(2)O were concluded to be caused by the H-D exchange reaction on H12, the process of CH(2)-->CHD-->CD(2). MS spectroscopy also confirmed these H-D exchanges. The kinetics of this reaction were analyzed as the successive reaction, and the mechanism was also proposed.
    CHEMICAL & PHARMACEUTICAL BULLETIN 08/2009; 57(7):653-6. · 1.59 Impact Factor
  • Article: [Effect of withdrawal of 5-fluorouracil bolus administration on recovery from neutropenia in colorectal cancer patients treated with mFOLFOX6 chemotherapy-comparison with total dosage reduction].
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    ABSTRACT: A combination of oxaliplatin(L-OHP), folinic acid and 5-fluorouracil(5-FU)(mFOLFOX6)has been widely administered to treat advanced or recurrent colorectal cancer. In this regimen, a bolus of 5-FU is administered intravenously, followed by its 46-hr continuous intravenous infusion. For 12 patients who showed neutropenia during mFOLFOX6 chemotherapy at Itami City Hospital, we investigated neutrophil recovery by comparing a patient group treated by the withdrawal of the 5-FU bolus administration(n=6)with a patient group treated by total dose reduction of L-OHP, as well as both the bolus and continuous 5-FU administration(n=6). After two weeks, the neutrophil numbers in the bolus withdrawal group showed a relatively higher value than that in the total dose reduction group[p= 0.032]. For patients showing neutropenia related to mFOLFOX6 chemotherapy, withdrawal of 5-FU bolus administration is suggested to be an effective method of promoting the recovery of neutrophil numbers.
    Gan to kagaku ryoho. Cancer & chemotherapy 06/2009; 36(5):789-93.
  • Article: Effect of ethanol on S-warfarin and diclofenac metabolism by recombinant human CYP2C9.1.
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    ABSTRACT: The effect of ethanol on the metabolism of S-warfarin and diclofenac by recombinant cytochrome P450 2C9.1 microsomes (CYP2C9.1) was studied. The 7-hydroxylation metabolism of S-warfarin was inhibited by as low as 0.1 vol% (17 mM) ethanol. Ethanol decreased the V(max)/K(m) and V(max) values of S-warfarin metabolism in a concentration-dependent manner, but the K(m) value was unchanged by ethanol. The inhibitory effect of ethanol on the 4'-hydroxylation metabolism of diclofenac was not observed even at 1.0 vol% (170 mM) ethanol. Ethanol at a concentration of 3.0 vol% (510 mM) increased the K(m) value of diclofenac metabolism without changes in the V(max), which indicates that diclofenac 4'-hydroxylation by CYP2C9.1 was competitively inhibited by ethanol. S-Warfarin metabolism by CYP2C9.1 was more sensitive to ethanol than diclofenac metabolism. These results suggest that ethanol inhibits the metabolism by CYP2C9.1 in a substrate-dependent manner.
    Biological & Pharmaceutical Bulletin 04/2009; 32(3):517-9. · 1.66 Impact Factor
  • Article: Effect of gender on theophylline clearance in the asthmatic acute phase in Japanese pediatric patients.
    Tsutomu Igarashi, Seigo Iwakawa
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    ABSTRACT: The effect of gender on theophylline clearance was investigated retrospectively in 96 Japanese pediatric patients (63 males and 33 females) ranging in age from 0.5 to 8 years and in weight from 6.3 to 36.8 kg. All patients received intravenous constant-rate infusion of aminophylline in the asthmatic acute phase. The theophylline clearances in males and females were 56.2+/-15.4 and 50.1+/-14.2 ml/h/kg for ages 0.5-<2 years, 58.7+/-18.8 and 48.3+/-6.5 ml/h/kg for ages 2-<4 years, and 65.7+/-12.0 and 52.1+/-16.8 ml/h/kg for ages 4-<9 years, respectively. At ages from 2 to 8 years, the theophylline clearance was 20% higher in males than in females (p<0.05). Our findings suggested that the initial dosage of theophylline should be adjusted according to the gender of pediatric patients and particularly in the case of infants.
    Biological & Pharmaceutical Bulletin 02/2009; 32(2):304-7. · 1.66 Impact Factor
  • Article: Effect of oxyethylene numbers on the pharmacokinetics of menatetrenone incorporated in oil-in-water lipid emulsions prepared with polyoxyethylene-polyoxypropylene block copolymers and soybean oil in rats.
    Kumiko Ueda, Yuriko Kawaguchi, Seigo Iwakawa
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    ABSTRACT: We have prepared lipid emulsions of approximately 200 nm in diameter with soybean oil (SO) and a series of Pluronics with various numbers of oxyethylene units and about 60 oxypropylene units (SO/Pluronics), and studied the pharmacokinetics of menatetrenone incorporated into SO/Pluronics in rats. Emulsions of approximately 200 nm in diameter were obtained when SO contents were 2.5% and 20% (w/w) for 2.4% (w/w) PL101 and Pluronics that more than 30% was made up by oxyethylene units, respectively. The half-life of menatetrenone in plasma when oxyethylene units made up less than 30% of the Pluronic (SO/PL101 and SO/PP103) was similar to that for SO/egg yolk phosphatides (SO/EYP), but longer than that when oxyethylene units composed more than 40% of the Pluronic (SO/PP104 and SO/PF108, by 3- and 10-fold, respectively). Pretreatment with dextran sulfate 500000, an inhibitor of emulsion uptake by the reticuloendothelial system (RES), resulted in a higher plasma concentration and a lower liver uptake of menatetrenone as SO/PL101 at 10 min and SO/PP103 at 60 min, indicating that both SO/PL101 and SO/PP103 were taken up by the RES, although SO/PP103 required some time to be recognized by the RES. These findings suggested that larger numbers of oxyethylene units of Pluronics with 60 oxypropylene units were required for the longer plasma circulation of SO/Pluronics due to evasion of the RES.
    Biological & Pharmaceutical Bulletin 01/2009; 31(12):2283-7. · 1.66 Impact Factor
  • Article: Effect of oil-in-water lipid emulsions prepared with fish oil or soybean oil on the growth of MCF-7 cells and HepG2 cells.
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    ABSTRACT: The growth of human breast cancer-derived MCF-7 cells was affected by oil-in-water lipid emulsions prepared with fish oil (FO) rich in n-3 fatty acids (FAs) and egg-yolk phosphatides (EYP) (FO-emulsions), but not by lipid emulsions prepared with soybean oil (SO) and EYP (SO-emulsions). On the other hand, the growth of human hepatocarcinoma HepG2 cells was affected by neither SO-emulsions nor FO-emulsions. The growth inhibition of MCF-7 cells in the presence of FO-emulsions was not affected by trolox, but was inhibited by alpha-lipoic acid, and was even potentiated by ebselen, which works as an antioxidant as well as a lipoxygenase inhibitor. Since prostaglandin E(3), generated from n-3 FAs by cyclooxygenases, has a suppressive effect on tumour cell growth, and increases when lipoxygenases are inhibited, these findings suggest that lipid emulsions incorporating triglycerides of n-3 FAs might be effective in suppressing the growth of MCF-7 cells, possibly via oxidative stress and through eicosanoid production with anti-proliferating activity against cancer cells.
    Journal of Pharmacy and Pharmacology 08/2008; 60(8):1069-75. · 2.17 Impact Factor
  • Article: Effect of ethanol on the binding of warfarin enantiomers to human serum albumin.
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    ABSTRACT: Ethanol is widely used as a pharmaceutical excipient for the solubilization of many hydrophobic drugs for injections. However, there are only few studies about drug interaction with pharmaceutical excipients in the body after injection. In this study, the effect of ethanol (500 mM) or several alcohols (500 mM) on the stereoselective binding of warfarin enantiomers to fatty acid-free human serum albumin (HSA) or proteins of commercial albumin preparations was investigated. An ultrafiltration method was used for the separation of unbound warfarin enantiomers. By the addition of ethanol or 1-propanol, the unbound fraction of the S-enantiomer was decreased. On the other hand, the unbound fraction of the R-enantiomer was increased by the addition of ethanol or 1-propanol. Unbound fractions of both the S- and R-enantiomer were decreased by 2-propanol. In various commercial albumin preparations, unbound fractions of both the S- and R-enantiomer were increased by ethanol. The different effects of ethanol among fatty acid-free HSA and commercial albumin preparations were observed.
    Biological & Pharmaceutical Bulletin 05/2007; 30(4):826-9. · 1.66 Impact Factor
  • Article: Effect of glimepiride and glibenclamide on S-warfarin 7-hydroxylation by human liver microsomes, recombinant human CYP2C9.1 and CYP2C9.3.
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    ABSTRACT: The effect of glimepiride on metabolism of S-warfarin to 7-hydroxywarfarin was studied using human liver microsomes and recombinant cytochrome P450 2C9 microsomes (CYP2C9.1 and CYP2C9.3), and was compared with the results from the experiments using glibenclamide as an inhibitor. S-Warfarin 7-hydroxylation by recombinant CYP2C9.1 and CYP2C9.3 was inhibited by glimepiride competitively. The apparent K(i) value of glimepiride was lower at CYP2C9.3 than at CYP2C9.1. Glimepiride also inhibited 7-hydroxylation of S-warfarin in a competitive manner by microsomes from human liver which showed the genotypes of CYP2C9, as CYP2C9*1/*1 or CYP2C9*1/*3. The apparent K(i) value of glimepiride was lower than that of glibenclamide. These results may provide valuable information for optimizing the anticoagulant activity of warfarin when glimepiride is co-administered to patients.
    Biological & Pharmaceutical Bulletin 10/2006; 29(9):1983-5. · 1.66 Impact Factor
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    Article: Effect of 2-methoxyestradiol, buthionine sulfoximine and hydrogen peroxide on the viability of renal carcinoma cell lines (ACHN and ACVB).
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    ABSTRACT: 2-Methoxyestradiol (2-ME), an endogenous metabolite of 17beta-estradiol, induces the intracellular accumulation of superoxide anion (O2*-) and buthionine sulfoximine (BSO) is an inhibitor of glutathione (GSH) synthesis. We have examined the combination anticancer effect of 2-ME and BSO accompanied with hydrogen peroxide (H2O2). 2-ME inhibited cell growth in renal carcinoma cell lines (ACHN and ACVB) accompanied by an increase in the intracellular contents of GSH. The combination of 2-ME, BSO and H2O2 showed a significant antiproliferation effect in both ACHN and ACVB. The intracellular levels of reactive oxygen species (ROS) with a combination with 2-ME and H2O2 in ACHN and ACVB pretreated with BSO were markedly increased, which may have contributed to the potential antiproliferative action.
    Biological & Pharmaceutical Bulletin 06/2006; 29(5):1064-7. · 1.66 Impact Factor
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    Article: Antiproliferative activity of Rhinacanthus nasutus (L.) Kurz extracts and the active moiety, Rhinacanthin C.
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    ABSTRACT: Rhinacanthus nasutus (L.) Kurz (Acanthaceae) is a shrub widely distributed in South China and India. In this study, the antiproliferative activity of the ethanol extract of root and aqueous extract of leaves of R. nasutus, and the supposed active moiety rhinacanthin C was assessed in vitro using the human cervical carcinoma cell line HeLa, its MDR1-overexpressing subline Hvr100-6, human prostate carcinoma PC-3 cells and human bladder carcinoma T24 cells. Rhinacanthin C was chemically synthesized and its content in the R. nasutus extracts was determined by HPLC with a photodiode array detector. The antiproliferative activity of the R. nasutus extracts was also assessed in vivo using sarcoma 180-bearing mice. It was suggested that 1) the in vitro antiproliferative activity of rhinacanthin C was comparable with or slightly weaker than that of 5-FU, 2) rhinacanthin C showed antiproliferative activity for MDR1-overexpressing Hvr100-6 cells, similarly to parent HeLa cells, 3) the in vitro antiproliferative activity of the ethanol extract of root R. nasutus was due to rhinacanthin C, whereas that of the aqueous extract of leaves of R. nasutus was due to constituents other than rhinacanthin C, and 4) both of the R. nasutus extracts showed in vivo antiproliferative activity after oral administration once daily for 14 d.
    Biological & Pharmaceutical Bulletin 08/2004; 27(7):1070-4. · 1.66 Impact Factor
  • Article: Effect of acyl chains of phosphatidylcholines on the pharmacokinetics of menatetrenone incorporated in O/W lipid emulsions prepared with phosphatidylcholines and soybean oil in rats.
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    ABSTRACT: Oil-in-water (O/W) lipid emulsions were prepared with phosphatidylcholines (PCs) of various acyl chains and soybean oil (SO) using a microfluidizer system, and the pharmacokinetics of menatetrenone incorporated in these oil particles were examined at the clinical injection volume (0.1 mL kg(-1)) in rats. The plasma half-life of menatetrenone incorporated in the oil particles prepared with SO and dipalmitoylphosphatidylcholine (DPPC) (SO/DPPC) was longer than that prepared with SO and eggyolk phosphatides (EYP) (SO/EYP) by 3 fold, while those of menatetrenone as oil particles prepared with SO and either dilauroyl phosphatidylcholine (DLPC), dimyristoyl phosphatidylcholine (DMPC), distearoyl phosphatidylcholine (DSPC), dioleoyl phosphatidylcholine (DOPC) or dilinoleoyl phosphatidylcholine (DLoPC) (SO/DLPC, SO/DMPC, SO/DSPC, SO/DOPC and SO/DLoPC, respectively) were similar to that of menatetrenone as SO/EYP. The menatetrenone uptake by the liver was not significantly different from that as SO/EYP in all SO/PCs examined, but the menatetrenone uptake by the spleen as SO/DPPC and SO/DSPC was higher than that as SO/EYP. The menatetrenone uptake by the lungs as SO/DPPC was also higher than that as SO/EYP. These findings suggest that SO/DPPC is a good candidate drug carrier for the prolonged plasma circulation of lipophilic drugs.
    Journal of Pharmacy and Pharmacology 08/2004; 56(7):855-9. · 2.17 Impact Factor
  • Article: Prolonged circulation of menatetrenone by emulsions with hydrogenated castor oils in rats.
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    ABSTRACT: Previously, we reported that plasma half-lives of a drug incorporated in lipid emulsions prepared with soybean oil (SO), a long-chain triglyceride, and hydrogenated castor oils (HCOs) (SO/HCOs) were markedly longer, while those as SO/polyoxyethylene sorbitan esters (SO/PSs) were similar, compared to that as SO/egg yolk phosphatides (SO/EYP) [J. Pharm. Pharmacol. 54 (2002) 1357; J. Drug Target. 11 (2003) 37]. In the present study, lipid emulsions were prepared with Miglyol 812 (MO), a medium-chain triglyceride, and HCOs, and the kinetics of the incorporated drug, menatetrenone, were examined. The plasma half-lives and the liver uptake of menatetrenone as MO/polyoxyethylene-(10)-hydrogenated castor oils (MO/HCO10s) were similar to and larger than those as MO/EYP, respectively. On the other hand, the plasma half-lives and liver uptake of menatetrenone as MO/polyoxyethylene-(20)-hydrogenated castor oils (MO/HCO20s) or MO/polyoxyethylene-(60)-hydrogenated castor oils (MO/HCO60s) were markedly longer and lower than those as MO/EYP, respectively. The pretreatment of dextran sulfate 500,000, a reticuloendothelial system suppressor, raised the plasma concentration and inhibited liver uptake of menatetrenone as MO/HCO10, but not for MO/HCO20. These findings suggest that the minimum number of oxyethylene units within HCOs for the prolonged plasma circulation of menatetrenone was 20 for MO/HCOs, similarly to SO/HCOs.
    Journal of Controlled Release 03/2004; 95(1):93-100. · 5.73 Impact Factor
  • Article: Effect of particle size on the pharmacokinetics of menatetrenone incorporated in O/W lipid emulsions prepared with hydrogenated castor oils and soybean oil in rats.
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    ABSTRACT: Previously, we prepared lipid emulsions with soybean oil (SO; 20%) as oil phase and hydrogenated castor oils (HCOs; 2.4%) as emulsifiers (SO(20)/HCOs(2.4)), and found that the lipid emulsions prepared with HCO of 10 oxyethylene units (SO(20)/HCO10(2.4)) were quickly cleared from the plasma, while those prepared with HCO of 20 oxyethylene units (SO(20)/HCO20(2.4)) showed prolonged plasma circulation of the incorporated drug (Ueda et al., 2003). In the present study, the pharmacokinetics of menatetrenone incorporated into SO/HCO10s and SO/HCO20s of different particle sizes (100-280 nm), obtained by altering the SO contents, were examined in rats. The plasma half-lives of menatetrenone as SO/HCO10s were similar to each other, irrespective of particle size, even though the liver uptake of menatetrenone as SO(2.5)/HCO10(2.4) was larger than that as SO(20)/HCO10(2.4). The menatetrenone half-lives were also similar to each other for SO/HCO20s. The pretreatment with dextran sulfate 500,000 (DS500), a suppressor of the reticuloendothelial system (RES), increased the plasma concentration and inhibited the liver uptake of menatetrenone as SO/HCO10s, but not for those as SO/HCO20s. These findings indicated that the particle sizes did not affect the minimum oxyethylene units within HCOs for the prolonged plasma circulation of menatetrenone as SO/HCOs, which was 20.
    Journal of Drug Targeting 05/2003; 11(4):241-6. · 2.70 Impact Factor
  • Article: Effect of oxyethylene moieties in hydrogenated castor oil on the pharmacokinetics of menatetrenone incorporated in O/W lipid emulsions prepared with hydrogenated castor oil and soybean oil in rats.
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    ABSTRACT: Lipid emulsions with particle sizes of 190-270 nm were prepared with soybean oil (SO) and a series of hydrogenated castor oils (HCOs) with various oxyethylene numbers, and the effect of oxyethylene numbers of HCOs on the pharmacokinetics of menatetrenone incorporated into the lipid emulsions was studied in rats. Plasma half-life of menatetrenone after administration as the lipid emulsions prepared by HCO with 10 oxyethylene units (SO/HCO10) was similar to that after the administration as SO/egg yolk phosphatides (SO/EYP), but was shorter than that as the lipid emulsions prepared by HCOs with > 20 oxyethylene units (SO/HCO20, SO/HCO30, SO/HCO60, SOHC and SO/HCO100). Menatetrenone incorporated in SO/HCO10, SO/HCO20 and SO/HCO60 was not taken up by the blood cells in vitro, and the plasma level of menatetrenone incorporated in SO/HCO10 was similar to that of triglycerides, suggesting that menatetrenone was not released from the oil particles even after entering the circulation. Menatetrenone uptake by the liver for SO/HCO10 was similar to that for SO/EYP, while those for SO/HCO20, SO/HCO30, SO/HCO60 and SO/HCO100 was less than that for SO/EYP. These findings clearly demonstrate that 20 oxyethylene units in HCOs is the minimum requirement for the prolongation of the plasma circulation time of menatetrenone incorporated in SO/HCOs.
    Journal of Drug Targeting 02/2003; 11(1):37-43. · 2.70 Impact Factor
  • Article: Effect of oxyethylene moiety in polyoxyethylene sorbitan esters on the pharmacokinetics of menatetrenone incorporated in O/W lipid emulsions prepared with polyoxyethylene sorbitan esters and soybean oil in rats.
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    ABSTRACT: Oil-in-water (O/W) lipid emulsions are suitable drug carriers for lipophilic drugs; however, the effects of numbers or chains of oxyethylene units within a surfactant molecule such as polyoxyethylene sorbitan esters (PSs) on the biological fate of these lipid emulsions have not yet been clarified. In this study, a series of PSs and soybean oil (SO) were utilized to prepare menatetrenone-incorporated lipid emulsions (SO/PSs), and the biological fate of menatetrenone administered as SO/PSs was studied at a clinical injection volume (0.1 mL kg(-1)) in rats. The plasma concentration and organ uptake of menatetrenone administered as SO/20OE-PSs (PSs with 20 oxyethylene units) was similar to that of SO/egg-yolk phosphatides (SO/EYP). The plasma concentration of menatetrenone was extensively lower for SO/6OE-PSs (PSs with 6 oxyethylene units) and SO/20OE-3FA-PSs (PSs with 20 oxyethylene units and 3 fatty acid chains) than that for SO/EYP, and menatetrenone uptake by the liver and spleen was higher for SO/6OE-PSs and SO/20OE-3FA-PSs, respectively, than those for SO/EYP. Furthermore, menatetrenone uptake by the lungs was also increased for SO/6OE-PS and SO/20OE-3FA-PS with double bonds in the fatty acid moieties of the PSs. These findings suggested that shortening the oxyethylene units or decreasing the oxyethylene chain numbers of emulsifiers resulted in a rapid clearance of the lipid emulsions from the circulation by extensive uptake via the liver, spleen or lungs.
    Journal of Pharmacy and Pharmacology 11/2002; 54(10):1357-63. · 2.17 Impact Factor
  • Article: Genotyping of N-acetylation polymorphism and correlation with procainamide metabolism*
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    ABSTRACT: We studied the genotypes of polymorphic N-acetyltransferase (NAT2) in 145 Japanese subjects by the polymerase chain reaction-restriction fragment length polymorphism method. The rapid-type NAT2*4 was expressed at a higher frequency (68.6%) than the slow-type genes with specific point mutations (NAT2*6A, 19.3%; NAT2*7B, 9.7%; NAT2*5B, 2.4%). The frequency of NAT2* genotypes consisted of 44% of a homozygote of NAT2*4, 49% of a heterozygote of NAT2*4 and mutant genes, and 7% of a combination of mutant genes. The metabolic activity for procainamide to N-acetylprocainamide was measured in 11 healthy subjects whose genotype had been determined. Although the acetylation activity substantially varied interindividually, the variability was considerably reduced after classification according to the genotype. The N-acetylprocainamide/procainamide ratio in urinary excretion was 0.60 0.17 (mean SD) for those with NAT2*4/ *4, 0.37 0.06 for NAT2*4/ *6A, 0.40 0.03 for NAT2*4/ *7B, and 0.17 for NAT2*6A/ *7B. The results indicated that the NAT2* genotype correlates with acetylation of procainamide.
    Clinical Pharmacology &#38 Therapeutics 04/1997; 61(5):509-517. · 6.04 Impact Factor
  • Article: Effects of Transfection with the Cu, Zn-Superoxide Dismutase Gene on Xanthine/Xanthine Oxidase-Induced Cytotoxicity in Fibroblasts from Rat Skin
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    ABSTRACT: Purpose. The effects of transfection with the human Cu, Zn-superoxide dismutase (hSOD)4 gene on active oxygen-induced cytotoxicity in rat skin fibroblasts (FR) were studied for the purpose of developing the novel delivery system of hSOD using hSOD gene. Methods. An expression plasmid for hSOD, pRc/RSV-SOD, was constructed and used to transfect FR cells. Xanthine (X)/xanthine oxidase (XO) system were used to generate active oxygen species. The effects of transfection with the hSOD gene on active oxygen-induced cytotoxicity were assessed by comparing the number of surviving cells and the level of lipid peroxidation in host and transformants after exposure to X/XO system. Results. The cellular SOD activity in RSV-SOD cells transfected with pRc/RSV-SOD was significantly increased in comparison with host or RSV cells transfected with the pRc/RSV plasmid containing no hSOD gene as a control. Furthermore, Western blot analysis using an anti-hSOD antibody indicated the production of hSOD in RSV-SOD cells. On the other hand, although the numbers of surviving cells in both host and RSV-SOD cultures after exposure to X/XO system decreased in a time-dependent manner, the decrease in number of surviving RSV-SOD cells was less than that in host cells. In the presence of catalase, the decreases in number of surviving cells in both host and RSV-SOD cultures after exposure to the X/XO system were also less than those in the absence of catalase. However, the decreases in cell survival in RSV-SOD cultures were significantly less than those in host cells in the presence of catalase. Furthermore, the levels of lipid peroxidation in RSV-SOD cells exposed to the X/XO system in the presence or absence of catalase were lower than those in host cells. These results indicated that the increase in cellular SOD activity by transfection with the hSOD gene protects cells from oxidative stress. Conclusions. Human SOD gene therapy may be useful for treatment of diseases in which oxidative tissue damage is produced.
    Pharmaceutical Research 01/1996; 13(4):577-582. · 4.09 Impact Factor
  • Article: Intratracheal delivery of peptide and protein agents: Absorption from solution and dry powder by rat lung
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    ABSTRACT: Proteins of high molecular weight and low lipophilicity must be administered parenterally to achieve the desired therapeutic blood levels. We investigated the absorption of peptide and protein agents by rat lung following their intratracheal administration, expressing it as percent bioavailability. An aqueous solution and/or a dry powder of calcitonin, insulin, thyrotropin stimulating hormone (TSH), follicle stimulating hormone (FSH), and human chorionic gonadotropin (HCG) was delivered into the exposed trachea of anesthetized rats, and blood was sampled from the jugular vein at specified intervals. The bioavailabilities of TSH, FSH, and HCG delivered in a solution of neutral pH were 2.5, 2.3, and 0.2%, respectively. Transpulmonary absorption of a solution of these agents, administered with a surfactant or under acidic conditions, was 2-30 times greater than the values obtained in controls. The bioavailabilities of calcitonin, insulin, TSH, FSH, and HCG, given intratracheally as a dry powder, were 11.5, 6.5, 1.6, 0.6, and 0.1%, respectively. Following intratracheal administration, we noted a negative association between molecular weight and bioavailability. The intratracheal route may thus be useful for delivering peptide and protein agents.
    Journal of Pharmaceutical Sciences 05/1994; 83(6):863 - 867. · 3.06 Impact Factor

Institutions

  • 1996–2012
    • Kobe Pharmaceutical University
      Kōbe-shi, Hyogo-ken, Japan
  • 1989–2004
    • Kobe University
      • Department of Medicine
      Kōbe-shi, Hyogo-ken, Japan