• Korean Journal of Weed Science
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• v.4 no.2
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• pp.194-203
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• 1984

To evaluate the compatibility in systemic use of 4 kinds of herbicides on both weeds and soybeans, trials were conducted at Coll. Exp. Farm/Jonnam Nat'l. Univ., 1983. Among the experimented 4 herbicides, alachlor or metribuzin were applied at pre-emergence, and followed by postemergence spraying of acifluorfen or bentazon, respectively. All herbicides were applicated at rates of 0, 0.25, 0.5, and 0.75 kg active ingredients per ha. Under the conditions which Echinochloa crusgalli and Digitaria adscendense were dominating, most comprehensive compatibility was found from each rates 0.5 - 0.75 kg/ha at 60 days after crop seeding date. However, slight transient leaf burn was evident at the plots of metribuzin and/or acifluorfen applicated. The positive tendency of herbicide interactions in weeding efficacy was observed from the system in alachlor sequence. However, the results in crop growth and yields at hervest indicate the necessity of higher rates of each herbicides upto 0.75 kg/ha for the consistence weeding efficacies. And more excellent weeding results (crop growth and yields) on crop plants were provided from the plots which applicated by residual type herbicide, namely acifluorfen than bentzaon.

• Journal of Pharmaceutical Investigation
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• v.24 no.4
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• pp.289-295
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• 1994

Pharmacokinetic drug interaction between phenytoin and verapamil was investigated following i.v. administration of two drugs concomitantly to rabbits. Verapamil was coadministered with phenytoin (5 mg/kg) to rabbits at the doses of 0.5,1 and 2 mg/kg, respectively. Plasma concentration and AUC of phenytoin were increased significantly, but volume of distribution and total body clearance were decreased significantly (p<0.05) at doses of 1mg and 2mg/kg of verapamil, respectively. From the results of this experiment, it is desirable that dosage regimen of phenytoin should be adjusted and that therapeutic drug monitoring should be performed for reduction of side or toxic effect when phenytoin should be administered with verapamil in clinical practice.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.196-196
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• 1994

DDS에 활용될 수 있는 고분자 소재를 개발할 목적으로 물성 및 응용성이 우수한 고분자 겔에 관한 연구를 수행하였다. Ethylene oxide,propylene oxide 각각의 copolymer인 poloxamer등의 prepolymer들을 triisocyanate로 가교시키고 diisocyanate 로 chain이 연장된 "soft hydrogel"을 제조하였다. 모델 약물을 선정하여 crosslinker와 extender의 조절에 따른 hydrogel의 약물 방출 조절능을 조사하였으며 그 기전을 규명하고자 하였다. 가교부위에 urethane bond를 함유한 soft hydtogel은 건조상태에서도 고무와 같은 전연성을 보여 일반적인 hydrogel과 대비되는 특성을 보였으며 이에 따른 다양한 활용성이 기대되었다. Extender및 crosslinker의 비율에 따라서 이 rubber elasticity가 조절되었다. 가교도가 감소할수록 팽윤도가 상승하였고 이에 따른 약물방출도 증가함을 확인하였다. 또한 Prepolymer의 분자량 및 친수/소수성등의 물성에 따라 약물방출을 조절할 수 있었다. 제조된 hydrogel에 조절방출시 필요한 기능을 부가시키고자 poly(carylic acid)류와 IPN 공중합체를 합성하여 물성을 조사하였고 비이온성/양이온성/음이온성 모델약물을 선정하여 pH에 따른 가변적 팽윤도와 이온성 상호작용등에 근거한 약물 조절방출기전을 조사하였다.기전을 조사하였다.

• Journal of Pharmaceutical Investigation
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• v.26 no.2
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• pp.113-117
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• 1996

This study was attempted to investigate the pharmacokinetic interaction between sodium valproate (4, 8, 16 mg/kg, i.v.) and phenytoin (4 mg/kg, i.v.) in rabbits. The plasma concentration and area under the curve (AUC) of phenytoin were increased significantly (p<0.05, p<0.01) when coadministered with sodium valproate (4, 8, 16 mg/kg) in rabbits. The volume or distribution and total body clearance of phenytoin were decreased significantly (p<0.05, p<0.01) when coadministered with sodium valproate (8, 16 mg/kg) in rabbit. From the results of this experiment, it is desirable that dosage regimen of phenytoin should be adjusted and therapeutic drug monitoring should be performed for reduction of side or toxic effect when phenytoin will be coadministered with sodium valproate in clinical use.

• Journal of Pharmaceutical Investigation
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• v.13 no.4
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• pp.183-190
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• 1983

The interaction between probencid and nalidixic acid was studied pharmacokinetically in rabbits infused with or without acidic soiution (5% $NH_4Cl$). The results were as fellows. The blood level and the area under the blood concentration curve of nalidixic acid administered intravenously was elevated by coadministration of probenecid and more elevated in rabbits infused with acidic solution. Probenecid inhibited the urinary excretion of nalidixic acid in rabbits infused with adidic solution. Therefore, biolgcal half-life of nalidixic acid was prolonged by coadministration of probencid.

• Journal of Pharmaceutical Investigation
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• v.19 no.1
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• pp.15-20
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• 1989

The displacement of protein bound sulfonamides (sulfisoxazole, sulfamethoxazole, sulfisomidine) by furosemide was investigated in bovine serum albumin by equilibrium dialysis method. Furosemide $(2{\times}10^{-4}M)$ in bovine serum albumin ($7.24{\times}10^{-5}$, $1.45{\times}10^{-4}$, $2.89{\times}10^{-4}M$). Sulfisoxa캐1e and furosemide were bound reversibly to bovine serum albumin and competitive for the same binding sites when administered together. Consequently, dosage regimen of sulfisoxazole should be adjusted carefully when sulfisoxazole is administered along with furosemide.

• Journal of Pharmaceutical Investigation
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• v.23 no.1
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• pp.27-32
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• 1993

Pharmacokinetic drug interaction between phenytoin and diltiazem was investigated following i.v. administration concomitantly to rabbits. Diltiazem was coadministered at doses of 1, 2 and 3 mg/kg, respectively, with phenytoin (5 mg/kg) to rabbits. Plasma concentration and AUC of phenytoin were increased significantly, but volume of distribution and total body clearance were decreased significantly (p<0.05) at doses of 2 mg and 3 mg/kg of diltiazem. From the results of this experiment, it is desirable that dosage regimen of phenytoin should be adjusted and that therapeutic drug monitoring should be practiced for reduction of side or toxic effect when phenytoin should be administered with diltiazem in clinical practice.

• Journal of Pharmaceutical Investigation
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• v.16 no.1
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• pp.31-35
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• 1986

Effect of ethanol on the absorption rate, blood level and bioavailability of sulfamethazine (SM) in rats was determined. Absorption rate of SM was determined both by the in vitro and in situ experiment. In vitro, absorption rate of SM in rat small intestine was increased by 0.3, 1.0 and 3.0% ethanol. In situ, absorption rate of SM was increased by 0.3 and 1.0% ethanol but not by 3.0% ethanol. After oral administration, blood level of SM was elevated and relative bioavailability was significantly increased to 114.8% at the dose of 0.6g/kg ethanol but not significantly at the dose of 3.0g/kg ethanol. The time for attainment of peak blood level was changed from 2.5 to 1.5hr. Ethanol enhanced absorption rate constant of SM significantly and reduced elimination rate constant of SM administered orally at the dose of 0.6g/kg ethanol.

• Journal of Pharmaceutical Investigation
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• v.34 no.1
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• pp.15-21
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• 2004

The pharmacokinetics of orally administered verapamil (10 mg/kg) was studied in six rabbits after 20 min pretreatment with quercetin ad coadministration of quercetin (2.0 mg/kg, 1 mg/g and 20 mg/kg, respectively). Pretreatment with quercetin significantly (p < 0.01, p < 0.05) increased the plasma concentration of verapamil. However, coadministration of quercetin showed no significantly effect on the pharmacokinetic parameters of verapamil. The elimination rate constant $(K_{el})$ of verapamil pretreated with quercetin (1 mg/kg and 20 mg/kg) was significantly (p < 0.05) reduced compared with control. The area under the plasma concentration-time curve (AUC) and the peak concentration $(C_{max})$ of verapamil pretreated with quercetin (2.0 mg/kg, 10 mg/kg and 20 mg/kg) were increased significantly (p < 0.01, p < 0.05) compared with control. Pretreatment with quercetin (2.0 mg/kg, 10 mg/kg and 20 mg/kg) significantly (p < 0.01, p < 0.05) increased the relative bioavailability of verapamil to 159 - 219%. These results suggest that quercetin alters disposition of verapamil by inhibition of P-glycoprotein efflux pump and its first-pass metabolism. The dosage of verapamil should be adjusted when it is administered chronically with quercetin in a clinical situation.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.213-217
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• 2006

We evaluated the potential of major components of Phellodendri cortex to inhibit the activities of CYP2D6 and p-glycoprotein. The abilities of berberine, palmatine, limonin, and rutaecarpine to inhibit CYP2D6-mediated dextromethorphan O-demethylation and calcein AM accumulation were tested using human liver microsomes and L-MDR1 cell, respectively. Berberine strongly inhibited CYP2D6 isoform activity, whereas limonin and reuaecarpine did not. The $IC_{50}$ value of berberine was reduced after preincubation with microsomes in the presence of NADPH generating system, suggesting that berberine is a mechanism based inhibitor. In addition, all chemicals tested, didn't show inhibitory effect on p-glycoprotein activity. These results suggest that berberine has potential to inhibit CYP2D6 activity in vitro. Therefore, in vivo studies investigating the interactions between berberine and CYP2D6 substrates are necessary to determine whether inhibition of CYP2D6 activity by berberine is clinically relevant.