• Proceedings of the PSK Conference
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• 2002.04a
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• pp.219.1-219.1
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• 2002

• YAKHAK HOEJI
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• v.46 no.5
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• pp.320-323
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• 2002

A method for the determination of acidic drug, mefenamic acid and ibuprofen with ion-selective electrode(ISE) using Fe(II)-di-2-pyridyl ketone oxime complex as a counter ion were developed. Benzyl-2-nitrophenyl ether(BNPE) plasticized membrane was more selective and sensitive than the other tested membranes. The acidic drug selective electrode exhibits a linear response for 10$^{-2}$ M 510$^{-5}$ M of acidic drugs, mefenamic acid and ibuprofen with a slope of -55.9 and -56.3 mV/dec. in borate buffer solution (pH 8.9). Potentiometric selectivity measurements revealed negligible interferences from aromatic and aliphatic carboxylic acid salts. The electrodes were found to be useful for the direct determination of mefenamic acid and ibuprofen in pharmaceutical preparations.

• Korean Journal of Pharmacognosy
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• v.30 no.2
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• pp.163-167
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• 1999

A method for isolation and qantitative determination of anemarsaponin B from the rhizomes of Anemarrhena asphodeloides has been developed. Isolation of anemarsaponin B was achieved by silica gel and RP-18 column chromatography. The HPLC method for quantitative determination of anemarsaponin B provided a method for standardization of the crude drug. It suggested that the content of anemarsaponin B in Anemarrhena asphodeloides is about 0.12-1.48%.

• Korean Journal of Pharmacognosy
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• v.30 no.1
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• pp.48-53
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• 1999

Isolation and quantitative determination of costunolide from Saussurea lappa Clarke (Compositae) has been conducted by using HPLC method. Costunolide in an acetone extract from the crude drug was separated on a RP-18 column using a $MeOH-H_20$ mixture (65:35) as an eluent and the average content is about $1.32{\sim1.42%.$ The content of costunolide in dried extract was decreased by about 24% in seven days. However it showed a slight decrease in solution. It is highly recommended that quantitative determination of costunolide from Saussureae Radix should be conducted as early as possible after solvent extraction.

• Archives of Pharmacal Research
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• v.27 no.2
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• pp.127-135
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• 2004

Multiple drug administration is common in elderly, HIV, and cancer patients. Such treatments may result in drug-drug interactions due to interference at the metabolic enzyme level, and due to modulation of transporter protein functions. Both kinds of interference may result in altered drug distribution and toxicity in the human body. In this review, we have dealt with drug-drug interactions related to the most studied human transporter, P-glycoprotein. This transporter is constitutively expressed in several sites in the human body. Its function can be studied in vitro with different cell lines expressing P-glycoprotein in experiments using methods and equipment such as flow cytometry, cell proliferation, cell-free ATP as activity determination and Transwell culture equipment. In vivo experiments can be carried out by mdr1a(-/-) animals and by noninvasive methods such as NMR spectrometry. Some examples are also given for determination of possible drug-drug interactions using the above-mentioned cell lines and methods. Such preclinical studies may influence decisions concerning the fate of new drug candidates and their possible dosages. Some examples of toxicities obtained in clinics and summarized in this review indicate careful consideration in cases of polypharmacy and the requirement of preclinical studies in drug development activities.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.195.2-195.2
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• 2000

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.251.2-251.2
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• 2000

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.197.2-197.2
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• 2000

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.303.1-303.1
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• 2001

• Journal of Pharmaceutical Investigation
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• v.36 no.5
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• pp.309-314
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• 2006

The multicellular layers(MCL) of human cancer cells is a three dimensional(3D) in vitro model for human solid tumors which has been used primarily for the assessment of avascular penetration of anti-cancer drugs. For anti-cancer drugs with penetration problem, MCL represents a good experimental model that can provide clinically relevant data. Calcein-AM is a fluorescent dye that demonstrates the cellular vitality in a graded manner in cancer cell culture system. In the present study, we evaluated the use of calcein-AM for determination of anti-proliferative activity of anti-cancer agents in MCL model of DLD-1 human colorectal cancer cells. Optical sectioning of confocal imaging was compromised with photonic attenuation and penetration barrier in the deep layers of MCL. By contrast, fluorescent measurement on the cryo-sections provided a feasible alternative. Cold pre-incubation did not enhance the calcein-AM distribution to a significant degree in MCL of DLD-1 cells. However, the simultaneous determination of drug penetration and cellular vitality appeared to be possible in drug treated MCL. In conclusion, these data suggest that calcein-AM can be used for the simultaneous determination of drug-induced anti-proliferative effect and drug penetration in MCL model.