• Journal of Pharmaceutical Investigation
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• v.20 no.2
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• pp.65-71
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• 1990

Some studies reported physicochemical factors of drugs affecting solubility and dissolution rate. However, few have been reported about pharmaceutical application of crystal forms (habits). Therefore, using acetylsalicylic acid and phenacetin as model substances, we monitored the effects of crystal forms on the dissolution rates.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.46-47
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• 2001

• Journal of Pharmaceutical Investigation
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• v.10 no.1
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• pp.4-12
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• 1980

The studies of the compounding analgestic antipyretics were examined by the converted Koster's method (mice) and the converted Mac Donald's method (mice) induced on the three assumption crossover test. And the following results were found. 1. The same effect of the writhing inhibition in this compounding antipyretic dosage by it's oral administration is as follows. Aminopyrine 100mg/kg. (standard), aminopyrine 50mg/kg compounding with chlorpheniramine maleate 2mg/kg., compounding with diphenhydramine hydrochloride 8mg/kg., compounding with atropine sulfate 0.2mg/kg., or compounding with scopolamine hydrobromide 0.2mg/kg. And aspirin80mg/kg., Salicylamide 90mg/kg., sulpyrine 60mg/kg., or phenacetin 70mg/kg. compounding with the same dosage of the adjutants above. 2. The elevation-rate of the reaction threshold in this compounding antipyretic dosage by it's oral administration calculate as follows. When the elevation-rate (ER) of aminopyrine (100mg./kg.) is 1.00 (Standard), ER of aminopyrine (50mg./kg.) compounding with chlorpheniramine maleate (2mg./kg.) calculated 1.42, aspirin (80.mg./kg.) compounding with diphenhydramine hydrochloride (80mg./kg.) calculated 1.18, salicylamide (90mg./kg.) compounding with chlorpheniramine maleate (2mg./kg.) calculated 1.15, sulpyrine (60mg./kg.) compounding with chlorpheniramine maleate(2mg./kg.) calculated 1.28, and ER phenacetin (70mg./kg.) compounding with chlorpheniramine maleate (2mg./kg.) calculated 1.19.

• Biomolecules & Therapeutics
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• v.23 no.2
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• pp.189-194
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• 2015

P450 1A2 is responsible for the metabolism of clinically important drugs and the metabolic activation of environmental chemicals. Genetic variations of P450 1A2 can influence its ability to perform these functions, and thus, this study aimed to characterize the functional significance of three P450 1A2 allelic variants containing nonsynonymous single nucleotide polymorphisms (P450 $1A2^*8$, R456H; $^*15$, P42R; $^*16$, R377Q). Variants containing these SNPs were constructed and the recombinant enzymes were expressed and purified in Escherichia coli. Only the P42R variant displayed the typical CO-binding spectrum indicating a P450 holoenzyme with an expression level of ~ 170 nmol per liter culture, but no P450 spectra were observed for the two other variants. Western blot analysis revealed that the level of expression for the P42R variant was lower than that of the wild type, however the expression of variants R456H and R377Q was not detected. Enzyme kinetic analyses indicated that the P42R mutation in P450 1A2 resulted in significant changes in catalytic activities. The P42R variant displayed an increased catalytic turnover numbers ($k_{cat}$) in both of methoxyresorufin O-demethylation and phenacetin O-deethylation. In the case of phenacetin O-deethylation analysis, the overall catalytic efficiency ($k_{cat}/K_m$) increased up to 2.5 fold with a slight increase of its $K_m$ value. This study indicated that the substitution P42R in the N-terminal proline-rich region of P450 contributed to the improvement of catalytic activity albeit the reduction of P450 structural stability or the decrease of substrate affinity. Characterization of these polymorphisms should be carefully examined in terms of the metabolism of many clinical drugs and environmental chemicals.

• YAKHAK HOEJI
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• v.6 no.2
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• pp.23-28
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• 1962

To reduce the errors, in the microdetermination of carbon and hydrogen, by the electrical automatic combustion apparatus, measured the errors due to the positions of sample in the carbon and hydrogen combustion tube. The samples used are glucose, acetanilide, phenacetin and diazoaminobenzene. Experimented positions of samples were 3cm, 5cm, 7cm, and 9cm from the front edge of the long stationary burner. In this experiment, it was found that the most suitable position of sample in the carbon and hydrogen combustion tube is 8cm from the long stationary burner.

• Mass Spectrometry Letters
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• v.4 no.2
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• pp.34-37
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• 2013

Honokiol and magnolol, the major bioactive neolignans of magnolia officinalis, are the most important constituents of the crude drug prescriptions that are used in the therapy of neuroses and various nervous disorders. There have been limited reports on the effects of neolignoid compounds on human cytochrome P450 activity. Therefore, the inhibitory effects of honokiol and magnolol on seven human cytochrome P450 s were evaluated in human liver microsomes. Honokiol and magnolol showed the most potent inhibition of CYP1A2-mediated phenacetin O-deethylase activity ($IC_{50}$ values of 3.5 and 5.4 mM, respectively) among the seven P450s tested. These in vitro data indicate that neolignan compounds can inhibit the activity of CYP1A2 and suggest that these compounds should be examined for potential pharmacokinetic drug interactions in vivo.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.394.2-394.2
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• 2002

A sensitive and selective reversed-phase LC-ESI-MS method to quantitate pseudoephedrine in human plasma was developed and validated. Phenacetin was used as an internal standard. Samples were prepared simply by acetonitrile precipitation without an evaporation step. Chromatographic separation was achieved on a XTerra MS C18 column ($150{times}2.1$ mm I.D.. 3.5 $\mu\textrm{m}$ particles). using gradient elution with 0.5% (v/v) trifluoroacetic acid (TFA) in water and 0.5% (v/v) TFA in methanol at a flow-rate of 0.1 ml/min. (omitted)

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.480-485
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• 1997

The absorption profile of phenytoin Na emulsion were examined compared to that of phenytoin suspension after oral administration in the rat. The corn oil-in-water emulsion, particle size of $184{\pm}$57.8 nm, was prepared using a microfludizer, and phenytoin Na added by shaft homogenizer. The phenytoin emulsion or suspension, 100 mg/kg, were intubated intragastrically using oral dosing needle and blood samples were withdrawn via an indwelling cannula from the conscious rat. Plasma concentrations of phenytoin were measured with HPLC using phenacetin as an internal standard. The plasma concentration versus time data were fitted to a one compartment open model and the pharmacokinetic parameters were calculated using the computer program, Boomer. The phenytoin plasma concentrations from the emulsion at each observed time were about 1.5-2 times higher than those from the suspension, significantly at time of 5, 6 and 7 hr after administration. The absorption $(k_a)$ and elimination rate constant $(k_e)$ were not altered significantly, however the AUC increased from 65.6 to $106.7{\mu}ghr/ml$ after phenytoin suspension or emulsion oral administration, respectively. From an equilibrium dialysis study, the diffusion rate constant $(k_{IE})$ was considerably higher from the phenytoin Na emulsion $(0.0439 hr{-1})$ than phenytoin suspension $(0.0014 hr{-1})$.

• YAKHAK HOEJI
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• v.13 no.1
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• pp.1-15
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• 1969

A new method of qualitative and quantitative determination of barbiturates in the pharmaceuticals by means of $\alpha$-picoline-copper (II) was studied. Barbiturates in the pharmaceuticals were dissolved in the mixed solvent of 33% $\alpha$-picoline-Carbontetrachloride to yield Complex Compounds of barbiturates-copper (II)-$\alpha$-picoline. Complex Compounds of barbiturates show uniformly maximum absorption at the wavelength of 540m.mu. and wre to be identified at the concentration of 1 X 10$^{-4}$ Mole, and also was to be quantitatively determined at the concentration of 1 X 10$^{-3}$ Mole. By this method barbiturates in the pharmaceuticals could be determined in the presence of various compounds such as sulpyrine, isopropylantipyrine, antipyrine, phenacetin and etc. But Barbiturates could be also determined by this method after seperation with aminopyrine, acetaminophen, acetylsalicylic acid and etc. by column chromatography. And barbiturates and acetylsalicylic acid could be also determined by simultaneous equation while their complex compounds show uniformly each maximum absorption at the Wavelength of 540 m${\mu}$ and 620 m${\mu}$. I.R. spectra of these complex compounds show identification of Barbiturates derivatives. The composition ratio of these complex compounds were : barbiturates : Cu : ${\alpha}$-picoline=2:1:2.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.265-272
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• 1998

The effects of mixtures of diazinon(DA;5mg/kg), toxaphene(TOX;40mg/kg) and/or endrin(END; 5mg/kg) on the hepatic mixed-function oxygenase(MFO) system were stuided in ICR mice(18~22g) by oral intubation daily for 7 days. In general, TOX and TOX-containing mixtures were found to induced the metabolism of aminopyrine(22~60%), aniline(42~85%), phenacetin(145~194%) and benzo [a]pyrene(158~210%), and pentobaribtal biotransformation in the 9,000g liver supernatants and to increased the hepatic cytochrome p-450 contents(47~89%). Results of these may be, at least in part, associated with the MFO system. TOX pretreatment increased the aliesterase activity in the serum and liver homogenates and supernatants by 23~145%. The toxicity of TOX and TOX-containing mixtures would be lower than that of diazinon because of TOX-induced increase in the metabolism of diazinon(DA) or diazioxon(DO) and capability of TOX to stimulate the metabolism of diazinon and diazioxon and provide a pool of non-critical enzymes. These results suggest that this information might be helpful in the evaluation of the potential hazard due to occupational and/or environmental exposures to pesticides and their mixtures.