• Archives of Pharmacal Research
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• 제15권3호
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• pp.246-250
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• 1992

Acetaminophen (AAP) and ranitidine (RT) were coadministered orally to nine rats, and the possible contribution of the gastric emptying to the plasma concentration profiles of them was examined. The drugs showed multiple plasma peaks similar to the respective ones after separated administration of each durg. IT Implies that there is no significant interaction between AAP and RT in terms of the gastric emptying or drug absorption. There were no significant linear correlations of the peak patterns (peak height and peak time) between AAP andd RT. It is contrary to the expectation from the biphasic gastric emptying (BGE) theory previously suggested for AAP and RT. The BGE theory. Therefore, seemed to have some draw-backs in explaining satisfactorily the multiple plasma peaks of AAP and RT. Two more doubts raised previously against the BGE theory were also discussed.

• Journal of Electrochemical Science and Technology
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• 제3권2호
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• pp.90-94
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• 2012

A simple and sensitive electrochemical sensor for simultaneous and quantitative detection of ranitidine (RT) and metronidazole (MT) was developed, based on a poly(thionine)-modified anodized glassy carbon electrode (PTH/GCE). The modified electrode showed the excellent electrocatalytic activity towards the reduction of both RT and MT in 0.1M phosphate buffer solution (PBS, pH 7.0). The peak-to-peak separations (${\Delta}E_p$) for the simultaneous detection of RT and MT between the two reduction waves in CV and DPV were increased significantly from ca. 100 mV at anodized GCE, to ca. 550 mV at the PTH/GCE. The reduction peak currents of RT and MT were linear over the range from 35 to $500{\mu}M$ in the presence of 200 and $150{\mu}M$ of RT and MT, respectively. The sensor showed the sensitivity of 0.58 and $0.78{\mu}A/cm^2/{\mu}M$ with the detection limits (S/N = 3) of 1.5 and $0.96{\mu}M$, respectively for RT and MT.

• 약학회지
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• 제39권6호
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• pp.636-644
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• 1995

Comparison of bioavailabflity (BA) of three brands of ranitidine (RT) tablets has been studied m rats. The purpose of this study was to characterize the pharniacolunetics of RT tablets in the rat and to coinpare phannacolunetic parameters of three brands of RT tablets. In addition, it was investigated whether plasma RT concentrations m humans can be predicted from pharmacokinetic parameters obtained in rats. RT was administered intravenously in dose of RT.HCI 10mg/kg and orally in dose of RT.HCI 50mg/kg as solution or crushed sample of thablets. Plasma RT concentrations were determned by HPLC. Plasma RT concentrations as a function of time were fitted to two compartment model. Plasma RT concentrations declined with a terminal half life ($t_{{1}/2{\betha}}$) of 40.9 min. The plasma RT concentration-time curve showed two peak plasma concentrations following an oral administration of solution or crushed sample in rats like humans. No significant difference among pharmacokinetic parameters was observed except $T_{max2}$ (p<0.05). The BA for crushed sample A, B and C were found to be 54.6 40.7 and 40.0%, respectively. Equivalence of $C_{max1}$ and $T_{max2}$ were guaranteed in this study. However, it was concluded that three brands of RT tablets are bioequivalent, taking the following characteristics of RT into consideration;(1) rapid onset of the effect is not required, (2) $C_{max1}$ and $T_{max2}$ do not seem to influence the effectiveness of the drug during a long-term treatment by the usual administration of twice a day. Results from this study were combined with plarmacokinetic data for RT in dogs and humans to develop a basis for interspecies scale-up of the disposition characteristics of the drug. there were similarities in the general disposition of the drug. Allometric relationships were sought between pharmacokinetic parameters nd species body weight. Significant interspecies correlations were found for total body clearance($Cl_{t}$) and steady state volume of distribution ($Bd_{ss}$). Thus, plasma RT concentrations in humans can be predicted from pharmacokinetic parameters obtained in rats.

• The Korean Journal of Physiology and Pharmacology
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• 제18권2호
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• pp.183-190
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• 2014

This project's aim was to determine the reserpine-induced gastric ulcer preventive effect of polysaccharide of Larimichthys crocea swim bladder (PLCSB) in ICR mice. The anti-gastric ulcer effects of polysaccharide of Larimichthys crocea swim bladder was evaluated in mice model using morphological test, serum levels assay, cytokine levels assay, tissue contents analysis, reverse transcription-polymerase chain reaction (RT-PCR) analysis and western bolt assay. High concentration (50 mg/kg dose) of PLCSB reduced IFN-${\gamma}$ as compared to low concentration (25 mg/kg dose) and control mice. SS and VIP serum levels of PLCSB treated mice were higher than those of control mice, and MOT and SP serum levels were lower than control mice. Gastric ulcer inhibitory index of PLCSB treatment groups mice were much lower than control mice, and the high concentration treated mice were similar to the ranitidine treated mice. The SOD and GSH-Px activities of PLCSB treated mice were higher than control mice, close to normal mice and ranitidine treated mice. PLCSB treated mice also showed the similar contents of NO and MDA to normal group. By RT-PCR and western blot assay, PLCSB significantly induced inflammation in tissues of mice by downregulating NF-${\kappa}B$, iNOS, and COX-2, and upregulating $I{\kappa}B-{\alpha}$. These results suggest that PLCSB showed a good gastric ulcer preventive effect as the gastric ulcer drug of ranitidine. Polysaccharide of Larimichthys crocea swim bladder may be used as a drug material from marine products.