• Journal of Pharmaceutical Investigation
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• v.27 no.4
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• pp.313-321
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• 1997

Ion exchange resin complexes of famotidine have been prepared by the reaction of famotidine solution with activated ion exchange resins. Complex formation efficiency between famotidine and ion exchange resin was about $80{\sim}90%$ in average, calculated by HPLC determination. Drug release characteristics from the resin complexes were evaluated by the modified percolation method. Famotidine release was dependent on the type of ion exchange resins. In the case of weakly acidic resin complexes, the cumulative released amount of famotidine was more than 90% for 1hr in pH 1.2 buffer solution. However, in the case of strongly acidic resin complexes, it was less than 5% for 3hr in the same medium. Strongly acidic resins revealed some advantages over weakly, acidic resins for overcoming instability of famotidine in gastric juice. In addition, strongly acidic resin complexes showed controlled release of famotidine in pH 6.8 buffer solution, showing the result of about 60 to 70% of drug release for 5hr. After oral administrations of famotidine-resin complexes to rats as dose of 40 mg equivalent/kg, the pharmacokinetic parameters of famotidine were obtained by model independent analysis and compared with those of famotidine solution or suspension. $C_{max}$ of famotidine-resin complex was lower than that of famotidine solution or suspension. MRT, MAT, and MDT of the complexes were greater than those of famotidine solution or suspension. From these results, it was expected that famotidine was released slowly from the complexes and absorbed continuously into systemic circulation. It was recognized that drug release from the complexes was the rate-limiting step in drug absorption, since there were close correlations between in vitro drug release and in vivo pharmacokinetic parameters.

• Journal of Pharmaceutical Investigation
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• v.24 no.3
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• pp.139-144
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• 1994

The effect of some formulation variables on the release rate of famotidine, a $H_2$ receptor antagonist, from cellulose matrices containing hydroxypropylcellulose (HPC) in different ratios and types was investigated. The effects of tablet shape and compression pressure on dissolution rate of famotidine were studied. And the effect of the pH of dissolution media was also studied. Increase in the ratio of polymer to drug decreased the release rate of famotidine. Increase of the polymer viscosity also decreased the release rate. The release rate of famotidine was dependent on the pH of dissolution media. The release rate of drug was not much dependent on the compression pressure but dependent on the tablet shape and/or surface area. Consequently, the release rate of famotidine can be modified by changing the HPC contents, types of polymers with different viscosity grades or using appropriate fillers.

• Environmental Analysis Health and Toxicology
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• v.9 no.1_2
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• pp.9-17
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• 1994

The Ha-antagonist, cimetidine, has been shown to retard the hepatic elimination of low and high clearance drugs, and this has been attributed to inhibition of microsomal cytochrome P-450. This study was done to determine the effects of low (50$\mu\textrm{g}$) and high (1mg) dose of famotidine, another histamine H$_2$-receptor antagonist, on hepatic elimination of propranolol compared with cimetidine in the isolated perfused rat liver. Both low and high dose of cimetidine not only inhibited the elimination of propranolol but also increased the area under the perfusate propranolol concentration time curve (AUC). In contrast, low and high dose of famotidine did not affect hepatic elimination of propranolol. Our findings suggest that famotidine has not a propensity for hepatic microsomal inhibition.

• Environmental Analysis Health and Toxicology
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• v.5 no.3_4
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• pp.37-45
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• 1990

Experiments were performed on mice to investigate the influences of cimetidine, ranitidine and famotidine on the immune response. Immune response were evaluated by antibody, Arthus reaction (Arthus), delayed type hypersensitivity (DTH), rosette forming cell (RFC), phagocyte activity and whit( blood cell (WBC) in mice, sensitized and challenged with sheep red blood cells (SRBC). The weight of liver, spleen and thymus were measured. Following results obtained in this experiment. 1) The administration of cimetidine as compared to normal group significantly decreased Arthus, Hemagglutinin titer (HA), RFC, DTH, WBC and phagocyte activity, but increased the activity of serum albumin. 2) The administration of ranitidine as compared to normal group decreased RFC and HA. 3) The administration of Famotidine as compared to normal group decreased DTH and RFC, and significantly decreased HA, Arthus and serum protein. 4) The administration of ranitidine and famotidine decreased more humoral immune response than cellular immune response, but the administration of cimetidine significantly decreased humoral and cellular immune response, WBC and phagocyte activity.

• Journal of Pharmaceutical Investigation
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• v.37 no.5
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• pp.275-280
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• 2007

A rapidly disintegration famotidine tablet formulation in the oral cavity was developed using microcrystalline cellulose (MCC) and low-substituted hydroxypropyl cellulose (L-HPC), or additionally cropovidone as an internal disintegrant. Effects of disintegrants on the disintegration time in vitro and hardness were evaluated. Average wetting time of the tablets prepared in scale-up manufacturing process was less than 15 sec. Among the formulations tested, the tablet prepared with crospovidone as an internal disintegrant and Emcocel $90M^{(R)}$ as an external disintegrant showed fastest disintegration. These results may suggest that crospovidone and Emcocel $90M^{(R)}$ possessed excellent wetting nature, which result in the rapid disintegration of tablet.

• Archives of Pharmacal Research
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• v.16 no.1
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• pp.71-74
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• 1993

The protective effect of adenosine triphosphate (ATP) on gastic ulcer induced in rats has been studied. Gastic ulceration was induced by hypothemic restraint stress or dicolofenac sodium. Gastic acid secretion and mucosal injury produced by the hypothemic restraint stress was greater as compared with those produced by diclofenac sodifum. ATP significantly reduced area of injury, however, increased cyclic adenosine monophosphate (cATP) content. Administration of dipyridamole along with ATP did not change the total lesion area in both models when compared to ATP alone. Aminophyline antagonized antagonized the protective effect of ATP on the injured area. Famotidine was found to be effective in reducing gastric acid output as well as the total injured area without any change in cAMP content when given along with ATP.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.46-46
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• 1992

항궤양약 및 진경약의 효능을 검색할 수 있는 방법을 추구하는데 목적이 있다. 항궤양약의 약효는 Shay궤양, 수침 Stress궤양, indomethacin, histamine 및 prednisolone으로 유발된 궤양에 대하여 실시하였고 진경약의 효능은 흰쥐 fundus 절편을 이용한 in vitro 방법으로 실시하였다. 그 결과 항궤양약 효능시험은 shay 궤양에 있어서 omeprazole은 10mg/kg (i.d.)의 용량에서 유의성 있는 항궤양 효과를 나타내었으며, 수침 stress궤양에서 famotidine은 0.3mg/kg(p.o.), indomethacin 궤양에서 famotidine은 3mg/kg(p.o.), histamine궤양에서 cimetidine 은 50mg/kg(p.o.), prednisolone궤양에서 cimetidine은 1mg/kg(p.o.)의 용량에서 유의성 있는 효과를 나타내었다. 또한 진경약의 약효검색에 관하여는 세신(Asarum sieboldii)의 MeOH엑스가 흰쥐 위절편(fundus) 표본에서 비상경적 진정 작용이 있음을 확인하였고, 그 작용강도는 papaverine의 1/50에 해당되나 이를 분획하였을 경우에 hexane 분획에서 papaverine의 1/2에 해당하는 강도가 있다는 결과를 얻었다.

• Journal of Pharmaceutical Investigation
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• v.34 no.6
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• pp.505-511
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• 2004

A bioequivalence study of $Bestidine^{TM}$ tablets (Choong Wae Pharma. Corp., Korea) to Dong-A $Gaster^{TM}$ (Dong-A Pharmaceutical Co., Ltd., Korea) tablets was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty four healthy male Korean volunteers received each medicine at the famotidine dose of 40 mg in a $2{\times}2$ crossover study. There was a one-week wash out period between the doses. Plasma concentrations of famotidine were monitored by a high-performance liquid chromatography for over a period of 12 hours after the administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 12 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the Cmax ratio for $Bestidine^{TM}/Gaster^{TM}$ were log 0.90-log 1.06 and log 0.98-log 1.20, respectively. These values were within the acceptable bioequivalence intervals of 0.80-1.25. Thus, our study demonstrated the bioequivalence of $Bestidine^{TM}$ and $Gaster^{TM}$ with respect to the rate and extent of absorption.

• Journal of Veterinary Clinics
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• v.31 no.3
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• pp.220-222
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• 2014

A 14 year-old Shih-tzu was referred to the Veterinary Medical Teaching Hospital of Chungnam National University with a history of foreign body ingestion and vomiting. The vomitus contained ketoprofen plaster, which is used for orthopedic analgesia in humans. Supportive care and gastrointestinal (GI) protective agents were administered, including famotidine, misoprostol, sucralfate, omeprazole, and fluid therapy. However, the clinical signs worsened, and anemia, melena, leukocytosis, and azotemia developed. The patient was diagnosed with GI hemorrhage and underwent a whole blood transfusion followed by barium sulfate administration. After administering barium sulfate as a GI protectant, the clinical signs improved, and the patient was discharged.

• Korean Journal of Clinical Pharmacy
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• v.8 no.2
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• pp.113-121
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• 1998

To clarify whether nizatidine, a $H_2$ receptor antagonist, has the cholinergic activity, the effects of nizatidine on the guinea pig ileum and on the acetylcholinesterase in human serum were studied. And, the mechanism of excitatory effect of nizatidine on the cholinergic system in ileum was also studied. Nizatidine caused a concentration-dependent contractile response by the guinea pig ileum. The $EC_{50}\;was\;53\;{\mu}M$ and the maximum response was at $300\;{\mu}M$. Ranitidine also caused a contractile response by the guinea pig ileum, but cimetidine and famotidine did not. The pretreatment with $H_1$ receptor antagonist did not affect the actions of nizatidine on the guinea pig ileum, but the pretreatment with atropine completely blocked them. Nizatidine significantly enhanced the acetylcholine-induced response of the guinea pig ileum, but not the pilocarpine-induced response. Nizatidine did not affect the histamine-induced response of the guinea pig ileum. Nizatidine still exerted the small excitatory effect on the guinea pig ileum pretreated with the high concentration of physostigmine. Nizatidine significantly inhibited the acetylcholinesterase in human serum. These results suggest that nizatidine exerts an excitatory effect on guinea pig ileum which seems to be associated with the cholinergic system, probably through an indirect mechanism, inhibition of acetylcholinesterase and/or increased release of acetylcholine.