盐酸雷尼替丁泡腾颗粒剂的生物等效性研究

目的:测定盐酸雷尼替丁泡腾颗粒剂的生物等效性。方法:10名男性健康志愿者交叉口服盐酸雷尼替丁泡腾颗粒剂和盐酸雷尼替丁胶囊,采用HPLC法测定人血清中药物浓度进行生物等效性的研究。以ALLTMA C18为固定相,0.02mol·L-1磷酸二氢钾溶液-甲醇（70:30）为流动相,流速1.0mL·min-1,检测波长为320nm。结果:泡腾颗粒剂与胶囊的血药浓度曲线均符合二室模型。其主要药物动力学参数:Tpeak分别为（1.96±0.55）h和（2.21±0.39）h,Cmax分别为（665±213）μg·L-1和（547±181）μg·L-1,AUC分别为（3452±601）h·μg·L-1和（3053±579）h·μg·L-1。各参数经配对t-检验处理,均无显著差异（P>0.05）,泡腾颗粒剂的生物等效性经含量校正后为108％。结论:结果表明泡腾颗粒剂与胶囊剂具有生物利用等效性。     

多剂量口服盐酸氨溴索缓释胶囊的人体药代动力学及相对生物利用度

目的　研究多剂量口服盐酸氨溴索缓释胶囊的人体药代动力学和相对生物利用度。方法　选择盐酸奎宁为定量内标物 ,采用反相高效液相色谱法测定了多剂量口服 75mg盐酸氨溴索国产缓释胶囊和进口缓释胶囊在健康人体内的盐酸氨溴索血药浓度 ,以考察盐酸氨溴索缓释胶囊多剂量口服达稳态过程和稳态药代动力学特征。结果　 75mg盐酸氨溴索缓释胶囊连续口服d 4起 ,体内盐酸氨溴索血药浓度基本达稳态水平。国产缓释胶囊和进口缓释胶囊的稳态药代动力学参数Tmax分别为 (4 2± 0 7)h和 (4 1± 0 8)h ,Cmax分别为 (2 0 8 73± 31 91) μg·L-1和 (2 12 5 6± 2 9 6 4) μg·L-1,Cmin分别为 30 76± 10 47μg·L-1和 (2 9 80± 10 2 3)μg·L-1,AUCss分别为 (2 113 90± 430 6 0 ) μg·h·L-1和2 0 88 2 2± 40 2 5 2 μg·h·L-1,Cav分别为 (88 0 8± 17 94) μg·L-1和 (87 0 1± 16 77) μg·L-1,DF分别为 (2 0 7± 0 31)和(2 16± 0 37) ,多剂量口服 75mg国产盐酸氨溴索缓释胶囊的相对生物利用度为 10 1 10 %± 6 33 %。结论　盐酸氨溴索国产缓释胶囊和进口缓释胶囊的主要稳态药代动力学参数差异均无显著性 ,两种制剂具有生物等效性     

盐酸雷尼替丁片在健康志愿者的人体药代动力学和生物等效性

目的:研究国产盐酸雷尼替丁片和葛兰素威康生产的雷尼替丁片(商品名:善卫得)在健康人体内的药代动力学过程,并评价这两种制剂的生物等效性。方法:20例健康男性受试者随机分组、自身对照单次po盐酸雷尼替丁片300 mg后,用反相HPLC法测定血浆中雷尼替丁的浓度,依据血药浓度一时间数据进行有关参数计算及生物等效性评价。结果:对照制剂与试验制剂主要药代动力学参数C_(max)分别为1278.3±449.5 μg·L~(-1)及1200.5±433.1 μg·L~(-1);t_(max)分别为2.73±0.80 h及2.95±0.83 h;t_(1/2)分别为2.97±0.43 h及2.98±0.49 h;AUC_(0→t)分别为5582.2±1428.7 μg·h·L~(-1)及5199.0±1275.0μg·h·L~(-1); AUC_(0→∞)分别为5928.2±1389.3μg·h·L~(-1)及5413.3±1318.0 μg·h·L~(-1);试验制剂相对于对照制剂的生物利用度F为(94.6±16.1)％。结论:试验制剂与对照制剂生物等效。     

盐酸雷尼替丁胶囊人体药动学和生物等效性研究

目的:评价国产盐酸雷尼替丁胶囊与进口盐酸雷尼替丁片的人体生物等效性。方法:采用反相高效液相色谱法,测定20名健康志愿者随机分组、自身对照单次口服盐酸雷尼替丁胶囊或盐酸雷尼替丁片300mg后不同时刻的血药浓度,计算药动学参数,并进行方差分析和双单侧t检验。结果:盐酸雷尼替丁片与盐酸雷尼替丁胶囊的Cmax分别为(1247.1±547.5)、(1294.8±613.2)μg/L;tmax分别为(2.98±0.73)、(2.73±0.80)h;t1/2分别为(3.17±0.36)、(3.33±0.42)h;AUC0～t分别为(5805.9±1403.5)、(5941.2±1526.3)(μg·h)/L;AUC0～∞分别为(6163.8±1456.4)、(6351.8±1652.7)(μg·h)/L;盐酸雷尼替丁胶囊相对于盐酸雷尼替丁片的生物利用度为(104.3±24.3)%。结论:2种制剂具有生物等效性。     

克拉霉素颗粒剂和片剂的正常人体药物动力学和生物等效性

8名健康男性志愿者自身交叉单剂量口服 5 0 0mg克拉霉素颗粒剂和片剂 ,采用微生物法测定经时过程血药浓度 .用 3P87程序拟和 ,两制剂的血药浓度 时间曲线均符合单室模型 .求得克拉霉素颗粒剂和片剂药物动力学参数 .Ka分别为 (3.5 5± 0 .92 )和 (1.6 2± 0 .16 )h-1;t1/2 分别为(4.90± 0 .19)和 (5 .0 6± 0 .2 5 )h ;Cmax分别为 (2 .6 3± 0 .2 7)和 (2 .2 9± 0 .2 6 ) μg/mL ;Tmax分别为(1.12± 0 .10 )和 (1.6 8± 0 .0 6 )h ;AUC分别为 (2 1.6 7± 2 .5 4)和 (2 1.13± 3.19) μg·h/mL .经统计学处理 :两制剂的药动学参数Ka、Cmax、Tmax均有显著性差异 (P <0 0 5 ) ,t1/2 无显著性差异 (P >0 0 5 ) ,克拉霉素颗粒剂相对于片剂的生物利用度F为 (10 3.36± 11.15 ) % .经方差分析、单双侧检验法分析 ,证明两制剂具有生物等效性 .     

阿奇霉素干混悬剂 颗粒剂和胶囊的人体药代动力学研究

目的使用高效液相色谱-质谱(HPLC-MS)联用法测定人血浆中阿奇霉素的浓度,并研究阿奇霉素干混悬剂、颗粒剂和胶囊在健康人体内的药代动力学情况。方法 20名健康男性志愿者单剂量口服500mg阿奇霉素后,采集不同时间点血样测定血药浓度。结果阿奇霉素的线性范围为2.71～1084μg/L,日内和日间相对标准偏差(RSD)均<5.0%。阿奇霉素干混悬剂主要药代动力学参数为:Cmax:(453±130)μg/L;tmax:(2.3±0.9)h;t1/2:(48±6)h;平均驻留时间(MRT):(53±8)h;曲线下面积(AUC)0-t:(4694±903)μg·h-·1L-1;AUC0-∞:(5118±919)μg·h-1·L-1。结论 3种剂型阿奇霉素的药代动力学参数的差异无统计学意义。     

进口盐酸托烷司琼胶囊在中国人体的药代动力学

目的　研究进口盐酸托烷司琼胶囊的人体药代动力学。方法　采用HPLC 二极管阵列紫外法测定 18名健康志愿者口服剂量为 10mg的盐酸托烷司琼胶囊后受试者血浆中的盐酸托烷司琼的浓度。并应用 3P97软件对盐酸托烷司琼的血药浓度 -时间数据进行了拟合 ,求算其药代动力学参数。结果　进口盐酸托烷司琼胶囊的药代动力学参数为 :达峰时间 (Tmax)为 (2 5 3± 0 5 2 )h ,峰值浓度 (Cmax)为 (10 16± 2 89) μg·L-1,曲线下面积AUC0～ 2 4h分别为 (113 6 1±4 0 34)h·μg-1·L-1。结论　进口盐酸托烷司琼胶囊在志愿者体内分布及消除都很快 ,10mg单次给药安全     

单剂口服盐酸托烷司琼颗粒剂在健康人体的生物等效性

目的研究盐酸托烷司琼颗粒剂的药代动力学特征及生物等效性。方法用随机交叉给药方法,20名健康男性志愿者分别单剂量口服盐酸托烷司琼颗粒剂试验药及胶囊对照药20mg,用LC-MS/MS法测定血药浓度。计算2者的药代动力学参数及相对生物利用度。结果口服托烷司琼颗粒剂试验药及胶囊对照药20mg的主要药代动力学参数AUC0-t分别是:(523.82±432.96)和(547.04±455.59)ng·h·mL-1;AUC0-∞分别为(568.07±491.48)和(591.77±513.15)ng·h·mL-1;Cmax分别为(36.67±12.30)和(37.44±14.30)ng·mL-1;tmax分别为(1.85±1.66)和(1.85±0.79)h;t1/2分别为(9.76±6.33)和(9.77±5.51)h。相对生物利用度为(98.03±17.11)%。结论2种制剂具有生物等效性。     

注射用胸腺肽-α1在健康人体的生物等效性研究

目的 研究国产的注射用胸腺肽-α1在健康人体的药物动力学,并评价其与同剂量的进口参比制剂的生物等效性.方法 采用双周期交叉试验设计,20名男性健康受试者分别给予单剂量皮下注射试验制剂或参比制剂1.6mg.采用HPLC-MS/MS法测定给药后各时间点采集血样的血药浓度,计算主要药物动力学参数,以进口制剂为参比制剂,计算其相对生物利用度,判断其生物等效性.结果 试验制剂中胸腺肽-α1的主要药物动力学参数Cmax为(90.95±35.05)μg·L-1;tmax为(1.8±0.4)h;AUC0→12为(435.4±192.8)μg·h·L-1;t1/2为(3.9±1.2)h.参比制剂中胸腺肽-α1的主要药物动力学参数Cmax为(90.77±35.45)μg·L;tmax为(1.9±0.4)h;AUC0→12为(427.6±187.8)μg·h·L;t1/2为(3.9±1.3)h.受试制剂的相对生物利用度F为101.7%±8.0%.结论 2种制剂具有生物等效性.     

他克莫司对9例肾移植病人的药物动力学

目的 :研究单剂量口服他克莫司在肾移植病人体内药物动力学。方法 :9名肾移植病人单剂量口服他克莫司 2～ 3mg后 ,于 0 ,0 .3 3 ,0 .66,1,1.5 ,2 ,3 ,4,6,8,10 ,12h分别取外周静脉血 ,用微粒子酶免分析法 (MEIA)测定全血药物浓度 ,3P97模拟药物动力学模型 ,计算有关药物动力学参数。结果 :他克莫司符合二室模型 ,T12 α(0 .6± 0 .5 )h ;T12 β(13± 2 1)h ;Cmax(15± 7) μg·L- 1;Tmax(1.6±1.4)h ;V/F(15 6± 95 )L ;AUC0→∞(14 0± 166) μg·h·L- 1;Tlog(0 .3 0± 0 .0 5 )h ;Cssmin(10± 7) μg·L- 1。结论 :9例肾移植病人单剂量口服他克莫司后药物动力学参数与国外文献报道基本相符。     

紫外系数倍率法测定雷尼替丁血药浓度

目的 :测定雷尼替丁血药浓度。方法 :采用紫外系数倍率法 ,以甲醇作对照液 ,在波长200nm～400nm范围内扫描 ,选定λ1=324nm、λ2=358nm ,绘制工作曲线。结果 :口服雷尼替丁血药浓度有明显的双峰现象。结论 :本方法简便 ,适宜于基层单位进行血药浓度检测。     

Concentration uniformity of extemporaneously prepared ranitidine suspension

The concentration uniformity of an extemporaneously prepared ranitidine suspension was studied. To prepare the ranitidine suspension, 36 150-mg tablets were pulverized and suspended in 180 mL of distilled water. This mixture was diluted with simple syrup to a total volume of 360 mL, resulting in a final ranitidine concentration of 150 mg/10 mL. Samples from each of three bottles that had been filled with 60 mL of the suspension were assayed for ranitidine content by high-performance liquid chromatography. The sedimentation of suspended ranitidine tablet particles was studied by visual observation of the setting process in 10-mL samples from the same batch. The overall mean concentrations (in milligrams per milliliter) of ranitidine were 14.53, 15.25, 13.92, 12.67, and 12.72 at 0, 3, 7, 14, and 21 days, respectively. Compared with baseline, the difference in the ranitidine concentration was not significant over days 0-7. The ranitidine concentration was significantly reduced during the following time intervals: days 0-14, days 0-21, and days 7-21. In the settling experiments, the mean time (+/- S.D.) for sediment to first appear on the test tube bottom was 14.67 +/- 5.35 seconds. Approximately 40-50% (mean level = 3.2 mm) of the total sedimentation level (mean level = 7.3 mm) was observed one minute after shaking. The uniformity of ranitidine suspensions compounded according to procedures described in this report possibly could be improved with sonication. The ranitidine suspension should be well shaken, the dosage should be measured immediately after shaking, and the suspension should be used within seven days of compounding.     

Determination of ranitidine in plasma by high-performance liquid chromatography

A high-performance liquid chromatographic method has been developed for the determination of ranitidine in plasma. Ranitidine was extracted with acetonitrile by adding it to the plasma and then salting it out with potassium carbonate. The chromatographic column was 5-microns ODS silica, the mobile phase being acetonitrile-7 mM triethylammonium ion in phosphoric acid (pH 3.00) (30:70, v/v). The ranitidine peak was monitored at a wavelength of 315 nm, the retention time for ranitidine being 4.6 min. A limit of detection of 3 ng ml-1 was obtained for a 100-microliters injection of ranitidine. The method was found to be reproducible with a relative standard deviation (RSD) between 0.8-5.3% (n = 5) over the concentration range 25-80 ng ml-1 in plasma. The ranitidine concentration was determined in 18 different patients' plasmas. Ranitidine and its metabolites ranitidine S-oxide, ranitidine N-oxide and desmethyl-ranitidine, were also studied for chromatographic resolution from each other. It was shown that a group of common drugs did not interfere with ranitidine determination.     

Transdermal iontophoresis of ranitidine: an opportunity in paediatric drug therapy

The objective of this study was to examine the use of transdermal iontophoresis for the delivery of ranitidine hydrochloride in children. Constant, direct current, anodal iontophoresis of ranitidine was performed in vitro across dermatomed pig skin. The effect of donor vehicle, current intensity, and drug concentration were first examined using aqueous solutions. It was found that drug delivery was higher at pH 7 (donor: 5 mM Tris) than pH 5.6 (donor: water). In the presence of low levels of competing background electrolyte, ranitidine delivery increased linearly with applied current but was independent of the donor drug concentration. The second part of the study evaluated two Pluronic^® F-127 gels as potential vehicles for ranitidine delivery. The formulations were characterised in terms of apparent viscosity, conductivity and passive permeation measurements. Iontophoretic delivery of ranitidine was only slightly affected when delivered from the gels relative to aqueous solutions. Overall the results demonstrated that therapeutic paediatric doses of ranitidine (neonates: 0.09–0.17 μmol/kg h; 1 month to 12 years: 0.36–0.71 μmol/kg h) could be easily achieved by transdermal iontophoresis with simple gel patches of practical surface area (0.2–1.5 cm²/kg).     

Ranitidine Hydrochloride-loaded Ethyl Cellulose and Eudragit RS 100 Buoyant Microspheres: Effect of pH Modifiers

A floating type of dosage form of ranitidine hydrochloride in the form of microspheres capable of floating on simulated gastric fluid was prepared by solvent evaporation technique. Microspheres prepared with ethyl cellulose, Eudragit^® RS100 alone or in combination were evaluated for percent yield, drug entrapment, percent buoyancy and drug release and the results demonstrated satisfactory performance. Microspheres exhibited ranitidine hydrochloride release influenced by changing ranitidine hydrochloride-polymer and ranitidine hydrochloride-polymer-polymer ratio. Incorporation of a pH modifier has been the usual strategy employed to enhance the dissolution rate of weakly basic drug from floating microspheres. Further citric acid, fumaric acid, tartaric acid were employed as pH modifiers. Microspheres prepared with ethyl cellulose, Eudragit^® RS100 and their combination that showed highest release were utilized to study the effect of pH modifiers on ranitidine hydrochloride release from microspheres which is mainly affected due to modulation of microenvironmental pH. In vitro release of ranitidine hydrochloride from microspheres into simulated gastric fluid at 37° showed no significant burst effect. However the amount of release increased with time and significantly enhanced by pH modifiers. 15% w/w concentration of fumaric acid provide significant drug release from ranitidine hydrochloride microspheres prepared with ranitidine hydrochloride:ethyl cellulose (1:3), ranitidine hydrochloride:Eudragit^® RS100 (1:2) and ranitidine hydrochloride:ethyl cellulose:Eudragit^® RS100 (1:2:1) whereas citric acid, tartaric acid showed significant cumulative release at 20% w/w. In all this study suggest that ethyl celluose, Eudragit^® RS100 alone or in combination with added pH modifiers can be useful in floating microspheres which can be proved beneficial to enhance the bioavailability of ranitidine hydrochloride.     

Ranitidine clearance during hemodialysis with high-flux membrane: comparison of polysulfone and cellulose acetate hemodialyzers

OBJECTIVE: To compare the effect of hemodialysis using two different types of dialyzer membranes, polysulfone (PS), a high-flux membrane, and cuprophane (CP), a conventional membrane, on blood ranitidine concentration. BACKGROUND: Recent advances in hemodialyzer membranes have improved the removal of small and middle size uremic toxins, while little is known about the change of drug removal by new membranes. METHODS: Eight patients with chronic renal failure who received ranitidine (150 mg/day) on a chronic basis were included. During the dialysis, blood samples were obtained from both the arterial and venous sides (before and after, respectively) of the dialyzer. RESULTS: Serum concentration of ranitidine decreased more on PS [54 +/- 3% (+/- SEM) reduction after 3 h] than on CP (35 +/- 4%). The dialyzer clearance of ranitidine on PS membrane (67.2 +/- 4.4 ml/min/m2) was significantly higher than that on CP (43.1 +/- 3.8 ml/min/m2, P < 0.001). Elimination fraction (EF) of the drug during the dialysis with PS was also significantly higher than that with CP (72 +/- 2% versus 44 +/- 3%). Apparent half-life of ranitidine during dialysis with PS (2.9 +/- 0.4 h) was shorter than that with CP (5.1 +/- 0.7 h). However, the amount of ranitidine removed by a single dialysis with PS membrane was less than 20 mg. CONCLUSION: Ranitidine clearance by hemodialysis is significantly higher with PS than with CP. Although additional dose adjustment may not be needed for ranitidine, the type of dialyzer membrane can affect drug elimination and should be taken into account for consideration of drug removal by hemodialysis.     

Determination of the time of onset of action of ranitidine and famotidine on intra-gastric acidity

BACKGROUND: No standard methods exist for determining the onset of action of gastric antisecretory agents in human subjects. METHODS: Intragastric pH was measured when placebo, ranitidine 150 mg, ranitidine 75 mg or famotidine 10 mg were administered 30 min after the end of a meal. RESULTS: When the onset of action was defined as the earliest time that mean gastric pH with active treatment was statistically significantly higher (P < 0.05) than the corresponding placebo value, the onsets of action of ranitidine 75 mg and 150 mg were 55 min, and of famotidine 10 mg, 90 min. When onset was defined in terms of a particular decrease in gastric acid concentration for the group as a whole or for individual subjects, there was an important variation in the relative times of onset of ranitidine 75 mg and famotidine 10 mg. CONCLUSIONS: When administered after a meal, the onset of action of ranitidine and famotidine on gastric pH can be determined for individual subjects as well as for the group as a whole. When onset was determined for the group using statistical significance, which does not depend on arbitrary cut-off points, ranitidine 75 mg had an earlier onset of action than did famotidine 10 mg.     

Possible interaction of ranitidine with phenytoin

Clinical and animal studies have shown that cimetidine and ranitidine can inhibit hepatic cytochrome P-450-mediated metabolism of a variety of other drugs. This occurs to a lesser extent with ranitidine than with cimetidine at doses commonly used to treat gastric acid-related disorders. We recently observed a 66-year-old man whose steady-state serum phenytoin concentration increased 40 percent during one month after the addition to his regimen of ranitidine 150 mg bid. Because the ranitidine had been prescribed postsurgically for prophylaxis, it was discontinued and the patient's serum phenytoin concentration declined to the previous steady-state level with no change in dose or other drug therapy. This case indicates that the serum phenytoin concentration should be monitored for the first month after the addition of ranitidine to the regimens of patients on chronic phenytoin therapy. As well, further clinical investigation of factors affecting the interindividual inhibitory action of ranitidine is warranted.     

The effects of antacid and propantheline on the absorption of oral ranitidine

The effects of propantheline bromide and an aluminum hydroxide/magnesium hydroxide suspension on absorption of ranitidine were evaluated in 12 healthy volunteers according to a Latin square design. Ranitidine 150 mg was administered alone, with 30 ml antacid or preceded by 15 mg propantheline. Ten serum samples were obtained over 12 hours during each treatment period for measurement of ranitidine concentration. The antacid had no significant effect on ranitidine absorption, but propantheline increased the relative bioavailability of ranitidine by 22%. In addition, there was a trend, although not statistically significant, for propantheline to increase the maximum ranitidine serum concentration and the time to maximum serum concentration. Ranitidine can be administered concomitantly with the evaluated doses of antacid and propantheline without a clinically significant alteration in its absorption.     

荧光探针测定雷尼替丁、尼扎替丁和西咪替丁

目的:建立一种测定雷尼替丁、尼扎替丁和西咪替丁3种H2组胺受体药物的高灵敏度的荧光探针新方法。方法:本方法是基于小檗碱和葫芦[7]脲生成稳定的包合物并使其荧光强度显著增强,当加入3种药物中的任何一种均能使葫芦[7]脲/小檗碱包合物的荧光显著猝灭。据此建立了一种以小檗碱为荧光探针测定3种H2组胺受体药物的新方法。结果:药物在一定的浓度范围内与其相应的荧光猝灭值ΔF之间呈良好的线性关系,雷尼替丁、尼扎替丁和西咪替丁检测限分别为0.007,0.007,0.020μg·mL-1,比一般的光谱方法高2个数量级。同时对药物制剂和加标尿样进行测定,获得了满意的回收率。结论:该方法可用于药物制剂和生物体液中上述3种H2组胺受体药物的测定。