Bioequivalence evaluation of two brands of metformin 500 mg tablets (Dialon & Glucophage)--in healthy human volunteers

A randomized, two-way, crossover study was conducted in 24 fasting, healthy, male volunteers to compare the bioavailability of two brands of metformin 500 mg tablets; Dialon (Julphar, UAE) as test and Glucophage (Lipha Pharmaceutical Industries, France) as reference product. The study was performed at the International Pharmaceutical Research Centre (IPRC), in joint venture with Al-Mowasah Hospital, Amman, Jordan. The drug was administered with 240 ml of water after a 10-h overnight fasting on two treatment days separated by 1-week washout period. After dosing, serial blood samples were collected for a period of 30 h. Plasma harvested from blood was analyzed for metformin by validated HPLC method with UV-visible detector capable to detect metformin in the range of 0.05-5.0 microg/ml with limit of quantitation of 0.05 microg/ml. Various pharmacokinetic parameters including AUC(0-t), AUC(0-proportional to), C(max), T(max), T(1/2), and lambda(Z) were determined from plasma concentrations of both formulations and found to be in good agreement with reported values. AUC(0-t), AUC(0-proportional to) and C(max) were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence interval (97.9-110.8% for AUC(0-t), 97.4-110.7% for AUC(0-proportional to); 95.3-110.5% for C(max)) of test/reference ratio for these parameters were found within bioequivalence acceptance range of 80-125%. Based on these statistical inferences, it was concluded that Dialon is bioequivalent to Glucophage.     

The effect of food on the pharmacokinetics of nifedipine in two slow release formulations: pronounced lag-time after a high fat breakfast

AIMS: The aim of this study was to investigate the effect of concomitant food intake on the bioavailability of two nifedipine containing modified release dosage forms for once daily administration. The clinical study was performed to investigate the in vivo relevance of pH-dependent differences in the in vitro release properties of the two dosage forms. METHODS: This was a randomized, open, 4-way crossover study in 24 healthy, male subjects. Following an overnight fast of 12 h single doses of Adalat OROS or Slofedipine XL were administered either in the fasted state or immediately after a high fat American breakfast. Nifedipine plasma concentrations in samples obtained until 48 h after drug administration were determined using a validated LC-MS/MS method. Calculation of pharmacokinetic parameters was conducted model-independently. The two dosage forms as well as the two administration conditions were compared by calculating point estimates and 90% confidence intervals for the relevant pharmacokinetic parameters. In vitro dissolution tests were performed using a paddle apparatus 3 acc. USP, a pharmacopoeial dissolution system consisting of reciprocating cylinders in flat-bottomed glass vessels, with various buffer systems covering the entire physiological pH-range of the gastrointestinal tract. RESULTS: After fasted administration the extent of bioavailability of nifedipine as characterized by AUC(0,infinity) was slightly lower for Slofedipine XL compared with Adalat OROS with a point estimate of 82.3% primarily resulting from pronounced differences in nifedipine concentrations during the first 15 h after administration. Accordingly, maximum plasma concentrations were lower after administration of Slofedipine XL compared with Adalat OROS (point estimate: 84.3%). Under fed conditions the differences in bioavailability between the two products as characterized by the pharmacokinetic parameters AUC(0,tn) and Cmax were greater than after fasting conditions with point estimates of 69.6% and 81.0%, respectively. However, most striking was a pronounced delay in nifedipine absorption observed under fed conditions after administration of Slofedipine XL which resulted in lag-times of more than 15 h in 15 out of 24 subjects. Owing to this lag-time under fed conditions the relative bioavailability of nifedipine from Slofedipine XL compared with Adalat OROS was only 28% over the intended dosing interval of 24 h. CONCLUSIONS: In this study a dosage form-dependent food interaction was observed which, under fed conditions, resulted in pronounced differences in the relative bioavailability of nifedipine between Slofedipine XL and Adalat OROS over the intended dosing interval of 24 h. The delay in nifedipine absorption when Slofedipine XL is administered after a high-fat breakfast may be explained by the formulation properties. Slofedipine XL is an erosive tablet with an acid resistant coating whereas Adalat OROS is designed with an osmotic push-pull system. Under fed conditions drug from the single unit enteric coated dosage form exhibits a delayed absorption probably due to an extensively prolonged gastric residence time which does not allow drug release, on the other hand the osmotically driven push-pull system is not sensitive to concomitant food intake. The observed phenomenon might be of therapeutic relevance. For example a change from taking Slofedipine XL in the fed to the fasted state might result in increased systemic concentrations of nifedipine.     

劳拉西泮片在健康人体的药代动力学和生物等效性

目的研究劳拉西泮片(镇静药)在中国健康人体的药代动力学和生物等效性。方法健康志愿者20名,随机双交叉单剂量口服试验和参比制剂劳拉西泮片3mg;于服药后48h内,抽取静脉血;用高效液相色谱法测定血浆中劳拉西泮浓度;用3P97药代动力学程序计算相对生物利用度并评价2种制剂生物等效性。结果劳拉西泮的药代动力学参数Cmax分别为(35.77±6.84),(36.95±4.60)μg·L-1;tmax分别为(2.38±0.56),(2.23±0.48)h;t1/2(Ke)分别为(13.72±2.07),(13.83±2.49)h;AUC(0-48)分别为(542.19±84.33),(527.53±63.52)ng·h·mL-1;AUC(0-inf)分别为(605.22±93.52),(599.37±71.56)ng·h·mL-1。试验制剂与参比制剂的相对生物利用度F=(103.5±15.9)%。结论2种制剂具有生物等效性。     

液相色谱-串联质谱法测定苯妥英在健康人体的血药浓度并研究其生物等效性

目的建立快速、灵敏的液相色谱-串联质谱法测定健康人血浆中的苯妥英(抗癫痫药),并进行生物等效性研究。方法血浆样品50μL经液- 液萃取后,以甲醇-水-甲酸(90:10:0．2)为流动相,Zorbax SB-C18柱分离; 样品经大气压化学电离源(APCI)正离子化后,通过三重四极杆串联质谱仪, 用选择反应监测(SRM)对苯妥英(m／z 253→m／z 182)和柳胺酚(m／z 230→ m／z 121,内标)进行测定。用此法测定了20名受试者单剂量口服受试和参比制剂后苯妥英的血药浓度。结果线性范围为2．5—3 000 ng·mL-1,定量下限为2．5 ng·mL-1;日内、日问精密度(RSD)均<7．0％,准确度(RE)在 -0．5％～2．3％。2种制剂的Cmax、AUC0-t均无显著性差异。结论该法专属、灵敏、快速,适用于复方制剂中苯妥英的生物等效性评价。     

多潘立酮口腔崩解片在健康人体的生物等效性

目的观察多潘立酮口腔崩解片(胃动力药)在健康人体的生物等效性。方法22名健康受试者随机交叉单剂口服多潘立酮口腔崩解片剂及多潘立酮片剂后,用HPLC法测定多潘立酮血药浓度。结果2种制剂的Cmax分别为(40.43±12.89),(42.31±20.32)μg·mL-1;tmax分别为(0.84±0.29),(0.91±0.48)h;t1/2(ke)分别为(11.23±5.06),(10.13±4.02)h;AUC0-tn分别为(187.61±81.20),(189.07±97.69)μg·h·mL-1;AUC0-∞分别为(220.18±106.93)和(215.57±102.13)μg·h·mL-1;F0-tn、F0-∞分别为(102.61±16.41)%和(101.96±16.06)%。结论试验制剂和参比制剂具有生物等效性。     

克拉霉素缓释胶囊在健康人体的药代动力学和生物等效性

目的评价克拉霉素缓释胶囊与片(大环内酯类抗生素)在健康人体的药代动力学和生物等效性。方法用双周期自身交叉对照试验设计,男性志愿者20名,随机分成2组,单剂和多剂口服克拉霉素缓释胶囊和普通片,用微生物杯碟法测定血清中克拉霉素浓度。结果单剂量:缓释胶囊和片的Cmax分别为(1.44±0.74)和(1.56±0.67)μg·mL-1;tmax分别为(4.20±0.89)和(1.92±0.61)h;AUC0-14分别为(7.90±2.81)和(8.22±2.76)μg·h·mL-1。多剂量:AUCs0s-24h分别为(28.02±12.55)和(27.25±12.31)μg·h·mL-1,Cmssax分别为(3.19±1.35),(2.86±1.00)μg·mL-1和Csmsin分别为(0.18±0.13),(0.46±0.18)μg·mL-1。缓释胶囊相对片的Cmax降低,tmax延迟,相对生物利用度为(96.11±13.22)%。结论克拉霉素缓释胶囊与片为生物等效,且有缓释特征。     

国产与进口吲达帕胺片在中国健康人体的生物等效性

目的研究国产和进口吲达帕胺片(抗高血压药)在中国健康人体的药代动力学,并评价2种制剂的生物等效性。方法用随机交叉试验,22名健康男性单剂量空腹口服国产和进口吲达帕胺片2.5mg,采集72h内动态血标本;用液相色谱-串联质谱法测定全血中吲达帕胺的浓度,计算药代动力学参数,并进行生物等效性评价。结果国产和进口片剂的tmax分别为(2.0±0.8)和(2.6±1.2)h,Cmax分别为(121.9±22.3)和(118.5±22.3)μg·L-1,AUC0-72h分别为(2464.9±423.2)和(2317.0±455.2)μg·h·L-1,t1/2分别为(15.4±1.9)和(15.2±2.1)h。国产制剂的相对生物利用度为(107.5±12.7)%。结论2种制剂具有生物等效性。     

复方盐酸二甲双胍片的人体生物等效性

目的研究试验制剂国产复方盐酸二甲双胍片与参比制剂格列本脲片、盐酸二甲双胍片的人体生物等效性。方法健康志愿者20名,随机双交叉单剂量口服2种制剂,2次服药间隔为2 wk。分别于服药后24 h内多点抽取静脉血,用RP-HPLC测定血浆中格列本脲和盐酸二甲双胍的浓度。血药浓度经3P97程序处理,用非房室模型估算药动学参数。结果试验制剂和参比制剂血浆中格列本脲的ρmax分别为(190.91±45.01)(、175.71±27.47)μg.L-1,tmax分别为(2.60±0.87)、(2.35±0.71)h,AUC0→24分别为(1 110.85±275.12)(、1 074.77±202.76)μg.h.L-1,AUC0→∞分别为(1 187.91±275.55)(、1 168.52±168.65)μg.h.L-1;二甲双胍的ρmax分别为(3.06±0.63)、(3.06±0.55)mg.L-1,tmax分别为(1.57±0.37)(、1.65±0.37)h,AUC0→12分别为(12.05±1.92)、(12.05±1.79)mg.h.L-1,AUC0→∞分别为(12.47±1.97)(、12.51±1.80)mg.h.L-1。以格列本脲和盐酸二甲双胍计算的人体相对生物利用度分别为(103.8±17.9)%和(100.7±13.0)%。结论2种制剂具有生物等效性。     

洛美利嗪片剂与胶囊剂的人体生物等效性比较

目的:评价洛美利嗪片与参比制剂(洛美利嗪胶囊)是否生物等效。方法:男性健康受试者20名,随机分成2组,交叉口服受试制剂(洛美利嗪片)和参比制剂各40 mg,用高效液相色谱紫外检测法测定人血清中洛美利嗪浓度,所得数据经BECS软件处理得到主要药动学参数。结果:洛美利嗪片与参比制剂洛美利嗪胶囊的t_(max)分别为:(2．7±s 0．3)h和(2．6±0-3)h,c_(max)分别为:(93±11)μg·L~(-1)和(90±11)μg·L~(-1),用梯形法计算所得的AUC_(0-t)分别为(435±71)μg·h·L~(-1)和(432±77)μg·h·L~(-1)。对经对数转换后的c_(max),AUC_(0-t),进行方差分析和双单侧t检验及90％可信限判断,洛美利嗪片的c_(max)落在参比制剂的963％～11 1．7％范围内,AUC_(0-T)落在参比制剂的91．7％～110．6％范围内,t_(max)经非参数检验法检验无显著差异,洛美利嗪片AUC_(0-t) 的相对生物利用度为(101±12)％。结论:2种制剂具有生物等效性。     

硫酸茚地那韦胶囊的人体药动学及生物等效性

目的:评价健康受试者单剂量口服国产和进口硫酸茚地那韦胶囊的药动学及生物等效性。方法:20例男性健康受试者交叉单剂口服国产和进口硫酸茚地那韦胶囊800mg。用HPLC-UV法测定血浆中茚地那韦的血药浓度,并用SPSS 10．0统计软件对药代参数进行药动学及生物等效性研究。结果:受试制剂和参比制剂C_(max)分别为(13．14±3．92)和(13．51±3．23)mg·L~(-1);T_(max)分别为(0．63±0．18)和(0．63±0．17)h;AUC_(0→8h)分别为(23．02±6．24)和(23．62±7．27)mg．h·L~(-1);t_(1/2)分别为(1．2±0．4)和(1．2±0．5)h。受试制剂对参比制剂的相对生物利用度F为(99．2±13．9)%。结论:受试制剂与参比制剂具有生物等效性。