Modeling in Frequency Domain Used for Assessment of In Vivo Dissolution Profile

Purpose. To present a model-dependent approach for the assessment of the in vivo drug dissolution profile based on in vitrodata for the multiple unit dosage form, as an alternative to the numerical method proposed in the study by Hayashi et al, Pharm. Res. 12:1333–1337 (1995). Methods. The data for aspirin granules administered to healthy subjects obtained in the above mentioned study were re-evaluated. The subject dissolution system was considered to consist of two subsystems connected in series, i.e. the subsystem describing the gastric-emptying process and the subsystem describing the intestinal dissolution process. The frequency response method was used to model the subject dissolution system. Results. The model in vivodissolution profile of aspirin, assessed as the integral of the model weighting function of the subject dissolution system, was in agreement with the in vivo cumulative absorption profile calculated by the Wagner-Nelson method. Conclusions. Comparison of dynamic properties of the subject dissolution system with the subsystem describing the gastric-emptying process yielded quantitative confirmation of the decisive role of the gastric-emptying process in the in vivodrug dissolution after administration in the multi unit dosage form.     

BIOEQUIVALENCE BETWEEN rhGH FOR RECONSTITUTION AND READY-TO-USE rhGH IN TWO LIQUID FORMULATIONS

Objective To evaluate the bioequivalence between recombinant human growth hormone （rhGH） for reconstitution, and two dosages of liquid formulation of rhGH [ （151U） 5mg or （301U） lOmg per 3ml ]. Methods The study drugs were tested in a randomized, single-blind and three-period crossover studies in 24 healthy male subjects. The three drugs were administered by subcutaneous injection at a dose of O. 21U/kg body weight. A continuous somatostatin infusion was given in order to suppress the secretion of endogenous GH. The ve- nous blood samples were drawn at different time points to test the serum concentration of GH. The pharmacokinetic parameters were analyzed by statistical methods. Results 90% confidence intervals （CI） of AUC0-24h among three products were all within 80% - 125% interval （ 103. 4% - 116. 5%, 105. 7% - 119. 6% and 91.9% - 103. 7%, respectively）, and the Cls of C,~ among three products were all within 70% - 143% interval （91.9% - 114. 0%, 103. 7% -127. 2% and 81.6% -97. 4%, respectively）. There was no statisitical difference of tmax among all the three products. Conclusion These data demonstrate that there is bioequivalence between rhGH for reconstitution and two liquid formulations of rhGH.     

An Approach for Widening the Bioequivalence Acceptance Limits in the Case of Highly Variable Drugs

Purpose. Highly variable drugs pose a problem in bioequivalence assessment because they often fail to meet current regulatory acceptance criteria for average bioequivalence (80–125%). This paper examines alternative approaches to establishing bioequivalence. Methods. Suggested solutions have included alternate study designs, e.g., replicate and multiple dose studies, reducing the level of the confidence interval, and widening the acceptance limits. We focus on the latter approach. Results. A rationale is presented for defining wider acceptance limits for highly variable drugs. Two previously described methods are evaluated, and a new method having more desirable properties is proposed. Conclusions. We challenge the one size fits all current definition of bioequivalence acceptance limits for highly variable drugs, proposing alternative limits or goal posts which vary in accordance with the intrasubject variability of the reference product.     

头孢克洛缓释片在健康人体的药代动力学及生物等效性

目的 研究头孢克洛两种缓释片在健康志愿者体内的药代动力学和相对生物利用度。方法 20名健康男性受试者随机交叉单剂量及多剂量口服受试制剂375mg和参比制剂375mg,用液相色谱一串联质谱法测定给药后不同时刻的血浆浓度,求得主要药代动力学参数。结果 单剂量口服获得的主要药动学参数,t_(max)分别为2.23±0.64和2.05±0.56 h,C_(max)分别为2.54±0.89和2.38±0.65 mg·L~(-1),AUC_(0-t)分别为7.38±1.66和7.09±1.71 mg·h.L~(-1),t_(1/2)分别为1.08±0.12和1.07±0.13h,F为(105.0±11.2)％。多剂量口服获得的主要药动学参数AUC_(ss)分别为7.22±1.37和7.02±1.53mg·h·L~(-1),C_(max)分别为2.61±0.61和2.34±0.55 mg·L~(-1),C_(min)分别为3.48±1.33和3.65±1.23 μg·L~(-1),C_(av)分别为602±114和585±128μg·L~(-1),DF分别为4.3±0.7和4.0±0.6,F为(105.5±19.9)％。统计学结果显示,两种制剂的药动学参数无显著性差异,符合生物等效性标准。结论 头孢克洛两种缓释片均具有较好的缓释特征,两种制剂生物等效。     

多西环素肠溶微粒胶囊与片剂的人体生物等效性

目的 :研究多西环素肠溶微粒胶囊和多西环素片的人体生物等效性与药动学。方法 :2 0名男性健康志愿者随机分 2组 ,按双周期交叉口服单剂量 2 0 0mg多西环素的 2种制剂 ,分别于服药前及服药后 0 5 ,1,1 5 ,2 ,2 5 ,3,4,6 ,8,12 ,2 4,48,72h取血样 ,以HPLC法测定血浆中多西环素浓度 ,计算 2种制剂相对生物利用度参数 ,并评价其生物等效性。结果 :口服受试制剂多西环素肠溶微粒胶囊和参比制剂多西环素片的药动学参数 :cmax分别为 (3 6 5± 0 81) μg·mL-1和 (3 6 5± 0 73) μg·mL-1,tmax分别为 (2 5± 0 3)h和 (2 2± 0 7)h ,T1/ 2 (消除半衰期 )分别为 (2 1 4 8± 3 2 0 )h和 (2 1 85± 3 11)h ,AUC0→ 72 分别为 (72 18±2 2 6 8) μg·h·mL-1和 (72 0 6± 2 1 0 8) μg·h·mL-1,AUC0→∞ 分别为 (81 4 4± 2 4 94) μg·h·mL-1和 (81 82± 2 3 19) μg·h·mL-1,多西环素肠溶微粒胶囊相对生物利用度为 (10 1 9± 2 5 2 ) %,对参数cmax,AUC0→ 72 先进行方差分析 ,再进行双单侧t检验 ,表明 2种制剂的参数生物等效 ,tmax经非参数检验表明无统计学差异。结论 :多西环素肠溶微胶囊和多西环素片具有生物等效性。     

国产甲磺酸倍他司汀片剂与其进口片人体生物等效性

目的:对健康受试者单剂量口服国产和进口甲磺酸倍他司汀片后的药代动力学特性及生物等效性进行评价。方法:20名健康志愿者随机交叉口服24mg国产和进口甲磺酸倍他司汀两种片剂。用高效波相色谱-串联质谱法测定血浆中倍他司汀主要代谢物2-吡啶乙酸含量,并进行药代动力学和生物等效性研究。结果:国产及进口制剂中2-吡啶乙酸的C_(max)分别为308.6±208.8及339.4±213.4mg·L~(-1);t_(max)分别为1.13±0.66及0.98±0.47h;AUC_(0-t)分别为1168.5±794.9及1129.3±725.2mg·L~(-1);AUC_(0-∞)分别为1213.2±819.2和1178.9±752.5mg·L~(-1)。国产甲磺酸倍他司汀片的相对生物利用度为(106.31±29·1)％。结论:对AUC_(0-t),AUC_(0-∞),C_(max)和t_(max)分别进行方差分析后,进行双单侧检验及90％置信限判断,两制剂具有生物等效性。     

头孢克肟胶囊在健康志愿者的生物等效性研究

目的:研究头孢克肟胶囊在健康人体内的生物等效性。方法:20名健康男性志愿者双周期、随机交叉、自身对照,口服单剂量试验和对照头孢克肟胶囊200 mg。用HPLC-UV检测法和微生物法测定血药浓度,所得数据用3P97软件处理,按一室模型计算药代动力学参数。结果:试验及对照制剂HPLC法测定的C_(max)分别为2.317±0.536和2.87±0.492 mg·L~(-1);t_(max)分别为4.1±0.7和4.3±0.7 h;AUC_(0-16)分别为17.251±5.087和16.954±4.536 mg·L~(-1)·h;AUCO_(0-∞)分别为18.386±4.559和18.138±3.931 mg·h·L~(-1)。微生物法测定的C_(max)分别为2.437±0.495和2.361±0.435 mg·L~(-1);t_(max)分别为4.13±0.65和3.90±0.45 h;AUC_(0-16)分别为18.741±3.931和18.064±3.350 mg·h·L~(-1);AUCO_(0-∞)分别为20.109±4.497和19.403±3.693 mg·h·L~(-1)。对AUCO_(0-16)、AUC_(0-∞)、C_(max)进行双向单测检验,无显著性差异。HPLC法和微生物法测定的试验品相对生物采利用度分别为(101.53±18.21)％,(103.30±15.78)％,结论:试验头孢克肟胶囊和对照制剂具有生物等效性。HPLC法与微生物法呈相关性。     

头孢克肟片和胶囊在健康人体的生物等效性

目的 评价头孢克肟片剂、胶囊剂与参比制剂在健康人体内的药代动力 学及其生物等效性。方法用三交叉全排列组合设计,18名健康男性受试者 交叉单剂量口服试验药头孢克肟片、胶囊和对照药头孢克肟胶囊剂,用高效液 相色谱法测定其的血药浓度。结果受试制剂头孢克肟片、胶囊与对照药头孢 克肟胶囊的Cmax分别为:(1．64±0．45),(1．58±0．37)和(1．67±O．46)μg· mL-1;tmax分别为:(3．78±0．38),(3．75±0．34)和(3．86±0．28)h;AUC0-24分 别为:(13．58±3．78),(13．49±3．63)和(13．36±4．16)mg·h·L-1;AUC0-∞ 分别为:(14．49±3．94),(14．32±3．87)和(14．05±4．31)mg·h·L-1。经统 计学分析,3组间均无显著性差异(P>0．05)。结论3种制剂具有生物等效 性。     

重组人生长激素2种制剂人体生物等效性研究

目的:评价重组人生长激素(rhGH)注射液(2种规格:T1和T2)与注射用rhGH冻干粉针剂(参比制剂,R)的人体生物等效性。方法:运用随机、单盲、三阶段交叉方法分别对24名健康男性志愿者单次皮下注射0.2IU·kg-1的R,T1和T2。测定不同时间点生长激素血药浓度,并进行相关药动学参数分析。结果:T1,T2的AUC0～24的90%置信区间分别落在R的103.4%～116.5%和105.7%～119.6%范围内,T1的AUC0～24的90%置信区间落在T2的91.9%～103.7%范围内;T1和T2的cmax的90%置信区间分别落在R的91.9%～114.0%和103.7%～127.2%范围内,T1的cmax的90%置信区间亦落在T2的81.6%～97.4%的范围内。tmax在R及T1,T2间无统计学差异(P>0.05)。结论:T1,T2与R具有生物等效性。     

国产去羟肌苷散剂与进口去羟肌苷片剂的人体生物等效性

目的:评价国产去羟肌苷散剂与进口去羟肌苷片剂的人体生物等效性。方法:20名健康男性受试者,随机分为A和B两组,自身交叉口服单剂量国产去羟肌苷散剂250mg和进口去羟肌苷片剂200mg。血浆采用固相萃取处理,以HPLC测定去羟肌苷的经时血药浓度,计算2种制剂相对生物利用度参数,并评价其生物等效性。结果:国产去羟肌苷散剂和进口去羟肌苷片剂的主要药动学参数,tmax为(0.67±s0.04)h和(0.66±0.06)h,cmax为(0.84±0.26)mg·L-1和(0.9±0.3)mg·L-1,t1/2为(2.6±0.4)h和(2.5±0.3)h,AUC0~10为(1.7±0.8)mg·h·L-1和(1.7±0.7)mg·h·L-1,AUC0~∞为(1.8±0.9)mg·h·L-1和(1.9±0.9)mg·h·L-1。国产去羟肌苷散剂的相对人体生物利用度是(96±21)%(n=20,以AUC0~10计)。去羟肌苷散剂和片剂的主要药动学参数经交叉试验方差分析显示差异无显著意义(P>0.05)。2种制剂的AUC0~10,AUC0~∞,cmax经双单侧t检验示90%置信区间位于有效区间80%~125%范围内。结论:国产去羟肌苷散剂与进口去羟肌苷片剂具有生物等效性。