美洛昔康片溶出度的测定

美洛昔康（meloxicam)为环氧化酶抑制剂，用于治疗关节炎和类风湿性关节炎，疗效好。本文建立紫外可见分光光度法测定溶出度，测定波长362nm，在2.4-12μg/ml范围内，线性关系良好，回收率99．7％，RSD＝0．50％。美洛昔康片的溶出度测定条件为：以pH7.2的磷酸盐缓冲液900ml为溶剂，照中国药典1995版溶出度测定第二法，转速为60r/min，取样时间为45min，限度为70％。三批供试品溶出度符合要求，且与进口片无显著差异。     

国产与进口地高辛片人体生物利用度的研究

目的：国产地高辛片长期以来存在着生物利用度差的问题,为此杭州民生药厂进行了工艺改进。方法：以英国Ｌａｎｏｘｉｎ片为对照,采用荧光偏振免疫分析法测定了８名健康男性受试者口服单剂量０．５ｍｇ地高辛片的药时数值,经ＰＫＢＰＮ１程序拟合,计算其药动学参数。结果：国产和进口的Ｃｍａｘ分别为３．０±０．６ｎｇ·ｍｌ－１和２．５±０．５ｎｇ·ｍｌ－１;Ｔｍａｘ分别为１．１±０．６ｈ和１．１±０．４ｈ;ＡＵＣ分别为３７．９±４．２ｎｇ·ｈ·ｍｌ－１和３７．２±６．１ｎｇ·ｈ·ｍｌ－１;杭州民生药厂工艺改进后的片剂相对生物利用度为１０３．８％±１７．０％。结论：国产片与进口片地高辛完全等效。这为临床应用提供参考,也为药品的国际接轨提供依据     

二氟尼柳片剂人体相对生物利用度

目的比较二氟尼柳片剂与胶囊剂人体药物动力学和生物利用度.方法采用高效液相色谱法测定10名健康志愿者单次口服500mg片剂或胶囊剂后,二氟尼柳在血浆中的药物浓度,计算两者的药物动力学参数和相对生物利用度.结果二氟尼柳片剂和胶囊剂人体药-时曲线符合一室开放模型,其主要药物动力学参数T1/2分别为(10.46±1.33)和(10.75±2.21)h;cmax分别为(30.76±3.20)和(29.93±2.26)mg/L;tmax分别为(2.22±0.31)和(2.13±0.61)h;MRT分别为(17.33±1.84)和(17.48±2.88)h;AUC0→t分别为(434.33±53.21)和(428.55±68.00)mg*h/L;二氟尼柳片剂对胶囊剂的相对生物利用度为(102.2±8.94)%.两制剂的AUC、cmax及lnAUC、lncmax经方差分析和双单侧检验法证明无显著性差异(P＞005).结论二氟尼柳片剂和胶囊剂具有生物等效性.     

盐酸氟桂利嗪片的人体相对生物利用度

目的:比较盐酸氟桂利嗪(A)与参比片(B)的药物动力学和相对生物利用度.方法:采用HPLC荧光法测定10名健康受试者po 24mg A和B后,盐酸氟桂利嗪在血浆中的浓度,计算两者的药物动力学参数和相对生物利用度.结果:A和B的AUC_(0—∞)分别为(481.82±21.33)、(497.24±36.03)(μg·h)/L,t_(?)分别为(3.69±0.27)、(3.69±0.32)h,C_(?)分别为(4O.29±2.71)、(40.89±3.6Oμg/L,两者的AUC,t_(?)、c_(?)均无显著性差异(P>0.05).采用梯形法计算两者的AUCO_(0—t)分别为(459.26±14.75)、(468.32±34.44)(μg·h)/L,A的相对生物利用度为(98.4±6.6)%.结论:被试片剂与参比片剂具有生物等效性.     

Dissolution and bioavailability of digoxin tablets

A dissolution test is described for tablets of digoxin B.P. Dissolution profiles are reported for 11 brands of digoxin tablets available in Gt. Britain in 1972. Good correlations exist between both the area under the serum concentration/time curve from 0–6 h and (1) the amount of digoxin dissolved in 1 h, (2) the reciprocal of the time for 50% dissolution.     

Dissolution rates of hydrocortisone and prednisone utilizing sugar solid dispersion systems in tablet form

The utilization of ternary sugar solid dispersion systems and the incorporation of these systems into tablet dosage forms were investigated. The dispersion systems were prepared by the fusion method using 50% sucrose-50% mannitol and 50% sorbitol-50% mannitol. Other systems investigated utilized sorbitol, mannitol, and polyethylene glycol 6000 for comparison. The drug component was hydrocortisone or prednisone. The results from a modified NF XIII dissolution rate determination revealed that the mannitol system had the fastest dissolution rate, followed by sorbitol-mannitol, sucrose-mannitol, sorbitol, and finally, polyethylene gylcol 6000. The corticosteroids were stable and did not decompose during preparation of the dispersion systems or direct compression of the tablets. A short-term stability study revealed that the tablets retained their fast dissolution rates and that the tablet characteristic tests, i.e., tablet hardness, remained unchanged. The use of sugar combinations overcame some difficulties previously reported with single sugar systems.     

Dissolution of meprobamate from various tablet formulations

The effect of some formulation variables on the release of meprobamate from compressed tablets has been investigated. Possible interaction among the various variables was also studied. As a diluent, lactose produced a better dissolution rate than did starch. Tablets made with starch paste as the binder produced a faster release of meprobamate than those made with gelatin solution. Acacia proved to be the best disintegrating agent when compared to microcrystalline cellulose or starch, especially when the formulation already contained starch as the diluent. Under these conditions, microcrystalline cellulose was a better disintegrating agent than starch. Magnesium stearate or talc when used as a lubricant did not reduce the rate of release of meprobamate. Formulations containing a large proportion of starch (about 50%) did not produce a fast release of meprobamate.     

Dissolution and relative bioavailability of two carbamazepine preparations for children with epilepsy.

The in-vitro dissolution profiles of two carbamazepine formulations (Tegretol and a generic carbamazepine) have been assessed and the bioavailability of carbamazepine compared in 12 epileptic children at steady-state. Dissolution from the generic formulation (100 and 200 mg tablets) tended to be greater than for the proprietary tablets. However, the bioavailability and pharmacokinetics of carbamazepine when assessed at steady-state were similar for the two formulations. It appears, therefore, that the breakthrough seizures and higher incidence of neurological side-effects observed when children were given generic carbamazepine in place of the proprietary formulation cannot be accounted for by differences in bioavailability or pharmacokinetics.     

国产格列齐特片剂的生物利用度比较

目的：研究不同厂家生产的两种格列特剂在健康人体内的药物动力学和相对生物利用度。方法：采用ＨＰＬＣ测定１０名志愿者单剂量ｐｏ ８０ｍｇ格列齐特片剂后的血药浓度变化情况。结果：两种片剂的药物动力学参数：Ｃｍａｘ分别为５．１０和３．９７μｇ／ｍｌ，ｔｍａｘ分别３．５５和３．９７ｈ；ＡＵＣ分别８７．９７和９２．４４（ｈ．μｇ）／ｍｌ，Ｔ１／２分别为１０．７４和１０．７６ｈ。经统计学处理表明，两种片剂的ＡＵ     

罗红霉素分散片人体相对生物利用度研究

采用自身前后交叉对照试验方法以 12例男性健康自愿受试者 ,单剂量口服罗红霉素分散片和罗红霉素片 (对照药品 )进行人体生物利用度比较研究。应用高效液相色谱法 (HPL C)测定服药后 48h内的血清罗红霉素浓度。结果表明罗红霉素分散片和罗红霉素片的主要药动学参数达峰时间 Tmax分别为 1.6 7± 0 .6 0和2 .31± 0 .48h,峰值血药浓度 Cmax为 11.0 9± 1.6 8和 9.35± 1.31mg/L ,T1 / 2β分别为 19.5 9± 8.11和 17.70± 4.2 2 h。药时曲线下面积 AUC分别为 16 9.90± 6 6 .41和 142 .77± 40 .0 9mg.h/L ,经双单侧 t检验两者的 Tmax、T1 / 2β无显著性差异 (P>0 .0 5 )。罗红霉素分散片的 Cmax高于普通片 (P<0 .0 5 ) ,AUC略高于普通片 ,但无明显差异 (P=0 .2 386 )。罗红霉素分散片对罗红霉素片的平均相对生物利用度为 118.89% ,以上说明罗红霉素分散片的生物利用度略优于普通片。     

Gastroretentive mucoadhesive tablet of lafutidine for controlled release and enhanced bioavailability

Abstract

Lafutidine a newly developed histamine H2-receptor antagonist having biological half-life of 1.92?±?0.94?h due to its selective absorption from upper part of gastrointestinal tract the development of mucoadhesive sustained release drug delivery system is recommended in order to enhance the bioavailability. A mucoadhesive tablets was developed using the natural polymer, sodium alginate, xanthan gum and karaya gum. Mucoadhesion is a complex phenomenon which involves wetting, adsorption and interpenetration of polymer chains. The prepared tablets of various formulations were evaluated for a total mucoadhesion time, buoyancy lag time and percentage drug released. The formulation with xanthan gum showed better results. Thus, it may be useful for prolonged drug release in stomach to improve the bioavailability and reduced dosing frequency. Non-fickians release transport was confirmed as the drug release mechanism from the optimized formulation by Korsmeyer–Peppas. The optimized formulation (B3) showed a mucoadhesive strength >35?g. In vivo study was performed using rabbits by X-ray imaging technique. Radiological evidences suggest that, a formulated tablet was well adhered for >10?h in rabbit’s stomach. Optimized lafutidine mucoadhesive tablets showed no significant change in physical appearance, drug content, mucoadhesive properties and in vitro dissolution pattern after storage at 40?°C temperature 75?±?5% relative humidity for 3 months.     

头孢克洛咀嚼片的人体相对生物利用度

目的 :研究 2 0名男性健康受试者单剂量口服 75 0mg头孢克洛咀嚼片和胶囊后 ,头孢克洛咀嚼片相对生物利用度。方法 :采用RP HPLC测定人血浆中头孢克洛浓度 ,并用 3P97程序拟合。结果 :单剂量口服 75 0mg头孢克洛咀嚼片和胶囊后的AUC0→ 3 5h分别为 (2 1 90± 3 3 5 ) ,(2 2 4 8± 3 66) μg·h·mL-1;cmax分别是 (18 10± 3 77) ,(18 3 6± 4 0 3 ) μg·mL-1;tmax分别是 (0 70± 0 2 0 ) ,(0 80± 0 2 0 )h ;T1/ 2 分别为 (0 4 9± 0 0 6) ,(0 5 6± 0 17)h ,头孢克洛咀嚼片和胶囊的所有药动学参数经统计学处理均无显著性差异 (P >0 0 5 )。结论 :头孢克洛咀嚼片和胶囊具有生物等效性     

Buprenorphine pharmacokinetics: relative bioavailability of sublingual tablet and liquid formulations.

Buprenorphine is an effective new treatment for opiate dependence. This study compared the bioavailability of buprenorphine from a tablet to that from a reference solution. Six men experienced with, but not dependent on, opiates (DSM-III-R) were each administered 7.7 mg of buprenorphine in liquid form and 8 mg in tablet form 1 week apart in a balanced crossover design. Plasma levels were measured by electron capture capillary gas chromatography (GC), and concentration-time curves were constructed. Pharmacokinetic data were analyzed by analysis of variance. The bioavailability from the tablet was approximately 50% that from the liquid and was not affected by saliva pH. Lower bioavailability from the tablet may be due to slow dissolution.     

尼莫地平漂浮缓释片的人体药物动力学及相对生物利用度

目的:比较尼莫地平(Nim)漂浮缓释片与普通片的药物动力学、相对生物利用度及体内外相关性.方法:10例男性健康受试者自身交叉对照、单剂量po Nim漂浮缓释片或普通片各120mg,采用HPLC法测定血浆Nim浓度,单室模型拟合药物动力学参数.结果:Nim缓释片和普通片的t_(max)分别为(2.83±0.45)和(0.87±0.27)h(P<0.01),C_(max)分别为(32.82±6.36)和(48.71±8.94)ng/ml(P<0.01),AUC分别为(204.81±45.03)和(159.98±39.96)h·ng/ml(P<0.01).数据经对数转换后进行双单侧检验,两种制剂生物不等效;缓释片的相对生物利用度为(129.89±17.02)%;其体内吸收与体外释药具有显著的相关性(P<0.01).结论:Nim漂浮缓释片生物利用度优于普通片,达到剂型设计要求.     

西洛他唑片的人体相对生物利用度

目的　研究2种西洛他唑片在正常人体内的药代动力学与相对生物利用度。方法　用HPLC法测定24名志愿者随机交叉口服2种国产西洛他唑100mg后的血药浓度,用3P97软件计算2药的药代动力学参数与相对生物利度。结果　试验与参比药物的体内药-时曲线呈二室摸型。tmax分别为(3.25±0.99) 和(3.88±1.19) h;Cmax分别为(1.02±0.41)和(0.99±0.37) mg.mL-1;AUC(0-T)分别为(12.65±3.83) 和(12.84±4.10) mg.h.mL-1;t1/2β分别为(19.50±13.72) 和(17.40±11.58) h。经配对t检验,2药药代动力学参数无显著性差异(P>0.05)。西洛他唑片相对生物利用度为 (98.52±13.52)%。结论　2种国产西洛他唑片具有生物等效性。     

Comparative bioavailability of two tablet preparations of metronidazole

In a randomized cross-over study, eight healthy volunteers received single 200 mg doses of metronidazole tablets (as either the May and Baker or Servipharm preparation) after an overnight fast. The bioavailability of these two preparations did not differ significantly as judged from the peak plasma concentration, time to peak plasma concentration and area under the plasma concentration-time curve. Metronidazole was found to have a plasma clearance of 1.05 +/- 0.14 (s.d.) and 0.98 +/- 0.17 ml min-1 kg-1, a plasma terminal half-life of elimination of 9.15 +/- 1.01 and 10.35 +/- 1.59 h, and an apparent volume of distribution of 0.83 +/- 0.06 l kg-1 (the values obtained with the May and Baker preparation being shown before the Servipharm preparation in each case).     

Comparative bioavailability of intravenous and oral chloramphenicol in adults

The comparative bioavailability of chloramphenicol from intravenous succinate, oral palmitate, and oral base preparations was studied in a crossover manner in 12 adult patients. Chloramphenicol was administered at a dose of 1 Gm every 6 hours, and blood samples were collected at steady state. For the succinate study, total urine output was also collected. The bioavailability of active chloramphenicol from the succinate preparation averaged 85.8 +/- 42.3 and 78.8 +/- 50.1 per cent of the free base and palmitate forms, respectively. This lower availability appeared to be due to variable excretion of unchanged succinate in the urine, averaging 27 +/- 11 per cent of the dose. Regardless of dosage form or route of administration, plasma chloramphenicol concentrations remained in the therapeutic range (5 to 25 mg/liter) for the entire dosage interval, implying that no change needs to be made when changing dosage form or route of administration. The interpatient variability, however, supports the need for monitoring of plasma chloramphenicol concentrations, especially in newborn infants, persons with liver disease, or those receiving other medications that alter chloramphenicol metabolism.     

Comparative bioavailability of two tablet preparations of diltiazem in healthy volunteers.

Comparative bioavailability of two formulations of diltiazem (Dilzene, CAS 42399-41-7), a calcium antagonist, was evaluated on 10 healthy volunteers (5 males and 5 females) in a cross-over study. A single dose of 120 mg of diltiazem was administered to the volunteers in the form of either two 60-mg tablets or a 120 mg controlled-release tablet. Plasma concentrations of diltiazem over a 24-h time interval were determined by HPLC analysis. Results of this investigation demonstrate that the controlled-release formulation of diltiazem has a lower Cmax value when compared to the 60 mg conventional tablet formulation, but a longer tmax and a superimposable AUC.