Pharmacokinetic and Pharmacodynamic Comparison of Immediate-Release and Sustained-Release Adinazolam Mesylate Tablets After Single- and Multiple-Dose Administration

The effect of adinazolam release rate on psychomotor performance and sedation was assessed by administering 40 mg adinazolam mesylate immediate-release (CT) tablets, 60 mg sustained-release (SR) tablets, and placebo in a double-blind crossover study in 15 healthy male subjects. A separate panel of 16 subjects received the above single doses and multiple-dose regimens of 40 mg CT tablets every 8 hr and 60 mg SR tablets every 12 hr according to a crossover design. Psychomotor performance was assessed by digit symbol substitution test, card sorting tasks, and sedation ratings. Following single-dose administration, dose-corrected adinazolam and N-desmethyladinazolam (NDMAD) AUC values were equivalent for SR and CT tablets. Peak adinazolam and NDMAD levels were lower and occurred later for the SR tablets. Decrements in card sorting were 50 and 3% at 1 hr and 17 and 20% at 6 hr for the CT and SR tablets, respectively. Maximal sedation scores were lower for the SR tablets compared to the CT. Dose-corrected AUC was comparable between single and multiple doses for both adinazolam and NDMAD; no differences were observed in 24-hr AUC at steady-state between CT and SR tablets. Fluctuation ratios were reduced for both adinazolam and NDMAD following SR tablets. Psychomotor and sedative effects were attenuated upon multiple dosing. Thus, the reduction in peak plasma NDMAD following SR tablet administration results in a lesser sedation and psychomotor impairment on acute administration, and tolerance to these effects occurs on mulitiple dosing.     

Absence of effect of food on alprazolam absorption from sustained release tablets

This study examined the effect of food on alprazolam absorption from a mixed polymeric matrix sustained release (SR) tablet in 21 healthy adults. Each subject received each of three treatments according to a crossover design: 1 mg alprazolam SR tablet while fasting; 1 mg alprazolam SR tablet immediately after a standardized breakfast; 1 mg alprazolam conventional tablet while fasting. The breakfast contained approximately 33 g protein, 55 g fat, and 58 g carbohydrate (850 calories). Serial blood samples were obtained and plasma alprazolam levels determined by HPLC. Results indicate that the SR tablet was minimally affected by food. Relative bioavailabilities of the SR tablet while fasting and with food were 100 per cent and 97 per cent, respectively. Although statistically significant, differences in mean Cmax values between SR tablets administered with and without food were small (12 per cent increase with food). Rates of absorption as measured by mean tmax values were also nearly the same: 7.2 h while fasting and 7.0 h with food. Absorption was relatively uniform with the SR tablets. Coefficients of variation for Cmax, tmax, and AUC were somewhat smaller with the SR tablet than with the conventional tablet.     

The pharmacokinetics and pharmacodynamics of adinazolam: multi-ethnic comparisons

The pharmacokinetics and pharmacodynamics of adinazolam and N-demethyladinazolam (NDMAD), its major active metabolite, were compared in 39 healthy male volunteers (13 Asian, 12 Caucasian and 14 African-American). In a four-way, double-blind crossover design, subjects were administered (1) 30 mg oral adinazolam mesylate SR tablets, (2) 10 mg parenteral (IV) adinazolam mesylate, (3) 30 mg IV NDMAD and (4) placebo. Venous blood samples were collected at specific time intervals after drug administration and assayed for adinazolam and NDMAD concentrations. Sedation was rated at the time of each blood draw according to the Nurse-Rated Sedation Scale, and the digit-symbol substitution test was administered to evaluate psychomotor performance. After IV administration of adinazolam, Asians manifested significantly higher C_max, larger AUC and lower CL of both adinazolam and NDMAD than their Caucasian and African-American counterparts. Likewise, after IV NDMAD Asians had significantly higher NDMAD C_max and AUC than Caucasians and African-Americans. Most of these differences remained statistically significant after controlling for body surface area. With PO adinazolam, Asians also manifested substantially higher C_max, larger AUC and lower CL for both adinazolam and NDMAD; however, with the exception of C_max, these differences did not reach statistical significance. These results are in accordance with previous observations for ethnic-related differences in drug pharmacokinetics. In contrast, pharmacodynamic differences were not noted among the three study groups. Received: 19 June 1996/Final version: 17 September 1996     

Effect of food on the relative bioavailability of two oral formulations of posaconazole in healthy adults

AIMS: This randomized, crossover, single-dose study evaluated the relative oral bioavailability of posaconazole suspension and coprecipitate tablet formulations. Additionally, the study determined whether systemic exposure to posaconazole was affected by prandial status or by the fat content of a meal. METHODS: This was a randomized, open-label, four-way crossover, single-dose study in 20 healthy men. Posaconazole pharmacokinetics were evaluated over 72 h following a single oral dose of posaconazole suspension (200 mg/5 ml) administered with a high-fat meal, a nonfat breakfast, or after a 10 h fast, or posaconazole tablets (2 x 100 mg) administered with a high-fat meal. RESULTS: The posaconazole suspension showed a significant increase in bioavailability compared with the tablet (increase in AUC(0,72 h) = 137% (90% confidence interval (CI) 119%, 156% and Cmax = 123% (90% CI 104%, 146%). The mean increases in AUC(0,72 h) and Cmax values were about 400% when administered with a high-fat meal compared with administration of the suspension in the fasting state (AUC(0,72 h) 90% CI 343%, 448%; Cmax 90% CI 352%, 493%). Administration of the suspension with a nonfat meal enhanced exposure, resulting in an increase in AUC(0,72 h) of 264% (90% CI 231%, 302%) and in Cmax of 296% (90% CI 250%, 350%) relative to the fasted state. CONCLUSIONS: The suspension formulation of posaconazole was associated with enhanced systemic exposure and increased relative bioavailability compared with the tablet. Food substantially enhanced the rate and extent of posaconazole absorption in healthy subjects.     

索磷布韦片在中国健康受试者中的药代动力学和安全性研究

目的：研究中国人群中索磷布韦及其代谢产物GS-331007和GS-566500的主要药代动力学特征和安全性。方法：本试验共入组12例健康受试者,分为四个周期;前三周期为单次给药（低剂量400 mg空腹组、高剂量800 mg空腹组和低剂量400 mg高脂餐组）药代动力学试验;第四周期为多次给药（低剂量400 mg空腹组）药代动力学试验。采用HPLC-MS/MS测定给药前后不同时间点人血浆中索磷布韦及其代谢产物GS-331007和GS-566500的浓度。结果：索磷布韦及其代谢产物GS-566500的暴露与剂量有成比例增加趋势。在多次给药试验中,未观察到明显蓄积现象。与空腹相比,餐后状态下索磷布韦的Cmax变化不大,AUC增加约30%;GS-331007的Cmax和AUC分别减少约30%和10%;GS-566500的Cmax和AUC分别增加约15%和25%。饮食对索磷布韦、GS-331007和GS-56650的Tmax无显著影响。未发生严重不良事件和导致退出的不良事件,所有受试者耐受性良好。结论：在中国健康受试者中,开展的索磷布韦片药代动力学研究结果表明,其药动学特征和安全性与国外研究数据无明显差异,安全性和耐受性良好。     

Effect of food on the pharmacokinetics and bioavailability of oral imiquimod relative to a subcutaneous dose

OBJECTIVES: The present study, the first clinical pharmacokinetic report of the immune response modifier imiquimod, was conducted to assess the effect of food on the oral absorption of imiquimod, to characterize its pharmacokinetics, and to estimate its oral bioavailability. SUBJECTS AND METHODS: Sixteen healthy male volunteers completed this open-label, randomized, three-period crossover study. Subjects received a 100 mg oral dose of imiquimod after fasting in one period, after a standarized, high fat meal in another, and a 30 mg subcutaneous dose in the third period. RESULTS: The oral bioavailability of imiquimod was on average 47%, and independent of whether imiquimod was administered with or without food. Oral imiquimod was absorbed in both fasted and non-fasted states with an absorption half-life of approximately 1 hour. However, there seemed to be a delay in the initiation of the absorption process when food was administered, which translated in to a Tmax of approximately 2.6 hours while fasting and one hour later in the non-fasted state. Imiquimod was rapidly eliminated with a half-life of approximately 2.5 hours and a total body clearance of approximately 970 ml/hxkg. Although equivalence could not be established due to the large intersubject variability, no significant differences in rate (Cmax) and extent (AUC) of oral absorption were observed between the fasted and non-fasted states. In addition, the Cmax, AUC and bioavailability values for individual subjects were consistent between both oral treatments. CONCLUSION: This study suggests that food does not have a major effect on the rate, extent of absorption or bioavailability of oral imiquimod, and thus, it is suitable to administer imiquimod orally in either the fasted or non-fasted states.     

Pharmacokinetics and bioavailability of ergoloid mesylates

The pharmacokinetics and bioavailability of ergoloid mesylates following single administrations of various dose levels (3-9 mg), dosage forms (oral swallow and sublingual tablets, solution) and under different dosing conditions (fasted, with meal) were studied in young healthy volunteers. Male and female subjects showed a similar rate and extent of bioavailable ergoloid after drug treatment. The absorption of ergoloid using either the tablet dosage forms or the drug administered as a solution was rapid, with peak levels of about 60-80 pg ml-1 mg-1 dose achieved after 0.6 to 1.3 h. The elimination half-life for ergoloid in plasma was 2-5 h. Administration of drug with food had no effect on the extent of absorption (AUC) but lowered the absorption rate. This resulted in a reduction of (by 25 per cent) and delay in (by 1 h) achieving peak levels (Cmax). Increasing the ergoloid dose caused a proportional increase in the AUC, but a smaller than proportional increase for Cmax. The tablet formulations provided similar AUCs as the solution; the objective of the sublingual tablet formulation to provide improved bioavailability over the swallow tablet via circumvention of first-pass metabolism was therefore not realized. Transient decreases in blood pressure after ergoloid treatment paralleled the plasma level profiles. Higher ergoloid levels were paired with the larger pressure decreases.     

Adinazolam pharmacokinetics and behavioral effects following administration of 20–60 mg oral doses of its mesylate salt in healthy volunteers

The pharmacokinetics and pharmacodynamics of adinazolam were studied in 15 normal, healthy, non-obse volunteers. Placebo capsules and capsules containing 20, 40, and 60 mg adinazolam mesylate were administered as single oral doses in a randomized, 4-way crossover design. Plasma concentrations of adinazolam and mono-N-desmethyladinazolam (NDMAD) were determined by HPLC. Psychomotor performance and memory tests were performed and the degree of sedation assessed at designated times following drug administration. Adinazolam and NDMAD pharmacokinetics were linear throughout the dosage range studied. The ratio of NDMAD to adinazolam area under the curve was approximately 4:1. Dose-related decrements in psychomotor performance and memory were observed up to 8h after dosing (P<0.025 in all cases). Psychomotor performance decrements correlated more closely with NDMAD plasma concentrations than with adinazolam concentrations. These results suggest that NDMAD is responsible for a significant degree of the sedative and psychomotor effects observed after the administration of adinazolam.     

Absence of food effect on the pharmacokinetics of telbivudine following oral administration in healthy subjects

The influence of food on the pharmacokinetics of telbivudine, a candidate antiviral agent against hepatitis B virus (HBV), was investigated in healthy adult subjects following a 600-mg oral dose administered with and without a high-fat/high-calorie meal. Telbivudine was well tolerated under fasting and fed conditions. Oral absorption of telbivudine as measured by maximum plasma concentration (Cmax), time to reach Cmax (Tmax), and area under the plasma concentration-time curve (AUC(0-t) and AUC(0-infinity)) was not altered by food intake immediately before oral dosing. Values of Cmax, Tmax, and AUC were comparable when telbivudine was administered under fed and fasting conditions. Results from this study indicated that the absorption of telbivudine was not affected by a high-fat/high-calorie meal; telbivudine can therefore be administered orally with no regard to the timing of meals.     

The effect of dosing regimen on the pharmacokinetics of risedronate

AIMS: To examine the effect of timing of a risedronate dose relative to food intake on the rate and extent of risedronate absorption following single-dose, oral administration to healthy male and female volunteers. METHODS: A single-dose, randomized, parallel study design was conducted with volunteers assigned to four treatment groups (31 or 32 subjects per group, 127 subjects total). Each subject was orally administered 30 mg risedronate. Group 1 was fasted for 10 h prior to and 4 h after dosing (fasted group); Groups 2 and 3 were fasted for 10 h and were dosed 1 and 0.5 h, respectively, before a high-fat breakfast; and Group 4 was dosed 2 h after a standard dinner. Blood and urine samples were collected for 168 h after dosing. Pharmacokinetic parameters were estimated by simultaneous analysis of risedronate serum concentration and urinary excretion rate-time data. RESULTS: Extent of risedronate absorption (AUC and Ae ) was comparable (P=0.4) in subjects dosed 2 h after dinner and 0.5 h before breakfast; however, a significantly greater extent of absorption occurred when risedronate was given 1 or 4 h prior to a meal (1.4- to 2.3-fold greater). Administration 0.5, 1, or 4 h prior to a meal resulted in a significantly greater rate of absorption (Cmax 2.8-, 3.5-, and 4.1-fold greater, respectively) when compared with 2 h after dinner. CONCLUSIONS: The comparable extent of risedronate absorption when administered either 0.5-1 h before breakfast or 2 h after an evening meal support previous clinical studies where risedronate was found to have similar effectiveness using these dosing regimens. This flexibility in the timing of risedronate administration may provide patients an alternative means to achieve the desired efficacy while maintaining their normal daily routine.     

Pharmacokinetics and bioavailability of alpha-, gamma- and delta-tocotrienols under different food status

We have investigated the pharmacokinetics and bioavailability of alpha-, gamma- and delta-tocotrienols under fed and fasted conditions in eight healthy volunteers. The volunteers were administered a single oral dose of mixed tocotrienols (300 mg) under fed or fasted conditions. The bioavailability of tocotrienols under the two conditions was compared using the parameters peak plasma concentration (Cmax), time to reach peak plasma concentration (Tmax) and total area under the plasma concentration-time curve (AUC(o-infinity)). A statistically significant difference was observed between the fed and fasted logarithmic transformed values of Cmax (P < 0.01) and AUC(0-infinity) (P < 0.01) for all three tocotrienols. In addition, the 90% confidence intervals for the ratio of the logarithmic transformed AUC(0-infinity) values of alpha-, gamma- and delta-tocotrienols under the fed state over those of the fasted state were found to lie between 2.24-3.40, 2.05-4.09 and 1.59-3.81, respectively, while those of the Cmax were between 2.28-4.39, 2.31-5.87 and 1.52-4.05, respectively. However, no statistically significant difference was observed between the fed and fasted Tmax values of the three homologues. The mean apparent elimination half-life (t(1/2)) of alpha-, gamma- and delta-tocotrienols was estimated to be 4.4, 4.3 and 2.3 h, respectively, being between 4.5- to 8.7-fold shorter than that reported for alpha-tocopherol. No statistically significant difference was observed between the fed and fasted t(1/2) values. The mean apparent volume of distribution (Vd/f) values under the fed state were significantly smaller than those of the fasted state, which could be attributed to increased absorption of the tocotrienols in the fed state.     

Extent and Variability of the First-Pass Elimination of Adinazolam Mesylate in Healthy Male Volunteers

The pharmacokinetics of adinazolam and N-desmethyladinazolam (NDMAD) were studied in 14 healthy male volunteers who received 15 mg adinazolam mesylate orally as a solution and 5 mg adinazolam mesylate intravenously in a crossover design. Two weeks prior to the crossover study, each subject received 5 mg/kg indocyanine green (ICG) as an intravenous bolus injection to estimate liver blood flow. The absolute bioavailability (F), calculated as the dose-corrected ratio of oral to iv adinazolam area under the curve (AUC) values, was found to be 39%. NDMAD AUC values were similar following oral and iv administration, and adinazolam mean absorption time was approximately 0.77 hr. Thus, adinazolam is completely and rapidly absorbed after oral administration in man; the incomplete bioavailability is due to first-pass metabolism. Mean liver blood flow, adinazolam systemic clearance, blood/plasma ratio, and extraction ratio were 1189 ml/min, 498 ml/min, 0.70, and 0.57, respectively. The extraction ratio agrees with that calculated as 1-F (0.62), suggesting that the liver is primarily responsible for first-pass metabolism of adinazolam. The unbound fraction of adinazolam in plasma was 0.31 (range, 0.25–0.36); adinazolam free intrinsic clearance (a reflection of metabolic capacity) was 4285 ml/min (range, 2168–6312 ml/min). These results suggest that the majority of the variability in adinazolam plasma concentrations following oral administration is due to the variability in the metabolic capacity of the liver for adinazolam, rather than variability in plasma protein binding.     

The bioequivalence study of folifer-Z: a new formulation of sustained-release iron and zinc

The bioequivalence of Folifer-Z tablets, a new sustained-release iron and zinc formulation was evaluated and compared to that of Fefol-Z capsules in 30 healthy male subjects. Each subject received a single oral dose of either product according to a randomized two-way crossover design. A washout period of 1 week was allowed after each treatment. Blood samples were obtained over a 24-h period, and iron and zinc concentrations were measured. The pharmacokinetic parameters of Folifer-Z were Cmax (103 +/- 46.2 micrograms/dl), Tmax (5.93 +/- 2.94 h) and AUC0-24 h (1937 +/- 706 micrograms/dl per h), whereas the corresponding Fefol-Z values were Cmax (109 +/- 41.5 micrograms/dl), Tmax (6.64 +/- 2.54) and AUC0-24 h (1865 +/- 699 micrograms/h per dl). Analysis of variance on log-transformed data for Cmax and AUC0-24 h revealed lack of significant differences among the two formulations. The mean relative bioavailability of AUCtest/AUCreference was 1.07 (90% confidence interval range: 99-115%) and for Cmax test/Cmax reference was 0.96 (90% confidence interval range: 88-105%). Regarding the zinc results, the pharmacokinetic parameters of Folifer-Z values were Cmax (101 +/- 20.7 micrograms/dl), Tmax (4.86 +/- 1.53 h) and AUC0-24 h (1944 +/- 202 micrograms/h per dl), while the corresponding Fefol-Z values were Cmax (102 +/- 20.7), Tmax (4.93 +/- 1.51) and AUC0-24 h (1953 +/- 200). Analysis of variance on log-transformed zinc data for Cmax, Tmax and AUC0-24 h revealed lack of significant difference among the two formulations. The mean relative bioavailability of AUCtest/AUCreference was 0.98 (90% confidence interval range; 95-101%) and for Cmax test/Cmax reference was 0.92 (90% confidence interval range: 89-96%). The results also indicate a possible inhibition of zinc absorption by iron content of both formulations. It is concluded that Folifer-Z product is bioequivalent to Fefol-Z product.     

The effect of food on the oral bioavailability and the pharmacodynamic actions of the insulinotropic agent nateglinide in healthy subjects

Nateglinide (Starlix, SDZ DJN 608 or A-4166), a new insulinotropic agent, is intended to be administered prior to a meal in order to improve early insulin release in non-insulin-dependent diabetes mellitus patients. The effects of a meal on the oral bioavailability and pharmacodynamic actions of nateglinide were investigated. Twelve healthy male subjects completed this randomized, single-dose, four-way crossover study in which each subject received a 60 mg dose of nateglinide 10 minutes before the start of and immediately after a high-fat breakfast meal. In addition, each subject received a single 30 and 60 mg dose of nateglinide underfasting conditions. Plasma and urine concentrations of nateglinide were determined by an HPLC method while plasma glucose and insulin concentrations were measured by standard immunoassay methods. Compared to the fasted state, administration of nateglinide 10 minutes before the meal was associated with an increase in the rate of absorption (12% increase in Cmax and 52% decrease in tmax), while there was no significant effect on the extent of absorption (AUC). Alternatively, when nateglinide was given after the meal, a food effect was observed that was characterized by a decrease in the rate of absorption: 34% decrease in Cmax and a 22% increase in tmax but no significant effect on AUC. Nateglinide was rapidly eliminated with plasma t 1/2 = 1.4 hours. Its plasma renal clearance, 20.7 ml/min, appears to be due mostly to active tubular secretion. However, only 13% to 14% of the dose is recovered as nateglinide in the urine. The 30 and 60 mg tablets were dose proportional in terms of both AUC and Cmax; both tmax and t 1/2 were dose independent. Regardless of timing, the combination of a meal and nateglinide produced a larger increase in insulin levels than did nateglinide alone. Meal-related glucose excursions were eliminated when nateglinide was taken prior to the meal. Thus, the rapid onset/short duration stimulation of insulin release by nateglinide should allow good control of prandial hyperglycemia while limiting exposure to hyperinsulinemia.     

食物对氧氟沙星生物利用度的影响

在空腹和进食条件下分别交叉给９名健康志愿者（男性，平均年龄２５±ｓ７ａ）口服氧氟沙星片２×１００ｍｇ，采用ＨＰＬＣ法测定经时过程血药和尿药浓度，并计算其药物动力学参数。结果表明：进食对氧氟沙星片剂生物利用度无明显影响，但可延缓该药的吸收。     

Influence of food on the absorption of theophylline administered in the form of sustained release tablet and microgranules

Two sustained-release formulations of theophylline, tablets (T) and microgranules (MG) forms, were administered in a randomized order to 8 healthy subjects in fasting or with a high-protein test meal (50 per cent). Blood was collected for 32h post-dose. In fasting subjects, absorption of theophylline was significantly faster for T (tmax 5 h) as compared with MG (tmax 8 h, p less than 0.05), but Cmax and AUC were comparable; intersubject variability was higher with T. Administration of a high-protein test meal with T produced a significant decrease of the zero-order absorption rate constant of theophylline (K omicron 37.8 +/- 9.1 mgh-1 after meal versus 58.8 +/- 13 mgh-1 in fasting, p = 0.01), tmax was doubled to 10 h, and Cmax increased by 25 per cent (6.33 +/- 2.16 mgl-1 versus 5.04 +/- 1.28 mgl-1, p less than 0.02); with MG, tmax were the same (8 h), Cmax were not significantly increased (4.79 +/- 0.84 mgl-1 versus 4.55 +/- 0.67 mgl-1), absorption was delayed (lag-time 1.28 +/- 0.58 h) and the absorption was slightly accelerated (K omicron 50.4 +/- 10.4 mgh-1 versus 42.3 +/- 11.9 mgh-1, NS). For each form bioavailability was not significantly modified by food. This study demonstrated that food rich in protein modifies the absorption rate of theophylline in a sustained-release tablet formulation but is without influence in a pH-independent, sustained-release microgranule formulation.     

Clinical pharmacology of adinazolam and N-desmethyladinazolam mesylate following single intravenous infusions of each compound in healthy volunteers

Summary The tolerability, pharmacokinetics and pharmacodynamics of adinazolam and N-desmethyladinazolam (NDMAD) were assessed following intravenous infusions of 5, 10, 15, and 20 mg adinazolam mesylate, 10, 20, 30 and 40 mg NDMAD mesylate, and placebo. Six subjects per dose level received treatments in a double-blind crossover design.No clinically significant changes were seen in blood pressure, pulse, respiration, or clinical laboratory parameters. Untoward effects typical of benzodiazepines were observed almost exclusively after NDMAD administration. Adinazolam and NDMAD pharmacokinetics were dose-independent. NDMAD clearance was 50% of the value for adinazolam. Adinazolam and NDMAD administrations increased uric acid clearance and decreased plasma uric acid. Adinazolam administration had no significant effect on psychomotor performance. NDMAD administration produced dose related decreases in performance; 286 ng/ml NDMAD produced a 50% decrease in DSST.These results confirm that adinazolam and NDMAD both produce uricosuria and definitively show that adinazolam is devoid of benzodiazepine-like effects at therapeutic concentrations; NDMAD mediates these effects. Uricosuric activity is present for both compounds, but the relative potencies are still unknown.Presented in part at the Nineteenth Annual Meeting of the American College of Clinical Pharmacology, Las Vegas, NV, November 4–8, 1990     

Effect of food and gastric acidity on absorption of orally administered ketoconazole

Effects of food and gastric acidity on the bioavailability of ketoconazole tablets were investigated in 12 volunteers using a six-treatment, randomized, Latin-square crossover design. All volunteers received all treatments, as follows: (A) ketoconazole 200 mg administered after a fast; (B) ketoconazole 200 mg with a standardized high-fat meal; (C) ketoconazole 200 mg with a standardized high-carbohydrate meal; (D) ketoconazole 200 mg after pretreatment with glutamic acid hydrochloride 680 mg as capsules; (E) ketoconazole 200 mg in a simulated achlorhydric state induced with cimetidine and sodium bicarbonate; and (F) ketoconazole 200 mg administered with glutamic acid hydrochloride in a simulated achlorhydric state. Ketoconazole concentrations were measured by high-performance liquid chromatography in plasma samples drawn immediately before and at various times over 24 hours after drug administration. Bioavailability variables, including natural logarithm transformation for area under the concentration-time curve (AUC), were subjected to analysis of variance followed by Duncan's Multiple Range testing. Treatments B and C significantly prolonged the times required to achieve the peak plasma ketoconazole concentration, and treatment C also significantly reduced the peak plasma ketoconazole concentration (Cmax) compared with treatment A. There was a trend toward increased AUC values with treatment B and decreased AUC values with treatment C. Treatment D produced a higher Cmax compared with treatment A, and treatment E produced large, significant reductions in Cmax and AUC values compared with treatment A. Treatment F significantly increased AUC values and Cmax compared with treatment E.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relative bioavailability study of two nifedipine tablet formulations in healthy male volunteers

OBJECTIVE: To assess the bioequivalence of two oral formulations containing 10 mg of nifedipine. The test preparation were Macorel tablets, the reference preparation were Adalat tablets. SUBJECTS, MATERIAL AND METHODS: The study was designed as a single-dose, three-period crossover randomized design to 18 non-smoker, healthy male volunteers under fasting conditions. Seventeen volunteers completed the study. Plasma samples were analyzed for nifedipine by HPLC after solid-phase extraction. The pharmacokinetic parameters used to assess the bioequivalence of the two formulations were AUC(0-infinite) and AUC(0-t) for the extent of absorption and Cmax and Tmax for the rate of absorption. Statistical comparisons of AUC(0-infinite) AUC(0-t), and Cmax data were evaluated after logarithmic transformation by two-way analysis of variance (ANOVA), and differences of Tmax were tested non-parametricaly. RESULTS: Point estimates (90% confidence intervals) of the test/reference ratios were 97.4% (87.6%-108.3%) for AUC(0-infinite) 97.0% (85.6%-110.1%) for AUC0-t, and 107.7% (89.1%-130.7%) for Cmax. No statistically significant difference was found for Tmax and elimination half-life values. CONCLUSION: Therefore, in accordance with the European Union bioequivalence requirements, the test and reference nifedipine preparations are bioequivalent for both the extent and the rate of absorption.     

国产与进口美洛昔康片单次给药后人体药动学(英文)

目的 :比较健康志愿者国产与进口美洛昔康片的人体药动学和相对生物利用度。方法 :采用单次给药 2周期交叉设计 ,HPLC法测定 12名健康男性志愿者口服 15mg美洛昔康后血药浓度 ,计算药动学参数和国产片的相对生物利用度。结果 :2种制剂的药时曲线符合一级吸收的一室开放模型。国产与进口片的药动学参数分别是AUC0 - 96 为 (6 7±s 14 )mg·h·L- 1和 (6 4± 15 )mg·h·L- 1;AUC0 -∞ 为 (73± 19)mg·h·L- 1和 (70± 18)mg·h·L- 1;Cmax为 (2 .3± 0 .5 )mg·L- 1和 (1.6± 0 .3)mg·L- 1;Tmax为 (2 .0± 1.6 )h和 (6± 3)h ;T12 ke为 (2 5± 6 )h和 (2 4± 5 )h ;MRT为 (4 0± 13)hand (39±8)h。方差分析表明两者AUC之间无显著差异 (P>0 .0 5 ) ,但两者的Cmax和Tmax之间有显著差异 (P<0 .0 5 )。结论 :国产片的释药速率比进口片快 ,其相对生物利用度为 (10 5± 13) %。