Risedronate Gastrointestinal Absorption Is Independent of Site and Rate of Administration

Purpose. Two studies were conducted to compare the absorption of risedronate administered as a solution to three different gastrointestinal sites (study A) and to determine the extent of absorption of risedronate solution administered by rapid and slow infusion to the second part of the duodenum (study B). Methods. Each study was designed as a single-dose, crossover (three periods, study A; two periods, study B) trial in healthy male subjects, with a 14-day washout period between dosing. Subjects fasted overnight before drug administration and for 4 hours after drug administration. In study A, a risedronate solution of 40 mg in 30 mL of water was administered directly into the stomach, the second part of the duodenum, or the terminal ileum over 1 minute via a nasoenteral tube in a three-period crossover design. In study B, a risedronate solution of 40 mg in 30 mL of water was administered directly into the second part of the duodenum over 1 minute and over 1 hour in a randomized, two-period crossover design. Serum and urine samples were obtained for 48 hours after dosing for risedronate analysis. Results. Eight subjects completed each study. No statistically significant site-specific differences in any pharmacokinetic parameter were observed (study A). Based on the area under the serum concentration-time profile and the amount of drug excreted in the urine unchanged, the extent of risedronate absorption did not differ significantly following a rapid or a slow infusion (study B). Only minor symptomatic complaints were reported by subjects, such as headaches and body aches. Conclusions. These studies indicate that the rate and extent of risedronate absorption are independent of the site of administration along the gastrointestinal tract, and that the extent of absorption is not affected by the rate of administration.     

Evaluation of an enteric-coated naproxen pellet formulation

An enteric-coated, pellet formulation of naproxen has been evaluated in eight healthy subjects. Each volunteer was dosed with 153Sm-labelled, enteric-coated pellets on two occasions, once whilst fasted and once after breakfast. Gastrointestinal transit was followed using gamma scintigraphy and drug absorption compared with that from uncoated naproxen pellets dosed on a separate occasion. The pH in the stomach and intestines was monitored using radiotelemetry capsules. Gastric emptying was delayed by dosing after breakfast, but small intestinal transit of the enteric-coated formulation was the same on both occasions. The highest pH recorded from the stomach was 4.0 and in all subjects the pH rose to at least 7.3 in the small intestine. The onset of drug absorption was fastest from the uncoated formulation and slowest from the coated pellets taken after breakfast. The total amount of drug absorbed was the same on all three occasions.     

The effect of time‐of‐day dosing on the pharmacokinetics and pharmacodynamics of dexlansoprazole MR: evidence for dosing flexibility with a Dual Delayed Release proton pump inhibitor

Aliment Pharmacol Ther 31 , 1001–1011

Summary

Background Dexlansoprazole MR is a Dual Delayed Release proton pump inhibitor formulated to extend the duration of acid suppression. Aim To evaluate the pharmacokinetics and pharmacodynamics of dexlansoprazole MR dosed before 4 different meal times. Methods In this randomized, open‐label, four‐way crossover study, 48 healthy subjects received dexlansoprazole MR 60 mg once daily 30 min before breakfast, lunch, dinner or an evening snack. Pharmacokinetics of dexlansoprazole MR and intragastric pH were assessed over a 24‐h postdose interval on day 5 for each regimen. Results Absorption was delayed when dexlansoprazole MR was administered before each regimen relative to breakfast; however, systemic exposures of dexlansoprazole at all regimens were bioequivalent. There were no statistically significant differences in mean 24‐h intragastric pH between dosing before dinner or an evening snack vs. breakfast; however, there was a small (0.2), but statistically significant difference between lunch and breakfast. There was a statistically significant difference of 7 percentage points in the percentage of time intragastric pH was >4 for the snack regimen relative to the breakfast regimen, but there were no statistically significant differences between lunch or dinner compared with breakfast. Conclusion Dexlansoprazole MR provides comparable acid control when administered at different times of the day.     

Pharmacokinetics of cerivastatin when administered under fasted and fed conditions in the morning or evening

OBJECTIVE: The influence of food and time of drug dosing on the pharmacokinetics of cerivastatin, a potent HMG-CoA reductase inhibitor, was evaluated in 24 healthy male subjects between 21 and 44 years of age. METHODS: A single-dose, four-way crossover design was employed, with each subject receiving cerivastatin 0.8 mg at weekly intervals under each of four conditions: 8 a.m. dosing after an overnight fast (reference), 8 a.m. dosing with a high-fat breakfast (test), 6 p.m. dosing with the evening meal (low-fat; test), and 10 p.m. dosing 4 h after dinner (reference). Plasma concentrations of the parent compound and its active metabolites were measured by high performance liquid chromatography with fluorescence detection subsequent to post-column derivatization. RESULTS: The calculated 90% confidence intervals for cerivastatin AUC and Cmax were completely contained within the range 0.8 to 1.25. Thus, no relevant influence of food could be detected, although the presence of food increased the Cmax of cerivastatin on average by 12% (90% confidence interval: 1.04 - 1.21) under morning, but not evening dosing. With respect to the effect of daytime on cerivastatin pharmacokinetics, AUCs were bioequivalent for all treatment conditions, with Cmax values slightly lower (8 - 19%) following evening dosing, irrespective of food intake. Cerivastatin was well tolerated by the subjects in the study. CONCLUSION: Food effect bioequivalence according to current guidelines could be demonstrated. Cerivastatin can be administered independent of meal intake at dinner or at bedtime, the preferred time of dosing for statins because the rate of hepatic cholesterol synthesis is greatest at night.     

Circadian changes of valproate kinetics depending on meal condition in humans.

The objective of this study was to examine the effect of meal condition on circadian changes in valproic acid (VPA) kinetics. Two experiments were performed in 16 healthy men that were synchronized with diurnal activity and nocturnal rest as their routine life. In both experiments, four 200-mg tablets of VPA were given orally on two occasions in the morning (8:30 AM) or in the evening (8:30 PM). In each study, a randomized, single-dose, two-way crossover design was used, and 2 weeks elapsed between morning and evening trials. In experiment 1, eight subjects took a light meal as breakfast between 8:00 and 8:15 AM and a heavy meal as dinner between 6:00 and 6:30 PM to fit the subject's usual food amount. The mean peak plasma concentration (Cmax) was significantly higher (P less than .01), the time to peak concentration (tmax) was shorter (P less than .05), and the absorption rate (Ka) was larger (P less than .05) after the morning dose than after the evening dose. In experiment 2, the size and contents of meal in breakfast and dinner were prepared in the same manner as the standard breakfast for the subjects. Namely, eight subjects took the same light meal between 8:00 and 8:15 AM in the morning and between 8:00 and 8:15 PM in the evening. There was no significant circadian change in VPA kinetics under this same meal condition. These results suggest that the differences of meal condition between morning and evening in our daily life play a major role in the mechanism underlying the circadian changes of VPA absorption in man.     

THE EFFECT OF TWO NEW α-GLUCOSIDASE INHIBITORS ON METABOLIC RESPONSES TO A MIXED MEAL IN NORMAL VOLUNTEERS

1. alpha-Glucosidase inhibitors delay carbohydrate absorption and have been proposed as adjunctive therapy for diabetes mellitus. 2. To determine the effects of two new alpha-glucosidase inhibitors, Bay-m-1099 and Bay-o-1248, on meal carbohydrate and lipid tolerance, plasma glucose, insulin and triglyceride levels were measured at 15-60 min intervals over 12 h after ingestion of a standard breakfast, lunch and dinner of identical composition in 31 normal volunteers. 3. The volunteers were randomized to receive either Bay-m-1099 (50 or 25 mg) or placebo prior to each meal, or the single administration of Bay-o-1248 (20 or 10 mg) or placebo prior to breakfast. 4. Only Bay-m-1099 at the 50 mg dose reduced significantly the postprandial increase in plasma insulin levels after each meal when compared with placebo (25, 36, 54% at breakfast, lunch, and dinner, respectively; P less than 0.05). Both drugs were well tolerated, with side effects limited to complaints of flatulence. 5. Thus, with the dosage schedule employed, Bay-m-1099, but not Bay-o-1248, significantly reduced postprandial increments in plasma insulin.     

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.     

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.     

Effect of food on the bioavailability of adinazolam from a sustained release formulation: effect of meal timing and lack of dose dumping

Food effects on adinazolam absorption from sustained release (SR) adinazolam mesylate tablets were assessed in 28 healthy male volunteers. Subjects received 15 mg SR tablets, 15 mg immediate release tablets, 15 mg oral solution, administered after an overnight fast, and 15 mg SR tablets after a high fat breakfast. Treatments were administered in a crossover design. Plasma adinazolam and N-desmethyladinazolam (NDMAD) concentrations were determined by HPLC. Adinazolam and NDMAD AUC values were unaffected by food. Cmax for SR tablets was increased 33 per cent and 18 per cent for adinazolam and NDMAD, respectively, when administered postprandially. Tmax occurred later in the fed state; no dose dumping was observed. Meal timing effects on adinazolam absorption from SR tablets were assessed in 24 healthy subjects, who received 30 mg SR tablets 1 h before, 0.5 h after, 2 h after a high fat meal, and in the fasted state. Postprandial administration had no effect on AUC, but resulted later and higher adinazolam and NDMAD Cmax. Differences in these values were less than 11 per cent. Administration of SR tablets before meals yielded Cmax and Tmax values which were similar to the fasted state. Results suggest that meal timing does not substantially affect adinazolam absorption from the SR tablet.     

Reduced Systemic Availability of an Antiarrhythmic Drug,Bidisomide, with Meal Co-administration: Relationship with Region-Dependent Intestinal Absorption

Purpose. The aim of this research was to determine the mechanism by which a co-administered meal decreases the oral absorption of bidisomide and does not influence the oral absorption of the chemically-related antiarrhythmic agent, disopyramide. Methods. Bidisomide plasma levels, following oral administration and intravenous infusion in the fasted state and with various meal treatments, were determined in human subjects. A dialysis technique was employed to examine the potential for drug binding to meal homogenates. Plasma levels, following drug administration through duodenal and jejunal intestinal access ports and following various meal treatments with oral drug co-administration, were compared for bidisomide and disopyramide in a canine model. Results. Bidisomide plasma AUC was significantly reduced following oral drug co-administration with breakfast compared to fasted-state controls in human subjects and in dogs independent of the composition of the solid cooked breakfast. While intravenous bidisomide infusion in human subjects showed a statistically significant reduction in AUC 15 minutes after oral administration of a high fat breakfast as compared to drug infusion in the fasted state, the reduction (–13%) was substantially smaller than the reduction (from –43% to –63%) observed with oral bidisomide meal co-administration. The percentages of bidisomide and disopyramide lost by binding to homogenates of cooked breakfast were 25.0 ± 5.7% and 23.7 ± 7.7%, respectively, as determined by dialysis at 4 hours. In dogs, the extent of absorption of disopyramide was comparable from oral, duodenal and mid-jejunal administration while the extent of bidisomide absorption from mid-jejunal administration was significantly lower than for oral or duodenal administration. Non-viscous liquid meals decreased C_max but not AUC, while viscous homogenized solid meals decreased both C_max and AUC for bidisomide with oral drug-meal co-administration. Oral non-caloric hydroxypropyl methylcellulose meals decreased bidisomide to the same extent as homogenized solid meals but did not lower disopyramide AUC. Conclusions. The significant reduction in bidisomide plasma levels observed with meal co-administration in human subjects was predominantly mediated through a reduction in drug absorption and was independent of solid meal composition. The difference in meal effect on the absorption of the two drugs in humans did not appear to be a function of drug binding to cooked meal components over typical human upper gastrointestinal residence times. In dogs, the high-viscosity medium generated by oral co-administration of a solid meal reduced the upper intestinal absorption of bidisomide and disopyramide. Bidisomide AUC was decreased since it was well absorbed in the upper but not lower small intestine. Disopyramide AUC was not significantly affected since it was well absorbed from both regions. A similar mechanism may play a role in drug plasma level reductions following oral co-administration with solid meals for drugs showing similar regionally-dependent absorption profiles.     

The timing of the evening meal affects the pattern of 24-hour intragastric acidity

The object of the study was to examine the effect of varying the time of the evening meal on the pattern of 24-h intragastric acidity. Ten healthy subjects were studied; they ate regular meals throughout the day, but between 17.00 and 21.35 hours were separated into three groups. On three different days each group was fed the same dinner at either 17.15, 19.15, or 21.15 hours (early, standard or late). Variation in the evening meal's time caused significant changes in the pattern of acidity in the afternoon and evening, but did not affect 24-h intragastric acidity or nocturnal acidity. Integrated afternoon acidity (14.00 hours to dinner) was 69, 169 and 324 mmol.h/L when the subjects ate early, standard and late meals, respectively; evening acidity (dinner to midnight) was 235, 43 and 1 mmol.h/L with the three meals, respectively. The results suggest that, to control intragastric acidity, when the evening meal is eaten early (17.15 hours) dosing with an H2-antagonist should be after that meal, when eaten at the standard time (19.15 hours) dosing should be at bedtime, but when dinner is late (21.15 hours) the optimal regimen may involve dosing after lunch and also at bedtime.     

Effect of dietary fat content on the bioavailability of a sustained release quinidine gluconate tablet

Quinidine gluconate 324 mg sustained release tablets (Quinaglute) was administered as a single dose to 15 healthy male subjects following an overnight fast, immediately following a high fat (HF) breakfast or immediately following a low fat (LF) breakfast. Serum samples were obtained over a 48 h period and analyzed for quinidine content using a high performance liquid chromatographic assay. Under the conditions of the study, both the rate and extent of quinidine bioavailability was significantly affected by food. The extent of bioavailability was statistically significantly greater (p less than 0.05) following both the HF and LF meals as compared to that in the fasted state. Rate of bioavailability was significantly enhanced following the LF meal as compared to that of the other two treatment groups. Although peak concentrations were greater and time to peak concentrations somewhat later following the HF meal versus those under fasting conditions, these differences were not statistically significant. In addition, the characteristics of the serum concentration-time profile (as defined by the number, magnitude, and time of occurrence of the multiple absorption maxima) was unique for each of the three treatment groups. Possible mechanisms underlying these results are explored.     

Effect of food on early drug exposure from extended-release stimulants: results from the Concerta,Adderall XR Food Evaluation (CAFE) Study

Stimulant therapy is the mainstay of treatment for children, adolescents and adults with attention-deficit/hyperactivity disorder (ADHD). Once-daily, extended-release oral formulations offer long acting control of symptoms by modifying drug delivery and absorption. In particular, consistency in early drug exposure is important for symptom control during school or work hours. Because these once-daily formulations are usually taken in the morning, the timing of the doses with breakfast is important. This study compared the effect of a high-fat breakfast on early drug exposure from a morning dose of two extended-release stimulant formulations: the osmotic-controlled OROS tablet of methylphenidate HCI (CONCERTA) and the capsule containing extended-release beads of mixed amphetamine salts (ADDERALL XR). The study had a single-dose, open-label, randomised, four-treatment, crossover design in which healthy subjects received either 36 mg CONCERTA or 20 mg ADDERALL XR in the morning after an overnight fast or a high-fat breakfast. Serial blood samples were collected over 28h to determine plasma concentrations of methylphenidate and amphetamine. The food effect on early drug exposure and the pharmacokinetic profiles up to 8 h after dosing of the two extended-release stimulants were directly compared using partial area (AUC(p4h), AUC(p6h) and AUC(p8h)) fed/fasted ratios. Amphetamine concentrations were markedly lower when the subjects had eaten breakfast, resulting in lower early drug exposures (p < 0.0001). By contrast, methylphenidate concentrations over the same 8 h were unaffected by breakfast, providing consistent levels of early drug exposure. Therefore, as a child's or adult's eating pattern varies, methylphenidate exposure over the first 8 h would be expected to have less day-to-day variation compared with amphetamine exposure. The osmotic-controlled OROS tablet provides a reliable and consistent delivery of methylphenidate HCI, independent of food, for patients with ADHD.     

The effect of food on the bioavailability of dolasetron mesylate tablets

Anzemet® (dolasetron mesylate) is being developed for the prevention of chemotherapy-induced emesis and postoperative nausea and vomiting. Twenty-four healthy male subjects were orally dosed with dolasetron mesylate, 200 mg, after either an overnight fast or a high-fat breakfast. The ratio of the mean area under the plasma concentration–time curve of the reduced active metabolite (MDL 74 156) to infinity (AUC(0–∞)) values in fed compared to fasting subjects was 86.3% with a 90% confidence interval for the ratio within (80, 125)%, indicating bioequivalence. The ratio of the mean MDL 74 156 maximum plasma concentration (C_max) values was 70.6% in fed versus fasted subjects. The time to C_max was statistically significantly longer after the high-fat breakfast (mean values, 1.11 h fasting and 1.80 h fed), probably due to delayed gastric emptying. It may be concluded that, although the rate of absorption was somewhat delayed, the extent of absorption did not change significantly when dolasetron mesylate was given with food. © 1998 John Wiley & Sons, Ltd.     

Effect of meal timing not critical for the pharmacokinetics of tegaserod (HTF 919).

This study assessed the pharmacokinetic profiles of administering tegaserod (HTF 919) at different time intervals with respect to a meal. It was a randomized, open-label, two-phase, five-period crossover study. In the first phase, 18 healthy subjects received a single 12 mg oral dose of tegaserod administered either 30 or 15 minutes prior to the start of the 600-calorie, fat-rich breakfast. In the second phase, subjects received a single 12 mg oral dose of tegaserod 1 minute before, 2.5 hours after the start of meal, or with a continued 4-hour postdose fast. Safety assessment and plasma samples for the determination of drug concentration were obtained for 24 hours postdose. Noncompartmental analysis results indicated that the AUC of tegaserod was reduced by almost half under fed conditions compared to the fasted condition. Exploratory analyses were implemented to further investigate the absorption characteristics of tegaserod under different fed conditions. A numerical deconvolution approach was used to obtain the tegaserod oral absorption versus time profiles under both fasted and fed conditions. The tegaserod oral absorption versus time profiles were then fitted by NONMEM to a model containing two absorption phases. Based on the absorption analyses, we found that the reduction in the bioavailability of tegaserod under fed conditions was primarily due to a decrease in the extent of absorption and less so to a decrease in the absorption rate(s). Therefore, although the timing of administration of food does not appear to significantly alter the pharmacokinetics of tegaserod, the administration of food reduces the AUC by approximately 50%.     

Comparative oral bioavailability of azimilide dihydrochloride in the fed and fasted states

AIMS: This study investigated the relative oral bioavailability of azimilide dihydrochloride following administration in the fed (high-fat meal) and fasted states. METHODS: This was a single-dose, randomized, two-way crossover study in 30 healthy, Caucasian, male subjects. Following oral administration, blood samples were collected over 27 days and analysed for azimilide using h.p.l.c. with u.v. detection. Pharmacokinetic parameters were determined using 'noncompartmental' analysis and compared using an ANOVA and 90% or 95% confidence intervals. RESULTS: The extent of absorption was equivalent in the fed and fasted states (ratio = 96.2%; 90% CI=90.5% -102.4%). However, Cmax was decreased 19% following a high-fat meal (ratio=81.4%; 90% CI= 76.2% -87.0%). No difference in tmax or t(1/2),z was observed. CONCLUSIONS: Azimilide dihydrochloride may be orally administered to patients without regard to the prandial state.     

Effect of time of meal consumption on bioavailability of a single oral 5 mg tacrolimus dose

Tacrolimus (FK506, Prograf) is marketed for the prophylaxis of organ rejection following allogenic liver or kidney transplantation. This study investigated the effect of timing of a standardized breakfast meal on both the rate and extent of tacrolimus absorption following a single 5 mg oral dose. The protocol used a randomized, open-label, four-period, four-treatment, four-sequence crossover design in 16 healthy, nonsmoking, drug-free male subjects between the ages of 22 and 45 years who were within 15% of their ideal body weight. The four treatments were the following: (A) fasting for 10 hours, (B) ingestion 1 hour before breakfast, (C) ingestion immediately following consumption of the breakfast, and (D) ingestion 1.5 hours after beginning consumption of the breakfast. The breakfast, which was consumed over 15 minutes, contained 848 kcal, with 30%, 16%, and 54% of calories derived from fat, protein, and carbohydrate, respectively. Tacrolimus absorption in the fasting state provided the greatest relative bioavailability (p < 0.05 compared with all other three treatments). AUC(0-infinity)) averaged 312, 276, 205, and 203 ng x h/mL for treatments A, B, C and D, respectively. In contradistinction to taking the drug 1 hour prior to a meal, which had a relatively minor impact on the relative extent of absorption (approximately 12%) compared to the fasting state, ingestion of tacrolimus immediately after a meal (treatment C) or 1.5 hours subsequent to a meal (treatment D) had a more pronounced influence. Mean AUC(0-infinity) ratios (fasting to either postmeal treatments) were approximately 1.5, indicating that absorption extent was considerably reduced by ingesting tacrolimus capsules immediately after eating or 1.5 hours thereafter. Absorption was also prolonged following drug ingestion after a meal, as indicated by a mean tmax value in the fasting state of 1.84 hours, relative to 3.41 hours (immediately aftermeal, p = 0.0035) and 3.22 hours (1.5 hours postmeal, p = 0.0094). The only discernable difference in parameters between treatments C and D was with Cmax, with values of 7.19 and 9.04 ng/mL, respectively, but was not statistically significantly different (p = 0.231). Based on these results and those from a prior study, it is recommended that under therapeutic conditions, oral tacrolimus be administered in a consistent manner, both with respect to the type of meal as well as timing of ingestion relative to consumption of the meal.     

Effect of time of dosing on the disposition of oral cibenzoline

Single oral doses of cibenzoline were administered to eight healthy volunteers on two different occasions, once at 8.00 am and once at 10.00 pm, in a randomized crossover design with at least one week separating treatments. A fast was maintained for 12 hours prior to and for 2 hours after the morning dose and the subjects did not lie down for at least 12 hours after dosing. A standard dinner was eaten 3 hours prior to the evening dose, and a fast was maintained for 10 hours after dosing; the subjects laid down 2 hours after dosing for at least 6 hours. Blood was collected at specific times for 72 hours and the total volume of urine voided was collected through 72 hours. Cibenzoline concentrations in plasma and urine were measured by HPLC. Cibenzoline absorption was slower in 7 of the 8 volunteers following the evening dose relative to the morning dose. Mean +/- S.D. tmax for the evening dose was 2.6 +/- 0.5 hours compared to 1.7 +/- 0.8 for the morning dose. The corresponding mean +/- S.D. Cmax following the morning dose was 446 +/- 124 ng ml-1 compared to 402 +/- 114 ng ml-1 after the evening dose. The mean +/- S.D. AUC was 3328 +/- 1101 ng . h . ml-1 after the morning dose and 3561 +/- 1430 ng . h . ml-1 after the evening dose. The harmonic mean half-life was 7.4 hours after both treatments. These data indicated that the total amount of drug absorbed and the elimination rate constant of the drug had not varied between treatments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Improved effect of glibenclamide on administration before breakfast

Summary In an attempt to assess whether intake of glibenclamide before meals would improve its therapeutic capacity, the present investigation compared the effect of glibenclamide 2.5mg t.i.d. given before and together with meals. In addition, these effects were compared with that of glibenclamide given as a single morning dose of 7.5mg. The subjects studied were six Type 2 diabetics not previously exposed to sulphonylurea drugs. Irrespective of dosage and mode of administration, addition of glibenclamide to a standardized breakfast, lunch and dinner enhanced plasma IRI concentrations and reduced blood glucose concentrations as compared to administration of meals without the drug. The different modes of glibenclamide administration did not differ significantly with respect to IRI responses. However, the blood glucose reduction after breakfast was significantly greater when glibenclaimde 2.5mg had been given before the meal than when 2.5 or 7.5mg were given with the meal; a similar, but non-significant tendency was observed after lunch; no consistent difference was seen after dinner. Food intake did not affect glibenclamide kinetics. It appears that administration of glibenclamide 2.5mg before breakfast improved glucose utilization following the breakfast load, due to earlier attainment of an effective concentration of glibenclamide.