Population Pharmacokinetics of Ibrutinib in Healthy Adults.

BACKGROUND AND OBJECTIVES: Ibrutinib is an antineoplastic agent that reduces B-cell proliferation by inhibiting Bruton's tyrosine kinase. We describes population pharmacokinetics of ibrutinib in healthy adults, and explores potential patient characteristics associated with ibrutinib pharmacokinetics. METHODS: A population pharmacokinetic modeling approach was applied to 39 healthy subjects. Modeling was performed using Monolix (v.2019R2). Serial blood samples to measure the plasma ibrutinib concentration were collected following the oral administration of 140 mg ibrutinib on two different occasions under fasting conditions. Demographic and clinical information were evaluated as possible predictors of ibrutinib pharmacokinetics during model development. Simulations (using mlxR: R package v.4.0.2) following the administration of therapeutic doses were performed to explore the clinical implications of identified covariates on ibrutinib steady-state concentrations. RESULTS: A two-compartment model with zero order absorption best fit the data. Inter-individual and inter-occasion variability were quantified by the proposed model. We identified smoking status as a significant covariate associated with ibrutinib clearance. Smoking was found to increase ibrutinib clearance by approximately 60%, which resulted in a reduction in simulated steady-state concentrations by around 40%. CONCLUSION: The model can be used to simulate clinical trials or various dosing scenarios. The proposed model can be used to optimize ibrutinib dosing based on the smoking status.

Clarithromycin laurate salt: physicochemical properties and pharmacokinetics after oral administration in humans.

OBJECTIVE: To prepare and characterize the physicochemical and pharmacokinetic properties of clarithromycin laurate (CLM-L), a fatty acid salt of clarithromycin (CLM). METHODS: CLM-L was prepared by a simple co-melting process. The formation of CLM-L was confirmed using FTIR, 1H NMR, and 13C NMR. Solubility, intrinsic dissolution rate (IDR), and partitioning properties of CLM-L were determined and compared to those of CLM. Bioavailability of CLM from CLM-L tablets was evaluated in healthy volunteers and compared to immediate release CLM tablets. RESULTS: CLM-L showed lower aqueous solubility, higher partitioning coefficient, and slower dissolution rate. Tablets of CLM-L also showed a significantly slower in vitro release in comparison to CLM tablets. Cmax, Tmax and AUC0→∞ of CLM-L tablets and immediate release CLM tablets did not show a significant difference. However, the AUC0→∞ for the CLM-L tablets tended to be higher than that of CLM tablets at all-time points. CONCLUSION: CLM-L was successfully prepared and its formation was confirmed. CLM-L was more hydrophobic than CLM. It exhibited a slight in vivo absorption enhancement in comparison to CLM. However, its pharmacokinetic behavior was comparable to that of CLM.

Pharmacokinetics of betamethasone after single-dose intramuscular administration of betamethasone phosphate and betamethasone acetate to healthy subjects.

BACKGROUND: Betamethasone is used for its antiinflammatory and immunosuppressive effects in disorders of many organ systems. However, the pharmacokinetic properties of betamethasone in plasma after intramuscular injection of betamethasone sodium phosphate and betamethasone acetate dual-acting suspension need further investigation. OBJECTIVES: The main aim of this study was to determine the pharmacokinetic parameters of betamethasone, betamethasone acetate, and betamethasone phosphate after the administration of a single intramuscular dose of the dual-acting suspension to healthy human volunteers. METHODS: Two different studies were conducted in healthy males. Volunteers were judged healthy based on their medical history, physical examination, and laboratory test results. Before confinement, all volunteers were tested for freedom from alcohol and drugs of abuse. Following a 10-hour overnight fasting, a single dose of 1 mL of the dual-acting suspension containing 3 mg of betamethasone phosphate and 3 mg of betamethasone acetate was administered by intramuscular injection. Blood sampling covered 48 hours. The plasma samples obtained in the second study were stabilized to enable pharmacokinetic profiling of betamethasone esters. RESULTS: Twenty-four healthy males with mean (SD) age of 27 (6.62) years participated in each study. No incidences of serious adverse events were recorded during the studies. Six mild adverse events were reported in 2 subjects in the second study. One subject suffered from pain at the injection site and insomnia, and another subject complained of heartburn and drowsiness. Betamethasone phosphate appeared to be readily absorbed with a mean AUC(0-t) of 96.01 ng/h/mL and an AUC(0-∞) of 97.96 (23.38) ng/h/mL. Betamethasone peak plasma concentration reached a mean t(½) of 12.92 hours. Betamethasone acetate was not detected in the volunteers' plasma in either study (total of 2208 plasma samples). CONCLUSION: The observed pharmacokinetic parameters suggested that the acetate ester, and not the phosphate ester, of betamethasone acts as a prodrug or reservoir for betamethasone, conferring on it sustained- and extended-release characteristics.

LC-MS/MS determination of betamethasone and its phosphate and acetate esters in human plasma after sample stabilization.

Two specific liquid chromatography-mass spectrometric (LC-MS/MS) assays were developed and validated for the determination of betamethasone (BET), and its acetate (BA) and phosphate (BP) esters. The plasma and the blood used for the development and validation of these two methods were previously stabilized. Liquid-liquid extraction techniques were used after the addition of prednisolone as internal standard (IS). Samples were chromatographed using C8 column, while mass detection was carried out by electrospray ionization in the positive mode (ESI+). The method was proved linear over a working range 0.50-50.00 ng/ml for BET (r(2)>0.99), while BA linear range was 1.0-20.0 ng/ml (r(2)>0.99). Sensitivity was determined as 0.50 ng/ml for BET and 1.00 ng/ml for BA. Betamethasone phosphate LC-MS/MS method involved solid phase extraction after the addition of prednisolone phosphate as (IS). Separation was carried out using C18 column, while detection was by ESI+. The method showed good linearity over the working range 2.0-200.0 ng/ml (r(2)>099). Both methods were applied to determine BET, BA and BP in plasma samples obtained for pharmacokinetics studies in human.

A retrospective, open-label analysis of the population pharmacokinetics of a single 10-mg dose of loratadine in healthy white Jordanian male volunteers.

BACKGROUND: Loratadine is a long-acting tricyclic antihistamine with selective peripheral histamine H(1)-receptor antagonist activity. Loratadine 10-mg tablets have been reported to be rapidly absorbed after once-daily administration for 10 days in healthy adult subjects, with a T(max) of 1.3 hours for loratadine and 2.5 hours for its major active metabolite, descarboethoxyloratadine. The t(1/2) in normal adult subjects has been reported to be 8.4 hours (range, 3-20 hours) for loratadine and 28 hours for its metabolite. OBJECTIVE: The aim of this study was to determine the population pharmacokinetics of loratadine after oral administration. METHODS: A retrospective analysis was conducted of prior noncompartmental analysis results from healthy white Jordanian male subjects who participated in 2 pharmacokinetic studies. After a 10-hour overnight fast, a single 10-mg loratadine tablet was administered orally followed by 240 mL of water. Blood samples were collected before dosing and at 0.33, 0.66, 1, 1.5, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72, and 96 hours after dosing. Mean and population plasma level profiles were examined. The calculated primary and secondary pharmacokinetic parameters were V(d)/F, k(e), absorption rate constant, lag time, distribution rate constant, redistribution rate constant, T(max), and C(max). RESULTS: A total of 72 healthy male subjects with a mean (SD) age of 23 (3.57) years participated in the 2 studies. The analytical method was linear over the concentration range from 0.10 to 20.00 ng/mL (r > 0.999). The lower limit of quantitation was 0.1 ng/mL with 95% accuracy. Precision, expressed as %CV, was 7.44%. Intraday accuracy ranged from 91.9% to 97.2% at high and low quality control levels, respectively. Interday accuracy ranged from 93.57% (%CV, 4.35%) to 98.78% (%CV, 5.78%), respectively. Population ke, t(1/2), absorption rate constant, and absorption t(1/2) were 0.19 hour(-1), 3.65 hours, 1.31 hours(-1), and 0.53 hour, respectively. Distribution rate constant, redistribution rate constant, and lag time were 0.31 hour(-1), 0.02 hour(-1), and 0.32 hour, respectively. The noncompartmental estimate for C(max) was 3.02 ng/mL, which occurred at 1.30 hours, with a t(1/2) of 5 hours and a k(e) of 0.14 hour(-1). No adverse events were recorded during the study. CONCLUSION: The population t(1/2) for loratadine was 3.65 hours in this group of healthy white Jordanian male volunteers, shorter than that observed in previous research.

Determination of imatinib plasma levels in patients with chronic myeloid leukemia by high performance liquid chromatography-ultraviolet detection and liquid chromatography-tandem mass spectrometry: methods' comparison.

The aims of this study were to validate and compare HPLC and LCMSMS analytical methods and their applicability for the quantitation of imatinib in human plasma. A total of 50 patients with chronic myeloid leukemia (CML) in chronic phase (CP) receiving 400 mg/day imatinib were enrolled in the study. Drug levels were determined by HPLC-UV and LCMSMS. HPLC intra-day accuracy ranged from 100.51 to 103.19%. LCMSMS accuracy ranged from 89.72 to 106.29%. The correlation coefficient between both methods was r(2)=0.96. HPLC can be used for imatinib levels' determinations in patients accurately and precisely.

Bioequivalence evaluation of two brands of fluoxetine 20 mg capsules (Flutin and Prozac) in healthy human volunteers.

A bioequivalence study of two oral formulations of 20 mg fluoxetine was carried out in 24 healthy volunteers following a single dose, two-sequence, crossover randomized design at International Pharmaceutical Research Centre (IPRC), Amman, Jordan. The two formulations were Flutin capsules (Julphar, UAE) as test and Prozac capsules (Eli Lilly, UK) as reference product. Test and reference capsules were administered to each subject after an overnight fasting on two treatment days separated by a 28 day washout period. After dosing, serial blood samples were collected for a period of 360 h. Plasma harvested from blood was analysed for fluoxetine by a sensitive, reproducible and accurate LC-MS method. Various pharmacokinetic parameters including AUC(0-t), AUC(0-infinity), C(max), T(max), T(1/2), and lambda(Z) were determined from plasma concentrations for both formulations and found to be in good agreement with reported values. AUC(0-t), AUC(0-infinity) and C(max) were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence interval (94.60%-106.41% for AUC(0-t), 94.6%-108.14% for AUC(0-infinity); 91.88%-103.65% for C(max)) for test/reference ratio of these parameters were found within FDA acceptance range of 80%-125%. Based on these statistical inferences, it was concluded that Flutin is bioequivalent to Prozac and can be used interchangeably in medical practice.

Variable omeprazole kinetics in healthy Jordanian adults.

OBJECTIVES: The objective of this study was to examine the pharmacokinetics of orally administered omeprazole in healthy adult Jordanian men. METHOD: Plasma concentrations of omeprazole were measured over a 12 h period after administration of a single oral dose of 40 mg omeprazole (Losec), AstraZeneca, UK). Subjects were healthy adult Jordanian men age 18-38 (24 +/- 4, mean +/- SD). The pharmacokinetic parameters were derived from the plasma concentration-time profiles for AUC(0-t), AUC(0-inf), C(max), t(max), t(1/2e) and K(e). RESULTS: The pharmacokinetic of omeprazole were scattered over a wide range. The median AUC(0-inf) was 784.86 +/- 1182.88 (ng.h/ml), and the median C(max) was 521 +/- 354 (ng/ml) (median +/- SD). In general, most subjects showed normal distribution (approximately 90%). Some subjects (10%) did show very high AUC and C(max) compared with the reported AUC and C(max) levels. These subjects had higher half-lives and lower rates of elimination. CONCLUSION: Significant difference in the pharmacokinetics of omeprazole after a single dose administration was noted. Approximately 10% of the study group showed very high omeprazole plasma levels and AUCs. Differences in the pharmacokinetics might be due to differences in the genetic make-up of subjects.

Bioequivalence assessment of Lovrak (Julphar, UAE) compared with Zovirax (Glaxo Wellcome, UK)--Two brands of Acyclovir--in healthy human volunteers.

Two studies were performed to assess the relative bioavailability of Lovrak (Julphar, UAE) compared with Zovirax (Glaxo Wellcome, UK) at the International Pharmaceutical Research Center (IPRC), Amman, Jordan. One study involved acyclovir tablets and the other acyclovir suspension. Each study enrolled 24 volunteers and in both studies, after an overnight fasting, the two brands of acyclovir were administered as a single dose on 2 treatment days separated by 1 week washout period. After dosing, serial blood samples were collected for a period of 16 h. Plasma harvested from blood, was analysed for acyclovir by an HPLC method with UV detection. Various pharmacokinetic parameters including AUC0-t, AUC0-infinity, Cmax, Tmax, T1/2 and Kelm were determined from plasma concentrations for both formulations and found to be in good agreement with the reported values. AUC0-t, AUC(0-proportional to), and Cmax were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence intervals for the test/reference ratio of these parameters were found within the bioequivalence acceptance range 80%-125%. Based on these statistical inferences it was concluded that a Lovrak tablet is bioequivalent to a Zovirax tablet and that Lovrak suspension is bioequivalent to Zovirax suspension.

Comparative bioavailability of two brands of atenolol 100 mg tablets (Tensotin and Tenormin) in healthy human volunteers.

A bioequivalence study of two oral formulations of 100 mg atenolol was carried out in 24 healthy volunteers following a single dose, two-sequence, cross-over randomized design at the International Pharmaceutical Research Centre (IPRC), as a joint venture with Al-Mowasah Hospital, Amman, Jordan. The two formulations were Tensotin (Julphar, UAE) as test and Tenormin (Zeneca, UK) as reference product. Both test and reference tablets were administered with 240 ml of water to each subject after an overnight fast on 2 treatment days separated by a 1 week washout period. After dosing, serial blood samples were collected for a period of 36 h. Whole blood was analysed for atenolol by a sensitive, reproducible and accurate HPLC method with fluorescence detection capable of detecting atenolol in the range of 20-1600 ng/ml with a limit of quantitation of 20 ng/ml. Various pharmacokinetic parameters including AUC0-t, AUC0-proportional to), Cmax, Tmax, T1/2 and lambdaZ were determined from blood concentrations of both formulations and found to be in good agreement with reported values. AUC0-t, AUC0-proportional to), and Cmax were tested for bioequivalence after log-transformation of data using ANOVA and 90% confidence interval and were found within the acceptable range of 80%-125%. Based on these statistical inferences, it was concluded that Tensotin is bioequivalent to Tenormin.

A two-way cross-over bioequivalence study comparing two products of diclofenac sodium suppositories in healthy human volunteers.

This report presents the results of two treatment cross-over investigations on 20 healthy male volunteers to assess the bioequivalence of two suppository products of diclofenac sodium. The study was carried out under US Food and Drug Administration Guidelines. The two products were voltaren (100 mg) suppository (Ciba-Giegy), as a reference product, and Inflaban (100 mg) suppository (The Arab Pharmaceutical Manufacturing Company, Ltd. "APM"), as a test product. Both products were administered rectally as a single dose (100 mg) separated by a one-week wash-out period. Following drug administration, blood samples were collected over 12 hr, and serum harvested from the blood was analyzed for diclofenac sodium using a sensitive and specific high performance liquid chromatographic assay. The results of this investigation indicated that there were no statistically significant differences between the two products in either the mean concentration-time profiles or in the obtained pharmacokinetic parameters, including area under the serum concentration-time curve for 12 hr (AUC(0-12h)), lag time between product administration and first appearance of the drug in serum (T(lag)), peak serum concentration (C(max)), and time to reach this peak serum concentration (T(max)). Concerning the relative extent of absorption, assessed by the AUC ratio (Inflaban/Voltaren) for 12 hr, the average value was found to be 1.00+/-0.09 with a 95% confidence limits (C.L.) of 0.82-1.18. Thus, these findings clearly indicate that the two products are bioequivalent in terms of rate and extent of drug absorption.

Bioequivalence evaluation of two brands of amoxicillin/clavulanic acid 250/125 mg combination tablets in healthy human volunteers: use of replicate design approach.

The purpose of this study was to apply a replicate design approach to a bioequivalence study of amoxicillin/clavulanic acid combination following a 250/125 mg oral dose to 23 subjects, and to compare the analysis of individual bioequivalence with average bioequivalence. This was conducted as a 2-treatment 2-sequence 4-period crossover study. Average bioequivalence was shown, while the results from the individual bioequivalence approach had no success in showing bioequivalence. In conclusion, the individual bioequivalence approach is a strong statistical tool to test for intra-subject variances and also subject-by-formulation interaction variance compared with the average bioequivalence approach.

In vitro and in vivo evaluation of glibenclamide in solid dispersion systems.

The purpose of this work is to improve the dissolution and bioavailability characteristics of glibenclamide as compared to Daonil tablets (Hoechst). Solid dispersions of glibenclamide in Gelucire 44/14 (Formula 1) and in polyethylene glycol 6000 (PEG 6000) (Formula 2) were prepared by fusion method. In vitro dissolution studies showed that the dispersing systems containing glibenclamide and Gelucire 44/ 14 or PEG 6000 gave faster dissolution rates than the reference product Daonil. The in vivo bioavailability study was assessed in six healthy male volunteers in crossover design with a 1-week washout period. Both formulas were found to be significantly different from Daonil with regard to the extent of absorption as indicated by the area under serum concentration-time curve. Both formulas are not significantly different from Daonil with respect to time of peak plasma concentration Tmax. It is concluded from this pilot study that the ranking of the in vitro dissolution is similar to the ranking of in vivo availability. The ranking of the three preparations in term of dissolution rate and extent of absorption is as follows: Formula 2>Formula 1 >Daonil.

Bioequivalence evaluation of two brands of aceclofenac 100 mg tablets (Aceclofar and Bristaflam) in healthy human volunteers.

A randomized, two-way, crossover, bioequivalence study in 24 fasting, healthy, male volunteers was conducted to compare two brands of aceclofenac 100 mg tablets, Aceclofar (Julphar, UAE) as test and Bristaflam (Bristol Myers Squibb, Egypt) as the reference product. The drug was administered with 240 ml of water after a 10 h overnight fast on two treatment days separated by 1 week washout period. After dosing, serial blood samples were collected for a period of 24 h. Plasma harvested from blood was analysed for aceclofenac by a validated HPLC method with UV-visible detection capable of detecting aceclofenac in the range 0.2-8.0 microg/ml with the limit of quantitation as 0.2 microg/ml. Various pharmacokinetic parameters including AUC(0-t), AUC(0- infinity ), C(max), T(max), T(1/2), and lambda(Z) were determined from plasma concentrations for both formulations and found to be in good agreement with reported values. AUC(0-t), AUC(0- infinity), and C(max) were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence interval (100.0%-106.4% for AUC(0-t), 100.2%-106.8% for AUC(0- infinity ); 83.3%-102.8% for C(max)) of test/reference ratio for these parameters were found to be within the bioequivalence acceptance range of 80%-125%. Based on these statistical inferences, it was concluded that Aceclofar is bioequivalent to Bristaflam.

Determination of ketotifen in human plasma by LC-MS.

Analytical validation of a new liquid chromatographic-mass spectrometric (LC-MS) method for determination of total amount of ketotifen (unchanged and conjugated) in human plasma is presented. Pizotifen was used as an internal standard. An enzyme hydrolysis of conjugated ketotifen was conducted with a combination of beta-glucuronidase and aryl sulfatase. After enzyme hydrolysis a liquid-liquid extraction was performed as a cleaning step. The quantitative determination was obtained using selected ion monitoring (SIM) LC-MS. Chromatographic condition was a combination of reverse phase gradient system and a switching column technique. A satisfactory hydrolysis, acceptable accuracy, improved precision in the linear range from 0.5 to 20.0 ng/ml plasma, absolute recovery of 98.04% for ketotifen and 95.13% for pizotifen and stability for 7 months at -20 degrees C have been achieved.

Bioequivalence evaluation of two brands of enalapril 20 mg tablets (Narapril and Renitec) in healthy human volunteers.

The bioequivalence of two brands of enalapril 20 mg tablets was demonstrated in 24 healthy human volunteers after a single oral dose in a randomized cross-over study, conducted at IPRC, Amman, Jordan. Reference (Renitec, MSD, Netherlands) and test (Narapril, Julphar, UAE) products were administered to fasted male volunteers; blood samples were collected at specified time intervals, plasma separated and analysed for enalapril and its active metabolite (enalaprilat) using a validated LC-MS/MS method at Cartesius Analytical Unit, Institute of Biomedical Sciences, USP, Sao Paulo, Brazil. The pharmacokinetic parameters AUC(0-t), AUC(0-infinity), Cmax, Tmax, T(1/2) and elimination rate constant were determined from plasma concentration-time profile for both formulations and were compared statistically to evaluate bioequivalence between the two brands, using the statistical modules recommended by FDA. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals fell within the acceptable range for bioequivalence. Based on these statistical inferences it was concluded that the two brands exhibited comparable pharmacokinetic profiles and that Julphar's Narapril is bioequivalent to Renitec of MSD, Netherlands.

Bioequivalence evaluation of two brands of furosemide 40 mg tablets (Salurin and Lasix) in healthy human volunteers.

A randomized, two-way, crossover, bioequivalence study was conducted in 24 fasting, healthy, male volunteers to compare two brands of furosemide 40 mg tablets, Salurin (Julphar, UAE) as test and Lasix (Hoechst AG, Germany) as reference product. The study was performed at the International Pharmaceutical Research Centre (IPRC), in a joint venture with Al-Mowasah Hospital, Amman, Jordan. One tablet of either formulation was administered with 240 ml of water after a 10 h overnight fast. After dosing, serial blood samples were collected for a period of 12 h. Plasma harvested from blood was analysed for furosemide by a validated HPLC method. Various pharmacokinetic parameters including AUC(0-t), AUC(0-infinity), C(max), T(max), T(1/2), and elimination rate constant were determined from plasma concentrations of both formulations. Statistical modules (ANOVA and 90% confidence intervals) were applied to AUC(0-t), AUC(0-infinity), and C(max) to assess the bioequivalence of the two brands which revealed no significant difference between them, and 90% CI fell within the US FDA accepted bioequivalence range of 80%-125%. Based on these statistical inferences, Salurin was found to be bioequivalent to Lasix.

Pharmacokinetics and bioequivalence evaluation of two simvastatin 40 mg tablets (Simvast and Zocor) in healthy human volunteers.

The pharmacokinetics of two brands of simvastatin 40 mg tablets were compared in 24 healthy human volunteers after a single oral dose in a randomized cross-over study, conducted at IPRC, Amman, Jordan. Reference (Zocor, MSD, Netherlands) and test (Simvast, Julphar, UAE) products were administered to fasted volunteers; blood samples were collected at specified time intervals, plasma separated and analyzed for simvastatin and its active metabolite (beta-hydoxy acid) using a validated LC-MS/MS method at Cartesius Analytical Unit, Institute of Biomedical Sciences - USP, Sao Paulo, Brazil. The pharmacokinetic parameters AUC(0-t), AUC(0-variant), C(MAX), T(MAX), T(1/2) and elimination rate constant were determined from plasma concentration-time profile for both formulations and were compared statistically to evaluate bioequivalence between the two brands, using the statistical modules recommended by FDA. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals fell within the acceptable range for bioequivalence. Based on these statistical inferences it was concluded that the two brands exhibited comparable pharmacokinetic profiles and that Julphar's Simvast is bioequivalent to Zocor of MSD, Netherlands.

Comparison of two cyclosporine formulations in healthy Middle Eastern volunteers: bioequivalence of the new Sigmasporin Microoral and Sandimmun Neoral.

A study was conducted to establish bioequivalence between two oral cyclosporine 100 mg capsules, Sigmasporin Microoral (Gulf Pharmaceutical Industries - Julphar, United Arab Emirates, under technical co-operation with Sigma Pharma, Brazil) and Sandimmun Neoral (Novartis, Switzerland), in a Middle Eastern population, even though both formulations were found to be bioequivalent earlier in a Brazilian population (data on file). It was designed as a randomized, open label, two-way crossover study in which 30 fasting, healthy male volunteers received a single 100 mg cyclosporine dose with 240 ml of water on two treatment days separated by a 1 week washout period. After dosing, serial blood samples were collected for a period of 24 h. Plasma was analyzed for cyclosporine A by a sensitive, reproducible and accurate HPLC method with MS detection capable of detecting cyclosporine A in the range of 5-400 ng/ml with a limit of quantitation of 5 ng/ml. Various pharmacokinetic parameters including AUC(0-t), AUC(0- proportional, variant ), C(max), T(max), T(1/2), and lambda(Z) were determined from plasma concentrations of both formulations. AUC(0-t), AUC(0- proportional, variant ), and C(max) were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence intervals (82.98-110.57% for AUC(0-t), 81.57-124.71% for AUC(0- proportional, variant ), 80.15-98.91% for C(max)) for these parameters were found to be within the bioequivalence acceptance range of 80-125%. Based on these statistical inferences, it was concluded that Sigmasporin Microoral is bioequivalent to Sandimmun Neoral.

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.