Bioequivalence evaluation of 2 brands of cefuroxime axetil 250 mg tablets in healthy human volunteers

OBJECTIVE: To assess the bioequivalence of 2 oral cefuroxime axetil (250 mg) tablets formulation. The reference preparation was Zinadol/Glaxo Wellcome, England, while the test preparation was cefuroxime axetil/Pharmathen, Athens, Greece. SUBJECTS, MATERIAL AND METHODS: The study was an open, randomized, 2-period, 2-sequence, 2-treatment crossover, involving 24 healthy male and female volunteers. All volunteers completed the study. Cefuroxime axetil plasma concentrations were measured utilizing a sensitive, reproducible and accurate HPLC method. Care was taken through the collection and analysis of the samples due to instability of cefuroxime axetil in light. Pharmacokinetic parameters used to assess bioequivalence were AUC(0-last), AUC(0-inf) for the extent of absorption and Cmax and tmax for the rate of absorption. Statistical evaluation of Cmax, AUC(0-last), and AUC(0-inf) was done using 2-way analysis of variance (ANOVA) after semilogarithmic transformation. Tmax values were tested using the distribution-free Hodges-Lehman interval. RESULTS: The parametric 90% confidence intervals for ratio T/R ranged from 98.91-111.65% (point estimate 105.09%) for AUC(0-last), 99.41-111.78% (point estimate 105.41%) for AUC(0-inf) and 87.61-102.89% (point estimate 94.95%) for Cmax, respectively. Based on the results of tmax, K(el) and t(1/2) there were no statistically significant differences. CONCLUSION: The 2 cefuroxime axetil preparations, examined in accordance with the European Union bioequivalence requirements, are equivalent with respect to rate and extent of absorption.     

Bioequivalence evaluation of two brands of glimepiride 4 mg tablets in healthy subjects

OBJECTIVE: This paper describes a bioequivalence study with two oral glimepiride (4 mg) tablets formulations. The reference preparation was Solosa/Aventis Pharmaceuticals Inc., USA, and the test preparation was Glimepiride/Specifar, Athens, Greece. SUBJECTS, MATERIAL AND METHODS: The study design was open, randomized, two-period, two-sequence, two-treatment with crossover involving 24 healthy male and female subjects. All subjects completed the study. Glimepiride plasma concentrations were measured utilizing a sensitive, reproducible and accurate HPLC method. Pharmacokinetic parameters used to assess bioequivalence were AUC(0_last), AUC(0-inf) for the extent of absorption and Cmax and tmax for the rate of absorption. Statistical evaluation of Cmax, AUC(0_last), and AUC(0-inf) was done after semilogarithmic transformation using a two-way analysis of variance (ANOVA). Tmax values were tested using the distribution-free Hodges-Lehman interval. RESULTS AND CONCLUSION: The parametric 90% confidence intervals for ratio T/R ranged from 90.60-108.00% (point estimate 98.90%) for AUC(0-last), 90.70-107.90% (point estimate 98.90%) for AUC(0-inf) and 86.70-103.70% (point estimate 94.80%) for Cmax, respectively. Based on the results of tmax, Kel and t(1/2), there were no statistically significant differences and the two glimepiride preparations are equivalent with respect to rate and extent of absorption as defined by the European Union bioequivalence requirements.     

Evaluation of the bioequivalence and pharmacokinetics of two lisinopril tablet formulations after single oral administration in healthy volunteers

An open, two-period, randomized, crossover trial of two lisinopril (1-[N2-[(S)-1-carboxyl-3-phenylpropyl]-L-lysil]-L-proline, CAS 76547-98-3) formulations (Adicanil as test and another commercially available preparation as reference) was performed in 24 healthy volunteers. A single 20 mg oral dose of lisinopril was administrated and pharmacokinetic parameters were compared. Lisinopril plasma concentrations were measured by a fully validated LC-MS method. The parametric 90% confidence intervals of the geometric mean values of the test/reference ratios were 95.38% to 105.94% (point estimate: 100.52%) for AUC(0-last), 94.01% to 103.47% (point estimate: 98.63%) for AUC(0-infinity) and 92.34% to 103.97% (point estimate: 97.98%) for Cmax, being within the acceptance criteria for bioequivalence (80%-125%). T(1/2), k(el) and Tmax values were also tested and the difference was not statistically significant. Therefore, it is concluded that the test and the reference lisinopril formulations are bioequivalent both in the extent and the rate of absorption.     

Evaluation of the bioequivalence of two tablet formulations of enalapril/hydrochlorothiazide after single oral administration to healthy volunteers

The pharmacokinetic parameters of two oral formulations of 20/12.5 mg tablets of enalapril/hydrochlorothiazide (CAS 75847-73-3 and CAS 58-93-5, respectively; Penopril as test and another commercially available preparation as reference) were compared in an open-label randomized single oral dose two-period cross-over design to 24 healthy volunteers under fasting conditions. Plasma concentrations of enalaprilat (CAS 76420-72-9), the pharmacologically active metabolite of enalapril, and hydrochlorothiazide were determined by a validated GC/MS and HPLC assay, respectively. Serial blood samples were collected prior to each administration and at 19 timepoints within 36 h after dosing. The parametric 90% confidence intervals of the geometric mean values of the test/reference ratios for enalaprilat were 99.3% to 118.9% (point estimate: 108.7%) for AUC(0-infinity), 97.3% to 116.9% (point estimate: 106.7%) for AUC(0-t), and 92.5% to 113.0% (point estimate: 102.3%) for Cmax, and for hydrochlorothiazide 92.3% to 105.1% (point estimate: 98.5%) for AUC(0-infinity), 92.7% to 105.4% (point estimate: 98.9%) for AUC(0-t), and 97.6% to 115.3% (point estimate: 106.0%) for Cmax, within the acceptance criteria for bioequivalence (80%-125%). Tmax values were analyzed by the nonparametric Wilcoxon test and the difference was not statistically significant. Therefore, it is concluded that the test and reference enalapril/hydrochlorothiazide formulations are bioequivalent for both the extent and the rate of absorption.     

Effect of food on the pharmacokinetics of sunitinib malate (SU11248), a multi-targeted receptor tyrosine kinase inhibitor: results from a phase I study in healthy subjects

The effect of food on the oral bioavailability of sunitinib malate (SU11248, an oral, multi-targeted tyrosine kinase inhibitor with anti-angiogenic and anti-tumor activities) was assessed in a randomized open-label, two-way crossover study. A 50-mg dose of SU11248 was administered to 16 healthy subjects after a 10-h fast in one period and after a high-fat, high-calorie meal in the other period. The 90% confidence intervals (CIs) for maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) were within the 80-125% bioequivalence range, indicating the absence of a food effect. SU11248 exposure increased slightly in the fed compared with the fasted state (ratios of fed/fasted geometric least square means: Cmax 104%, AUC0-last and AUC0-infinity both 112%). There was a delay in the formation/absorption of the active metabolite SU12662 in the fed state (mean Cmax decreased 23%), but exposure remained unaffected (90% CIs for AUC0-last and AUC0-infinity were within 80-125%). These results indicate that SU11248 can be administered with or without food.     

Relative bioavailability of two isosorbide dinitrate sublingual tablet formulations administered as single doses in healthy subjects

OBJECTIVE: The purpose of this study was to evaluate the relative bioavailability and bioequivalence of a test and a reference sublingual tablet each containing 5 mg of isosorbide dinitrate in healthy volunteers. METHODS: The study was conducted as an open-label, randomized, single-dose, two-period crossover design in 20 healthy volunteers with a washout period of 7 days, under fasting conditions. Plasma concentrations of the major active metabolite isosorbide 5-mononitrate were quantified, using a validated capillary gas chromatographic assay, with electron-capture detection. The pharmacokinetic parameters used to assess the bioequivalence of the two preparations were AUC(0-infinity) and AUC(0-infinity) for the extent of absorption and Cmax and tmax for the rate of absorption. RESULTS: The calculated 90% confidence intervals of the geometric mean values of the test/reference ratios were 98.2% to 103.2% (point estimate; 100.7%) for AUC(0-infinity) 96.9% to 103.8% (point estimate; 100.3%) for AUC(0-infinity), and 87.9% to 98.2% (point estimate; 92.9%) for Cmax. No statistically significant difference was found for tmax and elimination half-life (t 1/2) values. CONCLUSION: From the results of the present study, it is concluded that the test and reference isosorbide dinitrate sublingual preparations are bioequivalent in both extent and rate of absorption and it can be assumed that they are therapeutically equivalent and exchangeable in clinical practice.     

Evaluation of the bioequivalence and pharmacokinetics of two formulations of rizatriptan after single oral administration in healthy volunteers

The pharmacokinetic parameters of two oral formulations of rizatriptan (CAS 144034-80-0, a capsule preparation as test and rizatriptan tablet as reference), given at a single dose of 10 mg each, were compared in an open-label, randomized, single oral dose, two-period cross-over design in 20 healthy volunteers under fasting conditions. Plasma concentrations of rizatriptan were measured by a validated HPLC assay. The parametric 90% confidence intervals of the geometric mean values of the test/reference ratios were 91.9% to 101.9% (point estimate: 97.3%) for AUC(0-infinity), 93.0% to 102.2% (point estimate: 96.5%) for AUC(0-t), 90.1% to 100.0% (point estimate: 95.4%) for Cmax, being within the acceptance criteria for bioequivalence (80%-125%). Tmax values were analyzed by the nonparametric Wilcoxon test and the difference was not statistically significant. Therefore, it is concluded that the test and reference rizatriptan formulations are bioequivalent with regard to both the extent and the rate of absorption.     

Comparative bioavailability of two immediate-release tablets of lisinopril/hydrochlorothiazide in healthy volunteers

AIM: Two formulations of lisinopril/hydrochlorothiazide (20 mg/12.5 mg) were evaluated for bioequivalence after single dosing in healthy volunteers. METHODS: The study was conducted according to an open, randomized, 2-period crossover design with a 2-week washout interval between doses. Twenty-four volunteers participated and all completed the study successfully. Lisinopril and hydrochlorothiazide were determined in plasma by HPLC. The pharmacokinetic parameters AUC(0-t), AUC(0-infinity), Cmax and Cmax/AUC(0-infinity) were tested for bioequivalence after logarithmic transformation of data and ratios of tmax were evaluated non-parametrically. RESULTS: For lisinopril, the parametric analysis revealed the following test/reference ratios and their confidence intervals (90% CI): 1.01 (0.84-1.22) for AUC(0-t), 0.98 (0.81-1.19) for AUC(0-infinity), 1.02 (0.83-1.25) for Cmax and 1.03 (0.99-1.08) for Cmax/AUC(0-infinity). The 90% CI for tmax was 0.94-1.07. All parameters showed bioequivalence between both formulations. As for hydrochlorothiazide, test/reference ratios and their confidence intervals (90% CI) were: 1.05 (0.95-1.17), 1.02 (0.93-1.12) for AUC(0-infinity), 0.99 (0.89-1.07) for Cmax and 0.97 (0.90-1.04) for Cmax/AUC(0-infinity). The 90% CI for tmax was 1.00-1.41. All parameters showed bioequivalence between both formulations except for tmax. A discrete fall in both systolic (SBP) and diastolic (DBP) blood pressure was observed after drug administration. The time course of both parameters was similar for the 2 formulations. Heart rates also followed a similar time profile. CONCLUSIONS: The bioequivalence of the 2 formulations of lisinopril/hydrochlorothiazide was demonstrated.     

Bioequivalence of two oral formulations of triflusal capsules in healthy volunteers

Triflusal (CAS 322-79-2) is an antiplatelet agent related to salicylates used in several European and Latin American countries in the treatment of cardiovascular diseases. The aim of this paper was to evaluate the bioequivalence of triflusal derived from two preparations using both parent drug and metabolite pharmacokinetic data. The bioavailabolity was measured in 24 healthy male Caucasian volunteers following a single oral dose (600 mg) of the test or reference products in the fasting state. Blood samples were collected for 120 h. Plasma concentrations of triflusal and its metabolite 3-hydroxy-4-trifluoromethylbenzoic acid (HTB) were analyzed by high-performance liquid chromatography with UV and fluorescence detection, respectively. The non-compartmental method was used for pharmacokinetic analysis. Log-transformed Cmax, AUC0-t and AUC0-infinity were tested for bioequivalence using ANOVA and Schuirmann's two-one sided t-test. Tmax was analyzed by nonparametric pharmacokinetic parameters of triflusal and HTB derived from the two formulations were nearly consistent with previous observations. Triflusal parameters derived from the test and reference drug were as follows: Cmax (16.85 +/- 11.41 vs 14.48 +/- 7.22 mg/l), AUC0-t (18.43 +/- 10.91 vs 16.22 +/- 7.58 mg/l per hour), Tmax (1 range 0.25-2h vs 0.875 range 0.25-1.5 h), and t(1/2) (0.49 +/- 00.27 vs 0.76 +/- 0.64). HTB parameters after test and reference formulation administration were as follows: Cmax (68.13 +/- 23.05 vs 65.51 +/- 19.44 mg/l), AUC0-t (2748.18 +/- 971.91 vs 2877.97 +/- 881.2 h x mg/l), AUC0-infinity (3350.15 +/- 1182.62 vs 3372.49 +/- 1110.35 h x mg/l), Tmax (2 range 1-10 h vs 2 range 0.75-12 h), and t(1/2) (42.19 +/- 7.82 vs 43.13 +/- 6.56 h). 90% of confidence intervals for the test/reference ratio of Cmax AUC0-t and AUC0-infinity derived from both triflusal and HTB were found within the range of 80%-125% acceptable for bioequivalence. No significant difference was found between the Tmax values for triflusal and HTB. It was concluded that the two preparations are bioequivalent and may be prescribed interchangeably.     

Pharmacokinetics and bioequivalence evaluation of 2 levosulpiride preparations after a single oral dose in healthy male Korean volunteers

OBJECTIVE: To evaluate the bioequivalence of a single oral 25 mg dose of 2 levosulpiride preparations in healthy male Korean volunteers. SUBJECTS, MATERIALS AND METHODS: The study was conducted as a randomized, 2-period crossover design in 28 healthy male Korean volunteers who received a single oral dose of 25 mg levosulpiride tablet in each study period. There was a 6-day washout period between the doses. Serum concentrations of levosulpiride up to 36 hours after the administration were determined using a validated HPLC method with fluorescence detection. In addition, in vitro dissolution profiles of both preparations were examined. The pharmacokinetic parameters such as AUC(0-t) (the area under the curve from zero to the time), AUC(0-infinity) (the area under the curve from zero to infinity), Cmax (maximum serum concentration), tmax (time to reach Cmax) and t1/2 (terminal half-life) were analyzed by non-compartmental analysis, and the analysis of variance (ANOVA) was carried out using logarithmically transformed AUC(0-t), AUC(0-infinity) and Cmax, and untransformed Tmax. RESULTS: In vitro dissolution profiles were similar by calculating similarity factor (f2 = 67.73). There were no significant differences between the 2 preparations in AUC(0-t), AUC(0-infinity) and Cmax. The point estimates (90% confidence intervals) for AUC(0-t), AUC(0-infinity) and Cmax were 1.085 (1.003-1.173), 1.069 (0.991-1.153) and 1.075 (0.954 to 1.210), respectively, satisfying the bioequivalence criteria of 0.80-1.25 as proposed by the US FDA and the Korean legislation. No statistically significant difference was found for tmax and t1/2 values. CONCLUSION: From the results of the present study, it is indicated that the 2 preparations of levosulpiride are bioequivalent and it can be assumed that they are therapeutically equivalent and exchangeable in clinical practice.     

Bioequivalence study of generic gliclazide and Diamicron formulations in healthy Thai male volunteers

The objective of this study was to compare the bioequivalence of 80 mg gliclazide in healthy Thai males. A single dose of each preparation was administered after an overnight fast in a 2-period crossover design with a 2-week washout period. Serial blood samples were collected over a period of 60 hours. Plasma gliclazide concentrations were determined using HPLC and the pharmacokinetic parameters were analyzed by non-compartmental analysis. Results: The median time to reach the maximal concentration (Tmax) for the test formulation was identical to that of the reference Diamicron (11.5 h). Similarly, the mean elimination half-lives (t1/2) for the test (20.4 +/- 7.8 h) and Diamicron (21.5 +/- 9.4 h) were comparable. Analysis of variance was carried out using logarithmic transformations of AUC(0-infinity) and Cmax as well as non-transformed Tmax. The mean (90% CI) of the difference in Tmax (h) was 0.08 ((-1.44)-1.61). The mean (90% CI) of the AUC(0-infinity) and Cmax ratios for (test/reference) were 1.08 (0.98-1.18) and 1.09 (0.89-1.34), respectively. Since these values fall within the bioequivalence criteria, our study demonstrates bioequivalence of the 2 products.     

Bioequivalence of two tablet formulations of atenolol after single oral administration in healthy volunteers

The pharmacokinetic parameters of two oral formulations of 100 mg tablets of atenolol (CAS 29122-68-7; Azectol as test and another commercially available preparation as reference) were compared in an open-label, randomized, single oral dose, two-period cross-over design to 17 healthy volunteers under fasting conditions. Serial blood samples were collected prior to each administration and at 17 points within 36 h after dosing. Plasma concentrations of atenolol were measured by a validated HPLC assay with fluorometric detection. The parametric 90% confidence intervals of the geometric mean values of the test/reference ratios were 94.4% to 112.9% (point estimate: 103%) for AUC0-infinity, 93.7% to 112.8% (point estimate: 103%) for AUC0-36, and 88.3% to 112.1% (point estimate: 100%) for Cmax, within the acceptance criteria for bioequivalence (80%-125%). Tmax values were analyzed by the nonparametric Wilcoxon test and the difference was not statistically significant. Therefore, it is concluded that the test and reference atenolol formulations are bioequivalent for both the extent and the rate of absorption.     

Fluconazole bioequivalence study: quantification by tandem mass spectrometry

To develop a new method for quantifying fluoconazole in human plasma and to compare the bioavailability of two fluconazole capsule formulations, an open, randomized, two-period crossover study with a one-week washout interval was conducted in 24 healthy volunteers. Plasma samples were obtained up to 168 hours after drug administration and the serum fluconazole concentrations were analyzed using electrospray tandem mass spectrometry coupled to liquid chromatography using multiple reaction monitoring mode. The pharmacokinetic parameters obtained for fluconazole after the administration of each formulation included the Area under the curve (AUC)(0-168h), AUC(0-infinity), Cmax, Cmax/AUC(0-168h), Tmax, elimination rate constant (Ke), and half-life (T1/2). Within- and between-run imprecision was less than 2.3% and 8.2%, respectively. Inaccuracy within and between runs was -1.5% and -9.7%, respectively. The pharmacokinetic parameters for bioequivalence showed a normal distribution, and the variance of AUC(0-168h), AUC(0-infinity), and Cmax were homoscedastic. The geometric mean for the Fluconal/Zoltec (Fluconal; Libbs Farmacêutica Ltda, S?o Paulo, Brazil; Zoltec; Laboratórios Pfizer Ltda., S?o Paulo, Brazil) individual percent ratio was 94.9% for AUC(0-168h), 94.7% for AUC(0-infinity), 80.1% for Cmax, 102.6% for Ke, 97.5% for T1/2, and 0.93 for Tmax (arithmetic mean of individual differences). We have developed a method in which liquid chromatography is coupled with electrospray tandem mass spectrometry to improve the pharmacokinetic analysis of fluconazole. Because the 90% CI AUC is within the interval proposed for the Food and Drug Administration, we concluded that Fluconal is bioequivalent to Zoltec in terms of absorption. The CV was 27.5% for the Cmax parameter, indicating that fluconazole's absorption rate is highly variable. The European Union Regulatory Agency accepts an interval of 70-143%, and because the 90% CI for Cmax is within the interval proposed for the European Union agency, we conclude that Fluconal is bioequivalent to Zoltec for the rate of absorption.     

Bioequivalence of two oral ciprofloxacin tablets formulations

The relative bioavailability of a new 750 mg tablet formulation of ciprofloxacin (test formulation supplied by Dr. August Wolff GmbH and Co., Germany) was compared with that of Ciprobay tablets 750 mg (reference formulation from Bayer Vital GmbH and Co., Germany). Twenty-four healthy volunteers (12 male and 12 female) were included in this single-dose, 2-sequence, crossover randomized study. Blood samples were obtained prior to dosing and at 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, 8, 10, 12, 18, 24 and 30 hours after drug administration. Plasma concentrations of ciprofloxacin were determined by HPLC. No differences were found when the in vitro dissolution profiles of both formulations were compared. The pharmacokinetic parameters AUC(0-t), AUC(0-infinity), Cmax and Cmax/AUC(0-infinity) were tested for bioequivalence after log-transformation of data, and ratios of tmax were evaluated nonparametrically. The parametric analysis revealed the following mean values for the test/reference ratios (90% standard confidence intervals in parenthesis (ln-transformed data): 1.01 (0.95-1.07) for AUC(0-t), 0.99 (0.93-1.05) for AUC(0-infinity), 1.05 (0.97-1.14) for Cmax and 1.06 (0.97-1.15) for Cmax/AUC(0-infinity). The nonparametric confidence interval for tmax was 0.77-1.15. All parameters showed bioequivalence between both formulations as their confidence intervals were within the bioequivalence acceptable range of 0.80-1.25 limits; the 90% confidence interval for tmax slightly exceeded limits of bioequivalence. We conclude that both formulations show bioequivalence for both the rate and the extent of absorption.     

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.     

Comparative bioavailability study of doxycycline hyclate (equivalent to 100 mg doxycycline) capsules (doxycin vs vibramycin) for bioequivalence evaluation in healthy adult volunteers

This investigation was carried out to evaluate the bioavailability of a new capsule formulation of doxycycline (100 mg), doxycin, relative to the reference product, vibramycin (100 mg) capsules. The bioavailability was carried out in 24 healthy male volunteers who received a single dose (100 mg) of the test (A) and the reference (B) products after an overnight fast of at least 10 hours on 2 treatment days. The treatment periods were separated by a 2-week washout period. A randomized, balanced 2-way cross-over design was used. After dosing, serial blood samples were collected for a period of 48 hours. Plasma concentrations of doxycycline were analyzed by a sensitive and validated high-performance liquid chromatography assay. The pharmacokinetic parameters for doxycycline were determined using standard noncompartmental methods. The parameters AUC(0-t), AUC(0-infinity), Cmax, K(el), t(1/2) and Cmax/AUC(0-infinity) were analyzed statistically using log-transformed data. The time to maximum concentration (tmax) was analyzed using raw data. The parametric 90% confidence intervals of the mean values of the pharmacokinetic parameters: AUC(0-t), AUC(0-infinity), Cmax and Cmax/AUC(0-infinity) were within the range 80-125% which is acceptable for bioequivalence (using log-transformed data). The calculated 90% confidence intervals based on the ANOVA analysis of the mean test/reference ratios of AUC(0-t), AUC(0-infinity), Cmax and Cmax/AUC(0-infinity) were 95.98-109.56%, 92.21 to 107.66%, 93.90-112.56%, and 96.0 to 106.91% respectively. The test formulation was found bioequivalent to the reference formulation with regard to AUC(0-t), AUC(0-infinity), Cmax and Cmax/AUC(0-infinity) by the Schuirmann's two 1-sided t-tests. Therefore, the 2 formulations were considered to be bioequivalent.     

Comparison of two microemulsion of cyclosporine A in healthy volunteers

This study evaluated the bioequivalence of a new Cyclosporine A microemulsion formulation in comparison to the reference market standard. Twenty-four adult healthy volunteers were randomised to receive the two Cyclosporin A microemulsion formulations, at a dose of 2.5 mg/kg, according to a cross-over design. Blood samples were taken before drug administration and at 12 points within 24 hours. Cyclosporine A whole blood concentrations were determined by HPLC. The pharmacokinetic parameters AUC0-t and AUC0-infinity were calculated by the trapezoidal rule, Cmax and Tmax were obtained directly from blood data. AUCs and Cmax were tested for bioequivalence after log transformation of data, differences for Tmax were evaluated by the rank test of Wilcoxon for paired data. The 90% confidence interval ratio between tested/reference drug was 0.98 for AUC0-t, 0.96 for AUC0-infinity and 1.01 for Cmax. All of them were within the range of bioequivalence. Tmax was 1.60 +/- 0.44 hours after test drug and 1.67 +/- 0.48 after reference drug (p = 0.27, Wilcoxon test). According to these results the two Cyclosporine A microemulsion formulations can be considered bioequivalent.     

Estimated coefficient of variation values for sample size planning in bioequivalence studies

OBJECTIVE: The aim of the present communication is to provide information regarding the intrasubject coefficent of variation obtained from 30 bioequivalence studies covering 16 drugs which can be used for estimation of sample size. Additionally, an attempt was also made to estimate the test power of each of the studies conducted. METHODS: The intrasubject coefficient of variation was estimated from the residual mean square error obtained from analysis of variance of the parameters AUC0-infinity, Cmax and Cmax/AUC0-infinity after logarithmic transformation. The test power in the analyses of the above parameters was subsequently estimated using nomograms provided by Diletti et al. [1991]. RESULTS AND CONCLUSION: Thirty products covering 16 drugs were studied in which 22 were immediate-release (including one dispersible tablet) and 8 were sustained-release formulations. The intrasubject coefficient of variation for the parameter AUC0-infinity was smaller than Cmax, and hence considerably more studies were able to attain a power of greater than 80% using 12 volunteers for the AUC0-infinity, compared to the Cmax. However, the variability in the Cmax could be reduced by using the parameter Cmax/ AUC0-infinity, and thus, provide a more realistic estimation of sample size, since the latter reflects only the rate of absorption and not both the rate and extent as in the case of Cmax [Endrenyi et al. 1991].     

In vivo bioequivalence study of Sulpirid (GYKI-Alkaloida) and Dogmatil fort (Delagrange) 200 mg sulpiride tablets in healthy volunteers]

A single-dose, "crossover" bioequivalence study was conducted in healthy volunteers by comparing sulpiride serum levels after oral administration of the Test Product Sulpiride (200 mg) (GYKI-Alkaloida) in fasting subjects with those produced after oral administration of a marketed reference product (200 mg) (Delagrange Co., France). Statistical comparisons of Cmax, Tmax and AUC0-infinity have been performed utilizing ANOVA with subject, group, subject within group, period and product as sources of variance. No significant differences between the Test Drug and the Reference Drug considering the pharmacokinetic parameters Cmax, Tmax and AUC0-infinity were found. The 95% confidence intervals were as follows: AUC0-infinity: -20.46% and 31.19%, Cmax: -28.05% and 26.65% and Tmax: -43.53% and 20.67%. In the study for the analysis of Sulpiride a specific HPLC procedure with uv detection (lambda = 228 nm) and an internal standard were applied according to P. Nicolas et al. with modification. Sulpiride levels in serum reached a maximum at 4.4 hr +/- 1.5 (S.D.) following administration of Sulpiride tablet and at 5.0 hr +/- 0.8 (S.D.) after Dogmatil fort tablet. The maximal serum concentrations were 506.1 ng/ml +/- 87.2 (S.D.) and 509.1 ng/ml +/- 101.9 (S.D.) for Sulpiride and Dogmatil fort, respectively. The half-life of Sulpiride in serum was 9.9 hr +/- 1.3 (S.D.) following dosing with Dogmatil fort tablet and 12.2 hr +/- 3.0 (S.D.) following dosing with Sulpiride tablet.     

Comparative bioavailability study of cefixime (equivalent to 100 mg/5 ml) suspension (Winex vs Suprax) in healthy male volunteers

This investigation was carried out to evaluate the bioavailability of a new suspension formulation of cefixime (100 mg/5 ml), Winex, relative to the reference product, Suprax (100 mg/5 ml) suspension. The bio-availability study was carried out in 24 healthy male volunteers who received a single oral dose (200 mg) of the test (A) and the reference (B) products on 2 treatment days after an overnight fast of at least 10 hours. The treatment periods were separated by a one-week washout period. A randomized, balanced two-way crossover design was used. After dosing, serial blood samples were collected over a period of 16 hours. Plasma concentrations of cefixime were analyzed using a sensitive high-performance liquid chromatographic assay. The pharmacokinetic parameters for cefixime were determined using standard non-compartmental method. The parameters AUC(0-t), AUC(0-infinity), Cmax, Kel, t1/2 and Cmax/AUC(0-infinity) were analyzed statistically using raw and log-transformed data. The time to maximum concentration (tmax) was analyzed using raw data. The parametric 90% confidence intervals of the mean values of the pnfinity harmacokinetic parameters: AUC(0-t), AUC(0-infinity) Cmax, and Cmax/AUC(0-infinity) were within the range 80 - 125% which is acceptable for bioequivalence (using log-transformed data). The calculated 90% confidence intervals based on the ANOVA analysis for the mean test/reference ratios of AUC(0-t), AUC(0-infinity), Cmax, and Cmax/AUC(0-infinity) were 88.93 - 107.10%, 89.09 - 107.11%, 89.63 - 108.58% and 96.85 - 105.29%, respectively. The test formulation was found bioequivalent to the reference formulation with regard to AUC(0-t), AUC(0-infinity), and Cmax using the Schuirmann's two one-sided t-tests. Therefore, the two formulations were considered to be bioequivalent.