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A Mirfazaelian

Publications and source records attributed to A Mirfazaelian.

11 recordsLinked to original sources

Time dependent pharmacokinetics of albendazole in human.

The pharmacokinetics of the main metabolites of albendazole (albendazole sulphoxide (ABZ-SO) and albendazole sulphone (ABZ-SO2) were studied in 12 healthy human volunteers in a double blind design on the first and last days of oral administration of 800 mg albendazole daily for 15 days. No significant differences were observed in C(max), T(max) and V(d)/F of ABZ-SO, whereas the AUC, AUMC and T(1/2) of this metabolite were significantly reduced and Cl/F was significantly increased in multiple dosing. There were also no significant differences in the C(max), T(max), V(d)/F and T(1/2) of ABZ-SO2, whereas the AUC and AUMC of this metabolite were significantly reduced and Cl/F was significantly increased in multiple dosing. These observations suggest time dependent pharmacokinetics of albendazole (observed for ABZ-SO and ABZ-SO2), which was explained on the basis of the induction of enzymes involved in the metabolism of ABZ-SO (albendazole sulphoxide) to metabolites other than albendazole sulphone in multiple dosing.

Administration, Oral↗

A high performance liquid chromatography method for simultaneous determination of albendazole metabolites in human serum.

A simple assay for albendazole (ABZ) main metabolites-albendazole sulphoxide (ABZ-SO), albendazole sulphone (ABZ-SO(2)) and albendazole amino sulphone (ABZ-SO(2)-NH(2))-in serum using high performance liquid chromatography was developed. The method involves liquid-liquid extraction of the serum by ethyl acetate, clean up with n-hexane and re-extraction with ethyl acetate, followed by separation on RP-C(8) column with a mixture of methanol: acetonitrile: acetic acid: water (40:1:10:49) as the eluting solvent. ABZ-SO and mebendazole-used as internal standard-were detected by UV (lambda=286 nm), and ABZ-SO(2) and ABZ-SO(2)-NH(2) with fluorescence spectrophotometer at (Excitation=286 nm, Emission=333 nm) and (Excitation=286 nm, Emission=315 nm), respectively. The assay was accurate and reproducible with a detection limit of 10 ng/ml for ABZ-SO, 2 ng/ml for ABZ-SO(2) and 4 ng/ml for ABZ-SO(2)-NH(2). Disregarding ABZ determination, which is not of pharmacokinetic importance as it is not found in human plasma after oral administration, the proposed method is appropriate for further pharmacokinetic and metabolism study of this drug.

Albendazole↗

Effect of gender in the disposition of albendazole metabolites in humans.

The pharmacokinetics of albendazole in different single oral doses (400 mg, 800 mg & 1200 mg) was studied and compared in healthy male and female human volunteers using a double-blind design. The serum levels of albendazole main metabolites (albendazole sulphoxide and albendazole sulphone) were analysed using a modified high-pressure liquid chromatography method. For both metabolites, there was no significant difference in the biological half-life ( t(1/2)), time to reach peak concentration (t(max)) and mean residence time (MRT) between men and women, whereas apparent oral clearance (Cl(p)/F) and apparent distribution volume (V(d)/F) were less and serum peak concentration (C(max)), area under the serum concentration-time curve (AUC) and area under the first moment curve (AUMC) were more in women than in men. These observations indicate sex dimorphism in pharmacokinetics of albendazole (observed for albendazole sulphoxide and albendazole sulphone) which were explained on the basis of a change in fraction of the main drug turned to metabolite as a result of more extensive first-pass metabolism of the main drug in the liver of adult female subjects.

Administration, Oral↗

Dose dependent pharmacokinetics of albendazole in human.

Pharmacokinetics of albendazole sulphoxide (ABZ-SO) in three different single oral doses of albendazole (ABZ) (400, 800 and 1200 mg) was studied in 10 healthy human volunteers in a double blind three-way crossover design. The serum levels of albendazole main metabolite, albendazole sulphoxide (ABZ-SO), were analysed by a modified high-pressure liquid chromatography method. (ABZ is not detectable in biological fluids itself.)For ABZ-SO, there was no significant difference in the biological half life, normalized serum peak concentration (C(max-ABZ-SO)/Dose(ABZ)), time to reach peak concentration (T(max)) and mean residence time (MRT), whereas apparent clearance (Cl(p)/F), apparent distribution volume (V(d)/F), normalized area under the serum concentration-time curve (AUC(ABZ-SO)/Dose(ABZ)) and normalized area under the first moment curve (AUMC(ABZ-SO)/Dose(ABZ)) of albendazole main metabolite (ABZ-SO) were statistically different at different doses of the parent drug, resulting in substantially lower serum concentration and thereafter AUC(ABZ-SO)/Dose(ABZ) and AUMC(ABZ-SO)/Dose(ABZ) in higher doses. These observations indicate dose dependent pharmacokinetics of albendazole (observed for ABZ-SO), which were explained on the basis of a change in fraction of dose absorbed (F) as a result of slow and incomplete dissolution of the main drug in the GI tract.

Adult↗

Effect of smoking on single dose pharmacokinetics of phenobarbital.

In order to determine interaction of smoking with single dose pharmacokinetics of phenobarbital, a 60 mg tablet of the drug was given to 12 healthy male subjects in two groups (6 smokers and 6 non-smokers) in a double blind study. An HPLC method using UV detection was developed to assess phenobarbital in plasma of the subjects. Pharmacokinetic parameters were calculated and compared in the two groups. Pharmacokinetic parameters of the two groups were not significantly different in the two groups (p<0.05). The results show no considerable effect of cigarette smoking on phenobarbital pharmacokinetics, which is in agreement with enzyme studies performed previously.

Adult↗

A quantitative thin layer chromatography method for determination of theophylline in plasma.

A simple assay method for theophylline in plasma using thin layer chromatography (TLC) was developed. The method involves extraction of the drug and internal standard (acetaminophen) by chloroform-isopropanol (75:25) followed by separation on TLC silica plates using a mixture of acetic acid, isopropanol, toluene (1: 12: 6), as the eluting solvent. Both peak height ratios and peak are ratios showed high correlation coefficient (r>0.98, p<0.001). However we used peak heights for the determinations. Within-day and between-day coefficients of variation were less than 4.4% and 7.8% respectively. The assay proved inexpensive, accurate and reproducible with a limit of detection of 100 ng/ml that makes it suitable for bioavailability studies.

Biological Availability↗