Ab initio and molecular simulation methods were used in calculations of the neutral individual betulin molecule, and molecular simulations were used to optimize the betulin molecule immersed in various amounts of water. Individual betulin was optimized in different force fields to find the one exhibiting best agreement with ab initio calculations obtained in the Gaussian03 program. Dihedral torsions of active groups of betulin were determined for both procedures, and related calculated structures were compared successfully. The selected force field was used for subsequent optimization of betulin in a water environment, and a conformational search was performed using quench molecular dynamics. The total energies of betulin and its interactions in water bulk were calculated, and the influence of water on betulin structure was investigated.

• MeSH
• molekulární konformace MeSH
• molekulární modely MeSH
• počítačová simulace MeSH
• simulace molekulární dynamiky MeSH
• triterpeny chemická syntéza   chemie   MeSH
• voda chemie   MeSH
• vodíková vazba MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The aim of this study was to compare the bioavailability of two atorvastatin formulations (Divator Drogsan Pharmaceuticals, Ankara, Turkey, as the test formulation, and Lipitor, Pfizer Ireland Pharmaceuticals, Dublin, Ireland, as the reference formulation) in 52 healthy volunteers. The study was conducted using a randomised, single-dose, two-way crossover study with a 2-week washout period between the doses. Since the 90% confidence intervals for Cmax, AUC0-72 and AUC0-proprtional to ratios for both, the parent atorvastatin and its main active metabolite ortho-hydroxy atorvastatin, were within the pre-defined Bioequivalance acceptance limits approved by EMEA, we concluded that the atorvastatin formulation elaborated by Drogsan Pharmaceuticals, was bioequivalent to the Lipitor in its rate and extent of absorption.

• MeSH
• biotransformace MeSH
• dospělí MeSH
• farmaceutická chemie MeSH
• financování organizované MeSH
• hmotnostní spektrometrie MeSH
• klinické křížové studie MeSH
• kyseliny heptylové aplikace a dávkování   farmakokinetika   chemie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• plocha pod křivkou MeSH
• pyrroly aplikace a dávkování   farmakokinetika   chemie   MeSH
• statiny aplikace a dávkování   farmakokinetika   chemie   MeSH
• terapeutická ekvivalence MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• Publikační typ
• randomizované kontrolované studie MeSH
• srovnávací studie MeSH

A randomized, two-way, crossover, bioequivalence study was conducted in 26 fasting, healthy, male volunteers to compare two brands of citalopram 40 mg tablets, Citol (Abdi Ibrahim Ilaç San. ve Tic A.S., Istanbul, Turkey) as a test and Cipramil (H. Lundbeck A/S, Copenhagen, Denmark) as a reference product. One tablet of either formulation was administered with low-carbonate water after 10 h of overnight fasting. After dosing, serial blood samples were collected during a period of 24 hours. Plasma samples were analysed for citalopram by a validated HPLC method. The pharmacokinetic parameters AUC0-24, AUC(0-alpha), Cmax, Tmax, K(el), T(1/2), and CL were determined from plasma concentration-time profiles for both formulations and were compared statistically to evaluate bioequivalence between the two brands of citalopram, 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 (CI) fell within the acceptable range for bioequivalence. Based on these statistical inferences it was concluded that the two brands exhibited comparable pharmacokinetics profiles and that Abdi Ibrahim's Citol is equivalent to Cipramil of H. Lundbeck, Copenhagen, Denmark.

• MeSH
• aplikace orální MeSH
• citalopram aplikace a dávkování   farmakokinetika   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• selektivní inhibitory zpětného vychytávání serotoninu aplikace a dávkování   farmakokinetika   MeSH
• terapeutická ekvivalence MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH