Hanna Kortejärvi

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In vitro dissolution tests can be used to waive in vivo bioequivalency studies (biowaiver), if drug has high solubility and high permeability according to biopharmaceutics classification system (BCS I). Then absorption of BCS I drugs is not dependent on drug dissolution or gastrointestinal transit time and the solid dosage form behaves like oral solution.(More)
In this study, solvent-mediated phase transformations of theophylline (TP) and nitrofurantoin (NF) were measured in a channel flow intrinsic dissolution test system. The test set-up comprised simultaneous measurement of drug concentration in the dissolution medium (with UV-Vis spectrophotometry) and measurement of the solid-state form of the dissolving(More)
The efficacy of central nervous system (CNS) drugs may be limited by their poor ability to cross the blood-brain barrier (BBB). Transporters, such as p-glycoprotein, may affect the distribution of many drugs into the CNS in conjunction with the restricted paracellular pathway of the BBB. It is therefore important to gain information on unbound drug(More)
Literature and experimental data relevant to the decision to allow a waiver of in vivo bioequivalence testing for the approval of immediate release (IR) solid oral dosage forms containing ranitidine hydrochloride are reviewed. According to the current Biopharmaceutics Classification System (BCS), ranitidine hydrochloride should be assigned to Class III.(More)
In vitro-in vivo correlation (IVIVC) models for formulation series are useful in drug development, but the current models are limited by their inability to include data variability in the predictions. Our goal was to develop a level A IVIVC model that provides predictions with probabilities. The Bayesian approach was used to describe uncertainty related to(More)
The aim of this study was to investigate the possibility of developing different levels of correlation between in vitro release and in vivo absorption rate for four modified-release levosimendan capsule formulations. Differences and similarities in the in vitro dissolution curves were compared with pharmacokinetic parameters describing absorption rate.(More)
The mRNA level expression of MDR1, MRP1-6, BCRP and CYP3A4 was determined by quantitative PCR in wild type (Caco-2WT) and vinblastine-treated (Caco-2VBL) Caco-2 cells at different passage levels (32-53). Differentiation increased the mRNA levels of MDR1, BCRP and all the MRPs except MRP4. Corresponding mRNA levels were observed in Caco-2WT and Caco-2VBL,(More)
Currently, the EMEA, FDA, and WHO as regulatory authorities accept rapidly dissolving (>85% dissolved in 30 min) biopharmaceutics classification system (BCS) I drug products for biowaiver candidates. In the draft EMEA guideline the requirement has been set tighter, that is, the drug product should be very rapidly dissolving (>85% dissolved in 15 min) to be(More)
The usefulness of selected conventional surfactant media to enhance dissolution of BCS class II drugs similarly to fasted state simulated intestinal fluid (FaSSIF) and to predict the absorption of drugs in vivo was evaluated. Dissolution behavior of danazol (Danol), spironolactone (Spiridon) and N74 (phase I compound) was compared between FaSSIF, containing(More)
The bioavailability and bioequivalency of oral drug depends on gastrointestinal tract physiology and drugrelated physicochemical and pharmacokinetic factors. In general, bioavailability of a new drug substance or new formulation is studied in vivo with healthy volunteers. In vivo bioequivalency studies are needed for generic drug products or if a(More)