Use of different stationary phases for separation of isoniazid, its metabolites and vitamin B6 forms.

The ability of different stationary phases developed for the analysis of polar compounds (ZIC-HILIC, ZIC-pHILIC and Zorbax SB-Aq) to separate isoniazid, its metabolites (acetylisonazid, pyridoxal isonicotinoyl hydrazone, pyridoxal isonicotinoyl hydrazone 5-phosphate), pyridoxine, pyridoxal and pyridoxal 5-phosphate under MS compatible conditions was systematically investigated using HPLC-UV. The mobile phase strength, pH and buffer concentration were modified to assess their impact on the retention of these compounds. The best available separation of the compounds was achieved using 1 mM ammonium formate (pH≈6) and ACN (20:80, v/v) on ZIC-HILIC and employing 5 mM ammonium formate (pH 3.

No evidence for induction of ABC transporters in peripheral blood mononuclear cells in humans after 14 days of efavirenz treatment.

Intracellular concentrations of antiretroviral drugs in peripheral blood mononuclear cells (PBMCs) are an important determinant of therapeutic success. In vitro data indicate that efavirenz induces several ATP-binding cassette (ABC) transporters, and pharmacogenetic studies found an association between ABCB1(C3435T) and efavirenz exposure and between this polymorphism and improved virological outcomes. We therefore aimed to clarify whether efavirenz also induces ABC transporters in vivo in PBMCs and whether intracellular concentrations might be altered after induction.

Preliminary pharmaceutico-analytical evaluation of transkarbam 12 using liquid chromatography.

This paper deals with the search for optimal conditions for the identification of Transkarbam 12 (T 12) as a substance used for acceleration of transdermal penetration. Such substances are used in cases when drugs do not pass through the skin barrier under normal conditions. Other advantages are that they do not irritate the digestive system, provide continuous administration to an organism, and reduce fluctuations of drug concentration in blood.