High-performance liquid chromatography and capillary electrophoresis of L- and D-carnitine by precolumn diastereomeric derivatization.

A new method for the simultaneous assay of D- and L-enantiomers of carnitine is described. The method is based on precolumn derivatization with (+)-1-(9-fluorenyl)ethyl chloroformate [(+)FLEC] producing a diastereomeric derivative which can be detected both by UV absorbance and fluorescence detection. Also acyl esters of carnitine can be processed with this method, after alkaline hydrolysis. The D-enantiomer of carnitine and acylcarnitine can be detected at a concentration as low as 0.2% in the raw material and in pharmaceuticals. Assays can be carried out using an autoinjector either by HPLC or capillary electrophoresis (CE) because the derivative proved to be very stable. Its application is proposed for the routine assay of the enantiomeric excess of L-carnitine and their acyl esters in pharmaceutical products.

Time stability of a drug molecule sterilized through gamma rays.

In a previous work, we studied the possibility to process a drug molecule through a gamma rays sterilizing treatment. Optimal process conditions were studied and the related effects on the treated molecule were analyzed, as well. From obtained results, we concluded that there are not any contraindications to apply this sterilization process to the molecule treated. In this second paper we examined the time stability of the active ingredient treated with a gamma rays sterilization process. Among treated and untreated samples, stored in the refrigerator as well as room temperature, or slightly above, we did not observe any time-related in behaviour differences. Instead, samples stored at higher temperature (80 degrees C) showed behavioural differences between gamma treated and gamma untreated samples. This phenomenon, that at the beginning we found unexplainable, subsequently could be explained owing to further tests of "molecule stabilization" with temperature.

Approach to the sterilization with gamma rays of a drug. Note I: Treatment technique and effects at zero time.

Authors, considering a possible use of the sterilizing treatment with gamma rays for the productive process of a drug, performed a series of practical treatment tests. To this purpose, they used a single molecule, stable in time and with an easy analytical approach. The examined active principle is the injectable salt of acetylcarnitine chloride. For tests, they used irradiating doses by 2.5-5.0-7.5 Mrads in order to point out the process possible effects. The treatment, even at highest dosages, did not show damages to the molecule that could prevent from going on with the investigation.

Bioavailability of flufenamic acid in hard and soft gelatin capsules.

The biological availability of flufenamic acid after oral administration of the drug in both hard and soft gelatin capsules was studied in dogs and humans. The soft gelatin capsules produced consistently higher plasma concentration-time curves.