Investigation of the Metabolism of Albicar in Rats

The experiments were performed on male rats to which albicar was administered perorally in the form an 8% aqueous solution in a single dose of 500 mg kg. The products of the drug’s metabolism were determined in urine collected over a 48 h period of time from animals kept in special boxes. To extract the compounds for analysis, 2 ml of urine were mixed with 40 ml of chloroform in a 50-ml tube with a ground-glass stopper and treated in a shaker for 15 min. After extraction, the tubes were kept in a refrigerator at –15°C. The chloroform layer was separated from the frozen aqueous layer, quantitatively transferred into another tube, and concentrated in a rotor evaporator (IR-1 type) under vacuum (water-jet pump) to a final volume of about 2 ml. This residue was quantitatively transferred into a microtube and evaporated in a flow of nitrogen to a final volume of 20 – 50 l. The chloroform extracts were introduced into the evaporator of a Finnigan 3200F (USA) gas chromatograph – mass spectrometer system with automated data processing facility. Chromatographic separation of the sample components was effected in a 45-m-long capillary column with an inner diameter of 0.3 mm. The analyses were performed with SE-52 immobile liquid phase at a gas-carrier (helium) flow rate of 1.5 ml min. The column temperature program was as follows: 2 min at 150°C followed by heating to 290°C at a rate of 6°C min; the evaporator and pipeline temperature was 260°C. The analyzed sample volume was 0.6 l. Figure 1 shows a typical chromatogram of the chloroform extract of a rat urine sample taken and prepared as described above. The retention times of albicar and its metabo-