A COMPUTER-PROGRAM FOR THE ANALYSIS OF CHROMATOGRAMS USED IN PHARMACOKINETIC STUDIES

An analog/digital (A/D) converter and software written in BASIC langua ge have been developed for the analysis of chromatographic data which are needed for pharmacokinetic (PK) studies in humans and in experimen tal animals such as dogs and rats. Using an A/D converter, widely sold personal computers produced by NEC or EPSON are applicable to both hi gh-performance liquid-chromatography (HPLC) data analysis and PK analy sis. When chromatographic data is taken up by the computer and treated as a variable, a maximum of 12 000 data points are saved by the compu ter. As 10 digital data points are taken up by the computer per second through the A/D converter, the maximum run time of a chromatogram is 20 min. For the purpose of HPLC analysis, however, five digital data p oints per second are usually enough for routine analysis. In this soft ware, the program is written to take and save five digital data points /s. Therefore, the maximum run time of this software increased to 40 m in per chromatogram. All the digital data through the A/D converter ar e saved into the data file on a floppy disk or hard disk. For the chro matogram analysis, both automatic peak identification and manual peak identification, which must be selected with the use of the mouse drive r, are available. All the data, peak area, peak height, etc. are also saved into the data file. After a calibration curve is produced, follo wing the input of peak analysis data of known spiked samples, the drug concentration for each sample is estimated. These concentration-time data are also saved into the data file. The plasma drug concentration- time curve is plotted on the CRT display in semi-logarithmic scale, by reading the saved plasma concentration-time data from the data file. The drug concentration-time data finally obtained are saved into the d ata disk, which then may be used for PK analysis. This system does not require re-input of the data for PK analysis and thus significantly d ecreases the work of re-input.