Efficient evaluation of the precision of quantitative chromatographic analysis of soft capsules using a chemometric tool

Soft capsules may enhance oral absorption and bioavailability of active substances by appropriately combining them with excipients such as lipids and surfactants. However, these excipients affect the determination of active substances and warrant several considerations for establishing optimal analytical methods. The function of mutual information (FUMI) theory is a chemometric tool that estimates the relative standard deviation (RSD) of the peak area by approximating the baseline of a chromatogram with a stochastic process. In this study, we used a dutasteride (DUT) soft capsule as the specimen, and we propose a method to evaluate the RSD of the peak area of active substances in soft capsules based on the FUMI theory. Furthermore, we have established a method to evaluate the RSD of the peak area using a manual method for signal–noise resolution for soft capsules where the excipients interfere with the active substances. RSD (N = 1) obtained using this method was within the 95 % confidence interval of the RSD estimated using repetitive measurements (N = 6). In conclusion, the proposed method enables the efficient evaluation of precision without requiring repetitive measurements.