超临界流体-蒸发光散射法测定常见油脂类药用辅料皂化后的脂肪酸组成及其在油脂鉴别中的应用OA北大核心CSTPCDMEDLINE

Oils and fats are commonly used in the pharmaceutical industry as solvents,emulsi-fiers,wetting agents,and dispersants,and are an important category of pharmaceutical excipi-ents.Fatty acids with unique compositions are important components of oil pharmaceutical excipients.The Chinese Pharmacopoeia provides clear descriptions of the fatty acid types and limits suitable for individual oil pharmaceutical excipient.An unqualified fatty acid composition or content may indicate adulteration or deterioration.The fatty acid composition,as a key indi-cator for the identification and adulteration evaluation of oil pharmaceutical excipients,can di-rectly affect the quality and safety of oil pharmaceutical excipients and preparations.Gas chro-matography is the most widely used technique for fatty acid analysis,but it generally requires derivatization,which affects quantitative accuracy.Supercritical fluid chromatography(SFC),an environmentally friendly technique with excellent separation capability,offers an efficient method for detecting fatty acids without derivatization.Unlike other chromatographic methods,SFC does not use nonvolatile solvents(e.g.,water)as the mobile phase,rendering it compati-ble with an evaporative light-scattering detector(ELSD)for enhanced detection sensitivity.However,the fatty acids in oil pharmaceutical excipients exist in the free and bound forms,and the low content of free fatty acids in these oil pharmaceutical excipients not only poses challenges for their detection but also complicates the determination of characteristic fatty acid compositions and contents.Moreover,the compositions and ratios of fatty acids are influenced by environmental factors,leading to interconversion between their two forms.In this context,saponification provides a simpler and faster alternative to derivatization.Saponification de-grades oils and fats by utilizing the reaction between esters and an alkaline solution,ultimately releasing the corresponding fatty acids.Because this method is more cost effective than derivat-ization,it is a suitable pretreatment method for the detection of fatty acids in oil pharmaceuti-cal excipients using the SFC-ELSD approach.In this study,we employed SFC-ELSD to simulta-neously determine six fatty acids,namely,myristic acid,palmitic acid,stearic acid,arachidic acid,docosanoic acid,and lignoceric acid,in oil pharmaceutical excipients.Saponification of the oil pharmaceutical excipients using sodium hydroxide methanol solution effectively avoided the bias in the determination of fatty acid species and contents caused by the interconversion of fatty acids and esters.The separation of the six fatty acids was achieved within 12 min,with good linearity within their respective mass concentration ranges.The limits of detection and quantification were 5-10 mg/L and 10-25 mg/L,respectively,and the spiked recoveries were 80.93％-111.66％.The method proved to be sensitive,reproducible,and stable,adequately meeting requirements for the analysis of fatty acids in oil pharmaceutical excipients.Finally,the analytical method was successfully applied to the determination of six fatty acids in five types of oil pharmaceutical excipients,namely,corn oil,soybean oil,coconut oil,olive oil,and peanut oil.It can be combined with principal component analysis to accurately differentiate different types of oil pharmaceutical excipients,providing technical support for the rapid identi-fication and quality control of oil pharmaceutical excipients.Thus,the proposed method may potentially be applied to the analysis of complex systems adulterated with oil pharmaceutical excipients.