Determination of 26 anti-diabetic compounds in dietary supplements using a validated UPLC method

ABSTRACT

The purpose of this study was to validate a rapid, simple and accurate method using ultra-performance liquid chromatography (UPLC) for the simultaneous determination of 26 anti-diabetic compounds in illegally adulterated dietary supplements. The method was validated for specificity, linearity, limit of detection, limit of quantitation, precision, accuracy, recovery and stability. All compounds were separated with a resolution of over 1.5. The limits of detection and quantitation were 0.10–1.70 and 0.30–5.10 µg g^–1 in a solid sample, respectively; the corresponding values were 0.10–1.25 and 0.30–3.75 µg ml^–1 in a liquid sample. The correlation coefficient was > 0.99, precisions were 0.11–3.30% (intra-day) and 0.05–6.15% (inter-day), and accuracies were 83–108% (intra-day) and 85–109% (inter-day). The recoveries were measured with six dosage forms, and the results were acceptable as 87–117% with relative standard deviations ≤ 6.44%. The relative standard deviations of stability were ≤ 3.40% and the standard solution was stable for 48 h. Ninety-six samples were obtained from on/off-line markets and were analysed using the developed method. Among these samples, pioglitazone and glibenclamide were found in seven samples and the concentrations of each compound were 0.15% and 0.26–0.51%, respectively. With the increasing adulteration of dietary supplements with anti-diabetic drugs, this method may be helpful to protect public health and safety.

KEYWORDS:

• Determination
• anti-diabetes
• dietary supplements
• simultaneous analysis
• ultra-performance liquid chromatography
• monitoring
• validation

Additional information

Funding

This work was supported by the Ministry of Food and Drug Safety [grant number 15181MFDS521] in 2016.