Determination of Aloin A, Aloin B, and Aloe-Emodin in Raw Materials and Finished Products Using HPLC Multilaboratory...

A multilaboratory validation study was performed on AOAC Official Method 2016.09, for final action. Eight different laboratories throughout the world participated in the study and tested the same set of six different laboratory samples of raw materials (commercial) and formulated products (commercial), and all the laboratories successfully generated results within the acceptance criteria.

The intention of the study was to evaluate specificity, precision (variation), linearity/range, system suitability, LOD, and LOQ by multiple laboratories to satisfy the requirement for moving Official Method  2016.09 to final action status. Accuracy and ruggedness were already validated in earlier work through single-laboratory validation, and it was not necessary to include these validation parameters in the multilaboratory validation study.

Laboratory samples containing Aloe vera were sent out to participating laboratories. Each laboratory followed Official Method  2016.09 (First Action) to analyze the content of aloin A, aloin B, and aloe-emodin using HPLC. The results generated by each laboratory were collected and evaluated.

The specificity results show that blank and matrix chromatograms do not contain major interfering peaks at the retention time of aloin A, aloin B, and aloe-emodin. The precision (variation) results of duplicated preparations are not more than 0.05 parts per million (ppm) different. The linearity/range results from six standards (10 parts per billion [ppb], 20 ppb, 40 ppb, 80 ppb, 160 ppb, and 500 ppb) have correlation coefficient (R) values of ≥0.999. The system suitability results meet the acceptance criteria to show the instrument validity. The LOD results show that the S/N ratios of the 10 ppb standards for all three components are about 3. The LOQ results show that the S/N ratios of 20 ppb standards for all three components are about 10.

The parameters (specificity, precision [variation], linearity/range, system suitability, LOD, and LOQ) have been validated and show that the test method is suitable for its intended use.

The test method has been successfully validated by eight different laboratories around the world (United States, United Kingdom, Germany, and Canada). Each of the laboratories is managed independently by a site laboratory management team. This multilaboratory study has validated Official Method 2016.09 (First Action) and the method is fit for its intended purpose.