Low Lactose ERP - Review Book

2. Does the method contain system suitability tests or controls as specified by the SMPR? If not, please indicate if there is a need for such tests or controls and which ones. 3. Is there information demonstrating that the method system suitability tests and controls as specified in the SMPR worked appropriately and as expected? If no, please specify. 4. Based on the supporting information, is the method written clearly and concisely? If no, please specify the needed revisions. 5. Based on the supporting information, what are the pros/strengths of the method?

This method utilizes blanks for correction, and recommends a lactose control should be analyzed. Option to analyze a lactose standard is also included. All system suitability in the SMPR is addressed.

Yes, lactose standards were analyzed for bias and repeatability across a range of concentrations. The analysis of CRMs was also performed to determine bias. The data in the table for the result looks to be rounded as the bias calculation for the CRM data does not quite calculate to the reported bias in the table. There is a negative bias across most of the CRMs compared to the reference value, but is likely within the uncertainty associated with these reference values.

Yes, the method is written clearly and concisely.

The strengths of the method are the ability to quantitate below the SMPR analytical range in a variety of matrices that also meet the SMPR requirements for precision and accuracy. The ability to utilize the method in a high throughput laboratory with liquid handling instrumentation is also a benefit as the time to result is fairly quick compared to most HPLC and IC methods. The weaknesses of the method is this is a proprietary kit where many of the enzymes are specifically produced by the company selling the kit and may not be available with other suppliers. This does bring some risk with obtaining in the future. The other weakness I see is in regards to specificity of the beta galactosidase to only lactose. A linear increase in absorbance is used to calculate the correction for this. Not all of the compounds hydrolyze at the same rate with this enzyme, so it leaves some level of increased uncertainty for unknown product testing. I think this a very good high throughput method that can be utilized in the majority of the matrices the SMPR is intended for. They did an excellent job of testing out multiple conditions and solidifying the reaction conditions used in the analysis. There is increased uncertainty with the creep calculation for some GOS compounds, but I think a multi-lab with these types of products containing GOS compounds is ultimately going to show how variable this procedure can be in other laboratories. I would suggest the multi-lab contain matrices that will test this. I do recommend that this method be adopted as a First Action method and published in the Official Methods of Analysis. It meets all the necessary SMPR requirements and is definitely worthy of testing through a multi-lab validation to further confirm its applicability in these matrices. I do suggest that this method defines the creep calculation and the uncertainty associated with some of the GOS compounds that are corrected for with this calculation.

6. Based on the supporting information, what are the cons/weaknesses of the method?

7. Any general comments about the method?

V. Final Recommendation Do you recommend this method be adopted as a First Action and published in the Official Methods of Analysis of AOAC INTERNATIONAL? Please specify rationale.