BRIEFING

 〈317〉 ICP-OES Testing for Sodium Hydroxide and Potassium Hydroxide. A new chapter, based on validated methods of analysis, is being proposed by the Excipients Test Methods Expert Committee (ETM EC). The chapter is applicable to the analysis of sodium hydroxide and potassium hydroxide. It does not cover analysis of other related excipients.

 Part of USP's mission is to strengthen the global supply of quality medicines. Excipient standards are a major priority for USP and a key strategy in becoming a definitive source of global quality standards. USP aims to be more flexible and iterative in creating excipient standards, to expand on current compendial approaches, and to thereby advance the understanding and control of excipient composition and variability. This proposed chapter allows USP to maintain its relevance by introducing evolving approaches for excipient standards. It addresses the current deficiencies in the official monographs for Sodium Hydroxide and Potassium Hydroxide and helps address the needs of regulatory agencies, excipient users, and excipient manufacturers.

 As part of its stakeholder engagement model, USP published a General Chapter Prospectus for 〈317〉 on November 17, 2023, outlining the background on developing this general chapter. To provide additional background and clarity to USP stakeholders, the ETM EC shares the following information:

• The scope of this general chapter only covers analysis of Sodium Hydroxide and Potassium Hydroxide and does not cover analysis of other similar excipients. USP–NF monographs take precedence over general chapters as directed in General Notices, 3.10 Applicability of Standards.

• The Simple Excipients Expert Committee (SE EC) discussed all comments received on both proposals, which were published in PF 48(6). The PF 48(6) proposals were to replace the AAS procedures in Sodium Hydroxide and Potassium Hydroxide with the ICP-OES methods. As per SE EC suggestions, it was decided to continue with the assay and impurities procedures based on the AAS technique in the Sodium Hydroxide and Potassium Hydroxide monographs. It was also suggested not to include ICP-OES-based procedures in these monographs. USP inquired of the SE EC, about the possibility of adopting a general chapter approach to make use of the ICP-OES-based procedures for Sodium Hydroxide and Potassium Hydroxide, thus giving the end user an option to use the ICP-OES technique. The SE EC recommended the approach that the ICP-OES based methods should be included in a general chapter.

• Currently, the methods in this general chapter are not applicable to any USP–NF monographs. According to General Notices, 3.10 Applicability of Standards: “'Applicable general chapters' means general chapters numbered below 1000 or above 2000 that are made applicable to an article through reference in General Notices, a monograph, or another applicable general chapter numbered below 1000."

• The methods in this general chapter are nonmandatory and are not part of Sodium Hydroxide and Potassium Hydroxide monograph specification in the absence of a reference in the General Notices, a monograph, or another applicable general chapter numbered below 1000.

• In the NF monograph for Sodium Hydroxide and Potassium Hydroxide, the assay and impurities procedures are based on the AAS technique. USP received multiple complaints from stakeholders about challenges with the AAS techniques, such as obtaining an acceptable regression coefficient for the calibration curve and issues with repeatability and reproducibility of results.

• This prompted USP to develop and validate assay and impurities procedures using the advanced and highly reliable ICP-OES technique.

• The assay and impurity test method validations for Sodium Hydroxide and Potassium Hydroxide were formally completed by laboratory analysis. On the basis of these successful validations, USP introduced the procedures as revisions to the official monographs for Sodium Hydroxide and Potassium Hydroxide. The proposals were published in PF 48(6) [Nov.–Dec. 2022].

• USP received multiple comments on the proposals for Sodium Hydroxide and Potassium Hydroxide. Most stakeholders were positive about the inclusion of ICP-OES-based procedures for the assay and impurities tests. However, most stakeholders requested that USP retain the AAS-based procedures and introduce ICP-OES as optional.

• The SE EC was informed that the proposed chapter will not be a mandatory general chapter, and the end users can have an option to choose between the techniques as per their requirements. With major help from multiple labs, the procedures for the assays and impurities tests were optimized and successfully validated using ICP-OES.

• This new general chapter will help the end user by providing an option of an advanced technique for enhanced accuracy, precision, and sensitivity. The general chapter is intended to be applicable for assay and impurity testing for Sodium Hydroxide and Potassium Hydroxide only.

• Test methods, based on both AAS and ICP-OES techniques, have been validated for Sodium Hydroxide and Potassium Hydroxide Assay and Impurity testing. Therefore, either method can be selected.

 The proposal contains ICP-OES methods for the determination of Content of Sodium in Sodium Hydroxide and Content of Potassium in Potassium Hydroxide. The methods are based on the validated ICP-OES methods of analysis. Similarly, for the tests related to the estimation of potassium as an impurity in Sodium Hydroxide and sodium as an impurity in Potassium Hydroxide, an ICP-OES-based method is being proposed. A wavelength of 589.592 nm for sodium and 766.490 nm for potassium has been used.

 (ETM: D. Chavan)

 Case-ID—SUB-208