Ethanesulfonic acid, 2-hydroxy-, compd. with 4,4'-[1,5-pentanediylbis(oxy)]bis [benzenecarboximidamide];
4,4'-(Pentane-1,5-diylbis(oxy))dibenzimidamide bis(2-hydroxyethanesulfonate)4,4'-[Pentane-1,5-diylbis(oxy)]dibenzimidamide bis(2-hydroxyethane-1-sulfonate) [140-64-7]
BRIEFING
Pentamidine Isethionate. This proposal is based on the version of the monograph official as of May 1, 2020. It is proposed to revise the monograph with the following changes:
-
Update the chemical name of pentamidine isethionate in the Chemical Information section to be consistent with current USP naming conventions.
-
Replace the titration-based Assay with a validated LC procedure using the Symmetry C18 brand of column with L1 packing. The typical retention time for pentamidine is about 3 min.
-
The Acceptance criteria in the Definition and Assay are revised from 98.5%–101.5% to 98.0%–102.0% to be consistent with the chromatographic assay.
-
Revise Identification A to allow the flexibility of using either 197A or 197K with a recrystallization procedure.
-
Delete the wet chemistry-based Identification B, as the remaining tests are sufficient.
-
Rename Identification C to Identification B and revise with the chromatographic retention time agreement from the test for Organic Impurities to the Assay.
-
In the Organic Impurities test:
-
Add the Sensitivity solution to support the addition of the Signal-to-noise ratio requirement.
-
In the System suitability section, add the Relative standard deviation requirement of NMT 5.0% to be consistent with the expectations for modern chromatographic systems and based on the supporting data.
-
Add an equation to the Analysis section to calculate the impurities.
-
In the Acceptance criteria, the exclude limit (numerical reporting threshold) has been replaced with a reference to User-Determined Reporting Thresholds 〈477〉.
-
-
Delete the chemical formula of USP Pentamidine Isethionate RS in the USP Reference Standards section to be consistent with current USP style.
Additionally, minor editorial changes have been made to update the monograph to current USP style.
(SM1: M. Fadadu)
Case ID—SUB-389, SUB-503