Revision Bulletin

Fosinopril Sodium and Hydrochlorothiazide Tablets–Revision to Related Compounds Test

March 14, 2008

In accordance with the Rules and Procedures of the Council of Experts, this Revision Bulletin revises the limits for Fosinopril related compound A, Benzothiadiazine related compound A, any other individual impurity and total impurities under the Related compounds test in accordance with FDA approved manufacturers for this product as mentioned in Table 1.

This Revision Bulletin is official as of March 14, 2008. Official text will appear in the Second Supplement to USP 31–NF 26.

Please direct questions to Dr. Sujatha Ramakrishna, Scientific Liaison to the Monograph Development–Cardiovascular Expert Committee (+1–301–816–8349 or .

(See revised limits for related compounds in the table below)

Change to read:

Related compounds–

Table 1
Component Relative Retention
Time (RRT)		 Relative Response
Factor (RRF)		 Limit (%)
Benzothiadiazine related compound A 0.81 (relative to hydrochlorothiazide) 1.0 NMT 0.3 NMT 0.5
Fosinopril related compound A 0.72 (relative to Fosinopril) 1.2 NMT 0.8 NMT 4
Chlorothiazide 0.90 (relative to hydrochlorothiazide) 1.7 NMT 0.3
Any other individual impurity — — NMT 0.20 NMT 0.2 (relative to hydrochlorothiazide)
Total of all impurities — — NMT 0.8 NMT 5.0