Regulatory Open Forum

Hello all,  we have a vendor that acknowledges that an excipient we buy has a Class 3 residual solvent, however, they will not tell us what the solvent is.  Using the USP 467, Option 2, calculation for total solvents, how would you include this unknown solvent in the calculation?  The vendor's CoA only says "Class 3 solvent" and "<5000 ppm" as the result.   How would you handle this?  Thank you.

Besides finding a new vendor, the best and may be only solution would be to test the excipient and determine the class 3 solvent present.

If you do not want to go this way currently,  you have to assume the worst case scenario, assume, 5000 ppm(4999 ppm) and if you have other class 3 solvents in this excipient, you could assume that it is the same class 3 solvent, and then do your calculation for option 2 and see if under the requisite limits. If not then, you have no choice but to identify the solvent.  This approach may work in the  early development stage but eventually you will need to identify the class 3 solvent.

Regards,

------------------------------
Robert Blanks RAC
VP, Regulatory Affairs and Quality Assurance
[Ardelyx]
Auburndale MA
United States

Original Message:
Sent: 17-Dec-2020 17:38
From: Anonymous Member
Subject: Residual Solvents Calculation for Unknown Class 3 Solvent

This message was posted by a user wishing to remain anonymous

Hello all,  we have a vendor that acknowledges that an excipient we buy has a Class 3 residual solvent, however, they will not tell us what the solvent is.  Using the USP 467, Option 2, calculation for total solvents, how would you include this unknown solvent in the calculation?  The vendor's CoA only says "Class 3 solvent" and "<5000 ppm" as the result.   How would you handle this?  Thank you.

Hello all,  we have a vendor that acknowledges that an excipient we buy has a Class 3 residual solvent, however, they will not tell us what the solvent is.  Using the USP 467, Option 2, calculation for total solvents, how would you include this unknown solvent in the calculation?  The vendor's CoA only says "Class 3 solvent" and "<5000 ppm" as the result.   How would you handle this?  Thank you.

Hello all,  we have a vendor that acknowledges that an excipient we buy has a Class 3 residual solvent, however, they will not tell us what the solvent is.  Using the USP 467, Option 2, calculation for total solvents, how would you include this unknown solvent in the calculation?  The vendor's CoA only says "Class 3 solvent" and "<5000 ppm" as the result.   How would you handle this?  Thank you.