Background Image
Table of Contents Table of Contents
Previous Page  84 / 116 Next Page
Information
Show Menu
Previous Page 84 / 116 Next Page
Page Background

PDE5-003

analogs, nor does it include avanafil, lodenafil carbonate,

mirodenafil, udenafil as specified in SMPR 2014.012 for

PDE5 screening method.

Agilent 1200 is a 400 bar/6000 psi HPLC system, typically

using 0.007" ID tubing & capillary needle seat in flow

path from injector to column, and column to detector.

Authors refer to this as UHPLC system; is it possible their

UHPLC system is an Agilent 1260 or 1200SL (600

bar/9000 psi) system? Were any modifications made to

minimize extra column volume?

Supporting Data

General Comments

the power of MS/MS technique highlighted by ability to

distinguish Gendenafil (same M+H as Yohimbine) based

on examination of M+H product ions for both

compounds.

Authors provide sources for standards - again from 2012,

so this needs to be updated to current to reflect

additional known PDE5 inhibitors.

I also believe that MS/MS is going to be needed for a

proper screening method since analogs are closely

related and may not be fully resolved in HPLC/UHPLC to

allow for UV detection.

Method Optimization

not clear how this method was optimized or if further

optimization might be required with inclusion of

additional PDE5 analogs.

Method specifies Zorbax 1.8um SB-C18 50x2.1mm

column and indicates other C18 columns would need to

be evaluated for use in this procedure. Performance

criteria (e.g. efficiency, resolution, retention) for column

not indicated.

Performance Characteristics

Analytical Range:

working standards range of 1–5 μg/mL (1-5 ppm) ; 0.5-5

ug/mL (0.5-5 ppm) in LC/MS method.

LOQ:

Not specified

Accuracy/Recovery

Not specified

Precision (RSDr)

Not specified

Reproducibility (RSDR)

Not specified

System Suitability

Not specified

Safety Review