[PDF] Q3C (R8) Step 5 - impurities: guideline for residual solvents

How much residual solvent is acceptable?

It is considered thatamounts of these residual solvents of 50 mg per day or less (corresponding to 5,000 ppm or 0.5percent under Option 1) would be acceptable without justification. Higher amounts may also beacceptable provided they are realistic in relation to manufacturing capability and goodmanufacturing practice (GMP).

How many ppm of PDE should a pharmaceutical product have?

The stated limit of 1,500 ppm is based on a review of the safety data. 2 4 5 8 Solvents in Class 2 (Table 2) should be limited in pharmaceutical products because of their inherent toxicity. PDEs are given to the nearest 0.1 mg/day, and concentrations are given to the nearest 10 ppm.

What type of solvent should I use?

Ideally, less toxic solvents (CClass 3, see Table 3 in the companiondocument) should be used where practical. Recommended limits of Class 1 and 2 solvents or classification of solvents may change as newsafety data becomes available.

How do you convert ppm to M3?

The equation for an ideal gas, PV = nRT, is used to convert concentrations of gases used ininhalation studies from units of ppm to units of mg/L or mg/cubic meter (m3).