Method Validation - Accuarcy

[Chris]

For the accuracy part of my method validation exercise I can't prepare lab scale samples due to the low concentration of the active (0.019%) and the difference in active and excipient particle sizes seriously affects the homoginiety of the lab blend. The manufacturer is unable to prepare accurate samples at different concentrations and it is not possible to weight the amount of active required into the extraction vessel and add a placebo mix as I would have to add 0.06mg of active. My last solution is to add spiked extraction solvent to portions of the placebo mixture and assume that poor accuracy is also highlighted by a low recovery and poor repeatbility in a manufactured product at the nominal concentration.

Does this seem acceptable or does anyone have any other ideas.

Thanks

[Consumer Products Guy]

That's probably what I'd do, how we normally spike our placebo products.