According the guidance - "Powder Blends and Finished Dosage Units..." we have some tendency about the sample size determination. But I'm sure that the approach has to be individual. In my opinion we have to take different sample size for different cases. If we have to evaluate powder blend of 100 kg and of 500 kg, is the number of samples taken the same? Or, if we have API less than 5% in one product and more than 50% in another one, can we evaluate both with the same approach. Please, share some experience about these issues.