As per USP, the taps shall be done as 10,500,750 taps. The test will be completed if the difference between 2 successive taps is less than or equal to 1mL if we use 100mL measuring cylinder. If the difference is more than 1mL, further taps shall be done. What would be the no of taps after the initial 10,500,750?
Hi can you please specify which method and hich apparatus you are using for tapped density determination? Also you have specified 10, 500 and 750 taps but USP specified 10, 500 and 1250 taps. Even if we use 100 ml cylinder the tapping of 1250 taps is required if the results of tapped density are not met.
Refer USP Chapter <616>.
Thanks Deepak for the quick reply. Yes, indeed the taps are 10,500,1250. It is an error from my side. We follow USP chapter 616.
My query is that after 10,500,1250 taps, still the difference is more than 1mL. What is the next no of taps we shall go for?
USP Chapter has the answer of your query. Under Tapped density section Method I, it is stated that “if the difference between V500 and V1250 is less than or equal to 1 mL, V1250 is the tapped volume. If the difference between V500 and V1250 exceeds 1 mL, repeat in increments such as 1250 taps, until the difference between succeeding measurements is less than or equal to 1 mL. The modified test conditions are specified in the expression
of the results.”
So need to tap 1250 taps again and record your results.
Thanks for the clarification. I was also of the same opinion. Thanks