not sure about your question but I do know that if you heat up the milk by putting the bottle in a cup of hot water or if you make the formula without taking out the pipe inside, then the milk will go up the pipe and that can cause the dripping. IF the milk does get trapped in the pipe, leave the bottle to cool down for a while.
Could the problem be because you have changed to type 3 nipple ie the milk is flowing too fast for your bb to drink?
thanks marshmellow, in fact, i did not put the bottle in a cup of hot water and have never make the formula without taking out the pipe. but i am not sure if there is milk trapped in the pipe. i better check the next time.
is nipple #3 is one of the factor? i've just changed about 2 weeks ago. i thought the reason for leaking is because the milk is over the 8oz line since 7oz formula + water will ended up about 8oz, and never happened with 6.5oz formula.
if the milk is flowing too quickly for bb to drink, then it is easy for it to dribble out. You could try to change back to size 2 to see if the same thing happens. But it could also be because you have more milk in the bottle....although I do not have this problem when I make 7oz formula + water for my bb. Sorry cannot help you further ....