Chances are it is too many. Interruptions usually happen when there is a conflict of priorities between yourself and a colleague.
Interruptions soak up time like a sponge.
Stop conflicts and you stop the interruptions. Once you have been interrupted, it can be very tempting to use this as an excuse stop what you are doing. Note down a reminder of where you were before your interruption, and make sure that you get back to it straight afterwards. Incompletions drain your energy. Whilst complete work does take more time initially, it will save you time in the long run.