I will certainly not want to condemn Lactocalamine. It is good as a drying agent, particularly for oily facial skin. It also acts as a sun block. It is known to cause mild pigmentation of the skin, and sometimes allergic reactions. So, it is best to know these facts before using Lactocalamine.
The best thing is to try it on a small area of skin on the forearm and watch for any reactions for about two weeks. If okay, it can be used on a regular basis.