How do we sterilize the plastic plus silicon droppers that we get with Vit D syrup ? And how often should it be replaced ?

A. Ma’am if you’re keeping the dropper into the medicine only then you do not have to sterilise it because if you sterilise it it is going to have water into it because you cannot clean it completely and that contaminate the medicine which is why there is no need to satirise the dropper when you put the cap back with the dropper into the medicine you don’t have to clean it