The drop is an approximated unit of measure of volume, the amount dispensed as one drop from a dropper or drip chamber. It is often used in giving quantities of liquid drugs to patients, and occasionally in cooking and in organic synthesis.
In organic synthesis, a synthetic procedure will often call for the addition of a reagent "dropwise" with the aid of a syringe or a dropping funnel. The rate of addition for such a procedure is taken to be slow, but is otherwise vague since one chemist might consider dropwise to be one drop per second, while another might consider five to ten drops per second (almost a stream) to be dropwise. Furthermore, the volume of a drop will depend on the needle gauge or the dimensions of the glassware. Thus, to improve reproducibility, noting the total amount of time required to add the liquid or another measure of addition rate in the experimental procedure is now considered prudent. In a related usage, the amount of a reagent, whose precise quantity is unimportant, will sometimes be given in terms of the number of drops, often from a glass pipette. In this usage, a drop is typically considered to be approximately 0.05 mL. Giving quantities this way was more common in the past but this practice is now generally considered to be sloppy or unrigorous.
Simply, a drops is used to deliver medicine orally in concentrated form .