Comparison of the results of a metric relating to the rate of sale of a drug that maintains constant sale verses overstocking that leads to the discarding of expired drugs on the basis of constant sale. Two methods were used to determine the rate of sale. One is based on the residual drug at some time period and the other is determined by the actual rate of the sale of the drug (RS). We determine that the most effective method to determine the amount of the drug supply that ensures a constant sale of the drug while avoiding the loss of money due to overstocking issues based on the RS method described above. It is shown that the mean value for the rate of sale of the drug determined by the depletion of the drug containers allows to find the best value of drug storage to maintain the effective sales rate.
