The authors propose a multi-compartmental model based on molecular communication (MC) technology for drug delivery to the malignant cell without affecting healthy cells in the patient's body. The medical personnel can transfer/control the required drug to the targeted cell with the help of a group of bio-nanomachines connected to the Internet of biological Nano Things (IoBNT) and a bio-cyber interface in both the forward and reverse directions. The proposed model consists of a set of multi-differential equations that are used to identify molecular communication among bio-nanomachines and quantify drug concentration to the targeted cell. Unlike conventional compartmental models, the proposed model can deliver the desired drug to the targeted cell by accounting for extracellular and intracellular tumor compartments, resulting in fewer therapeutic doses with improved efficacy. Simulations were also carried out to evaluate the performance of proposed multi-compartmental model with changing the physical parameters.