The application of mathematical methods in pharmacology is relevant for the development of accurate models of drug action and optimisation of their dosing, which increases the effectiveness of treatment and reduces the risks of side effects, and accelerates and cheapens the process of developing new drugs. The purpose of this research is to explore the application of mathematical methods in pharmacology to optimise drug development and improve drug efficacy. The methods used include analytical method, classification method, functional method, statistical method, synthesis method. This research covers the main aspects of using mathematical modelling in pharmacology, covering a variety of issues that arise at different stages of drug development. Specific examples of using mathematical modelling to solve these problems are presented. Various approaches to modelling the pharmacokinetics (PK) of drugs, and the analysis of their absorption, distribution and excretion are reviewed. Mathematical methods for analysing efficacy and safety and approaches to determining the therapeutic window of a drug are discussed. The research into the application of mathematical methods in pharmacology is of practical significance as it contributes to the development of more accurate PK and pharmacodynamic (PD) models, optimisation of drug dosing and improved predictive accuracy, leading to the development of more effective and safer drugs.