Drug delivery refers to the method or process of administering a pharmaceutical compound to achieve a therapeutic effect in patients. This can involve various routes, such as oral, intravenous, or topical, depending on the drug's properties and the desired effect. Effective drug delivery systems ensure that the medication reaches the target site in the body at the right dose and time. Advancements in drug delivery technologies aim to improve the efficacy and safety of treatments. Techniques like nanoparticles, liposomes, and microneedles are being developed to enhance the absorption and distribution of drugs, minimizing side effects and improving patient compliance.