Innovative strategies for drug delivery, utilizing polymeric nanoparticles, microspheres, and liposomes, have displayed significant potential in augmenting the therapeutic impact of medications. Biodegradable polymers characterized by strong compatibility with biological systems, such as poly(lactic-co-glycolic acid) (PLGA), polylactic acid (PLA), and polycaprolactone (PCL), have gained widespread adoption in the advancement of particulate drug delivery mechanisms. Active pharmaceutical ingredients (APIs), encompassing both small molecules and biologic compounds, can be enclosed within microspheres and nanoparticles or affixed to their surfaces, facilitating precise drug delivery applications like controlled release, targeted therapy, and safeguarding APIs from untimely degradation. Following the administration of drug-loaded biodegradable nanoparticles and microparticles, the biocompatible polymer gradually degrades within the body via ester backbone hydrolysis, ultimately yielding non-toxic byproducts. By judiciously selecting the appropriate polymer type and refining the encapsulation process, the rate of drug release can be fine-tuned.