RECENT ADVANCES IN CONTROLLED AND SUSTAINED RELEASE DRUG DELIVERY SYSTEM: A SYSTEMATIC REVIEW

Abstract

Modern biopharmaceutics has been significantly reshaped by the evolution of controlled
and sustained drug delivery systems, which optimize therapeutic outcomes, cut down on
dosing frequency, limit systemic side effects, and boost patient adherence. Progress in
nanotechnology, smart biomaterials, and polymer engineering has greatly broadened the
scope of these advanced formulation platforms. Today, novel carriers-including polymeric
nanoparticles, liposomes, dendrimers, hydrogels, micelles, nanocrystals, exosomes, and
metal– organic frameworks-offer superior drug targeting, better bioavailability, and precise
site-specific release profiles. Furthermore, smart stimuli-responsive networks triggered by
internal or external factors like pH, temperature, enzymes, ultrasound, magnetic fields, or
light allow for exact spatio-temporal control over when and where the drug payload is
liberated. While sustained release formulations focus primarily on prolonging the temporal
availability of a drug through modified first-order kinetics, true controlled release systems
target structural and physiological parameters to achieve precise, zero-order release
profiles. This systematic review comprehensively evaluates the structural configurations,
functional classification, and recent breakthroughs in these delivery designs. Together, these
ongoing clinical innovations pave the way for highly tailored, efficient, and patient-centric
treatments, providing promising opportunities across diverse medical fields, particularly in
cancer chemotherapy, cardiovascular disorders, infectious diseases, and regenerative
medicine.