Stimuli-Responsive Hydrogels for Parenteral Drug Delivery

Abstract

In recent years, interest in hydrogels based on stimuli-responsive polymers is steadily increasing especially in the fields of controlled and self-regulated drug delivery systems. Stimuli-responsive, also termed as ‘environmental sensitive’, ‘intelligent’ or ‘smart’, these polymers are capable of returning to their initial state as soon as the trigger is removed. Stimuli may occur internally (e.g., a change in pH, temperature or in presence of specific enzymes or antigens, etc.) or externally (e.g., magnetic or electric fields, light, ultrasound, etc.). Injectable depots have been the subject of much research in the field of drug delivery. This chapter mainly focuses on the recent developments, current applications and future trends dealing with stimuli-responsive hydrogels in the field of parenteral drug delivery. This chapter also outlines injectable hydrogel materials and processing techniques used in drug delivery.