Administration of drugs is often associated with basic problems such as toxicity, instability and improper biodistribution.
Encapsulation of the drug in a suitable carrier such as liposomes is one of the well recognized methods that
protects the drug from the body milieu to improve stability, safety and targeting efficiency of the drug towards the target
site. However, while encapsulation provides a favorable biodistribution, low toxicity and improved stability of drugs, delivery
carriers should be capable of releasing encapsulated material at the appropriate site to exert their activity. Effective
intracellular drug delivery is desired for many therapeutic agents those having specific molecular targets in the cytoplasm,
nucleus, or other subcellular compartments of a cell such as mitochondria. Several nanocarriers that are designed to release
drugs at desired sites have been developed so far. Among these, exhaustive research has established liposomes as an
effective triggerable drug carrier. This mini review covers various aspects of triggering modalities examined to date such
as temperature, pH, enzymes and light using liposomes.