Drug delivery

Drug delivery refers to approaches, formulations, manufacturing techniques, storage systems, and technologies involved in transporting a pharmaceutical compound to its target site to achieve a desired therapeutic effect.

[1][2] Principles related to drug preparation, route of administration, site-specific targeting, metabolism, and toxicity are used to optimize efficacy and safety, and to improve patient convenience and compliance.

[4][8] Drug delivery is a concept heavily integrated with dosage form and route of administration, the latter sometimes being considered part of the definition.

[12] Since the approval of the first controlled-release formulation in the 1950s, research into new delivery systems has been progressing, as opposed to new drug development which has been declining.

[22] Interest in targeted drug delivery has grown drastically due to its potential implications in the treatment of cancers and other chronic diseases.

[23][24][25] In order to achieve efficient targeted delivery, the designed system must avoid the host's defense mechanisms and circulate to its intended site of action.

[26] A number of drug carriers have been studied to effectively target specific tissues, including liposomes, nanogels, and other nanotechnologies.

[29] Since then, countless other CR products have been developed to account for the physiochemical properties of different drugs, such as depot injections for antipsychotics and sex hormones that require dosing once every few months.

[30][31] Since the late 1990s, most of the research around CR formulations has been focused on implementing nanoparticles to decrease the rate of drug clearance.

[32] Pharmaceutical preparations containing peptides, proteins, antibodies, genes, or other biologic components often face absorption issues due to their large sizes or electrostatic charges, and may be susceptible to enzymatic degradation once they have entered the body.