The Ubiquitous Use of Polyethylene Glycol in Pharmaceutical Design and Development: Technological Aspects and Future Perspectives

Polyethylene glycol (PEG) has been extensively utilized in drug formulations due to its multifunctional properties, i.e., hydrophilicity and biocompatibility. The roles played by PEG (as a drug delivery carrier and a solubilizer) improve the dissolution profile of several active pharmaceutical ingredients (APIs), leading to an improved absorption, distribution, metabolism, excretion, and toxicity (ADMET) profile. Moreover, PEG aids in upgrading the existing mechanical properties (as a binding agent, a plasticizer, etc.). Furthermore, PEG, due to its unique ability to provide “stealth” properties, is a valuable tool in pharmaceutical nanotechnology. Exploiting physicochemical variables, PEG acts as a coating/conjugation component of nanocarriers for ameliorating permeability and enhancing in vivo circulation without clearance by the body’s immune system. Additionally, PEG’s presence at the target site decreases external interactions and enhances the pharmacological attributes in terms of loading efficiency and controlled release. Nevertheless, cases of hypersensitivity or allergy, as well as anaphylactic shocks and allergic reactions, have been detected. The topic of this article is the exploitation of PEG’s physicochemical properties in the study of drug delivery, focusing on solid dosage forms and nanovesicles, along with the evaluation of its contribution to the fabrication of safe delivery and theragnostic systems.