Advances in Lyotropic Liquid Crystals: Structure, Preparation, and Drug Delivery Potential

Abstract

Nanostructured self-assembling materials known as lyotropic liquid crystals (LLCs) consist of amphiphilic molecules in a solvent and having a number of mesophases such as cubic, hexagonal, and lamellar phases. Since LLCs are concentration-dependent and not temperature-dependent as it is the case with thermotropic liquid crystals, they are heavily applied in drug delivery, nanotechnology, and the biological sciences. Their ability to entrap hydrophilic and hydrophobic molecules supports controlled and site-specific drug release, promoting therapeutic efficacy and bioavailability. Stimuli-sensitive LLC systems have been found promising as devices for transdermal delivery, ocular delivery of drugs, and cancer therapy due to their sensitivity towards pH changes, temperature changes, or mechanical stress. Characterization techniques such as polarized light microscopy (PLM) and small-angle X-ray scattering (SAXS) are often employed to determine phase structures in order to understand their structural properties and enhance their formulations. Dynamic light scattering (DLS) helps in assessing colloidal stability. The fundamental concepts, types, compositions, and preparation methods—such as top-down and bottom-up strategies—of LLCs are all discussed elaborately in this article. It also addresses new advances in biomedical applications, control release strategies, targeted drug delivery systems, and their application to drug delivery. In addition, several case studies related to LLC formulations laden with anti-tumor drugs and their therapeutic capability are discussed. Formulation developments in LLC form are capable of reshaping present day drug delivery procedures and enhance therapeutic outcomes in biomedical applications.