Lecithin organogels as a potential phospholipid-structured system for topical drug delivery: A review

Abstract

The purpose of this review is to give an insight into the considerable potential of lecithin organogels (LOs) in the applications meant for topical drug delivery. LOs are clear, thermodynamically stable, viscoelastic, and biocompatible jelly-like phases, chiefly composed of hydrated phospholipids and appropriate organic liquid. These systems are currently of interest to the pharmaceutical scientist because of their structural and functional benefits. Several therapeutic agents have been formulated as LOs for their facilitated transport through topical route (for dermal or transdermal effect), with some very encouraging results. The improved topical drug delivery has mainly been attributed to the biphasic drug solubility, the desired drug partitioning, and the modification of skin barrier function by the organogel components. Being thermodynamically stable, LOs are prepared by spontaneous emulsification and therefore possess prolonged shelf life. The utility of this novel matrix as a topical vehicle has further increased owing to its very low skin irritancy potential. Varied aspects of LOs viz formation, composition, phase behavior, and characterization have been elaborated, including a general discussion on the developmental background. Besides a comprehensive update on the topical applications of lecithin organogels, the review also includes a detailed account on the mechanistics of organogelling.

Pluronic lecithin organogel as a topical drug delivery system

“…Pluronic lecithin organogel (PLO) is a very interesting system, owing to their biocompatibility, their amphiphilic nature, facilitating dissolution of various drug classes, as well as their permeation enhancement properties. A number of studies have shown that pluronic lecithin organogel have the unique capacity to deliver the drugs through the skin and particular medications such as NSAIDs, hormones, anti-emetics, opoids, anti-psychotic drugs, calcium channel blockers, and local anesthetics to a specific site when other routes of administration are not viable (Kumar & Katare, 2005;Murdan, 2005).…”

Lecithin promotes adipocyte differentiation and hepatic lipid accumulation

“…Lecithin is used as a nutritional supplement and thought to protect cells from oxidation, prevent cardiovascular disease and steatosis (2)(3)(4)(5)(6). It was also used in phospholipidstructured system for topical drug delivery (7). A study showed that the components of lecithin, such as oleic, palmitic and linoleic acid, activates peroxisome proliferator-activated receptor Á (PPARÁ) (8).…”

Organogels in Drug Delivery: A Special Emphasis on Pluronic Lecithin Organogels

“…However, the addition of small and critical quantities of a polar solvent induces an aggressive uniaxial growth of spherical micelles into tubular or cylindrical micellar aggregates ( Fig. 2) (36). The binding of the polar molecules in stoichiometric ratios to the hydrophilic head of lecithin molecules results in the formation of a linear framework, where two adjacent lecithin molecules are linked by a polar molecule (36)(37)(38).…”

“…2) (36). The binding of the polar molecules in stoichiometric ratios to the hydrophilic head of lecithin molecules results in the formation of a linear framework, where two adjacent lecithin molecules are linked by a polar molecule (36)(37)(38). This linear framework is a result of hydrogen bonds formed by polar molecules and the phosphate group of lecithin molecules.…”