Lipid-based drug delivery systems (LDDS): Recent advances and applications of lipids in drug delivery

Abstract

Recently, advances in pharmaceutical research is focused on new delivery systems utilizing new devices to achieve modification of delivery time, targeting, as well as improve the in vivo solubility and hence bioavailability of poorly soluble drugs. Lipid based drug delivery systems (LDDS) consists of diverse group of formulations, each consisting of varying functional and structural properties that are amenable to modifications achieved by varying the composition of lipid excipients and other additives. LDDS has evolved, overtime, from micro-to nano-scale enhancing the efficacy and therapeutic application of these systems. LDDS are accepted, proven, commercially viable strategies for formulating challenging pharmaceutical molecules and can be tailored to meet a wide range of product requirements. Generally, most lipid drug delivery systems used as drug carriers have high stability, high carrier capacity, feasibility of incorporating both hydrophilic and hydrophobic substances and feasibility of variable routes of administration, including oral, topical, parenteral and pulmonary routes. LDDS can also be designed to allow modified drug release from matrices. LDDS could be broadly grouped into four: solid lipid particulate dosage forms, emulsion based systems, solid lipid tablets, and vesicular systems. Modifications from these four types include: lipospheres, solid lipid nanoparticles (SLNs), nano structured lipid carriers (NLC), lipid drug conjugate nanoparticles (LDC), self emulsifying formulations (SEFs), pickering emulsions, dry emulsions, micro and nano-emulsions, solidified reverse micellar solution (SRMS) based tablets, liposomes, herbosomes, cryptosomes and transferosomes amongst others. This work exhaustively reviewed the advances in LDDS and also drew comparison between the different types based on history, methods of manufacture, applications, advantages and disadvantages.

Nanoemulsions — Advances in Formulation, Characterization and Applications in Drug Delivery

“…In many cases, this accelerates the digestion of the lipid formulation, improves absorption, and reduces food effect and inter-subject variability [7]. Self emulsifying formulations distribute readily in the GI tract, the digestive motility of the stomach and the intestines provides sufficient agitation enough for the spontaneous formation of emulsions [8,9].…”

Topical ophthalmic lipid nanoparticle formulations (SLN, NLC) of indomethacin for delivery to the posterior segment ocular tissues

“…A major advantage of the nanoparticulate systems is their uptake by epithelial cells, which allows for greater penetration into the surface layers [34–36]. Moreover, the small size, biocompatibility and mucoadhesive properties of SLNs improve their interactions and prolong the pre-ocular residence time of drugs, thus enhancing drug bioavailability [37, 38]. The literature suggests that surface modification of SLNs by coating with hydrophilic agents such as poly (ethylene) glycol derivatives (PEGs) or chitosan can further improve ocular penetration, mainly due to enhancing interactions with the ocular mucosa and increasing cellular uptake and internalization [39, 40].…”

Advancements in the oral delivery of Docetaxel: challenges, current state-of-the-art and future trends

“…Lipid-based materials have also proven their importance as a drug carrier, including solid lipid NPs (SLNs), liposomes, micro-/nanoemulsions, ethosomes, lipid-based tablets, proliposomes, lipopolymeric hybrid nanocarriers and so on. 90 Of these, liposomes are the only successful carrier approved by the FDA and a number of products are now available in the market. 91 The first anticancer liposomal doxorubicin was approved by the FDA in 1995.…”