Lipid-Based Nanocarriers for Oral Delivery of Poorly Soluble Drugs

The oral route is still the most desirable route of drug delivery because of its ease of use, patient compliance and cost, but there is a major limitation regarding poor solubility of many therapeutic compounds in aqueous medium, therefore, this limits the oral delivery of the drug and clinical outcome. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), as well as self-emulsifying drug delivery systems (SEDDS), are the latest approaches to address these shortcomings. The nanoscales protect labile compounds against degraded by gastrointestinal system, increase solubility of drugs, and facilitate absorption via lymphatic system bypassing first-pass metabolism. Preclinical and animal experiments have demonstrated that SLNs give sustained release and gastrointestinal protection, NLCs give drug loading, stability and controlled release, and SEDDS gives dissolution, systemic exposure and lymphatic uptake. Another advantage of LNCs is better tissue distribution, extended circulation, ameliorated pharmacokinetic and pharmacodynamic activity. Regardless of their promise, such challenges as formulation stability, large scale production, interspecies translational differences, and excipient safety are critical factors. Altogether, LNCs provide a versatile and promising system of creation of effective patient-friendly oral preparations of drugs that are hardly soluble, and their possible clinical translation and specific treatment use have significant potential.