ABSTRACT
This chapter reviews some approaches to develop lipid-based drug delivery systems (LBDDSs) for oral applications. The primary solvent in LBDDSs is the lipid component, which may be a single material or blend of several types of lipids. Lipid-based oral formulations contain emulsifiers to facilitate dispersion of the drug and formulation components after ingestion. Hydrophilic cosolvents may be used in lipid-based oral formulations if needed to improve drug solubilization. Self-emulsifying drug delivery systems are oral dosage forms consisting of drug, oils, surfactants, and sometimes cosolvents. Lipid-based formulations can be ready-to-use emulsions, liquid systems that are either diluted with water or juice before administration, or presented as liquid-filled capsules. Compared to parenteral formulations, toxicity is rarely a concern for oral lipid-based formulations. The mechanisms involved in dispersion of pharmaceutical formulations are diffusion and stranding, those driven by osmotic pressure imbalances, phase transformations, and changes owing to alteration of environmental conditions.
