Lipid microemulsions for improving drug dissolution and oral absorption: physical and biopharmaceutical aspects.

PURPOSE: This review highlights the state-of-the-art in pharmaceutical microemulsions with emphasis on self-emulsifying systems, from both a physical and biopharmaceutical perspective. Although these systems have several pharmaceutical applications, this review is primarily focused on their potential for oral drug delivery and intestinal absorption improvement.
METHODS: Physicochemical characteristics and formulation design based on drug solubility and membrane permeability are discussed.
RESULTS: Case studies in which lipid microemulsions have successfully been used to improve drug solubilization/dissolution and/or intestinal absorption of poorly absorbed drugs/peptides are presented.
CONCLUSIONS: Drug development issues such as commercial viability, mechanisms involved, range of applicability, safety, scale-up and manufacture are outlined, and future research and development efforts to address these issues are discussed.