Advances in lipid-based colloid systems as drug carrier for topic delivery.

INTRODUCTION: Based on the advantages of transcutaneous delivery and the application status of nanocarriers in transcutaneous delivery, this paper critically reviews the correlation of using different lipid-based colloid systems as permeation enhancement model. Particularly noteworthy, mechanisms of different action pathways of lipid-based colloid systems for topic delivery are illustrated, including free drug pathway, lipids enhancement, penetration with intact carrier and transappendageal pathway. AREAS COVERED: The authors focus on theories and detailed researches about liposome, lipid nanocapsules, solid lipid nanoparticles and microemulsion and nanostructured lipid carriers, revealing the advances and application states of these carriers as transcutaneous delivery system. FORWARD LOOK: Although lipid-based colloid systems show great superiority, some forward-looking ideas should be brought on agendas. In the future, more attention should be focused on skin stimulation. Mechanisms must be established to secure more information about the influence of excipient matrix. Some other issues including smart preparation forms and storage stability are also of current concerns and need more detailed research.