Cytotoxicity assessment of lipid-based self-emulsifying drug delivery system with Caco-2 cell model: Cremophor EL as the surfactant.
OBJECTIVE
Caco-2 cells are used extensively for in vitro prediction of intestinal drug absorption. However, toxicity of excipients and formulations used can artificially increase drug permeation by damaging cell monolayers, thus providing misleading results. The present study aimed to investigate cytotoxicity of common lipid-based excipients and formulations on Caco-2 cells.


METHODS
Medium-chain monoglycerides alone or in mixture with the surfactant Cremophor EL, with and without a medium-chain triglyceride, were prepared and incubated with Caco-2 cells from a series of culture stages with varying maturity. Cell viability was evaluated and cell membrane integrity assessed.


RESULTS
Cytotoxicity of lipid-based formulations was influenced by the maturity of Caco-2 cells and formulation composition. One-day culture was most sensitive to lipids. When cultured for 5days, viability of Caco-2 cells was significantly improved. The 21-day Caco-2 monolayers maintained the highest survival rate. Microemulsion formulations exhibited significantly less cytotoxicity than neat lipids or surfactant at all stages of cell maturity, and microemulsions containing 1:1 mixtures of monoglyceride and triglyceride appeared to be best tolerated among all the formulations tested. Mechanistically, the observed cytotoxicity was partially due to lipid-induced rupture of cell membrane.


CONCLUSIONS
Microemulsions of lipid-surfactant mixtures have less cytotoxicity than lipid alone. Maturity of Caco-2 cells renders significant resistance to cytotoxicity, and monolayers with 21-day maturity are more relevant to in vivo conditions and appear to be a more accurate in vitro model for cytotoxicity assessment.
Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, United States; Department of Biological Sciences, College of Liberal Arts and Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, United States.
Pengli
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Bu
Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, United States.
Silpa
S
Narayanan
ABITEC Corporation, 501W 1st Avenue, Columbus, OH 43215, United States.
Damon
D
Dalrymple
Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, United States.
Xingguo
X
Cheng
Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, United States. Electronic address: serajuda@stjohns.edu.
Abu T M
AT
Serajuddin
D018938:Caco-2 Cells; D002470:Cell Survival / Q000187:drug effects; D016503:Drug Delivery Systems / Q000009:adverse effects*; D004655:Emulsions; D004952:Esters; D005079:Excipients / Q000737:chemistry / Q000633:toxicity; D005990:Glycerol / Q000031:analogs & derivatives / Q000737:chemistry / Q000633:toxicity; D006801:Humans; D008055:Lipids / Q000737:chemistry / Q000633:toxicity*; D010316:Particle Size; D019946:Propylene Glycol / Q000737:chemistry / Q000633:toxicity; D013501:Surface-Active Agents / Q000737:chemistry / Q000633:toxicity*
D004655:Emulsions; D004952:Esters; D005079:Excipients; D008055:Lipids; D013501:Surface-Active Agents; C000515:cremophor EL; D019946:Propylene Glycol; D005990:Glycerol
Caco-2 cells; Cremophor EL®; Cytotoxicity assessment; Lipid-based drug delivery system; Medium-chain lipid; Monoglyceride; Surfactant; Triglyceride