Comparison between lipolysis and compendial dissolution as alternative techniques for the in vitro characterization of alpha-tocopherol self-emulsified drug delivery systems (SEDDS).
In vitro characterization of alpha-tocopherol SEDDS formulations was performed by (1) lipolysis in bio-relevant media, and (2) physical assessment by dissolution, particle size, and turbidity analyses. Both methods were statistically correlated using a 25-run, five-factor multiple-level d-optimal mixture design. Independent variables were SEDDS composition [vitamin E (12.5-25%), Tween 80 (10-40%), labrasol (0-10%), alcohol (0-10%), and captex 355 (20-50%)]. Measured responses were percent lipolysis, percent vitamin E retained in the aqueous layer of the digestion medium, and percent vitamin E dissolved in the dissolution medium. Percent lipolysis ranged from 0% to 66.3%. Percent vitamin E retrieved in the aqueous layer of the digestion and dissolution media ranged from 3% to 29.3% and from 25.9% to 101.7%, respectively. Turbidity ranged from 28 to 403JTU and the average droplet size was >1.0 microm. All formulation ingredients had significant (p<0.05) effect on percent lipolysis. Only two factors, Tween and vitamin E had significant effect on vitamin retention in the aqueous layer post-lipolysis. Tween, labrasol, and captex 355 had significant effect on vitamin E dissolution. Poor correlation was observed between the responses. Formulation ingredients influenced each response differently; and therefore, each method can only reveal distinctive characteristics of the SEDDS formulation and may not be used interchangeably.
Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71209-0497, United States.
Hazem
H
Ali
Mahmoud
M
Nazzal
Abdel-Azim A
AA
Zaghloul
Sami
S
Nazzal
D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers; D004339:Drug Compounding; D004655:Emulsions; D000431:Ethanol / Q000737:chemistry; D005989:Glycerides; D007700:Kinetics; D008049:Lipase / Q000737:chemistry; D008055:Lipids / Q000737:chemistry*; D008066:Lipolysis; D015233:Models, Statistical; D009391:Nephelometry and Turbidimetry; D009930:Organic Chemicals / Q000737:chemistry; D010316:Particle Size; D011136:Polysorbates / Q000737:chemistry; D012995:Solubility; D013678:Technology, Pharmaceutical / Q000379:methods*; D014280:Triglycerides / Q000737:chemistry; D014815:Vitamins / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D024502:alpha-Tocopherol / Q000737:chemistry*
D004337:Drug Carriers; D004655:Emulsions; D005989:Glycerides; D008055:Lipids; D009930:Organic Chemicals; D011136:Polysorbates; D014280:Triglycerides; D014815:Vitamins; C440220:Labrasol; D014867:Water; D000431:Ethanol; D008049:Lipase; D024502:alpha-Tocopherol