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.
Ali
Hazem
H
Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71209-0497, United States.
Nazzal
Mahmoud
M
Zaghloul
Abdel-Azim A
AA
Nazzal
Sami
S
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