Self Micro-Emulsifying Drug Delivery System: Formulation Development and Biopharmaceutical Evaluation of Lipophilic Drugs

Abstract

Several methods are being employed to improve the oral bioavailability of lipophilic drugs like using inert lipid vehicles such as Oils, Surfactant dispersions, Self Microemulsifying Drug Delivery Systems (SMEDDS) and Liposomes. SMEDDS is formulated with the help of oil or suitable lipid materials, Surfactants and hydrophilic Co-surfactants. Mixture of above ingredients can be filled in a soft capsule and ingested. When the mixture comes in contact with gastrointestinal fluid it forms a stable O/W Microemulsion. A pseudo ternary phase diagram is used for identifying the efficient Self micro-emulsification region. SMEDDS can be formulated to give sustained release by use of inert polymers. When this polymer comes in contact with GI fluids, it forms gelled polymeric matrix, which releases the micro-emulsified active principle in a continuous and prolonged manner. Physical characterization of SMEDDS should be carried out by droplet size analysis and spontaneity of emulsification. The purpose of this review is to provide a brief out line of the formulation of SMEDDS, possible mode for improving bioavailability, fate and evaluation of the same.

Enhanced Oral Bioavailability of Curcumin via a Solid Lipid-Based Self-Emulsifying Drug Delivery System Using a Spray-Drying Technique

“…The large specific surface area of the fine oil droplets also enables a more efficient drug transport through the intestinal aqueous boundary layer, leading to an improvement in oral bioavailability. 27) In the present study, the results obtained from the in vitro dissolution test confirmed that curcumin had been quickly released from the solid SEDDS and completely in both the 0.1 N HCl and phosphate buffer pH 6.8 dissolution media, whereas crude curcumin was less dissoluble. Accordingly, oral curcumin absorption in the solid SEDDS was significantly increased compared to that of the suspension formulation.…”

Nanomemulsion of megestrol acetate for improved oral bioavailability and reduced food effect

“…The secreted bile acid helps emulsification of oils. The emulsified-oil droplets enzymatically degraded to di-and monoglycerides and free fatty acids, forms micelles, and finally solubilization and absorption of drugs occurs (Patel and Sawant 2009). Nanoemulsion with low surface tension and large surface area facilitates oral absorption of drugs without the help of bile juices (Pouton 2000).…”

Self-microemulsifying drug-delivery system for improved oral bioavailability of 20(S)-25-methoxyl-dammarane-3β, 12β, 20-triol: preparation and evaluation

“…emulsion with a nanometric droplet size less than 100 nm when exposed to an aqueous medium or gastrointestinal fluids. [7][8][9] The small droplet size of a microemulsion can provide large interfacial surface areas, which is advantageous for drug release and absorption. A commercially available example of a SMEDDS preparation is Neoral ® (Novartis, Basel, Switzerland) (cyclosporine A).…”