Development of self emulsifying drug delivery system of itraconazole for oral delivery: formulation and pharmacokinetic consideration

A Comprehensive Insight on Self Emulsifying Drug Delivery Systems

BACKGROUND

The oral route is a highly recommended route for the delivery of a drug. But most lipophilic drugs are difficult to deliver via this route due to their low aqueous solubility. Selfemulsifying drug delivery systems (SEDDS) have emerged as a potential approach of increasing dissolution of a hydrophobic drug due to spontaneous dispersion in micron or nano sized globules in the GI tract under mild agitation.

OBJECTIVE

The main motive of this review article is to describe the mechanisms, advantages, disadvantages, factors affecting, effects of excipients, possible mechanisms of enhancing bioavailability, and evaluation of self-emulsifying drug delivery systems.

RESULTS

Self emulsifying systems incorporate the hydrophobic drug inside the oil globules, and a monolayer is formed by surfactants to provide the low interfacial tension, which leads to improvement in the dissolution rate of hydrophobic drugs. The globule size of self-emulsifying systems depends upon the type and ratio of excipients in which they are used. The ternary phase diagram is constructed to find out the range of concentration of excipients used. This review article also presents recent and updated patents on self-emulsifying drug delivery systems. Self-emulsifying systems have the ability to enhance the oral bioavailability and solubility of lipophilic drugs.

CONCLUSION

This technique offers further advantages such as bypassing the first pass metabolism via absorption of drugs through the lymphatic system, easy manufacturing, reducing enzymatic hydrolysis, inter and intra subject variability, and food effects.

Development of Solid Self-Emulsifying Formulation for Improving the Oral Bioavailability of Erlotinib

To improve the solubility and oral bioavailability of erlotinib, a poorly water-soluble anticancer drug, solid self-emulsifying drug delivery system (SEDDS) was developed using solid inert carriers such as dextran 40 and Aerosil® 200 (colloidal silica). The preliminary solubility of erlotinib in various oils, surfactants, and co-surfactants was determined. Labrafil M2125CS, Labrasol, and Transcutol HP were chosen as the oil, surfactant, and co-surfactant, respectively, for preparation of the SEDDS formulations. The ternary phase diagram was evaluated to show the self-emulsifying area. The formulations were optimized using the droplet size and polydispersity index (PDI) of the resultant emulsions. Then, the optimized formulation containing 5% Labrafil M2125CS, 65% Labrasol, and 30% Transcutol was spray dried with dextran or Aerosil® and characterized for surface morphology, crystallinity, and pharmacokinetics in rats. Powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) exhibited the amorphous form or molecular dispersion of erlotinib in the formulations. The pharmacokinetic parameters of the optimized formulations showed that the maximum concentration (C max) and area under the curve (AUC) of erlotinib were significantly increased, compared to erlotinib powder (p < 0.05). Thus, this SEDDS could be a promising method for enhancing the oral bioavailability of erlotinib.