Self-emulsifying therapeutic system: a potential approach for delivery of lipophilic drugs

Self-emulsifying therapeutic system (SETs) provide an effective and intelligent solution to the various issues related to the formulation of hydrophobic drugs with limited solubility in gastrointestinal fluid. Although the potential utility of SETs is well known, only in recent years has a mechanistic understanding of the impact of these systems on drug disposition emerged. These in situ emulsion-forming systems have a high stability when incorporated in various dosage forms. SETs are being looked upon as systems which can overcome the problems associated with delivery of poorly water soluble drugs. An in-depth knowledge about lipids and surfactants that can contribute to these systems, criterion for their selection and the proportion in which they can be used, represent some crucial factors determining the in vivo performance of these systems. This article presents a comprehensive account of various types of self-emulsifying formulations with emphasis on their composition and examples of currently marketed preparations.O sistema terapêutico auto-emulsionante (SETs) fornece solução eficaz e inteligente para os vários problemas relativos à formulação de fármacos hidrofóbicos com solubilidade limitada no fluido gastrintestinal. Embora a utilidade potencial dos SETs seja bem conhecida, só recentemente se compreendeu, mecanisticamente,o impacto desses sistemas na disposição de fármacos. Estes sistemas de formação de emulsão in situ têm alta estabilidade, quando incorporados em várias formas de dosagem. Os SETs têm sido considerados como sistemas que podem resolver problemas associados à liberação de fármacos pouco solúveis em água. O conhecimento profundo dos lipídios e tensoativos que podem ser utilizados para estes sistemas e o critério para a sua seleção e proporção na qual eles são utilizados são alguns dos fatores cruciais que determinam o desempenho do sistema in vivo. Este artigo apresenta o relato abrangente de vários tipos de formulações auto-emulsificantes, com ênfase em sua composição e exemplos das preparações que são correntemente comercializadas

Controlled Release of Oral Tetrahydrocurcumin from a Novel Self-Emulsifying Floating Drug Delivery System (SEFDDS)

The objectives of this study were to develop and evaluate a novel self-emulsifying floating drug delivery system (SEFDDS) that resulted in improved solubility, dissolution, and controlled release of the poorly water-soluble tetrahydrocurcumin (THC). The formulations of liquid self-emulsifying drug delivery system (SEDDS; mixtures of Labrasol, Cremophor EL, Capryol 90, Labrafac PG) were optimized by solubility assay and pseudo-ternary phase diagram analysis. The liquid SEDDS was mixed with adsorbent (silicon dioxide), glyceryl behenate, pregelatinized starch, sodium starch glycolate, and microcrystalline cellulose and transformed into pellets by the extrusion/spheronization technique. The resulting pellets with 22% liquid SEDDS had a uniform size and good self-emulsification property. The microemulsions in aqueous media of different self-emulsifying floating pellet formulations were in a particle size range of 25.9–32.5 nm. Use of different weight proportions of glyceryl behenate and sodium starch glycolate in pellet formulations had different effects on the floating abilities and in vitro drug release. The optimum formulation (F2) had a floating efficiency of 93% at 6 h and provided a controlled release of THC over an 8-h period. The release rate and extent of release of THC liquid SEDDS (80% within 2 h) and self-emulsifying floating pellet formulation (80% within 8 h) were significantly higher than that of unformulated THC (only 30% within 8 h). The pellet formulation was stable under intermediate and accelerated storage conditions for up to 6 months. Controlled release from this novel SEFDDS can be a useful alternative for the strategic development of oral solid lipid-based formulations