SNEDDS are formulated from gelatine or hydroxypropylmethyl cellulose as soft or hard gelatine capsules [17]. These vehicles are composed of isotropic mixtures of oil and surfactant and may have additional co-solvents. Anhydrous conditions exist within the
LY2109761 prior to oral administration however, following agitation and contact with gut fluids the spontaneous generation of an oil-in-water colloidal nanoemulsion (≤200 nm) occurs [153]. Drugs solubilized in SNEDDS have very high dissolution velocity due to significantly induced spontaneous surface area to volume ratio afforded by the nanoemulsion. It is this physical property that is so effective in facilitating dissolution of lipophilic drugs [154]. Further, several components of SNEDDS can enhance membrane permeation of therapeutic agents such as oily phases (oleic acid, monoglycerides of caprylic
acid and propylene glycol esters of caprylic acid) [155]. Surfactants such as Labrasol®, TPGS, and polysorbate 80 [156], [83], [157] and [158] and co-solvents including PEG 400, Transcutol® and alcohol. Emulsions stabilized by poloxamer have been utilized in the formulation of a wide range of drugs (danazol, atenolol and metoprolol) [159].
