Improvement of the stability of water-in-oil-in-water multiple emulsions by the addition of surfactants in the internal aqueous phase of the emulsions

Microporous microparticles designed as stable immunoadsorbents

“…Cross-sections of microparticles (Fig. 1B) confirm the most representative structure obtained to be a multivesicular type resulting from an incomplete coalescence of the inner aqueous droplets, or water influx across the oil phase (Ohwaki et al, 1993) and owing to an inadequate stability of the double-emulsion (Schugens et al, 1994). Indeed, it must be emphasized that the stability of both the primary and the secondary emulsions is of prime importance, and has a decisive effect on the morphology, the porosity, and the loading of microparticles.…”

Multiple Emulsions: An Overview

“…There are various factors that affect the stability of w/o/w emulsions which include method of preparation, the nature of entrapped materials, the phase volume ratio, concentration and the type of emulsifiers, nature of oil phase used, electrolytes, and other additives in inner and outer aqueous phase [5,7,28,29]. …”

“…Second method is the use of the internal tracer to establish entrapment efficiency of an impermeable marker molecule in the w 1 phase of emulsion. Several markers have been used like glucose [7], hydrogen ions [58,59], electrolytes [60,61], new coccine [28,62], ionic drugs (Ephedrine HCl), dyes (sulphane blue, polytartarazine), radioactive tracer (tritiated water), etc [63]. Emulsion yield can be measured by dissolving a marker compound in the inner aqueous phase of emulsion and measuring concentration of marker in the outer aqueous phase.…”

“…Addition of sodium chloride and hydrophilic surfactant into the internal aqueous compartment of the multiple emulsions also influences the break down of the suspending vesicular globules [28]. The stabilization of w/o/w emulsion by making inner aqueous phase hypertonic, addition of chitosan in the inner aqueous phase and phase inversion with porous membrane and its application to transcatheter arterial emobilzation (TAE) therapy was reviewed [79].…”

Water-In-Oil-In-Water Double Emulsions: An Excellent Delivery System for Improving the Oral Bioavailability of Pidotimod in Rats

“…The stability of double emulsions has always been evaluated by the changes in appearance, viscosity, droplets size distribution, and encapsulation efficiency of the emulsions. The use of different indicators, electrolytes such as MgSO 4 , 20 sugars such as glucose, 21 and dyes such as new coccine 22 enabled us to study the yield, release, and permeation of entrapped solutes in the emulsions. In addition, fluorescent probes such as 1,3,6,8, pyrenetetrasulfonic acid, 23 tetrasodium salt, some drugs such as diclofenac sodium 24 and dihydralazine 25 have also been used for formulation, stability, and release studies of W/O/W emulsions.…”