The influence of cosurfactants and oils on the formation of pharmaceutical microemulsions based on PEG-8 caprylic/capric glycerides

摘要: In the present study effect of type and concentration a cosurfactant oil on ability nonionic surfactant PEG-8 caprylic/capric glycerides (Labrasol) to solubilize both water phases was evaluated. Seven different cosurfactants (polyglyceryl-6 dioleate (Plurol Oleique) (PO), polyglyceryl-6 isostearate Isostearique (PI), polyglyceryl-4 (Isolan GI 34) (IGI34), octoxynol-12 (and) polysorbate 20 (Solubilisant gamma) 2421) (SG2421), PEG-40 hydrogenated castor gamma 2429) (SG2429), (Cremophor) RH 40) (CRH40) diethyleneglycol monoethyl ether (Transcutol) six oils (isopropyl myristate, ethyl oleate, decyl medium chain triglycerides, mineral olive oil) were used in phase behaviour studies quaternary system Labrasol/cosurfactant/oil/water. The amount required completely homogenize equal masses form single microemulsion (termed as balanced microemulsion) (S min, %w/w), minimal surfactant/cosurfactant blend produce (SCoS %w/w) well maximum solubilized investigated surfactant/oil surfactant/cosurfactant/oil mixtures (W(max), determined. obtained results indicated that Labrasol showed good efficiency presence lower molecular volume fatty acid esters with preferred chemical structure such isopropyl myristate min 56.14% (w/w); W(max) 12.28% (w/w)). Oils high (olive do not result formation. Transcutol decreased capacity for solubilization phases. tendency both, phases, favoured by polyglycerol-6 ester (PO PI) while influence polyglycerol-4 (IGI34) polyoxyethylene (CRH40, SG2421 SG2429) efficiency, significant. Furthermore, revealed significant mass ratio (K(m)) synergistic between formation microemulsions using phase. Optimized systems stabilized Labrasol/polyglyceryl-6 at K(m) 5:5 27.5% (w/w) W(max), 71.43% PI; SCoS 29.18% 65.00% PO) electrical conductivity measurement optimized their structures highly conductive indicating bicontinuous microstructure.