Preparation of monodisperse aqueous microspheres containing high concentration of l-ascorbic acid by microchannel emulsification.
Monodisperse aqueous microspheres containing high concentrations of l-ascorbic acid with different concentrations of sodium alginate (Na-ALG) and magnesium sulfate (MgSO4) were prepared by using microchannel emulsification (MCE). The continuous phase was water-saturated decane containing a 5% (w/w) hydrophobic emulsifier. The flow rate of the continuous phase was maintained at 10 mL h(-1), whereas the pressure applied to the disperse phase was varied between 3 and 25 kPa. The disperse phase optimized for successfully generating aqueous microspheres included 2% (w/w) Na-ALG and 1% (w/w) MgSO4. At a higher MgSO4 concentration, the generated microspheres resulted in coalescence and subsequent bursting. At a lower MgSO4 concentration, unstable and polydisperse microspheres were obtained. The aqueous microspheres generated from the MCs under optimized conditions had a mean particle diameter (dav) of 14-16 µm and a coefficient of variation (CV) of less than 8% at the disperse phase pressures of 5-15 kPa.
['Khalid|Nauman|N|', 'Kobayashi|Isao|I|', 'Neves|Marcos A|MA|', 'Uemura|Kunihiko|K|', 'Nakajima|Mitsutoshi|M|', 'Nabetani|Hiroshi|H|']
D000464:Alginates D001205:Ascorbic Acid D004339:Drug Compounding D045703:Emulsifying Agents D004655:Emulsions D020723:Glucuronic Acid D006603:Hexuronic Acids D057927:Hydrophobic and Hydrophilic Interactions D007477:Ions D008278:Magnesium Sulfate D008863:Microspheres D009997:Osmotic Pressure D010316:Particle Size D011312:Pressure D012964:Sodium D014783:Viscosity D014867:Water
monodispersity l-Ascorbic acid microchannel emulsification sodium alginate magnesium sulfate microencapsulation