چكيده لاتين :
In this study, pH-sensitive macrocapsules containing peppermint oil (PO) were prepared
using a new emulsification/polymer precipitation technique. An aqueous alkaline
solution of hydroxypropyl methylcellulose phthalate (HPMCP) was used to emulsify
PO in water (OfW) . This emulsion was then added dropwise to a solution of citric
acid to result in a solid dispersion of macrocapsules. Screening studies showed that
three different factors including the polymer and the acid concentrations, as well as the
essential oil to water (OfW) ratio have considerable effects on the encapsulation
process. Different formulations of macrocapsules were prepared and characterized in
terms of PO loading, encapsulation efficiency, and release using GC-FID analysis. A 2level
factorial design with 4-centre points was then used to optimize PO loading and
encapsulation efficiency against the above mentioned parameters. Optical microscopy
showed a polydispersed O/W emulsion, whereas the macrocapsules were uniformly
dispersed with mean diameter of 1 mm. The prepared macrocapsules could protect PO
from acidic condition of stomach and release it in a simulated intestinal fluid .
