**4. Conclusion**

*Nano- and Microencapsulation - Techniques and Applications*

similar molecular species composing CocoPEs.

applications [2].

hexagonal phase formation was consistent to cylindrical molecular shape attributed to CocoPEs. The CocoPEs gradual change of phase was estimated because of the

The phase behavior of CocoPEs dan CocoPLs above indicated that they were both had complex self-assembly structures which would be beneficial for future

**3.6 Encapsulation of vitamin C in coconut (CocoPLs and CocoPEs) liposomes**

Phospholipids has long been known as drug delivery substance due to their liposome forming ability. Liposome was a spherical aggregation structure with bilayer phospholipid as its shell surrounding aqueous core. This unique structure was especially a perfect vehicle for delivering hydrophilic and hydrophobic drugs with storage and controlled release purposes. In this paper as a preliminary study for further application of coconut phospholipid as drug delivery material we used vitamin C as a hydrophilic drug model to be encapsulated in coconut liposomes. Vitamin C was a hydrophilic drug and would be encapsulated inside the aqueous core of liposome. The study lead to that encapsulation efficiency of vitamin C in CocoPEs were higher than CocoPLs i.e. 94.44% and 92.40% respectively, **Figure 10**. In relation to their application as drug delivery, liposomes were usually made from phospholipid and a small amount of cholesterol. Cholesterol was added to the liposome membrane to control liposome rigidity and penetrability [33]. Therefore to explore the effect of cholesterol on the encapsulation efficiency of coconut liposomes we also prepared coconut liposomes with several different concentration of cholesterol namely 10%, 20%, 30% and 40%. The encapsulation efficiency of the liposomes were presented on **Figure 10**. The results suggested that addition of cholesterol up to 40% in the liposome's membrane reduced the encapsulation efficiency of CocoPEs and CocoPLs liposomes. Furthermore CocoPEs liposomes demonstrated slighter reduction than CocoPLs liposomes. The encapsulation efficiency of CocoPEs diminished gradually as the cholesterol concentration increased while for CocoPLs liposomes the decline was arbitrary. Addition up to 30% of cholesterol only reduced the CocoPEs encapsulation efficiency to around 80% while CocoPLs was as low as 52%. Cholesterol effect on the encapsulation efficiency of CocoPEs

*Encapsulation efficiency of CocoPLs and CocoPEs liposomes with cholesterol composition variation.*

**192**

**Figure 10.**

A total of (9.8 × 10−3%, w/w) of coconut phosphatidylethanolamine species (CocoPEs) was isolated from dried coconut meat. The CocoPEs were obtained in the form of a dark brownish gel. Parent ion screening by LCMSMS revealed that 15 species were found in CocoPEs. Characterization of fatty acyl chains by GCMS resulted in that the hydrophobic part of the species were comprised of capric, linoleic, oleic, stearic and arachidic acyl chains. Phase behavior analysis using DSC obtained at least four different phases on CocoPEs i.e. planar-shape gel phase, rippling phase, liquid crystal phase and hexagonal phase. Each phase change occurred at a particular temperature. The pre-transition temperature (Tp) was from planar-shaped gel to rippling phase at 25.29°C, the melting temperature (Tm) for major transition from gel to liquid crystal at 32.62°C, and the hexagonal phase formation from liquid crystal (Th) at 65.53°C. CocoPEs liposome had high encapsulation efficiency. The presence of cholesterol in the membrane liposome up to 30% did not change much of their encapsulation efficiency. The encapsulation efficiencies were above 80%. Meanwhile coconut phospholipids (CocoPLs) had them above 90% but then decrease irregularly to 52% at 0% and 30% cholesterol respectively.
