Esters nanoemulsions

Sahm N, Basri M, Rahman MB, Abdullah DK, Basri H. Modification of palm kernel oil esters nanoemulsions with hydrocolloid gum for enhanced topical delivery of ibuprofen. Int J Nanomedicine. 7 4739-4747,2012. 

Fatty acids were not discussed in the US patents or literature for the purpose of forming nanoemulsions, but they were included in the study for comparative purposes and because of their low viscosities compared to ester-oils that consist of three fatty acids molecules per oil molecule. The lower viscosity liquids are easier to shear in a homogenizer... 

Figure 14.23 shows the results for nanoemulsions based on esters, and the Ostwald ripening rates are listed in Table 14.5. Cj2 i5 alkylbenzoate appeared to give the highest ripening rate. 

Table 14J Ostwald ripening rates for nanoemulsions based on esters.

This method has been used to prepare nanoemulsions of such polymers as cellulose esters and epoxy resins, similar to latexes produced by emulsion polymerization. The nanoemulsions are prepared by direct emulsification of solutions of the polymers in organic solvents, followed by removal of the organic solvent by steam distillation under reduced pressure. The nanoemulsions produced in this fashion had stabilities > 1 year. 

The pH is adjusted to the desired value with an aqueous solution of NaOH or HCl, depending on the value that needs to be reached. The pH of the nanoemulsion is generally adjusted to 7-8 to allow physiological compatibility and maintain emulsion physical integrity by minimizing fatty acid ester hydrolysis of MCT-LCT and phospholipids. ... 

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