Wax inhibition of cold-pressed coconut oil for pharmaceutical and cosmetic applications

Research Title : Wax inhibition of cold-pressed coconut oil for pharmaceutical and cosmetic applications

Researcher : Thawatchai Phaechamud

Office : Silpakorn University

Research Grants : Public and Private Linkage for Commercialize Research Project

Year : 2011

Abstract

          Cold-pressed coconut oil (CO) has been utilized as the dietary fats for food, cosmetic and medicine in Southeast Asia and European countries.  The wax formation dispersed in this oil during storage at cool environment makes it not homogenous and opaque.  The utilization of this oil is limited for the cool climate countries and also it is difficult for using as injectable oil vehicle in pharmaceuticals.  Therefore the decrease of wax appearance temperature (WAT) will possibly diminish this problematic behavior.  In this study, the effect of CO production and additives addition were determined and the proper systems were chosen for incorporating with model drugs.  The physicochemical properties such as saponification value, iodine value and pour point (PP) were determined.  The methods for WAT determination was obtained from viscometry, ASTM standard and differential scanning calorimetry (DSC) methods.  Ibuprofen (IB) and cyproterone acetate (CPA) were used as model drugs. They were individually mixed with the proper systems to investigate the in vitro drug release and release kinetics.  For CO production, the sedimentation following with filtration process could decrease WAT.  Other oils, vehicles, surfactants, polymers and miscellaneous substances were used as additives.  Peppermint oil (PO), benzyl benzoate (BB) or N-methyl-2-pyrrolidone (NMP) were the proper wax inhibitors for incorporating with CO in the ratio of 1:1 because they could decrease WAT of CO which was not higher than 15ºC.  The release kinetics of IB and CPA was first order and Higuchi’s, respectively.  Addition of PO and BB could retard the release rate of CPA, whereas the addition of NMP could increase the release rate of CPA.  While the addition of PO, BB and NMP did not affect the release rate of IB. CO and CO modified with solutol HS were used as ingredient in cram prepared with homogenizer. Satisfaction questionnaire showed that the two creams were generally comfortable and acceptable. These results indicated that CO incorporated with wax inhibitors was suitable for application as vehicle in injectable and cream preparations.