Entrapment efficiencies of PR-NE (PR 3 mg mL−1), PR-NE (PR 6 mg mL−1) and PR-NE (PR 9 mgmL−1) were determined with ultrafiltration-centrifugation method. Hardly any PR could be detectedin the aqueous phase, indicating that the entrapment efficiencies were nearly 100% [28]. This maybe connected with the poor aqueous solubility of PR driving the apportioning of PR into oil center ofPR-NEs. Similar high entrapment efficiencies (>98%) have been detected in a number of othernanoemulsion systems [10, 28-30]