PEG-40 Hydrogenated Castor Oil

Rachmawati H, et al. Scientia pharmaceutica, 2017, 85(2), 18.

The safety assessment of the use of high concentrations of polyoxyl 40 (PEG-40) hydrogenated castor oil as an oral nanoemulsion surfactant was done in Webster mice. PEG-40 hydrogenated castor oil served to emulsify glyceryl monooleate (GMO) within the aqueous phase. As a co-surfactant, this work added polyethylene glycol 400 (PEG-400) and had a thermodynamically stable, spontaneously forming nanoemulsion.
· Preparation of nanoemulsions
A 1:8:1 mixture of GMO, PEG-40 hydrogenated castor oil and PEG-400 were used to create the nanoemulsion. This was stirred at 100 rpm for two hours, then sonicated with a bath sonicator for one hour to homogenise. The deionised water was then mixed in to the oil phase (5:1) and gently stirred to form the nanoemulsion.
· Safety of nanoemulsions based on PEG-40 hydrogenated castor oil
The safety assessment showed that the nanoemulsion exhibited no adverse effects when tested on various cell lines in vitro. This was corroborated by in vivo results following a daily single oral dose for 14 days. The high concentration of PEG-40 hydrogenated castor oil formed clear, stable oil droplets even when subjected to gastrointestinal tract simulation fluids, suggesting its suitability for the oral delivery of active compounds contained in the nanoemulsion.

Kiattisin K, et al. Journal of Agriculture and Food Research, 2024, 15, 101004.

A natural oil (avocado oil) nanoemulsion with anti-aging effects was successfully developed. For formulation optimization of the nanoemulsions, 24 formulations containing 8% or 16% w/w avocado oil were prepared. At 5-15% and 2.5-7.5 % w/w respectively, this work applied one and two emulsifiers: Tween 80, PEG 40 hydrogenated castor oil and Span 80.
All formulations contained 0.1% w/w potassium sorbate, 0.5% w/w phenoxyethanol, and deionized water to 100% w/w. Oil and water phases were homogenized in a high shear homogeniser at 5000 rpm for 10 min to form a coarse emulsion. The nanoemulsion mixtures were then made using an ultrasonicator (ultrasonic power at 40%, ultrasonic duration 10 min, temperature 50°C).
The optimal formulation (PS21) consisted of 8% w/w avocado oil, 7.5% w/w PEG 40 hydrogenated castor oil, 2.5% w/w Span 80, 0.1% w/w potassium sorbate, 0.5% w/w phenoxyethanol, and water.
The best formulation had nanoemulsion droplet size small, narrow polydispersity index, high zeta potential of 68.30 ± 3.08 nm, 0.24 ± 0.08, and -55.10 ± 2.66 mV, respectively, and good stability.
In addition, in cell culture experiments, the cell viability of all selected nanoemulsions at a concentration of 0.1% v/v was greater than 80% compared with the control group. The PS21 formulation at a concentration of 0.1% v/v showed the greatest collagen stimulation in human skin fibroblasts without cytotoxicity.