Development and characterization of evening primrose (Oenothera biennis) oil nanoemulsions

Abstract

a b s t r a c tEvening primrose (Oenothera biennis L., Onagraceae) seeds oil has great economic importance due to its wide industrial application, mainly for medicines and nutraceutics. However, to our knowledge, it remains almost unexplored regarding development of innovative formulations, such as nanoemulsions. On the present study, required Hydroprophile-Lipophile Balance of evening primrose seeds oil was determined (HLB 12) and a stable nanoemulsion (Day 1: mean droplet size: 214.3 ± 0.69 nm, polydispersity index: 0.253 ± 0.012. Day 7: mean droplet size: 202.8 ± 0.23 nm, polydispersity index: 0.231 ± 0.008) was achieved. Moreover, pseudo-ternary diagram allowed delimitation of nanoemulsion region, contributing to nanobiotechnology of natural products.

Formulation, characterisation and antibacterial activity of lemon myrtle and anise myrtle essential oil in water nanoemulsion

“…In another study, the wheat bran oil in water nanoemulsion with minimum droplet size (84.6 nm) and the narrow PDI (0.257) was obtained when mixture of span 80 (37.4%) and tween 80 (62.6%), with HLB value 11 was used (Rebolleda, Sanz, Benito, Beltran, Escudero, & Gonzalez San-Jose, 2015). The required HLB value for evening primrose seed oil was determined and reported to be 12 when mixture of span 80 (28%) and tween 80 (72%) was used (Rodrigues, et al, 2015). Rodríguez-Rojo, Varona, Núñez, and Cocero (2012) determined the required HLB for rosemary EO was 15.…”

“…Tween 80 (HLB 15) according to Rodrigues, et al (2015) as follows: 65.4:34.6 (HLB 8), 57:43 (HLB 9), 46.7:53.3 (HLB 10), 37.4:62.6 (HLB 11), 28:72 (HLB 12), 18.7:81.3 (HLB 13), 9.3:90.7 (HLB 14), 0:100 (HLB 15). The emulsions were prepared as mentioned above.…”

“…Different HLB value surfactant combinations ranging from 8 to 15 were prepared by mixing Span 80 (HLB 4.3) and Tween 80 (HLB 15) in various proportions. The required HLB of an oil can be determined by using a set formulation with a wide range of HLB and surfactant, which can be prepared by combining low and high HLB values (Rodrigues, et al, 2015). One day after nanoemulsions preparation HLB 8, 9, 10, 11 and 15 produced mean droplet size above 100 nm, whereas HLB 12, 13 and 14 produced mean droplet size below 100 nm, for both LMEO and AMEO.…”

“…The physicochemical properties of nanoemulsions are influenced by type and concentration of oil and surfactant, hydrophilic-lipophilic balance (HLB) of oil and processing condition (Solans, Izquierdo, Nolla, Azemar, & Garciacelma, 2005). Optimal stability is achieved when HLB value of surfactant mixture is close to that required of the oil, which produces the smallest mean droplet size with narrow distribution (Fernandes, Mascarenhas, Zibetti, Lima, Oliveira, Rocha, et al, 2013;Rodrigues, Costa, Almeida, Cruz, Ferreira, Vilhena, et al, 2015). Therefore formulation of an efficient delivery system should consider the required HLB value of oil, concentration of oil and surfactant, and mechanical energy applied.…”

Nanoemulsions for “Nose-to-Brain” Drug Delivery

“…Nanoemulsions (NEs) are oil-in-water (O/W) or water-in-oil (W/O) dispersions of two immiscible liquids stabilized using appropriate surfactant(s) [ 24 ], with a mean droplet diameter of about 100 nm [ 25 ], even if in literature upper size limits up to 300 nm [ 26 ] have been reported. As the size of the droplets is significantly smaller than the wavelength of visible light, NEs have either a transparent or from transparent-to-milky-white appearance [ 25 ].…”