Both pumpkin and kenaf seed oil with carnauba wax (CW) and beeswax (BW) are used to develop nanostructured lipid carriers (NLCs) loaded with Uvinul T150 and Uvinul A Plus Granular for a UV protection formulation. The study aims to optimize the concentration and the type of seed oil in order to develop a stable NLC formulation with high entrapment efficiency, drug loading, antioxidant activities, and UV absorbing properties. The physical properties of the NLCs are analyzed based on the mean particle size, polydispersity index (PDI), long‐term storage stability, Fourier‐transform infrared spectroscopy (FT‐IR), and differential scanning calorimetry (DSC). They are also compared for their entrapment efficiency, drug loading, in vitro antioxidant activities, and in vitro UV absorbing properties. The optimized NLC consists of 10% lipid phase and 1% Uvinul T150 and Uvinul A Plus Granular, respectively. It has mean particle size of 238.20 ± 3.61 nm and remains physically stable on storage at both 25 ± 2 and 40 ± 2 °C. Spherical amorphous NLC structure with encapsulated UV filters is observed by transmission electron microscopy (TEM). Besides, it shows high entrapment efficiency (≥95%) for both Uvinul T150 and Uvinul A Plus Granular in addition to its antioxidant activities as indicated by both DPPH and ABTS radical scavenging activities. In addition, the formulation had high UV absorbing properties, showing its potential to be utilized in the formation of sunscreen prototype. Practical Application: The preliminary study on pumpkin and kenaf seed oil shows bioactive potential with high antioxidant activities. The finding of kenaf seed oil‐NLC can be applied in the cosmetic industry to produce a wide variety of environmental‐friendly products with improved stability and beneficial properties. Also, the application of technology by forming NLCs can be used to develop lotions, creams, etc., with multifunctional properties. Besides, NLCs as carriers for UV filters is proven in the present study to exhibit high entrapment efficiency and drug loading properties. This is beneficial in developing advanced cosmetic prototypes that possess broad spectrum effectiveness with fewer side effects. Nanostructure lipid carriers (NLCs) are applied to encapsulate UV filters with pumpkin and kenaf seed oils. Kenaf seed oil‐NLC (F7) is selected as the best formulation for UV filters encapsulation. With spherical amorphous NLC structure, it shows high entrapment efficiency for the UV filters and antioxidant activities. Results indicate that F7 with high UV absorbing properties remains physically stable upon 12 weeks of storage period.

This study was aimed to produce a stable kenaf seed oil-nanostructured lipid carrier (KSO-NLC) sunscreen, which can help in the photoprotective effect. The nanostructured lipid carrier (NLC) formulation was optimized and selected based on the results of mean particle size, polydispersity index (PDI), and storage stability of formulas at both chilled (4 AE 2 C) and room (25 AE 2 C) temperatures. Uvinul A plus B was added to KSO-NLC with the optimized formula (80% w/w aqueous phase, 20% w/w lipid phase, and 7% w/w of surfactants with a ratio of 70:15:15 of Tween 20: poloxamer 188: lecithin). The mean particle size distribution (224.73 AE 1.56 nm) and PDI (0.41 AE 0.01) of KSO-NLC were determined and were found to be stable against storage without creaming or phase separation. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging and 2,2 0 -Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging activities of KSO-NLC were 5.43 AE 1.00 mg Trolox equiv. g −1 of NLC and 6.70 AE 0.31 mg Trolox equiv. g −1 of NLC, respectively. The Sun Protection Factor (SPF) of KSO-NLC, 41.38 AE 6.03 with a UVA/UVB ratio 0.64 AE 0.01, suggested a good photoprotective effect. The sustained release of Univul A plus B from KSO-NLC accompanied by its entrapment efficiency up to 64.09 AE 0.98% and drug loading (DL) of 32.05 AE 0.49% (maximum 50% DL capacity) proved that the degradation of the ultraviolet (UV) filter could be reduced. Therefore, the KSO-NLC sunscreen was a feasible solution for the photoprotective approach by using unconventional plant seed oil with a significant enhancement (P < 0.05) in many aspects compared to the formula without KSO incorporation. Keywords Particle size Á Polydispersity index (PDI) Á Uvinul a plus B Á Entrapment efficiency (EE) Á Drug loading (DL) J Am Oil Chem Soc (2019) 96: 201-211.

Pumpkin seed oil (PSO) with carnauba wax and beeswax was used to develop nanostructured lipid carriers (NLC) loaded with a UV filter, Uvinul ® A Plus B. The aims of the study were to optimize the concentration of PSO to develop a stable NLC formulation, determine storage stability of the NLC with and without PSO, and the synergistic effect of PSO-NLC with UV filter for photoprotective properties. The physical properties of NLC were optimized based on the mean particle size, polydispersity index, and storage stability. The optimized NLC consisted 10% lipid phase (3.5% carnauba wax, 3.5% beeswax, and 3.0% PSO) and 90% aqueous phase. After optimization, Uvinul ® A Plus B was added in the optimized PSO-NLC to produce a photoprotective formulation. Uvinul ® A Plus B consisted of both UVA (Diethylamino Hydroxybenzoyl Hexyl Benzoate) and UVB (Ethylhexyl Methoxycinnamate) filters. The NLC produced with PSO and Uvinul ® A Plus B had mean particle size of 135 AE 2 nm and showed good physical stability under storage time. Besides that, the NLC produced also proven to have positive effect in enhancing the entrapment efficiency and drug loading, which were 82.86 AE 0.15% and 55.41 AE 0.04%, respectively, and showed sun protection factor value of 16.61 AE 3.45. The results indicated the presence of synergistic effect among the PSO-NLC with Uvinul ® A Plus B.

The photoprotective skincare products are in high demand to meet the consumer market with concern on skin health. Seed oils are commonly used as ingredients in many cosmetic products due to their natural antioxidants and now being increasingly recognized for their effects on skin health and photoprotection. This article briefly reviews the application of seed oils in sunscreen development focusing on the antioxidants that contribute to photoprotection, thus preventing UV-induced erythema and photoaging. The addition of seed oils that contain specific natural bioactive compounds was discussed in the review. Besides that, seed oils acting in molecular pathways that benefit photoprotection were also summarized. Seed oils (pomegranate seed oil, castor oil, cocoa butter, jojoba oil, rosehip oil, grapeseed oil, kenaf seed oil, and pumpkin seed oil) utilization have high potential to act as natural UV filters and at the same time help in skin repairing. The seed oils contributed beneficial properties to the sunscreen formulation due to their synergistic effect with antioxidants, antiaging properties, anti-inflammatory effect, and potential hormetic effect. The finding of specific bioactive compound from seed oils provides a better understanding of the contribution of seed oils in sunscreen formulation.

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