Preparation and Evaluation of Sunscreens Nanoemulsions Containing

Avobenzone and Octyl Methoxycinnamate

Anayanti Arianto

, Hakim Bangun

, Josephine Yauvira

Department of Pharmaceutical Technology, Faculty of Pharmacy, Nanomedicine Centre,

Universitas Sumatera Utara, Medan Indonesia

anayantia@yahoo,com

Keywords: Avobenzone, Octyl methoxycinnamate, Nanoemulsion, Sunscreen

Abstract: The use of sunscreen for the purpose of effectively absorbing sunlight in order to prevent the occurrence of

premature aging and skin cancer. Nanoemulsion is very effective to be applied as cosmetic preparation due

to their characteristic properties of small droplet size with high surface area enables effective delivery of the

active ingredients. It is transparent appearance and thermodynamically stable. The formulation of the

nanoemulsions was prepared in various ratios of Tween 80 as a surfactant and ethanol as co-surfactant using

avobenzone and octyl methoxycinnamate as sunscreen agent.The nanoemulsion was evaluated for particle

size, centrifugation, stability during experiment for 12 weeks of storage at room temperature, pH, viscosity,

and SPF value. Nanoemulsion in the ratio of tween 80 and ethanol (34:26) had the smallest average particle

size of 163.31 nm with yellowish color, clear and transparent appearance, pH value (7.46 ± 0.00), viscosity

value (75cP ± 25), did not show any separation or creaming in the centrifugation, stable during experiment

for 12 weeks of storage at room temperature. The sunscreen nanoemulsion preparations containing

avobenzone and octyl methoxycinamate with the ratio of Tween 80 and ethanol 34:26 contributed to give SPF

value of 16.80 ± 0.08. This formulation could be considered efficient for sunscreen cosmetic use

1 INTRODUCTION

The skin is on the outer surface of the body so often

exposed to sunlight. Every year, about a million

people are diagnosed with skin cancer and about

10,000 die from malignant melanoma. In 2018, an

estimated 9,320 deaths from melanoma will occur.

The harmful effects of solar radiation caused by

solar radiation consist of UVA rays from 320 to 400

nm, UVB from 290 to 320 nm and UVC of 200-290

nm. UVC radiation is filtered by the atmosphere

before it reaches the earth. UVB radiation is not

perfectly filtered by the ozone layer and is

responsible for sunburn damage. UVA radiation

reaches the deeper layers of the epidermis and

dermis and causes premature aging of the skin. UV

radiation is one of the leading causes of skin cancer

(Dutra, et al. 2004; Mitsui, 1997; Parkin, et al.

2011).The formulation of sunscreen that is efficient,

stable and can be marketed is a challenge. The

stability of product appearance obtained during

storage is a problem of efficacy and consumer safety

(Lionetti and Rigano, 2017). Sunscreen products on

the market mostly available in the form of lotions,

gels, emulsions and creams. Nanoemulsion is very

attractive to be applied in cosmetics (sunscreen

products) because nanoemulsi has droplet size

smaller than emulsion ie in nano size (20-500 nm)

so it is more stable, can prevent creaming,

sedimentation or coalescence, besides also increase

solubility of an insoluble active ingredient in water.

Nanoemulsion is very useful to be applied in

cosmetic because of it is more stable, with low

viscosity, and transparent visual aspect, and a high

surface area allows effective delivery of the active

ingredient for the skin, thereby increasing the

efficacy (SPF value) of the sunscreen

product.(Rhein, 2007, Devarajan and Ravichandran,

2011). The Nanoemulsion is formed spontaneously,

generally without high-energy input. This research

uses chemical sunscreen, which is avobenzone as

absorbent of UVA and octyl methoxycinnamate as

UVB absorbent. The maximum concentration of

avobenzone used is generally 3% and the

concentration of octyl methoxycinnamate is 7.5%

(Rieger, 2000).The aim of this study was to obtain

nanoemulsion of avobenzone and octyl

methoxycinnamate (OMC), and to evaluate their

Arianto, A., Bangun, H. and Yauvira, J.

Preparation and Evaluation of Sunscreens Nanoemulsions Containing Avobenzone and Octyl Methoxycinnamate.

DOI: 10.5220/0010087207470751

In Proceedings of the International Conference of Science, Technology, Engineering, Environmental and Ramiﬁcation Researches (ICOSTEERR 2018) - Research in Industry 4.0, pages

747-751

ISBN: 978-989-758-449-7

747

physical stability and in vitro sunscreen activity

through Sun Protection Factor (SPF) determination

by spectrophotometric methods. in vitro testing

methods by spectrophotometric methods have been

developed because they are more rapid, less

expensive and above all because they prevent the

involvement of human volunteers with the related

ethical problems. The nanoemulsion in this study

was made by low energy spontaneous emulsification

method using 3% avobenzone and 7.5% octyl

methoxycinnamate as sunscreen agent and Tween

80 as surfactants and ethanol as co-surfactant.

Tween 80 is widely used as surfactant in the

preparation of nanoemulsion. In addition to having a

large HLB of 15, Tween 80 is stable against

electrolytes, weak acids, and bases (Rowe et al.,

2009). However, the use of Tween 80 singly is not

enough to reduce surface tension to form

nanoemulsion.Therefore, in the preparation of

nanoemulsion, surfactants are often combined with

cosurfactants.

2 MATERIALS AND METHODS

2.1 Materials

Avobenzone, octyl methoxcinnamate (India),

Tween 80, ethanol 96%, paraffin liquid, propylene

glycol were purchased from PT.Brataco (Medan,

Indonesia). Methyl paraben, propyl paraben, butyl

hydroxyl toluene and buffer pH solution purchased

from CV Rudang (Medan Indonesia).

2.2 Preparation of Nanoemulsion

In the preparation of nanoemulsion, Tween 80 as

surfactant combined with ethanol as cosurfactant.

The ratio of surfactant (Tween 80) and co surfactant

(ethanol) mixtures in nanoemulsion formulation as

shown in Table 1. The nanoemulsions were prepared

according the spontaneous emulsification method

(Cinar, 2017), where the oil phase (avobenzone

dissolved in ethanol, octyl methoxycinnamate, butyl

hidroxyl toluene, paraffin liquid) were mixed with

water phase (Tween 80, methyl paraben and propyl

paraben dissolved in hot distilled water, propylene

glycol) and stirred,then add with deonized water to

provide 3% w/w paraffin liquid in final

nanoemulsion and then stirred gently at 3000 rpm

(magnetic stirrer HI 190 M) for 4 hours until a clear

nanoemulsion was produced. Then the

nanoemulsion preparation was sonicated for 1 hour

(Ultrasonic Cleaner 1510 E-MT)) until a transparent

nanoemulsion was produced.

Table 1: Composisiton of nanoemulsions

2.3 Physical Stability Assessment

Prepared formulations were subjected to

centrifugation at 3750 rpm for 5 hours and were

observed for phase separation. (Lachman, et al.,

1994). The stability studies were performed by

keeping the selected formulation of nanoemulsion at

room temperature (25±2ᵒC) for a period of 3 months.

The viscosity, and pH were determined at 0, 1, 2, and

3 months (Alam, S M et al. 2015).

2.4 Determination of SPF Value

The SPF value is calculated using the Mansur

equation. The sample absorption spectrum was

obtained by using a UV-Vis spectrophotometer at

290-400 nm wavelength with 96% alcohol as blank,

the absorption value recorded per 5 nm interval

wavelength 290-320 nm and 10 nm interval

wavelength 320-400 nm. The value of absorption

obtained was multiplied by erythemal effects

spectrum (EE) x I for each interval. The value of EE

x I per interval could be seen in Table 2. The amount

of EE x I obtained multiplied with the final correction

factor, then the SPF value of the tested sample would

be obtained. The value of EE x I and correction factor

is a constant where the value of EE x I from the

wavelength 290-320 nm and every 5 nm difference

and the correction factor 10 has been determined by

(Sayre, 1979),

SPF = CF Σ





EE (ʎ) x I (ʎ) x Abs (ʎ)

CF = Correction factor

EE = Erythemal Effect Spectrum

I = Solar Intensity Spectrum

Abs = Sample absorption

ICOSTEERR 2018 - International Conference of Science, Technology, Engineering, Environmental and Ramiﬁcation Researches

748

Table 2. Correlation between the erythemogenic effect (EE)

and the radiation intensity at each wavelength (I) ( Mansyur

et al. 1986).

The value of EE x I and correction factor is a

constant where the value of EE x I from the

wavelength 290-320 nm and every 5 nm difference

and the correction factor 10 has been determined by

(Sayre, 1979).

2.5 Determination of Nanoemulsion

Droplet Size

The mean droplet size of the nanoemulsion was

determined by Vasco

CORDOUAN Technologies

Particle Size Analyzer Measurements were

performed at room temperature.

2.6 pH Determination

The pH of the formulation was measured using a

digital pH meter (Hanna Instrument). One g of

nanoemulsion was dissolved in 100 ml distilled

water. The measurement of pH of each formulation

2.7 Viscosity Measurement

The Viscosity of nanoemulsion was measured by

using Brookfield DV-E viscometer. The sample was

filled in a beaker and the viscosity was measured by

using Spindle number S62.

3 RESULT AND DISCUSSION

The result of all formulations showed a light yellow,

clear, and transparent nanoemulsion as shown in

Figure 1. One characteristic of nanoemulsions is a

bluish brightness and translucent aspect, whereas

macro emulsions display milky appearance

(Mason et al., 2006) The preparations of

nanoemulsion by spontaneous emulsification

method. This method can produce nanoemulsions at

room temperatures and no special devices are

required. When an oil phase with a water soluble

substance is mixed with water, oil droplets

spontaneously forms. The mechanism depends on

the movement of water dispersible substance from

the oil phase to the water phase. This leads to

interfacial turbulence and thus formation of

spontaneous oil droplets. The nanoemulsions stable

during experiment for 12 weeks of storage at room

temperature (Figure 2).



Figure 1: Appearance of the prepared sunscreen

nanoemulsion (F1, F2, F3) containing avobenzone and

octyl methoxycinnamate.



Figure 2: Appearance of the prepared sunscreen

nanoemulsion (F1, F2, F3) containing avobenzone and

octyl methoxycinnamate after storage for 12 weeks at room

temperature 

The centrifugation test was performed to determine

the stability of nanoemulsion. The centrifugation test

describes the stability of the preparation because of

the effect of gravitational force equivalent to one year

of storage. All of the nanoemulsions (Figure 3) were

stable, did not show any a phase separation or

creaming.

Figure 3: Appearance of the prepared sunscreen

nanoemulsion (F1, F2, and F3) containing avobenzone and

octyl methoxycinnamate before and after centrifugation

Preparation and Evaluation of Sunscreens Nanoemulsions Containing Avobenzone and Octyl Methoxycinnamate

749

Table 2: Globule size and globule size distribution

distribution of different nanoemulsion samples during

storage for 12 weeks at room temperature.

The results of the globule size determination show

the nanoemulsion (F1) that used the lowest surfactant

concentration with ratio of surfactant Tween 80 and

co-surfactant ethanol 34:26 was the smallest globule

size and was increased during storage for 12 weeks

at room temperature. (Table 2). The results of

viscosity and pH measurements of nanoemulsion

containing avobenzone and octyl methoxycinnamate

during experiment for 12 weeks of storage at

different temperature as shown in Table 3. The

viscosity of nanoemulsion was increased during 12

weeks of storage and with the decrease in

temperature the viscosity will increase and the

preparations become more viscous. The pH of

nanoemulsion was decreased during 12 weeks of

storage and with increasing storage temperature

(Table 3.).

Table 3: Viscosity and pH of nanoemulsion (F1) during

storage for 12 weeks at different temperature

From the experimental results, the nanoemulsion F1

that used the lowest surfactant concentration and the

small globule droplet size, while still maintaining

stability, centrifugal stability that selected for further

in vitro SPF value determination. Based on the result

that the SPF values resulted from the sunscreen

nanoemulsion F1 containing avobenzone and octyl

methoxycinnamate was 16.80 ± 0.08. This sunscreen

nanoemulsion preparation already has sun protection

activity in medium protection level (Lionetti and

Rigano, 2017).

4 CONCLUSION

The sunscreen nanoemulsion preparations containing

avobenzone and octyl methoxycinamate are

physically stable during experiment for 12 weeks of

storage at room temperature and characterized by the

absence of discoloration, creaming, or phase and

contributed to give SPF value of 16,80. This

formulation could be considered efficient for

sunscreen cosmetic use

ACKNOWLEDGEMENTS

This work was supported by University of Sumatera

Utara through the TALENTA Research, scheme of

Penelitian Guru Besar 2018.

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