Evaluation of Sebum Control and Safety for Daily Use of a Cosmetic Elastomer Formulated with Vegetable Oils from Peruvian Biodiversity

Abstract

This study aimed to evaluate the daily use safety and instrumental efficacy for sebum control of a cosmetic elastomer-type formulation containing the vegetable seed oils of Plukenetia huayllabambana, Physalis peruviana L., and Bertholletia excelsa. Assessments were conducted using a skin irritation index and the Sebumeter^® SM 815 from Courage + Khazaka Electronics GmbH, Cologne, Germany. Sebum control efficacy was determined in three groups of volunteers seated in a room at a temperature of 26 ± 1 °C. The forehead area was divided into two sections: one received the cosmetic elastomer while the other area received no product. The elastomer significantly reduced sebum levels in all three groups at 2, 4, and 5 h (p < 0.05) compared to the untreated area, and the third group exhibited higher sebum reductions, with 43.48%, 52.43%, and 43.95%, respectively. In conclusion, the dermatologically tested and safe cosmetic product contains a balanced combination of active ingredients that effectively control sebum levels, resulting in visibly oil-free skin.

1. Introduction

The epidermis is the outermost layer of the skin and is composed of the stratum basale, stratum spinosum, stratum granulosum, and stratum corneum; this is where the process of epidermal keratinocyte differentiation takes place. This metabolism allows the skin to be protected from external aggressions and to maintain the hydration of internal tissues. The dermis is the intermediate layer and is composed of fibroblasts, blood vessels, immune system cells, sensory endings, hair follicles, sebaceous glands, and sweat ducts attached to a dense connective tissue. Its main function is the mechanical and physiological support of the skin [1].

The lipids of the skin surface are a mixture of epidermal and sebaceous lipids, with their proportions varying depending on the area of the body. In areas with abundant sebaceous glands, such as the face (forehead, nose, and cheeks), the epidermal-to-sebaceous lipid ratios are between 3–5% and 95–97%, respectively. Epidermal lipids are a key component of the stratum corneum, ensuring cohesion between its multiple cell layers, and are responsible for the barrier function of the skin [2].

The primary function of the sebaceous glands is to produce and secrete a viscous fluid into the follicle infundibulum, known as sebum [3]. Sebum is composed of triglycerides, diglycerides, and free fatty acids (57.5%); wax esters (26%); squalene (12%); and cholesterols (1.5%). It has lubricating and antimicrobial properties and helps maintain skin hydration [4]. When natural sebum is deficient in linoleic acid, triglycerides and cholesterols increase to maintain total sebum content, resulting in a reduced supply of linoleic acid to the surface of the epidermis. This leads to an increased sebum secretion rate and, consequently, higher susceptibility to acne development and follicular hyperkeratosis [5]. Linoleic acid plays a role in metabolism and is present in epidermal sphingolipids as well as in acylglycosylceramides and acylceramides, which contribute to the preservation and recovery of the permeability of the epidermal barrier [6]. These acylglycosylceramides, in combination with lamellar bodies, form the lipid envelope that facilitates the union between the stratum corneum and stratum granulosum [7]. This connection ensures a good barrier function against the external environment and internal physiological maintenance.

Lipid excretion occurs through the disintegration of whole sebocytes. Sebocytes in the basal cell layer proliferate, accumulate lipids during differentiation, and migrate toward the gland opening. Their life cycle ends in a holocrine secretion of sebum. Linoleic acid is specific to sebum, and when it enters the β-oxidation pathway, it promotes sebocyte differentiation for energy production [8].

According to research, individuals aged 15–35 years exhibit a higher rate of facial sebaceous secretion, which is characterized by shiny, oily skin and visible blackheads [9]. Even older women between the ages of 40–55 years may have this type of skin [10]. Increased sebum secretion with follicular obstruction may trigger comedogenesis [11] and is involved in the pathophysiology of acne [12].

Acne vulgaris is an inflammatory disease of the pilosebaceous unit, primarily affecting the face and trunk. It affects approximately 9% of the global population, with approximately 85% of individuals, both men and women, aged 12–24 years, and 50% of individuals aged 20–29 years [13]. The classic pathogenesis of acne vulgaris includes four relevant factors: excessive sebum production, hyperkeratinization of pilosebaceous follicles, inflammation and, by the hyperseborrhoeic environment, triggering strains of Cutibacterium acnes, which have been shown to act as opportunistic pathogens [14]. Inflammatory lesions (papules, pustules, nodules, and cysts) and non-inflammatory lesions (blackheads and whiteheads) facilitate the timely diagnosis of acne type, enabling the initiation of appropriate treatment [15].

Active androgens contribute to the development of the sebaceous gland and regulate its function, which is why they exert effects on sebum excretion. Terminal differentiation of sebocytes is favored by peroxisome proliferator-activated receptor ligands (PPARs), found in sebocytes, and control several lipid metabolism genes [12].

The growing demand for natural cosmetic products has led to increased interest in discovering natural sources of vegetable oils and extracts to obtain beneficial bioactive compounds. Simultaneously, research is being conducted on the safety and toxicology of these components and products when applied on the skin. With the growth of the cosmetics industry, regulatory authorities require skin safety assessments to ensure consumer safety [16].

The cosmetic elastomer consists of a cross-linked silicone network that allows the incorporation of high levels of oils and can be defined as silicone polymers that exhibit the ability to withstand reversible elongations after being subjected to stress without any alteration. When applied, they primarily create a mattifying effect, giving the skin a soft, smooth, and even appearance [17].

In chemical composition investigations, vegetable seed oils from Plukenetia huayllabambana indicate 9.33%, 28.09%, and 54% for oleic, linoleic, and linolenic fatty acids, respectively [18]; Physalis peruviana reports 11.9% oleic acid, 76.1% linoleic acid, and 0.02% linolenic acid [19,20]; and Bertholletia excelsa has approximately 35% oleic acid, 40% linoleic acid, and 0.20% linolenic acid [21]. These three oils were chosen for the formulation of the present cosmetic elastomer due to their high linoleic acid content.

2. Materials and Methods

2.1. Formulation and Development of Cosmetic Elastomers

Table 1. Cosmetic elastomer, final formulation, and components.

Phase	Trade Name	INCI Name	%Purity/Origin	Amount% w/w
A	MSS-500/3H	Silica	100.0/South PlainfieldUSA	24.80
B	Super Sacha inchi	Plukenetia huayllabambana seed oil	100.0/Amazon—Peru	23.70
	Aguaymanto	Physalis peruviana seed oil	100.0/Huanuco—Peru	43.00
	Castaña de Indias	Bertholletia excelsa seed oil	100.0/Madre de Dios—Peru	7.500
	Vitamina E-Alfa tocoferol acetato	Tocopherol	98.6/Ludwigshafen—Germany	1.00

shows the formula of the cosmetic elastomer.

To obtain the cosmetic elastomer, first, the silica was poured in a mixer, which constituted phase A. Then, the natural oils and tocopherol were mixed and homogenized manually at room temperature 25 °C, which constituted phase B. Finally, phase B was added to phase A in a fine and continuous stream, with constant stirring, until complete homogenization was achieved. As a result, a viscous gel called elastomer was formed, which refers to a silicone matrix containing oils suspended within it. The BEAR Varimixer Teddy planetary mixer (Brondby, Denmark) at 100 rpm was used for this purpose. The final product was an elastic formula that was easy to spread on the skin, with a powdery texture at the end of application.

Super sacha inchi vegetable oil was purchased from Cloud Forest (Lima, Peru), and aguaymanto and horse chestnut were purchased from Candela Perú (Lima, Peru). In the case of raw materials, MSS-500/3H was purchased from KOBO Products Inc. (Plainfield, NJ, USA) and vitamin E from BASF SE (Ludwigshafen, Germany).

2.2. Study Design

Our research consisted of two evaluations at different times, the safety of cosmetic use and the sebum regulating effect, which were carried out in accordance with the Declaration of Helsinki and the national legislation of the National Institute of Health (INS) of Peru. The clinical trial regulations were approved by Supreme Decree No. 021-2017-SA24 [22].

The personal data collected were used only for the purposes established in the study and were protected in accordance with the provisions of the Directorate for Personal Data Protection pursuant to Article 34 of Law No. 29,733 (Personal Data Protection Law) and Articles 76, 77, 78, 79, and 81 of the Regulations of the Personal Data Protection Law approved by Supreme Decree No. 003-2013-JUS [23].

2.3. Safety Evaluation Protocol for Cosmetic Use

This cosmetic safety study was approved by the Institutional Research Ethics Committee of Socios en Salud, Peru Branch, with Certificate 019-2024/CIEI-SES and Registration Code 00050. This study was conducted under the supervision of a dermatologist (Peruvian Medicine Association License No. 15148, Peruvian Specialty Registration License No. 048982) for 3 weeks, with visits at baseline and at the end of the study.

In the first visit, volunteers with oily skin attended. Considering the inclusion and exclusion criteria, the dermatologist examined volunteers’ foreheads, cheekbones, and cheeks and selected 24 participants. By visual inspection and using a DermLite DL4 dermatoscope (Aliso Viejo, CA, USA), he examined any appearance, morphology, and possible lesions that could indicate the presence of erythema, oedema, papules, or vesicles. Using the assessment scale for reading reactions by the International Contact Dermatitis Research Group (ICDRG) [24,25], the dermatologist rated each volunteer with an initial clinical score on the parameters of erythema, edema, papules, and vesicles [26]. Participants were instructed on how long they should apply the cosmetic elastomer. Applications consisted of a dose of 0.50 g every 24 h in the mornings for 21 days. This was the amount necessary to ensure total coverage of the forehead, cheekbones, and cheeks.

At the second and final visit (21 days later), the dermatologist provided a final clinical score according to the evaluation scale used at the beginning of the study.

2.3.1. Inclusion Criteria

Healthy men and women aged 18–30 years with visibly oily skin and no open wounds were selected. Participants were required to sign an informed consent form, which explained the objectives of the study and required compliance with the procedures, including their presence in the laboratory on the designated assessment days.

2.3.2. Exclusion Criteria

One of the main indications was that the volunteers should not apply any other treatment or cosmetic product on their face to ensure that the results are attributed exclusively to the cosmetic elastomer.

Young individuals with a history of allergies to cosmetic products, active smokers, or individuals with tattoos in the area of application were excluded.

Pregnant or breastfeeding women were also excluded. Young people with any localized or generalized dermatological disease, such as vitiligo, psoriasis, lupus, and atopic dermatitis, and diseases that may directly interfere with the study or put the subject’s health at risk, such as diabetes mellitus, opportunistic infections, hypothyroidism, history of hypoglycemia, and immune insufficiency, were excluded as well. In addition, we chose not to include volunteers taking vitamins or using topical or systemic drugs, corticosteroids, immunosuppressants, and antihistamines.

2.3.3. Safety Analysis for Daily Use

The sum of Individual Skin Irritation Index ∑ (IdiI) was obtained by summing the skin irritation score of each volunteer at the beginning and end of the present study. The mean skin irritation index (MdiI) was calculated according to the following formula [27]:

$$\mathrm{M}\mathrm{d}\mathrm{i}\mathrm{I}={\displaystyle \frac{\sum \left(\mathrm{I}\mathrm{d}\mathrm{i}\mathrm{I}\right)}{\mathrm{N}\mathrm{u}\mathrm{m}\mathrm{b}\mathrm{e}\mathrm{r} \mathrm{o}\mathrm{f} \mathrm{s}\mathrm{t}\mathrm{u}\mathrm{d}\mathrm{y} \mathrm{p}\mathrm{a}\mathrm{r}\mathrm{t}\mathrm{i}\mathrm{c}\mathrm{i}\mathrm{p}\mathrm{a}\mathrm{n}\mathrm{t}\mathrm{s}}}$$

Table 2. Classification of the skin irritation potential.

Mdil	Result
MdiI = 0.0	Nonirritating, very good skin compatibility
MdiI < 0.2	Nonirritating, good skin compatibility
0.2 < MdiI < 0.5	Slightly irritating, regular skin compatibility
0.5 < MdiI < 1	Moderately irritating, poor skin compatibility
>MdiI 1	Irritating, very poor skin compatibility

shows the classification scale based on the irritation index obtained [24].

2.4. Protocol of the in Vivo Sebum Control Study

2.4.1. Study Design

This was an experimental, analytical, longitudinal, and prospective study conducted at the Centre for Cosmetic Research, Technology and Innovation (CITIC) of Universidad San Ignacio de Loyola in Lima, Peru.

2.4.2. Study Population and Sample

The study included young individuals with evident oily skin. The study sample consisted of 24 volunteers, both men and women, between 18 and 35 years of age, who signed an informed consent form before participating in the study.

2.4.3. Inclusion Criteria

The study included healthy volunteers (men and women) with visible oily and acne-prone skin on the face, without open wounds. Phototype: I–VI, Fitzpatrick classification [28].

2.4.4. Exclusion Criteria

The same exclusion criteria used in the daily use safety assessment, Section 2.3.2, were used.

2.4.5. In Vivo Instrumental Efficacy Evaluation

The Sebumeter^® SM 815 from Courage + Khazaka Electronics GmbH, Cologne, Germany, a high-tech non-invasive skin bioengineering device, was used to measure sebum in the skin. The Sebumeter quantitatively measured the exact amount of sebum in the skin as well as sebum levels after product application [29].

2.4.6. Instrumental Effectiveness Testing Procedures

The evaluation was conducted based on previous research [30,31,32], with modifications in temperature control, number of participants, and comparison target. The cosmetic elastomer was evaluated in three different groups consisting of 6, 8, and 10 individuals each. The evaluation was divided into three groups due to the maximum capacity of the acclimatization room and to keep temperature conditions under control, and the evaluation protocol was the same.

On the day of the trial, volunteers were informed of the purpose, methodology, duration, expected benefits, and limitations of the study. At the beginning of the test, baseline measurements were taken, and then the cosmetic elastomer was applied in one of the divisions to each volunteer. The room was then acclimatized to a temperature of 26 ± 1 °C and a relative humidity of 50 ± 5%.

The test lasted 6 h and included four measurements: before applying the product (basal measurement) and at 2, 4, and 5 h (during acclimatization at 26 °C) after application. At each time point, the amount of sebum in each area of the forehead was measured using the Sebumeter^® SM 815 from Courage + Khazaka Electronics.

The forehead area was divided in half into two equivalent assessment areas: blank (without elastomer application) and product (cosmetic elastomer application). A dose of 0.20 g was applied to one of the divisions of the T-zone, which was the necessary amount to ensure coverage. The area was gently massaged until total absorption. The other area was left bare. The product was randomly distributed between the right and left sides. The forehead has high sebum secretion compared to the cheeks. It belongs to the T-zone (forehead, nose, and chin) as opposed to the U-zone (cheeks on both sides). The T-zone has a higher sebum content than the U-zone [11].

2.5. Statistical Analysis

In both forehead areas and at each respective time, two measurements were taken at nearby points for averaging and comparison of results for each area. The results were analyzed statistically with IBM SPSS Statistics 29.0 software. A 95% confidence interval was considered, and values are expressed as mean, standard deviation, standard error, and percentage reduction.

Baseline measurements with and without product were analyzed with unrelated t-tests; accordingly, means were compared at each time with and without product. Shapiro–Wilk normality tests and Student’s t-test were used to compare the areas with and without product at each time.

3. Results

3.1. Safety for Cosmetic Use

Table 3. Results of the safety tests for daily use.

Results of the Skin Irritation Potential
Total number of participants	24
Σ skin reactions (Idil)	0.0
Mean skin irritation index (Mdil)	0.00
Final outcome (Mdil)	Nonirritating, very good skin compatibility

shows that the cosmetic elastomer had a skin irritation index of 0.00. The product did not cause any irritating phenomena nor significant sensitization during the study period.

None of the 24 participants had significant skin reactions (erythema, edema, papules, or vesicles) in the areas of application of the investigational product during the 24 weeks of application. In addition, improved control of sebum and seborrhea in the areas of application was observed in all cases.

3.2. Sebum Control

Table 4. Sebumetry results in group 1.

Control n = 6	2 h w/o Product	2 h w/Product	4 h w/o Product	4 h w/Product	5 h w/o Product	5 h w/Product
Average	122.17	72.58	178.17	117.67	184.42	123.17
Max	150.00	93.00	212.00	151.50	214.50	176.50
Min	96.50	60.50	143.50	70.50	130.50	72.50
SE	8.69	5.03	10.38	11.67	13.62	15.94
% reduction	−40.59%		−33.96%		−33.21%

,

Table 5. Sebumetry results in group 2.

Control n = 8	2 h w/o Product	2 h w/Product	4 h w/o Product	4 h w/Product	5 h w/o Product	5 h w/Product
Average	108.38	78.88	136.88	95.25	167.38	96.19
Max	152.00	204.00	131.50	217.00	146.00	224.00
Min	33.50	69.00	58.00	70.00	71.00	108.50
SE	14.04	16.36	8.65	15.98	8.03	13.00
% reduction	−27.22%		−30.41%		−42.53%

and

Table 6. Sebumetry results in group 3.

Control n = 10	2 h w/o Product	2 h w/Product	4 h w/o Product	4 h w/Product	5 h w/o Product	5 h w/Product
Average	63.30	112.00	70.45	148.10	77.35	138.00
Max	167.00	92.50	230.00	96.00	174.50	94.50
Min	34.00	40.00	48.00	37.00	71.00	65.00
SE	12.95	5.68	16.09	6.83	11.30	3.38
% reduction	−43.48%		−52.43%		−43.95%

show the mean sebum averages of the three groups during each evaluation time for the areas with product (w/product) and without product (w/o product). A significant reduction* (p < 0.05) from h 2 to 5 occurred in sebum values compared to the area without product (Figure 1, Figure 2 and Figure 3) in each respective group.

According to the inclusion criteria, four women and two men participated in group 1 with an average age of 25 ± 6.02. In group 2, seven women and one man participated with an average age of 26 ± 4.96; and in group 3, only ten women with an average age of 23 ± 3.98 participated.

Figure 4 shows a comparison of sebum reduction among the three groups, which shows that the cosmetic elastomer maintains its regulating effect at different ages and times, which strengthens the reliability of its results.

4. Discussion

Endocrine factors; internal factors, such as gender, age, and ethnicity; and external factors, such as temperature, relative humidity, and season, can affect the function of the sebaceous gland and sebum secretion. It has been noted that the increase in temperature modifies the viscosity of sebum, making it more fluid. In turn, sebaceous secretion is higher in the spring and summer months, although this secretion can also depend on multiple combined factors [2]. As the skin is highly susceptible to these factors, we evaluated the anti-sebaceous effect of the elastomer in three groups, to robustly corroborate its sebum-controlling effect, while controlling the variables temperature and season. We also believe that the inclusion of volunteers aged 18–35 years in the present study is appropriate, given that young people aged 15–35 years have a higher rate of facial sebaceous secretion as a result of hormonal changes [9].

Linolenic and linoleic acid are endogenous ligands of PPARs, which are a group of receptor proteins that function as transcription factors regulating the expression of related genes in cell differentiation and development and metabolism of lipids and carbohydrates [33]. Activation of PPARs by n-3 and n-6 polyunsaturated fatty acids is related to their long chain activation [34]. A decrease in linoleic acid impairs the follicular barrier, opening the way for other free fatty acids and bacteria, leading to inflammation, fatty acid distribution, and lipid peroxidation, thus activating PPARs. PPARα and PPARγ isoforms promote fatty acid beta-oxidation and lipid catabolism and lipogenesis, respectively [35]. Research on epidermal keratinocytes has shown that increased PPARγ expression as well as their activation by agonists induces positive changes in skin barrier function, balanced terminal differentiation, and reduced keratinocyte proliferation rates [36]. This may suggest that by including vegetable oils from P. huayllabambana, P. peruviana L., and B. excelsa with these types of polyunsaturated fatty acids, the cosmetic elastomer would activate PPARs in a balanced way, inducing the breakdown of fatty acids and sebum secretion under normal physiological conditions. This can be inferred from all the groups, as sebum values were significantly reduced from the second hour of measurement compared to the area without product.

Inflammatory processes occur early in the development of acne lesions, and normal IL-1 expression and secretion in non-inflamed skin are significantly increased in the early stages of acne development [37].

Polyunsaturated fatty acid insufficiency leads to increased levels of inflammation-associated and proliferative keratins: K17, K6, and K16 [38]. The increased expressions of these keratins trigger keratinocyte hyperproliferation, including immune alterations [39]. When there is an accumulation of keratinocytes in parallel with excessive sebum production, acne is triggered [40]. Although studies reveal that topically applied oils show variable penetration depending on their structure, some fatty acids, such as linoleic acid, can also modify lipid distribution in the epidermis and even in the dermis [41,42,43]. In this context, cosmetic elastomers containing these fatty acids may contribute to the modulation of the lipid composition of the skin and enhance its barrier function, which may indirectly influence factors associated with keratinocyte hyperproliferation and cutaneous manifestations of acne.

The 5α-reductase enzyme induces the conversion of testosterone to 5α-DHT, which is a testosterone-derived metabolite and the most active androgen in sebum-regulating function [44]. Unsaturated fatty acids (γ-linolenic acid > α-linolenic acid > linoleic acid > palmitoleic acid > oleic acid) have shown in vitro inhibition of microsomal 5α-reductase, and 5 α-DHT stimulates sebum production and promotes acne. Unsaturated fatty acids may play an important role in regulating the action of androgens on target cells, as they stimulate sebum production [45]. Studies have found a significant reduction of up to 20% with respect to baseline quantitative sebum measurements after topical application for 4 weeks of a cosmetic cream containing a mixture of vegetable oils from saw palmetto, sesame seeds, and argan oil. These vegetable species highlight the content of oleic, linoleic, γ-linolenic, and α-linolenic acids that inhibit types 1 and 2 of 5α-reductase [46]. Our cosmetic elastomer formula includes vegetable oils that have these polyunsaturated fatty acids, which may favorably regulate facial oil control.

A study was conducted with a W/O emulsion with Hippophae rhamnoides berry extract, which contains vitamin C, tocopherol, organic acids, and polyunsaturated fatty acids, and this gradually decreased sebum secretion in the cheeks of men over 60 days of daily use, which was 16–36 times lower compared to a base cream (without extract). This is consistent with the polyunsaturated fatty acids present in the chemical composition of the cosmetic elastomer [47].

In a formulation based on Pisidium guajava L leaf extract, a species characterized by the high presence of tannins, sebum levels decreased significantly for 28 days in areas of the forehead and nose, with 13.10% and 21.43% reductions, respectively [48]. This may suggest that because reduction of 43.95% was achieved by the cosmetic elastomer in a heated environment, it could be used on a daily basis on other areas of the face in individuals with oily skin problems. According to the dermatologist’s conclusions, safety studies showed a visible reduction in oily skin after 21 days of daily use.

In the short term, the cosmetic elastomer showed a significant decrease in sebum, both in men and women, with a reduction between 33.21% and 43.95% being observed at hour 5 in the three groups. Research reports that the period from stratum corneum formation to its elimination ranges from 20 to 30 days in young adults [49]. Therefore, a long-term study of cosmetic elastomer sebumetry in oily skin should be conducted. Furthermore, research found an anti-seborrheic efficacy of 31.26% in a facial toner with natural extract of Houttuynia cordata Thunb after 8 weeks of daily use [30].

A cosmetic product made with sodium hyaluronate, niacinamide, glycerin, panthenol, and tocopherol showed a remarkable anti-seborrheic effect after application on the foreheads of 30 women aged 25–34 years. This anti-sebaceous effect was evidenced by the decrease in bright spots and quantitatively by hour 4 according to the Sebumeter after product application [32]. Compared to our cosmetic elastomer, a significant reduction was evidenced in comparison with the untreated area in all groups, from hour 2 to the end of the study at hour 5. It should be mentioned that the cosmetic elastomer does not contain common ingredients and primarily uses vegetable oils from Peruvian biodiversity as active ingredients. Therefore, we could say that it has a comparable anti-seborrheic effect.

A study evaluated the reduction in sebum levels on the foreheads of six young women after 10, 60, and 120 min of applying 0.25% Juniperus communis and 0.25% Pelargonium graveolens essential oil tonics compared to 3% niacinamide. The tonic with P. graveolens oil showed a higher efficacy for visible sebum reduction than the other tonics after 2 h of application, producing values of 44 ± 5.13 µg/cm² compared to the other oil and niacinamide, which yielded values of 58 ± 9.07 and 100 µg/cm², respectively [31]. Compared to the cosmetic elastomer, the first group of six individuals obtained an average of 72.58 µg/cm². Considering that subjects were sitting in a room at 26 ± 1 °C, it is possible that the cosmetic elastomer may have a greater regulatory effect than niacinamide.

The shiny and greasy appearance of the skin may be due to excess sebum interacting with the skin surface [11]. Dermatologists have extensive knowledge on skin care and are capable of identifying the type of skin and any skin manifestations. From this perspective, research suggests that a product made with natural components does not necessarily imply that it is completely safe for consumers. Additionally, natural products with high concentrations of botanical extracts have been one of the main reasons for irritant and allergic contact dermatitis [16,50]. This cosmetic elastomer, despite containing high percentages of natural oils, did not induce skin irritations.

It included 1% of the antioxidant tocopherol, a percentage commonly used in cosmetic creams [51]. Vegetable oils have a variety of tocopherols; however, in cosmetic formulations with these oils, antioxidants need to be added, as fatty acid radicals can be generated by their level of instauration [52]. The elastomer preparation procedure did not involve heating; however, we consider the inclusion of this liposoluble antioxidant to be relevant due to the inclusion of P. huayllabambana, P. peruviana L., and B. excelsa in the formula.

In the safety test for daily cosmetic use, the dermatologist concluded that the cosmetic elastomer did not induce any skin irritation or sensitization phenomena, obtaining a skin irritation index of 0.00. Therefore, it may be considered safe for topical use, supporting the terms “dermatologically tested” and “non-irritant”. After observing a marked improvement in the control of oiliness and seborrhea in the area of application, and a high percentage of volunteers feeling much better control of seborrhea with continued use, further studies are required for the evaluation of the effects of the cosmetic product in controlling acne. These studies would support the therapeutic use of a natural product in the treatment of acne. This could be beneficial for young people who often lack of confidence in their social environment due to their visible oily skin [9]. This dermatological evaluation supports the safety of topical use and the visible sebum-controlling effect of the formulation. In this sense, under normal daily use, the cosmetic elastomer applied directly to the oily skin of young people will not produce any adverse reactions.

Our findings showed reduced sebum values, both quantitatively and qualitatively, which demonstrates the sebum-controlling effect of the cosmetic elastomer. These results suggest that the product can be used in individuals who need to reduce facial sebum levels.

5. Conclusions

The elastomer was proven to be safe for topical use with the terms “dermatologically tested” and “significant sebum controller”. The efficacy of the current mixture of natural active ingredients containing high levels of polyunsaturated fatty acids, such as linoleic and linolenic acid, improves the balance between epidermal and sebaceous lipids, resulting in better control of skin oiliness.