Topical formulation with ascorbyl tetraisopalmitate and synthetic tripeptide, combined with facial muscle exercisesAbstract
Facial aging involves natural processes such as bone resorption, subcutaneous volume loss, ligament laxity, and skin flaccidity. Currently, many aesthetic treatments are used to attenuate or delay the signs of facial aging, including facial exercises. They intend to improve skin elasticity, muscle tone, collagen production, and add (or reduce) volume of specific regions of the face. This study evaluated the effectiveness of a cosmetic formulation with ascorbyl tetraisopalmitate and synthetic tripeptide, combined with facial muscle exercises, in 43 healthy women aged between 30 and 65 years old. Participants were randomized into 3 groups: cosmetic formulation, cosmetic formulation + facial exercises, and facial exercises only. Instrumental measurements and self-assessment questionnaires were used to evaluate skin parameters. Significant improvement in skin firmness and elasticity were observed and attributed to the use of the cosmetic formulation. Additionally, participants noticed qualitative improvements in the appearance of their overall skin and wrinkles. High satisfaction scores were recorded for the facial exercise device and the formulation applied in the study. In conclusion, the cosmetic formulation had a positive impact on skin health, and the association of facial exercises, within time and conditions of this study, did not significantly increase the results caused by the formulation.
Keywords:
Ascorbic acid; Ascorbyl tetraisopalmitate; Instrumental methods; Skin aging; Synthetic tripeptide; Facial muscle exercises
INTRODUCTION
Aging is a universal and progressive process, resulting from intrinsic and extrinsic factors, which affect the skin in different ways (Fibrich, Lall, 2018; Harman, 2003). Intrinsic aging is the result of multiple internal factors, resulting in a natural wear and tear on the body, while extrinsic aging is influenced by external factors, such as exposure to ultraviolet radiation and lifestyle (Machado, Sigales, Solovy, 2018; Niamtu, 2019). Both lead to the formation of free radicals and the fragmentation of collagen in the dermal matrix, resulting in changes in the elasticity and appearance of the skin, marking the continuous cycle of skin aging (Fitzgerald, Carqueville, Yang, 2019).
The cosmetic industry has increasingly focused on strategies to combat photoaging mediated by oxidative stress, and while numerous antioxidant-based anti- aging products are on the market, there is demand for innovative and effective cosmetics such as peptides and ascorbic acid derivatives (Jagdeo et al., 2021).
Hyaluronic acid (HA) is involved in the regulation of several biological processes, such as skin repair, wound healing, tissue regeneration, anti-inflammatory and immunomodulation (Bukhari et al., 2018). Due to its remarkable biomedical and tissue regeneration potential, HA has been widely used in cosmetology and nutricosmetics. The synthetic tripeptide tetradecyl aminobutyroylvalylaminobutyric urea trifluoroacetate (TAUT) has been showing the potential to stimulate HA synthesis, and therefore, being an interesting option for composing innovative cosmetics (Campiche et al., 2019).
In addition to HA, another active ingredient with great potential for the prevention and treatment of aging skin - vitamin C - is a powerful antioxidant, that detoxifies the body from free radicals, protecting tissues, cell membranes, and DNA from oxidative damage. Vitamin C also decreases malondialdehyde contained in the skin, which is a marker of oxidative stress (Vergilio et al., 2022).
Nikkol VC-IP® (Nikkol, Japan) is a stabilized derivative of ascorbic acid that has an antioxidant, whitening, and lipid peroxidation inhibitory action, reducing and preventing the formation of inflammatory lesions on the skin and contributing to the reduction of DNA damage. In addition to the important antioxidant action that stimulates collagen synthesis, it reduces acne by diminishing inflammatory markers, protects the skin from the harmful effects of the sun, and inhibits oxidative reactions in melanin synthesis (Ochiai et al., 2006; Stamford, 2012).
Nowadays, many aesthetic treatments are being used, such as minimally invasive surgeries to improve skin elasticity, muscle tone, and collagen production, and reduce oxidizing agents using injectables (Campiche et al., 2020; Gutowski, 2016; Sieber, Kenkel, 2018). Plus, non-invasive strategies, such as facial exercise techniques or “facial yoga” are used to strengthen, move, improve muscle tone, add volume, and increase muscle elasticity (Abe, Loenneke, 2019).
Facial gymnastics is a widespread strategy for rejuvenation and combating sagging (Takacs, Valdrighi, Assencio-Ferreira, 2002). Physical exercise for body muscles is an ancient activity, and concepts that were applied to sports have been extended to health, and rehabilitation, among other areas (Paes, Toledo, Justino da Silva, 2007). Facial exercises are specific movements that aim to contract and relax the orofacial muscles, softening the physiognomy, in addition to giving the face a more harmonious, rejuvenated, and restored appearance, leaving the skin more toned, shiny, and soft (Furlan et al., 2023; Paes, Toledo, Justino da Silva, 2007). Additionally, the use of various devices such as the hyperboloid, tongue exerciser, lip exerciser, and facial exerciser was identified as a common practice to facilitate exercises and promote the development of facial muscles. However, their real efficacy especially in vivo are still not completely elucidated (Furlan et al., 2023).
The two main types of exercises used for the skeletal musculature are the isotonic and isometric. Isotonic exercises are the ones that produce repetitive movements. On the other hand, isometric exercises are those that promote muscle contraction without performing any movements, that is, being still and in the same position during all the execution (Baiocchi Souza et al., 2013). The stretches and manipulations developed by a healthcare professional can also be mentioned (Santos, Ferraz, 2010).
Therefore, this study aimed to develop and evaluate the efficacy of the topical application of cosmetic formulations containing ascorbyl tetraisopalmitate and TAUT, associated with facial muscle exercises to improve aging skin signs.
MATERIAL AND METHODS
Subjects
Forty-three (43) healthy women, aged between 30 and 65 years old were enrolled in the study. Non- inclusion criteria included other dermatological diseases, cognitive and verbal limitations, and allergic reactions to the cosmetic product (Table I). The subjects provided written informed consent before participation and the study was carried out following the Declaration of Helsinki. This study was approved by the local ethics committee by the number 13367219.5.0000.5404.
Development and stability of the formulation
The formulation ingredients were selected according to the target audience of this study, that is, individuals over 30 years old who show signs of aging such as progressive dehydration and loss of youthfulness, elasticity, and firmness of the skin. For this purpose, an emulsion with a medium-rich fat content was developed containing emollient and moisturizing ingredients, in addition to the active ingredients already mentioned with anti-aging action.
The formulation had its preliminary stability tested for 90 consecutive days under different storage conditions and temperatures. The storage conditions were: a) Room temperature (25 ± 2.0 ◦C) protected from light; b) Room temperature (25 ± 2.0 ◦C) in the presence of light; c) Refrigerator (5.0 ± 2.0 ◦C); and d) Oven (37 ± 2.0 ◦C). Organoleptic characteristics such as color and odor were observed throughout the period, in addition to measuring pH and evaluating spontaneous and centrifugal phase separation (Vergilio et al., 2023).
Experimental design
An open clinical trial with single-blinded evaluation of outcomes was carried out. The subjects were enrolled and randomized in three groups: (A) cosmetic formulation; (B) cosmetic formulation + facial muscles exercises, and (C) only facial muscles exercises.
Groups A and B applied the cosmetic formulation (approximately 2 mg1 cm-2) on the face once a day for 60 consecutive days. Table II shows the composition of the cosmetic formulation developed.
Quali-quantitative composition of the cosmetic formulation used in the clinical trial as intervention
Groups B and C were instructed to use a manual device coupled with weights made up of sand pockets to help performing the facial exercises (Figure 1).
Photo of the facial device coupled with weights to help performing the facial exercises and promote strengthening of facial muscles. The apparatus consists of elastic bands to attach it to the participant’s head in the correct facial positions. Each blue bag has a 9g sand weight, totaling a weight of 18g per device, positioned on top of the muscle to be worked during the exercise.
Therefore, the participants performed a series of isometric and myofunctional exercises proposed by the researchers with the aid of the device, daily for 10 minutes, to work and tone muscles of facial expression in the region of the zygomatic muscle, orbicularis lipis and platysma. The description of facial muscle exercises is presented in Table III and the illustration of the movements in Figure 2.
Illustrations of facial muscle exercises. Representation of the series of facial exercises, with the green areas indicating the muscle worked during each exercise.
Description of facial muscle exercises. The written instructions given to participants to perform the series of facial exercises at home in front of the mirror
Instrumental measurements and analyzed parameters
The skin was evaluated by instrumental techniques before and after the 60 days of study. The measurements were performed in the malar facial region. Before the measurements, participants remained for 20 min in an environment with controlled air temperature and relative humidity, 20–22°C and 45–55%, respectively, for acclimatization. All participants were advised to avoid washing their faces for at least 3 hours before the measurement (Aiello et al., 2021).
Assessment of the aqueous content of the stratum corneum
The stratum corneum (SC) hydration was assessed using the device Corneometer® (Courage & Khazaka, Germany). This device is based on the electrical capacitance measurement, specifically the variation of the dielectric constant of water. Five measurements were made at each instance, and the average of these values was then calculated (Aiello et al., 2021; Hugo Infante et al., 2022).
Assessments of skin viscoelastic properties
The mechanical properties of the epidermis were determined by using a non-invasive in vivo suction skin elasticity meter equipped with a 2 mm measuring probe. The time/strain mode 1 was used with a 3-second application of a constant negative pressure of 400 mbar followed by a 3-second relaxation. The average values of 3 measurements were taken for each test region and determined time, performed by the same operator (Nilforoushzadeh et al., 2023). The selected parameters evaluated and their possible interpretation according to the fabricant (Courage-Khazaka, Germany) were described below:
R0 = Uf. Amplitude at the end of the suction phase of the first curve. This parameter reflects the firmness/ pliability of the skin. This parameter represents the passive behavior of the skin to force. Result = distance in mm. Improving skin firmness normally shows a decrease in the value of R0.
R7 = Ur/Uf. Proportion of the immediate recovery compared to the amplitude after suction. The higher the value, the better the elastic properties of the skin. Result = %.
Self-assessment of clinical efficacy
To self-evaluate the efficacy of the intervention, all the participants answered a questionnaire based on Massufero Vergilio et al., (2022). This method was developed to assess data regarding the intervention and appearance of the skin. The skin parameters evaluated were general appearance, wrinkles, and expression lines. The evaluated parameters of the intervention and the developed facial gymnastics device were general acceptance, comfort, efficiency, and effort caused by facial exercises using the device (Table IV).
Questions applied in the analysis of participants’ self-perception. The questionnaire was applied after 60 days of study and the questions were related to evaluating the effectiveness of the cosmetic formulation and facial exercises. Hedonic properties of the comfort, efficiency, and effort attributes of the device were also evaluated
Statistical analysis
All statistical analyses were performed with the GraphPad Prism 8 program (GraphPad, San Diego, US). For parametric data, the 2-factor repeated measures ANOVA test and the Sidak test for multiple comparisons (α=0.05) were used and the results are described as mean and standard deviation. For non-parametric data, the Kruskal-Wallis’s test was performed and the metrics used were median and limits.
RESULTS
According to the obtained results, in the centrifugation test, there was no indication of physical instability in the studied formulation. No formulation heterogeneity was observed after subjecting the sample to agitation and gravitational force. In the organoleptic analysis, the appearance and color of the samples remained unchanged during the 90 days of the study and the pH analysis showed no change.
The descriptive data of the study participants are described in Table V. Information on age, Fitzpatrick phototype classification and alcohol and tobacco intake habits were separated by group.
Descriptive data of study participants. Information on age, Fitzpatrick phototype classification, alcohol consumption, and smoking habits
Figure 3 presents the measurement data for the aqueous content of the stratum corneum. The stratum corneum water content did not present significant improvement for any groups after 60 days (T60) in relation to their baseline values (T0).
Graphical representation of the comparative analysis of the parameter of aqueous content for groups A, B, and C, at times T0, and T60. Mean values that were found to be different are indicated with an asterisk p-value < 0.05 (*), and non-significance is indicated by ns (Two-way Repeated measures ANOVA followed by Sidak’s multiple comparison test). Caption: AU – arbitrary unit.
Figure 4 shows the data on the viscoelastic properties of the skin obtained in this study. A significant difference was observed in the R0 parameter (total deformation) in the malar region for groups A and B at T60 in relation to T0 (Figure 4A). For group A, there was a reduction in the value and for group C there was an increase in the value of R0 over time. As for the R7 parameter, a significant difference was observed for group B, indicating an increase in the R7 value over time (Figure 4B).
Graphical representation of the comparative analysis of the parameter of R0 (A), and R7 (B) for groups A, B, and C, at times T0, and T60. Mean values that were found to be different are indicated with an asterisk p-value < 0.05 (*), p-value <0.01 (**), p-value <0.001 (***), and p < 0.0001 (****) (Two-way Repeated measures ANOVA followed by Sidak’s multiple comparison test).
The hedonic scores obtained by the perceived effectiveness assessment questionnaire for general appearance, wrinkles, and expression lines were above 6.0, which means “Like slightly” (Figure 5). There was no significant difference between the groups for the parameters.
Self-assessment of clinical efficacy parameters, including general appearance, wrinkles, and expression lines for groups A, B, and C. Non-different values are marked with “ns” and determined using the Kruskal-Wallis’s test.
For the attributes of comfort, efficiency, and device- related comfort, all average values exceeded 7.0 (Figure 6A). Finally, the three different types of intervention, whether just the formulation, just the exercise, or both, obtained scores above 8.0, which means “Like very much” (Figure 6B). There was also no significant difference between the groups.
The assessment carried out by participants on the parameters of the FME device attributes comfort, effort, and efficiency, as well as general acceptance of the interventions. Non-significant values are marked with “ns” and determined using the Kruskal-Wallis’s test. Caption: FME = facial muscle exercise; CF = cosmetic formulation.
DISCUSSION
The formulations developed in this study presented great chemical-physical stability and showed great acceptance by the participants.
Regarding the clinical assessment performed in this study, it was observed that at T0 the participants already had adequate values of aqueous content in the stratum corneum (Heinrich et al., 2003). This data indicates that the participants already had good skin hydration even before starting the study, which is why the application of the cosmetic formulation made no significant difference in relation to this parameter (Heinrich et al., 2003).
Regarding the measurement of the viscoelastic properties of the skin, the R0 and R7 parameters of the Cutometer® equipment were selected, as they are related to skin firmness and elasticity, respectively (Nilforoushzadeh et al., 2023).
For group A, the significant decrease in the R0 value indicates an improvement in skin firmness, which can be related to the action of ascorbyl tetraisopalmitate. This ingredient is known for its activity in collagen and elastin synthesis. In addition to inducing collagen gene transcription, the ascorbic acid is also an enzymatic cofactor for lysyl and prolyl hydroxylases, key enzymes in the stabilization and cross-linking of collagen fibers (Kivirikko, Myllylä, 1985; Tajima, Pinnell, 1996). Several experimental studies in animals and humans have reinforced the important role of ascorbic acid in the synthesis, remodeling, and maintenance of the dermal extracellular matrix (Crisan et al., 2015; Sauermann et al., 2004; Vergilio et al., 2022).
On the other hand, in a randomized, placebo- controlled study carried out with 30 female participants aged between 40 and 60 years per group, the application of a formulation containing TAUT, twice a day, for 29 days showed a significant improvement in skin firmness. The result was obtained from a technique using the DynaSKIN device (Campiche et al., 2020). Therefore, these skin changes caused by ascorbyl tetraisopalmitate and synthetic tripeptide may have increased skin firmness.
The R7 parameter corresponds to the proportion of immediate recovery in relation to the amplitude after the suction and tends to decrease with age (Ohshima et al., 2012). Thus, the improvement in this parameter would show an increase in skin elasticity. It was possible to observe this significant increase only for Group B, suggesting an increase in skin elasticity, mainly due to the vitamin C derivative (Hinek et al., 2014; Tajima, Pinnell, 1996).
The hedonic scores obtained by the perceived effectiveness assessment questionnaire for general appearance, wrinkles, and expression lines had a positive impact and are consistent with the R0 viscoelasticity results, as participants observed an improvement in these attributes.
The FME device developed especially for this study was an innovative tool since there are no similar devices in the market, and it worked as expected and presented a positive impact. For the attributes of the FME device evaluated, all scores were high, showing that the device is suitable to assist in the execution of facial exercises. Furthermore, it is suggested that, overall, the study interventions were well received by participants. Regarding the acceptance of the use of the device, we believe that it is difficult for the participants to evaluate an experience that they had never had before, since it is unusual to exercise the facial muscles, especially with weight, which could have led to a negative experience, which was not the case.
In conclusion, the cosmetic formulation showed positive effects on skin firmness and elasticity, contributing to the reversal of signs of skin aging. Participant reviews supported these effects indicating improvements in skin appearance, wrinkles, and fine lines for all groups. This evaluation also indicated important points for optimizing the FME device such as increase the weight without compromising the acceptability of the device. Although facial exercises alone have not indicated an improvement in instrumental parameters, protocol changes can be used to obtain better results, such as changes in study duration, and the use of different and specific parameters to evaluate facial muscles.
DATA AVAILABILITY STATEMENT
Not Informed.
ACKNOWLEDGMENTS
The authors would like to thank the National Council for the Improvement of Higher Education Personnel (CAPES – No. 001); the São Paulo Research Foundation (FAPESP - No. 2020/08516-0); and the National Council for Scientific and Technological Development (CNPq – No. 305329/2022-7) for their financial support, and Espaço da Escrita – Pró-Reitoria de Pesquisa – UNICAMP - for the language services provided.
REFERENCES
-
Abe T, Loenneke JP. The Influence of Facial Muscle Training on the Facial Soft Tissue Profile: A Brief Review. Cosmetics. 2019;6(3):50. https://doi.org/10.3390/COSMETICS6030050
» https://doi.org/10.3390/COSMETICS6030050 -
Aiello LM, Vergilio MM, Monteiro e Silva SA, Anselmo T, Leonardi GR. Skin effect of facial cleansing combined with an electric sonic device. J Cosmet Dermatol. 2021;20(11):3537-44. https://doi.org/10.1111/jocd.14017
» https://doi.org/10.1111/jocd.14017 -
Baiocchi Souza C, Gomes Guerra J, Alves Barbosa M, Celeno Porto C. Rejuvenescimento facial por intervenção miofuncional estética. Revisão integrativa. Med Cutan Ibero Lat Am. 2013;41(4):165-71. https://doi.org/10.4464/MC.2013.41.4.5079
» https://doi.org/10.4464/MC.2013.41.4.5079 -
Bukhari SNA, Roswandi NL, Waqas M, Habib H, Hussain F, Khan S, et al. Hyaluronic acid, a promising skin rejuvenating biomedicine: A review of recent updates and pre-clinical and clinical investigations on cosmetic and nutricosmetic effects. Int J Biol Macromol. 2018;120:1682-95. https://doi.org/10.1016/j.ijbiomac.2018.09.188
» https://doi.org/10.1016/j.ijbiomac.2018.09.188 -
Campiche R, Jackson E, Laurent G, Roche M, Gougeon S, Séroul P, et al. Skin Filling and Firming Activity of a Hyaluronic Acid Inducing Synthetic Tripeptide. Int J Pept Res Ther. 2019;26(1):181-9. https://doi. org/10.1007/s10989-019-09827-1
» https://doi.org/101007/s10989-019-09827-1 -
Crisan D, Roman I, Scharffetter-Kochanek K, Crisan M, Badea R. The role of vitamin C in pushing back the boundaries of skin aging: an ultrasonographic approach. Clin Cosmet Investig Dermatol. 2015;8:463–70. https://doi.org/10.2147/CCID.S84903
» https://doi.org/10.2147/CCID.S84903 -
Fibrich BD, Lall N. Fighting the Inevitable: Skin Aging and Plants. Med. Plants Holist. Heal. Well-Being, Elsevier. 2018;77–115. https://doi.org/10.1016/B978-0-12-812475-8.00003-2
» https://doi.org/10.1016/B978-0-12-812475-8.00003-2 -
Fitzgerald R, Carqueville J, Yang PT. An approach to structural facial rejuvenation with fillers in women. Int J Women’s Dermatology. 2019;5(1):52-67. https://doi. org/10.1016/j.ijwd.2018.08.011
» https://doi.org/10.1016/j.ijwd.2018.08.011 -
Furlan AS, Vergilio MM, Vendruscolo CW, Leonardi GR. Facial Exercises: Enhancing Facial Structure and Reducing Signs of Aging - A Comprehensive Review. Curr Cosmet Sci. 2023;03:1-7. https://doi.org/10.2174/0126667797268583231213112215
» https://doi.org/10.2174/0126667797268583231213112215 -
Gutowski KA. Microfocused Ultrasound for Skin Tightening. Clin Plast Surg. 2016;43(3):577–82. https://doi.org/10.1016/j.cps.2016.03.012
» https://doi.org/10.1016/j.cps.2016.03.012 -
Harman D. The Free Radical Theory of Aging. Antioxid Redox Signal. 2003;5(5):557–61. https://doi. org/10.1089/152308603770310202
» https://doi.org/10.1089/152308603770310202 -
Heinrich U, Koop U, Leneveu-Duchemin MC, Osterrieder K, Bielfeldt S, Chkarnat C, et al. Multicentre comparison of skin hydration in terms of physical-, physiological- and product-dependent parameters by the capacitive method (Corneometer CM 825). Int J Cosmet Sci. 2003;25:45-53. https://doi.org/10.1046/j.1467-2494.2003.00172.x
» https://doi.org/10.1046/j.1467-2494.2003.00172.x -
Hinek A, Kim HJ, Wang Y, Wang A, Mitts TF. Sodium l-ascorbate enhances elastic fibers deposition by fibroblasts from normal and pathologic human skin. J Dermatol Sci. 2014;75(3):173-82. https://doi. org/10.1016/j.jdermsci.2014.05.011
» https://doi.org/10.1016/j.jdermsci.2014.05.011 -
Hugo Infante V, Maria Maia Campos P, Darvin M, Lohan S, Schleusener J, Schanzer S, et al. Cosmetic Formulations with Melaleuca alternifolia Essential Oil for the Improvement of Photoaged Skin: A Double- Blind, Randomized, Placebo-Controlled Clinical Study. Photochem Photobiol. 2022;99(1):176-83. https://doi. org/10.1111/php.13660
» https://doi.org/10.1111/php.13660 -
Jagdeo J, Kurtti A, Hernandez S, Akers N, Peterson RS. Novel Vitamin C and E and Green Tea Polyphenols Combination Serum Improves Photoaged Facial Skin. J Drugs Dermatology. 2021;20(9):996-1003. https://doi. org/10.36849/JDD.5818
» https://doi.org/10.36849/JDD.5818 -
Kivirikko KI, Myllylä R. Post-Translational Processing of Procollagens. Ann N Y Acad Sci. 1985;460(1):187–201. https://doi.org/10.1111/j.1749-6632.1985.tb51167.x
» https://doi.org/10.1111/j.1749-6632.1985.tb51167.x -
Machado KE, Sigales GL, Solovy I. Ação do acetilhexapeptídeo-3 no processo de rejuvenescimento facial. Infarma - Ciências Farm. 2018;30(3):185. https://doi.org/10.14450/2318-9312.v30.e3.a2018.pp185-193
» https://doi.org/10.14450/2318-9312.v30.e3.a2018.pp185-193 -
Niamtu J. The Aging Face. Art Sci. Facelift Surg., Elsevier. 2019;6–20. https://doi.org/10.1016/B978-0-323-61346-0.00002-4
» https://doi.org/10.1016/B978-0-323-61346-0.00002-4 -
Nilforoushzadeh MA, Heidari-Kharaji M, Fakhim T, Torkamaniha E, Tehrani S, Delavar S, et al. Treatment of periorbital hyperpigmentation using sublative fractional radiofrequency (SFR). Ski Res Technol. 2023;29(9):e13467. https://doi.org/10.1111/SRT.13467
» https://doi.org/10.1111/SRT.13467 -
Ochiai Y, Kaburagi S, Obayashi K, Ujiie N, Hashimoto S, Okano Y, et al. A new lipophilic pro-vitamin C, tetra-isopalmitoyl ascorbic acid (VC-IP), prevents UV- induced skin pigmentation through its anti-oxidative properties. J Dermatol Sci. 2006;44(1):37-44. https://doi.org/10.1016/j.jdermsci.2006.07.001
» https://doi.org/10.1016/j.jdermsci.2006.07.001 -
Ohshima H, Kinoshita S, Oyobikawa M, Futagawa M, Takiwaki H, Ishiko A, et al. Use of Cutometer area parameters in evaluating age-related changes in the skin elasticity of the cheek. Ski Res Technol. 2012;19(1):e238-42. https://doi.org/10.1111/j.1600-0846.2012.00634.x
» https://doi.org/10.1111/j.1600-0846.2012.00634.x -
Paes C, Toledo PN, Justino Da Silva H. Speech therapy and facial esthetic: cases studies. Rev CEFAC. 2007;9(2):213–20. https://doi.org/10.1590/S1516-18462007000200010
» https://doi.org/10.1590/S1516-18462007000200010 -
Santos CCG dos, Ferraz MJPC. Atuação da fonoaudiologia na estética facial: relato de caso clínico. Rev CEFAC. 2010;13(4):763–8. https://doi. org/10.1590/S1516-18462010005000043
» https://doi.org/10.1590/S1516-18462010005000043 -
Sauermann K, Jaspers S, Koop U, Wenck H. Topically applied vitamin C increases the density of dermal papillae in aged human skin. BMC Dermatol. 2004;4:13. https://doi.org/10.1186/1471-5945-4-13
» https://doi.org/10.1186/1471-5945-4-13 -
Sieber DA, Kenkel JM. Noninvasive Methods for Lower Facial Rejuvenation. Clin Plast Surg. 2018;45(4):571–84. https://doi.org/10.1016/j.cps.2018.06.003
» https://doi.org/10.1016/j.cps.2018.06.003 -
Stamford NPJ. Stability, transdermal penetration, and cutaneous effects of ascorbic acid and its derivatives. J Cosmet Dermatol. 2012;11(4):310–7. https://doi. org/10.1111/jocd.12006
» https://doi.org/10.1111/jocd.12006 -
Tajima S, Pinnell SR. Ascorbic acid preferentially enhances type I and III collagen gene transcription in human skin fibroblasts. J Dermatol Sci. 1996;11(3):250–3. https://doi.org/10.1016/0923-1811(95)00640-0
» https://doi.org/10.1016/0923-1811(95)00640-0 - Takacs A, Valdrighi V, Assencio-Ferreira V. Speech language pathology and esthetics: together for the facial beauty. Rev CEFAC. 2002;4:111–6.
-
Vergilio MM, Aiello LM, Furlan AS, Caritá AC, Azevedo JR, Bolzinger M, et al. In vivo evaluation of topical ascorbic acid application on skin aging by 50 MHz ultrasound. J Cosmet Dermatol. 2022;21(10):4921-6. https://doi.org/10.1111/jocd.14892
» https://doi.org/10.1111/jocd.14892 -
Vergilio MM, da Fonsêca JHL, d’Ávila MA, Leonardi GR. Evaluation of the influence of niacinamide and saccharide isomerate on the rheological behavior of a hydrogel for topical use. Biotribology. 2023;35– 36:100243. https://doi.org/10.1016/j.biotri.2023.100243
» https://doi.org/10.1016/j.biotri.2023.100243 -
Vergilio MM, Ricci Leonardi G, Moretti Aiello L, AnselmoT. Pretestquestionnaire for anti-ageing cosmetic claims substantiation: a description of validation of efficacy and sensory perception questionnaires. J Biomed Biopharm Res. 2022;19(2):397–409. https://doi.org/10.19277/bbr.19.2.298
» https://doi.org/10.19277/bbr.19.2.298
Edited by
-
Associated Editor:
Guilherme Martins Guelfuso
