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Cited by 4Advancements in Transdermal Drug DeliveryHydrogels: synthesis, properties, applicationsAdvanced Drug Delivery Systems

Formulation, Characterization and Optimization of Peel-Off Gel of Soybean Extract as a Face Mask

Open access
Faranak Salmannejad, Hoda Qorab, Tayebeh Ghari·2024·Tropical Journal of Natural Product Research
DOI 10.26538/tjnpr/v8i3.11
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Abstract

A peel-off mask is a type of dosage form that is gently applied onto the skin and peeled off after a few minutes. It is one of the most popular skincare products used to treat facial-related conditions. This study is aimed at designing and optimizing a peel-off facial mask formulation containing 20% w/w of soybean extract by response surface methodology (RSM). The peel-off mask was formulated using different concentrations of polyvinyl alcohol (PVA), ethanol, and carbomer 940. The isoflavonoids content of the soybean extract was determined using spectrophotometric method. Physicochemical properties (homogeneity, colour, odour, and pH) of the peel-off mask formulation were examined. Other parameters investigated include drying time, applicability, film-forming performance, and loading efficiency. The stability of the formulation was also investigated. The results showed that the PVA and ethanol concentrations significantly affected the drying time of the formulation. The PVA concentration and its quadratic term significantly influenced applicability of the formulation. The amount of carbomer in the formulation had the most significant impact on how well the film formed. The optimized formulation is composed of 20% soybean extract, 12.03% PVA, 8.36% ethanol, and 0.52% carbomer. Stability test results show that low temperature (5 ± 1°C) and room temperature, protected from sunlight (22 ± 2°C) have no effect on the stability of the formulation, and that phenoxyethanol at 1.0% w/w could preserve the formulation from microbial degradation undervarious storage conditions. Therefore, RSM was a helpful way to figure out the best conditions for making soybean peel-off facial masks.

AI snapshot

Written from the paper’s full text.

TL;DR

A soybean extract peel-off facial mask was formulated and optimized by response surface methodology using PVA, ethanol, and carbomer 940 as variables. The optimized formula contained 20% soybean extract, 12.03% PVA, 8.36% ethanol, and 0.52% carbomer, with good predicted applicability and film-forming performance and acceptable stability under normal storage conditions.

Key findings

  • The optimized formulation was 20% soybean extract, 12.03% w/w PVA, 8.36% w/w ethanol, and 0.52% w/w carbomer 940; predicted responses were drying time 21.3 min, applicability 5, and film-forming 4.7, with confirmation runs giving drying times of 23, 23, and 24 min, applicability 5, and film-forming 4.
  • PVA and ethanol significantly affected drying time: PVA coefficient = -5.64 and ethanol coefficient = -6.84, both p < 0.0001; quadratic terms indicated plateaus near 12% PVA and 8% ethanol.
  • Carbomer concentration had the most significant impact on film-forming performance (p = 0.0005), with a negative linear effect; PVA concentration positively influenced applicability (coefficient = 0.68, p = 0.0285), while carbomer and its quadratic term negatively affected applicability.
  • Extraction yield was about 17%, isoflavonoid content was 2.85%, loading efficiency was ≥81% in all formulations, and microbial load remained <1×10^1 CFU/g after 28 days under tested storage conditions.

Methods

  • Soybean seeds were extracted by maceration with 80% v/v ethanol at a 4:1 solvent-to-powder ratio; isoflavonoid content was determined spectrophotometrically at 261 nm.
  • Peel-off masks containing 20% w/w soybean extract were prepared with varying PVA, ethanol, and carbomer 940 concentrations based on a central composite design with α = ±1.5; responses were drying time, applicability, and film-forming performance.
  • Statistical optimization used response surface methodology, quadratic modeling, ANOVA, and a desirability function; physicochemical stability was monitored for 28 days at 5 ± 1°C, 45 ± 2°C, 22 ± 5°C exposed to sunlight, and 22 ± 2°C protected from sunlight, and microbiological stability was assessed by direct plate count.

Limitations

  • The paper states that one limitation of RSM is the number of experiments and recommends future studies use a tool with minimal testing and less computerization for easier chart interpretation.
  • Evident from the text: the quadratic models for applicability and film-forming performance had relatively low R² values (0.6794 and 0.6236, respectively) and low predicted R² values (0.4168 and 0.3629), despite adequate precision.
  • Evident from the text: stability testing lasted only 28 days, and applicability/film-forming scores were based on five volunteers or observers; no clinical efficacy or long-term stability data are reported.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.26538/tjnpr/v8i3.11

Cites

22 of 22 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 22 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    The extraction yield of dried soybean extract was about 17%.

    “In this study, the EY was about 17%.”
    • Also stated in: § Extraction Yield · plain
      “The extraction yield obtained in this study was about 17%.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Low temperature (5 ± 1°C) and room temperature protected from sunlight (22 ± 2°C) have no effect on the stability of the formulation.

    “Stability test results show that low temperature (5 ± 1°C) and room temperature, protected from sunlight (22 ± 2°C) have no effect on the stability of the formulation”
    Quote in the paperSubstantial claim
  • Findingown data

    The calibration curve regression equation was Y = 14488x -0.0503 with R2 = 0.9983.

    “The regression equation of the calibration curve is Y = 14488x -0.0503 with R 2 value of 0.9983.”
    Quote in the paperSubstantial claim
  • Findingown data

    PVA concentration exerted a positive influence (coefficient = 0.68) on the viscosity of the formulation.

    “The PVA concentration exerted a positive influence (coefficient = 0.68) (Table 4) on viscosity of the formulation”
    Quote in the paperSubstantial claim
  • Findingown data

    Carbomer concentration was the most influential factor on the peel-off facial mask film-forming performance (p = 0.0005).

    “Carbomer concentrations were the most influential on the peel-off facial mask film-forming performance (p = 0.0005) (Figure 1B).”
    Quote in the paperSubstantial claim
  • May combine two claims. 14
  • Classified as probably not a substantial claim. 12
  • The quote only partly states this claim. 1

  • May combine two claims.

    Findingown data

    The predicted values for drying time, applicability, and film-forming performance were 21.3 min, 5, and 4.7, respectively.

    “At the same time, the values of 21.3 min, 5, and 4.7 were reported for the drying time, applicability, and performance of film-forming predicted for the developed models, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The PVA quadratic term affected drying time positively (p = 0.0005), indicating a nonlinear association that comes to a plateau at nearly 12% concentration.

    “Besides, the PVA quadratic term (A 2 ) affected the drying time positively (p = 0.0005) (Table 4), indicating a nonlinear association, coming to a plateau at nearly 12% concentration (Figure 1A)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The PVA quadratic term (A2) affected applicability (coefficient = -0.86), indicating a nonlinear association that reached a plateau at nearly 12% concentration.

    “The PVA quadratic term (A 2 ) affected the applicability (p = -0.86)(Table 4), indicating a nonlinear association, which reached a plateau at nearly 12% concentration (Figure 1C)”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    These formulations get darker when the oxidation process occurs.

    “These formulations get darker when the oxidation process occurs.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The quadratic term for ethanol (B2) had a significant effect on the drying time of the film (p < 0.0001) and indicated a nonlinear association that reached a plateau at nearly 8% concentration.

    “Like PVA, the quadratic term for ethanol (B 2 ) had a significant effect on the drying time of the film (p ˂ 0.0001) (Table 4) and indicated a nonlinear association that reached a plateau at nearly 8% concentration (Figure 1A).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The optimized formula looked even and consistent before and after it dried.

    “The optimized formula looked even and consistent before and after it dried.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    PVA concentration has a nonlinear association with film-forming performance, suggesting that a specific PVA concentration is optimal for film-forming performance.

    “indicating a nonlinear association and showing that PVA of a specific concentration is suggested for film-forming performance, which is in agreement with previous reports.22”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [22]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Peel-off mask can improve the effectiveness of active substances on the epithelium and increase skin moisture due to the occlusive properties of the polymer.

    “Due to its ability to increase the skin's contact time with the active substances, peel-off mask can improve the effectiveness of active substances on the epithelium and increase the skin's moisture due to the occlusive properties of the polymer.[5][6][7][8]”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [5]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [6]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [7]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [8]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Soy has mild anti-inflammatory, moisturizing, light protecting, brightening, and skin-lightening effects.

    “Therapeutically, soy has mild anti-inflammatory, moisturizing, light protecting, brightening, and skin-lightening effects.4”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [4]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationnone given

    RSM based on CCD is a helpful way to figure out how different chemicals work together and their amounts based on the parameter being studied.

    “It was discovered that the RSM based on CCD is a helpful way to figure out how different chemicals work together and their amounts based on the parameter being studied.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Increasing or decreasing the PVA concentration is not beneficial for the uniformity and thickness of the PVA film.

    “This finding supports the research of Asthana and colleagues that shows that increasing or decreasing the PVA concentration is not beneficial for the uniformity and thickness of the PVA film.22”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [22]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Study design and conductown data

    Acceptable precisions of 6.665 for applicability, 24.064 for drying time, and 10.378 for film-forming performance indicated a good balance between signal and background noise, with adequate precision greater than 4.0.

    “Acceptable precisions of 6.665 (applicability), 24.064 (drying time), and 10.378 (film-forming performance) indicated a good balance between the signal and the background noise (adequate precision >4.0).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    One limitation of the RSM/CCD method is the number of experiments.

    “but one of the limitations of this method is the number of experiments.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    CCD has been successfully used in several studies for formulation development and optimization, as data obtained using CCD showed good and reliable predictions.

    “Additionally, CCD has been successfully used in several studies for formulation development and optimization, as data obtained using CCD showed good and reliable predictions.[10][11][12]”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [10]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [11]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [12]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    The decrease in drying time was probably due to the increase in the temperature of the formulation and the faster evaporation of ethanol after opening the lid of the tubes and using it.

    “probably due to the increase in the temperature of the formulation and the faster evaporation of ethanol after opening the lid of the tubes and using it.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationown data

    Addition of over 12% PVA would not be recommended.

    “which indicated that the addition of over 12% of the PVA would not be recommended.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Viscosity is one of the significant formulation characteristics associated with applicability.

  • May combine two claims.

    Interpretationown data

    The model has the capability to optimize all the responses promptly until reaching an acceptable stage, with individual desirability > 0.9.

    “indicating the model's capability to optimize all the responses promptly until reaching an acceptable stage considering the requirements (suggesting individual desirability of > 0.9).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Adding more than 8% (w/w) ethanol cannot be recommended because the drying time reduction is no longer proportional.

    “Consequently, adding more than 8% (w/w) of ethanol cannot be recommended as the drying time reduction is no longer proportional.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    When a topical preparation is thicker, it does not spread quickly.

    “But, when the topical preparation is thicker, it does not spread quickly.19”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [19]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Ethanol helps things dry faster and evaporates more quickly than water.

    “This is because ethanol helps things dry faster, and it evaporates more quickly than water.21”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [21]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Increasing PVA concentration shortened the film's drying time in previous reports.

    “This is in agreement with previous reports where increasing the PVA concentration shortened the film's drying time.19”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [19]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Previous reports found that adding purified water/EtOH in amounts more than that recommended for drying time in the formulation was no longer proportional.

    “This agrees with previous reports where adding purified water/EtOH in amount more than that recommended for drying time in the formulation was no longer proportional.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [22]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    How fast a material spreads depends on how much force is applied, for how long, and how thick the material is.

    “How fast the material spreads depend on how much force is applied, for how long, and how thick the material is.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [19]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Study design and conductown data

    The confirmation runs (n = 3) produced outcomes within the 95% prediction and 95% confidence intervals, confirming the model's good predictability and significant robustness for the responses found in the RSM design.

    “The confirmation runs (n = 3) were prepared to exert the obtained mathematical conditions experimentally, leading to outcome of the confirmation experiments within 95% prediction (PI) and 95% confidence (CI; Table 5) intervals, confirming the model's good predictability for all responses and the developed model's significant robustness for the responses found in the RSM design.”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Interpretationcitation

    When low polymer concentration does not influence the diffusion coefficient of water from the film, the time required for drying will be reduced.

    “Subsequently, the time required for drying will be reduced.18”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [18]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

25 of 25

  • The authors state this as an assumption.

    The response variables follow a quadratic model with interactions among the variables.

    “assuming a quadratic model within which the variables interacted.”

  • The paper relies on this without support.

    Viscosity is one of the significant formulation characteristics associated with applicability.

    “One of the significant formulation characteristics associated with applicability is viscosity.”
2 of 2

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Confirmation results fall outside the stated confidence intervals

    Major

    The paper says the confirmation experiments fell within both the prediction and confidence intervals. Table 5 gives film-forming results of 4 for all three runs, below its 95% confidence interval of 4.05-5.30; the drying-time result of 24 is also above its confidence interval of 19.58-23.09.

  • Conclusion overlooks a significant PVA effect on film formation

    Minor

    The conclusion says only carbomer concentration affected film-forming performance, but Table 4 also identifies the PVA quadratic term as significant, with p = 0.0058.

  • Two different combined desirability values are reported

    Minor

    The text reports a combined desirability of 0.976 for the optimized formulation, whereas Table 5 reports 0.964.

  • Applicability coefficient is labeled as a p-value

    Minor

    The text calls −0.86 a p-value for the PVA quadratic term. Table 4 lists −0.86 as its coefficient and 0.0126 as its p-value.

  • Film-forming coefficient is labeled as a p-value

    Minor

    The text calls −0.81 a p-value for the PVA quadratic term. Table 4 lists −0.81 as its coefficient and 0.0058 as its p-value.

  • Loading efficiency conflicts with the paper's formula

    Minor

    The formula defines loading efficiency as the weight of isoflavonoids divided by the total gel weight. With 20% soybean extract containing 2.85% isoflavonoids, that quantity cannot exceed 0.57%, yet the paper reports at least 81%.

6 of 6

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Baby AR, Zague V, Maciel CPM, Salgado-Santos IMN, Kawano Y, Arêas EPG, Kaneko TM, Consiglieri VO, Velasco MVR. Development of Cosmetic Mask Formulations. Semana Farmacêutica de Ciência e Tecnologia da FCF-USP. 2004; 40:159-61.

Cited by

Sorted by citations

Related

Authors
Salmannejad, F., Qorab, H., & Ghari, T.
Affiliations
Alborz University of Medical Sciences (IR)
Venue
Tropical Journal of Natural Product Research
Publisher
University of Benin
Published
2024-03-30
Volume
8
Issue
3
ISSN
2616-0684 (ISSN-L)
DOI
10.26538/tjnpr/v8i3.11
OpenAlex
W4393380413
Semantic Scholar
e1d44b285b01c69307bda8ac30bb74d54af13434
Cited by
4
References
22
Citations by year
2025: 2 · 2024: 1
FWCI
0.52
Type
journal article
Language
en
Open access
Licence
cc-by-nc-nd
Locations
  • Tropical Journal of Natural Product Research (publishedVersion, cc-by-nc-nd)
  • Tropical Journal of Natural Product Research (submittedVersion, cc-by-nc-nd)
Funders
Alborz University of Medical Sciences
Topics
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmaceutical Science › Advancements in Transdermal Drug Delivery
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Medicine › Hydrogels: synthesis, properties, applications
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmaceutical Science › Advanced Drug Delivery Systems
Keywords
soybean extract, polyvinyl alcohol, ethanol, Carbopol 940, isoflavonoids, drying time, formulation stability, skin care formulation, response surface methodology

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-11-01.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-11-01.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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