Soaps are some of the oldest surfactants known to humans and remain indispensable in modern health, personal care, and sustainability agendas. Still, the simple chemistry of salts of fatty acids reveals a rich, multiscale landscape of self-assembly and flow behavior that controls soap processing and sensorial attributes. This review integrates phase behavior with rheological analysis to demonstrate how distinct microstructures, ranging from micellar to liquid-crystalline phases, possess unique rheological signatures. We further demonstrate how the coexistence and combination of these phases in a product such as a soap bar introduce additional levels of structural and rheological complexity. In addition, we highlight how linear viscoelastic analysis resolves relaxation hierarchies and how yield stress and thixotropic responses are inherent to the multiphase brick-and-mortar microstructures in products such as soap bars. The complex rheology of soap bars necessitates constitutive models that incorporate elasticity, plasticity, and time-dependent structure to predict extrusion or stamping performance. We also explore how the microstructure relates to cleaning efficacy, foam richness, lather dynamics, and rinse feel by coupling rheology measures with in-use dilution behavior. Finally, we discuss open questions, challenges, and future directions for developing more sustainable products.

Fermented Miang (Camellia sinensis var. assamica) serves as a valuable source of bioactive polyphenols and probiotic-associated components. This study characterized the catechin composition of fermented Miang extracts and evaluated their antioxidant capacity and suitability for cosmetic formulations. High-performance liquid chromatography (HPLC) analysis showed that epigallocatechin gallate (EGCG) was the predominant catechin (7.00 ± 0.93 mg/g dry weight), followed by catechin (C), epicatechin (EC), epicatechin gallate (ECG), and epigallocatechin (EGC). The extracts remained physically and chemically stable for at least three months under various storage conditions, with the dried extract form offering advantages for handling and formulation. Fermentation duration significantly influenced phenolic accumulation and antioxidant activity, with four-month fermentation showing the highest activity. Prototype cleansing formulations, including transparent/opaque soap bars, liquid soap, and shampoo containing fermented Miang extract, exhibited acceptable physicochemical characteristics and retained antioxidant function. These findings highlight fermented Miang as a promising natural ingredient for antioxidant and probiotic-inspired cosmetic applications.

Sustainable valorization of animal tallow and Aloe abyssinica gel for bar soap formulation with physicochemical properties and quality assessment

Insect pests remain a major production bottleneck, particularly those that infest the crop during the post-flowering stage. Pod-sucking bug complexes can inflict severe damage on cowpea productivity if unchecked. A field trial consisting of intra-row spacings, sowing dates, and pesticides as a combination of Integrated Pest Management (IPM) was carried out on a complex of pod sucking bugs (CPSBs) population during the rainy seasons of 2015 and 2016, respectively, in Katsina. The experiment was laid out using a split-split plot design, with intra-row spacing allocated to the main plot, sowing dates to the sub-plot, and the sub-sub-plots allocated to pesticides. NKE powder was used at the rate of 5 kg ha⁻¹, mixed with 2 kg ha⁻¹ bar soap as an emulsifier. The viral suspension was diluted to a concentration of 7.57 × 10¹¹ and applied at 106 ml in 115 L of water per hectare. The synthetic insecticide containing cypermethrin (30 g L⁻¹) and dimethoate (250 g L⁻¹) was applied at 1.5 L ha⁻¹ using a CP-3 knapsack sprayer. The treatments were randomized and replicated three times. Data collected were measured on the CPSB population and final cowpea grain yield, which were subjected to analysis of variance, and means were separated using LSD at 5%. The result showed that varying cowpea sowing from 2nd July (1.29) to 13th Aug. (1.23) significantly (P≤ .05) reduced CPSBs, with its peak population occurring on cowpea sown on 23rd July (1.48), respectively, in all the sampling weeks. Use of MaviMNPV (1.30), neem (1.26), and cyper diforce (1.25) significantly reduced CPSBs population compared with the control (1.50). However, synthetic insecticidess recorded lower CPSB but were comparable to other control options. The result of the combined interaction showed that varying sowing to 23rd July and using cyper diforce produced the lowest effect (1.22) CPSB per plot. The result of the use of pesticides showed that, significantly (P≤ .05), the highest grain yield per hectare was recorded in the combine interaction of varying sowing to 13th Aug. + insecticidal spray (631.49 kg ha-1). Therefore, it is concluded that CPSB damage on cowpea is directly proportionate to their numbers. It is recommended that varying cowpea sowing and the use of pesticides will reduce CPSB populations on cowpea and, consequently, reduce cowpea damage in the study area.

This community service activity aims to address health issues and the management of tofu waste in Sidodadi Ramunia Village through the development of a hand soap formula based on tofu waste extract. In the context of sustainable development (SDGs), the importance of Clean and Healthy Living Behavior (PHBS) in densely populated areas is highly relevant, especially con4sidering the low awareness of the community regarding handwashing. This training was conducted on September 19, 2024, with 15 participants, using educational methods and practical soap-making sessions. Before the training, the team conducted organoleptic tests, pH tests, homogeneity tests, and effectiveness tests of the resulting soap. The test results indicated that the liquid soap meets safety standards and is effective in inhibiting the growth of microorganisms. This training not only enhanced the participants' skills in utilizing waste but also transformed their perception of tofu waste from being a waste product into a valuable resource. It is hoped that this activity will contribute to improving public health, environmental awareness, and entrepreneurial initiatives in the village.

Despite advances in COVID-19 vaccines and antivirals, SARS-CoV-2 remains a significant public-health threat. While handwashing helps prevent infection, the anti-SARS-CoV-2 activity of anionic surfactants in hand soaps has not been systematically evaluated. In this study, we compared five surfactants: potassium oleate (C18:1-K), potassium myristate (C14:0-K), potassium laurate (C12:0-K), sodium laureth sulfate (SLES), and sodium dodecyl sulfate (SDS). Viral infectivity assays demonstrated that C18:1-K exhibited remarkable efficacy, reducing SARS-CoV-2 infectivity by more than 10⁵-fold at a concentration of 1 mM. In contrast, SDS achieved only about a 10¹-fold reduction, and both SLES and C12:0-K showed minimal activity. Isothermal titration calorimetry revealed that C18:1-K-virus interactions exhibited a positive enthalpy change (ΔH), indicating endothermic hydrophobic interactions with viral-envelope lipids-contrasting with the results observed for influenza virus. By contrast, SDS and C12:0-K interactions showed negative ΔH values, suggesting exothermic electrostatic interactions with viral surface proteins. Transmission electron microscopy revealed extensive "rupture" images of viral particles after treatment with SDS or C12:0-K, whereas no such image was observed with C18:1-K. All surfactants induced concentration-dependent viral aggregation, suggesting that aggregation also contributes to viral inactivation. Among the surfactants tested, C18:1-K, which demonstrated the highest antiviral activity, also had the lowest critical micelle concentration, suggesting that hydrophobic interactions become pronounced above this threshold. These findings suggest that the inactivation mechanisms of SARS-CoV-2 vary according to the physicochemical properties of the surfactants. Surfactants with strong hydrophobic interaction capabilities may exert superior antiviral effects, offering insights for the rational design of effective disinfectants.

This study examines product innovation based on local natural resources as a crucial strategy in supporting sustainable development in the small industry sector. The purpose of this study is to analyze the commercialization potential of SERENA (Scented Effective Refreshing Essence from Natural Lerak), an eco-friendly hand soap made from soapberry (Sapindus rarak). The study was conducted using the SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis method through a qualitative descriptive approach. Data were obtained from field observations, market tests at Duta Bangsa University Surakarta, and interviews with potential consumers and micro-business owners in Surakarta. The results indicate that SERENA has significant commercialization potential because it offers desirable value, utilizes local raw materials, and aligns with market trends toward eco-friendly products. The recommended development strategy is the SO (Strength–Opportunity) strategy, which utilizes product strengths and market opportunities to expand marketing reach and strengthen the product's positioning as a sustainable product.

The recent increase in synthetic soap sales in the soap industry due to the up-and-coming challenges involving the production of natural soaps and obtaining raw ingredients has contributed to concerns of human health and the environment. Additionally, the COVID-19 pandemic brought attention to the importance of incorporating raw materials, biosurfactants, and plant-based ingredients into sanitizers and hand soaps. However, the pandemic also posed financial concerns for farmers and their families. It became difficult for farmers to provide natural ingredients for soap manufacture due to environmental regulations and increases in debt and electricity costs. Along with these obstacles, farmers were also faced with competition from more prominent synthetic soap companies in the industry. The use of comparative analysis revealed that natural soaps offer fewer adverse effects on humans and aquatic life when compared to synthetic soaps. Synthetic ingredients in soaps can cause allergic responses, skin irritation, and dryness. Natural soap products often include ingredients like aloe vera, neem, and tulsi, which can offer antibacterial protection to keep the skin moisturized. In addition to the impact on human skin, synthetic soaps can be harmful to aquatic species. Certain synthetic ingredients can be detrimental to aquatic populations by impacting major organs, including the gills, kidneys, and brain. This shift in soap ingredient use has led to concerns about potential health and environmental impacts of water pollution, which can be toxic to plants and could potentially cause an increased risk of cancer in animals, since they are being exposed to larger concentrations of toxic chemicals in their surroundings. The paper evaluates the impact of synthetic ingredients through an integrated framework of economics, public health, and environmental impact, linking economic policy reforms within the soap industry to their impact on the environment and household health. As opposed to existing models, which observe chemical toxicity, trade policies, or impacts on public health in isolated manners, the proposed framework embeds the aforementioned within a computable general equilibrium structure to determine the economic consequences of a transition from synthetic to natural soap ingredients.

Quantitative risk assessment (QRA) for dermal sensitization is essential for determining safe concentrations of skin sensitizers in consumer products. The fragrance industry developed the QRA2 approach, which uses the No Expected Sensitization Induction Level (NESIL) as a starting reference dose or point of departure (PoD). Animal alternatives for potency assessment have emerged to calculate quantitative PoDs. One such alternative is in vitro-based regression models. Herein, a framework for incorporating regression models into next-generation risk assessment (NGRA) is presented. The framework begins with hazard assessment using in vitro methods (OECD Guideline 497), followed by PoD calculation through regression models, and completed with QRA2. After determining a PoD, uncertainty factors may be considered to derive a new approach methodology NESIL (NAM-NESIL). Case studies are presented with two sensitizers, p-mentha-1,8-dien-7-al (CAS # 2111-75-3) and 3-propylidenephthalide (CAS # 17369-59-4), calculating acceptable exposure levels (AELs) for products like deodorants and bar soaps. Ratios of the AELs to consumer exposure levels (CELs) were then calculated to determine whether the current use is safe. Comparison of QRA based on NAM-NESILs to historically human-derived NESILs supports the reliability of in vitro models. This approach offers a promising alternative for PoD derivation, potentially eliminating the dependence on in-vivo data.

Paper soap served as a practical alternative for hand hygiene, especially for individuals with high mobility who required portable, lightweight, and hygienically stored products. This study aimed to formulate handwashing paper soap using a combination of coconut and olive oils, with potassium hydroxide (KOH) as the saponification agent, and to evaluate its quality based on the Indonesian National Standard (SNI) No. 2588:2017 for liquid hand soap. A laboratory-based pure experimental method was used to determine the optimal combination of ingredients. The soap base formulation that showed the most favorable characteristics consisted of coconut oil and olive oil mixed in equal proportions, with KOH as the alkali. This combination produced a liquid soap with good cleansing ability, softness, and skin moisture retention. The evaluation results showed that the final formulation met all quality parameters: a pH value of 9.37, foam height of 10.5 cm, and free fatty acid content of 0.985%. Among the two types of paper tested, dry cotton tissue proved to be the most suitable medium for soap application due to its excellent absorbency and even drying. Panelist testing further confirmed the acceptability of the product. Most respondents reported positive impressions regarding the product’s texture, foaming properties, and skin feel after use. The paper soap did not cause irritation or a burning sensation, and it was easy to use and dispose of, increasing its appeal for daily use and travel. In conclusion, the formulation successfully produced a functional and user-accepted paper soap that met national quality standards. The study demonstrated that natural ingredients could be effectively used to develop innovative hygiene solutions that are both practical and safe for everyday use.

This community service project addresses the environmental degradation and economic stagnation in Batu Silangit Village caused by unmanaged spent coffee grounds. Historically, this waste contributes to methane emissions and soil toxicity. Therefore, this study implements a circular economy strategy by converting coffee residue into organic bar soap. The methodology utilizes Community Based Participatory Research (CBPR) combined with the "Melt and Pour" technology, ensuring safety for untrained participants. Results indicate that the produced soap meets dermatological standards with a pH range of 9.5 to 10.1 and possesses significant antibacterial and antioxidant properties. Economically, the initiative is highly viable, demonstrating a profit margin exceeding 50% due to zero-cost raw materials. In conclusion, this program successfully transforms ecological burdens into financial assets. It provides a sustainable model for rural empowerment by integrating environmental mitigation with micro-entrepreneurship, fostering a resilient village economy through the practical application of effective green technology and innovative waste-to-wealth principles.

Controlling banana aphid (Pentalonia nigronervosa) vectors of banana bunchy-top disease is crucial for integrated disease management. Synthetic insecticides, though effective in aphid control, pose health and environmental risks. Biorational pesticides (including botanicals and soaps) are safer alternatives. This study screened four fresh and fermented aqueous plant extracts (chili pepper, garlic, neem, and peppermint) and three soaps (bathing, laundry bar, and liquid soap) singly or in mixtures against banana aphids through in vitro and in vivo experiments. Aphid-inoculated banana leaf-blade disks were used for the in vitro studies over 96 h. Potted plantlets were used for the in vivo studies over eight weeks. Applying these preparations resulted in significant (p ≤ 0.05) aphid mortality (28.6 to 100%) compared to the water control (3.3%) at 96 h post-spray (hps). In vitro, a single application of nimbecidine® (Azadirachtin 0.03%), garlic, chili-pepper botanicals, insecticidal, and bathing soap caused >50% mortality at 96 hps. Mixed applications of chili pepper, garlic-based, and neem botanicals with soap caused >70% mortality at 96 hps in vitro. Binary mixtures of neem oil, garlic, fermented garlic, or fermented peppermint with insecticidal soap, and neem oil with bar soap, were promising in vivo, reducing the aphid populations to <20/plant compared to the control, which had >200 aphids after week 8. However, these potential preparations incurred a higher cost (USD 1.30/banana mat) compared to the synthetic pesticide (USD 0.022/mat). Thus, biorational mixtures have a potential to effectively control banana aphids.

This study aims to analyze the influence of machine maintenance and just-in-time production on production volume at PT. Lambang Utama Medan, a leading manufacturer of cream and bar soap. The research adopts a quantitative approach with a sample of 60 respondents selected from 151 production employees using Slovin's formula. Data collection techniques include observation, interviews, questionnaires, and documentation. The data were analyzed using multiple linear regression, along with validity tests, reliability tests, classical assumption tests, t-test, F-test, and the coefficient of determination (R²).The findings indicate that machine maintenance has a positive and significant effect on production volume (t = 1.965; p &lt; 0.05), as does just-in-time production (t = 2.414; p &lt; 0.05). Simultaneously, both variables significantly affect production volume (F = 7.446; p &lt; 0.05), with an adjusted R² value of 0.751, meaning that 75.1% of the variance in production volume can be explained by these two variables. The study concludes that effective machine maintenance and the implementation of timely production schedules are crucial in optimizing and sustaining production volume. These findings provide valuable insights for operational management strategies and contribute to the academic development of production and efficiency studies in manufacturing industries.

Handwashing with soap and water is an essential preventive measure to reduce the spread of infections. Extracts from butterfly pea (Clitoria ternatea L.), beetroot (Beta vulgaris L.) and sappanwood (Caesalpinia sappan L.) contain flavonoids, saponins, tannins, steroids and terpenoids that act as antibacterial and antioxidant agents, while also serving as safe natural colourants. This study evaluated their antibacterial and antioxidant activities, both in raw extracts and in liquid hand soap formulations containing 1 % w/v extracts with visually appealing colours. Dried plant materials were extracted through ethanol maceration and formulated into liquid hand soap at 1 % w/v. The parameters evaluated included phytochemical constituents (triterpenoids, alkaloids, tannins and flavonoids), antioxidant activity determined by inhibition percentage and half-maximal inhibitory concentration (IC50), antibacterial activity against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative (Pseudomonas aeruginosa, Escherichia coli) bacteria using the inhibition zone assay. Sappanwood extract showed the highest alkaloid (30.21 mg AE/g) and flavonoid (29.17 mg QE/g) levels, while butterfly pea had the highest triterpenoid (7.62 mg LE/g) and tannin (39.38 mg TAE/g) contents. Sappanwood exhibited the strongest antioxidant activity (88.74 % inhibition, IC50= 0.01 ppm) and potent antibacterial effects, particularly against S. epidermidis (812 mm²). Liquid hand soap with 1 % w/v beetroot extract showed significant antibacterial activity, with inhibition zones of 438 mm² (S. aureus), 425 mm² (P. aeruginosa), 281 mm² (S. epidermidis) and 376 mm² (E. coli). These findings highlight the potential of 1 % w/v plant-derived extracts as multifunctional additives in hygiene products, combining antimicrobial, antioxidant and coloring properties, with promising applications for eco-friendly personal care formulations.

Hand hygiene is a simple thing that is often overlooked, especially in schools located in coastal areas with limited sanitation facilities. This community service activity aims to introduce innovations in the production of liquid hand soap and sea salt-based paper soap as an effort to improve health and empower the local economy. The implementation methods include education, demonstrations of production, and direct training for community partners. This service was carried out at Banda Aceh State Elementary School 61 from July to September 2025. The training produced 30 L of liquid soap and 1000 sheets of paper soap; by the end of the session, 75% of participants completed all production steps correctly (checklist). Entrepreneurial outputs included a student–teacher sanitation team and two product mock-ups with basic costing (estimated unit cost Rp 12.000 per 500 mL vs market price Rp 18.000). These results indicate technical feasibility and school-based micro-enterprise potential. For sustainability, the school committed to monthly in-house production led by the sanitation team and integrating the activity into UKS to secure continuous supply and ongoing skill transfer.

Accessible public transportation is the foundation of inclusive mobility, especially for people with disabilities. Unfortunately, executive train toilets in Indonesia have not fully met the physical and functional accessibility standards. Therefore, toilets that are easily accessible to all users are needed, ones that are not only functionally adequate, but also preserve the local cultural values. This study aims to design an accessible executive train toilet by combining universal design principles with local cultural values for all passengers. This study uses qualitative-quantitative methods and participatory design elements based on the universal design and local culture. The study was conducted in four main stages: collecting data on identifying the needs of the user through an online questionnaire with 84 respondents and a group discussion with seven stakeholders; studying the local culture using ethnographic interviews with 42 Javanese residents and in-depth interviews with cultural experts; quantitative and qualitative data analysis; and the design process, which includes deciding the size of the toilet components, visualization, and identifying alternative designs. The design evaluation stage is based on weighted scoring. The study resulted in a universally accessible executive train toilet design based on the local culture by increasing the width of the door, expanding the size of the toilet room, automating facilities, Braille signs, ergonomic design, emergency calls, and the local Javanese philosophy (color, ornaments, shape, materials, availability of water, bar soap). This study has practical implications for policymakers regarding the transportation policies and infrastructure development toward more inclusive railway services in developing countries.

The increasing demand for natural and eco-friendly personal care products has encouraged innovation in utilizing agricultural waste. This study aimed to formulate bar soap using essential oil extracted from pomelo peel (Citrus paradisi) and evaluate its physicochemical, organoleptic, and antibacterial properties. Two formulations of vegetable oil (coconut, olive, and palm oil) and three concentrations of essential oil (0%, 2%, 4%) were tested using a factorial randomized complete design. Parameters assessed included pH, moisture content, total fatty matter, sensory attributes (texture, aroma, color, and foam), and antibacterial activity against Aeromonas sp.. The results showed that all formulations met the national quality standard (SNI 3532:2021), with the best outcome observed in the soap containing 4% essential oil and Formula 1 (15% coconut, 20% olive, 65% palm oil). This treatment produced soap with optimal pH (8), moisture (15.64%), fat content (81.78%), and favorable texture and foaming performance. However, antibacterial activity was limited, with inhibition zones measuring only 6.0–6.5 mm. The findings support the use of pomelo peel essential oil in sustainable soap production and encourage further research on enhancing its functional efficacy. This study contributes to the valorization of citrus waste and the advancement of natural cosmetics

Hand hygiene is an essential step in preventing the transmission of infectious diseases, making the availability of safe and environmentally friendly hand soap an important necessity in daily sanitation practices. This community service activity aims to enhance students’ environmental literacy, technical skills, and ecological awareness through training on producing natural hand soap based on butterfly pea flower (Clitoria ternatea) extract, with the final product named Clitoria Nature. The program was implemented using the Participatory Action Research (PAR) method, which consists of four stages planning, action, observation, and reflection—through strategies including socialization, demonstration, and hands-on practice. The subjects of this activity were 32 students of Grade VIII Room 1 at MTsN 1 Palangka Raya City. The results showed an increase in students’ understanding of the benefits of natural ingredients, their ability to formulate liquid soap, and the development of behavior that favors the use of natural hygiene products. Theoretically, the anthocyanin and flavonoid content of butterfly pea flowers supports the antibacterial potential of the formulated soap. This program not only produced an environmentally friendly hand soap but also contributed to the formation of healthier and more sustainable sanitation behaviors.

The use of eco enzymes can enhance the quality of cleaning products, such as soap. These enzymes, including amylase, lipase, and protease, serve as catalysts and natural antibacterial agents, helping to break down carbohydrates, lipids, and proteins during the decomposition process. This study aims to evaluate the effect of adding eco enzymes on accelerating the saponification reaction and improving the quality of the produced bar soap. The method employed is the cold process, with variations of eco enzymes added at 0 g, 13 g, 26 g, and 39 g. All bar soap samples were analyzed according to the SNI 3532:2021 standard, and one sample that met this standard was selected for further enzymatic analysis. Of the five test parameters performed, soap products with the addition of 13 g, 26 g, and 39 g of eco enzymes complied with all SNI 3532:2021 standards. However, the soap with 0 g of eco enzymes did not meet one of the standards for total plate count microbe contamination, which produced a result of ≤ 4000 CFU/g. Additionally, lipase and protease enzymes were detected in the soap with the addition of 26 g of eco enzymes. The hardness levels of each soap variation were as follows: 1.3 N for 0 g, 1.7 N for 13 g, 2.03 N for 26 g, and 1.47 N for 39 g of eco enzymes.

Fragrande is an Indonesian local brand offering beauty care products consisting of body care and fragrance items. The brand plans to expand into international markets by introducing several products, including bar soap, body mist, nourishing hair oil, perfume oil, and face mist. Differences in target markets cause a product to adopt different packaging designs between domestic and export distribution. These changes involve visual design elements that shape the product’s character. This study aims to analyze the differences in visual elements of the packaging of Fragrande bar soap for domestic and export markets based on the visual elements in the packaging design theory of Klimchuk and Krasovec. The research employs a descriptive qualitative comparative method through visual observation of Fragrande bar soap packaging. The analysis is conducted by identifying packaging visual elements, including color, typography, layout, space, and material, and examining them through the design principles of balance, hierarchy, contrast, unity, and simplicity. The urgency of this research lies in contributing academically to visual communication design studies in product packaging, providing a reference for designers in developing packaging for global markets, and demonstrating that design changes are not merely aesthetic but function as a visual positioning strategy. The results show that the domestic packaging tends to present a dense and informative visual structure, whereas the export packaging displays a simpler composition emphasizing an emotional experience approach through hierarchy. Key Words: packaging, branding, local products, export products, design communication visual