No-Rinse Body Wash: Formulation, Evaluation, and Efficacy for Water-Limited Use

Water scarcity is a growing global concern, affecting every continent and impacting impoverished communities the most ^[1]. Around 2.2 billion people worldwide still lack access to clean and safe water, resulting in over a million deaths annually due to poor sanitation and hygiene-related illnesses ^[2]. Traditional hygiene practices heavily rely on water, making it difficult for people in water-stressed areas to maintain cleanliness and prevent disease ^[3].

With the increasing demand for water-conserving alternatives, there is a pressing need to develop hygiene solutions that do not require rinsing. A no-rinse body wash offers a practical approach for maintaining cleanliness without relying on water, especially in emergency settings or low-resource communities. This study focuses on the development of a no-rinse body wash designed to help individuals maintain personal hygiene while conserving water. It also aims to assess its usefulness among people with limited access to bathing, such as those with mobility issues or those constantly on the move.

This product may provide meaningful benefits for several groups, including bedridden patients, elderly individuals, post-surgery patients, and even outdoor enthusiasts like hikers and campers who may not have access to shower facilities ^[4]. By introducing a waterless hygiene option, the study seeks to contribute to the global effort of promoting health and cleanliness in the face of water scarcity. If proven effective, the no-rinse body wash may serve as an accessible, practical, and efficient hygiene solution in various challenging settings.

Literature Review

2.1 Solvent and Base Component

Deionized water is produced by treating regular water with electrically charged resins that remove dissolved salts through ion exchange. In this process, ions, electrically charged atoms or molecules with either a positive or negative charge, are replaced with hydrogen and hydroxide ions, resulting in highly pure water ^[5]. This method ensures the removal of contaminants, making the water suitable for sensitive applications.

Due to its high purity, deionized water is widely used in industries such as cosmetics, food processing, and pharmaceuticals. In manufacturing, it prevents salt deposits on machinery, helping maintain equipment efficiency. In pharmaceutical settings, its bacteria-free nature is essential for ensuring product safety and quality ^[5].

2.2 Surfactants and Cleansing Agents

Decyl glucoside is a mild, non-ionic surfactant commonly used in skincare and cosmetic products for its excellent foaming, cleansing, and emulsifying properties ^[6]. It effectively lifts away dirt and oil while maintaining skin hydration and softness, making it an ideal choice for formulations targeting sensitive skin. Beyond its cleansing action, it is also utilized as a skin and hair conditioning agent, as well as an emulsion stabilizer, enhancing the performance and feel of cosmetic products ^[7].

Among the family of alkyl glucosides, decyl glucoside stands out as the most frequently used due to its favorable safety and efficacy profile. Clinical studies have tested its potential for dermal irritation and sensitization at various concentrations through methods such as epicutaneous patch testing and soap chamber tests. These evaluations revealed that decyl glucoside was only slightly irritating at higher concentrations and showed no sensitizing effects, supporting its reputation as a gentle yet effective ingredient.

Cocamidopropyl betaine, another widely used surfactant, is derived from coconut oil and is known for its ability to remove oil and impurities while generating rich foam. Like decyl glucoside, it is considered mild and is preferred over harsher agents such as sodium lauryl sulfate. Its gentle nature makes it well-suited for products formulated for individuals with sensitive or delicate skin ^[8].

2.3 Moisturizers and Skin Conditioning Agents

Polyethylene glycol is a synthetic, colorless, and odorless compound known for its ability to absorb excess water and retain moisture. In cosmetics and personal care products, it functions as a preservative, humectant, and penetration enhancer, helping active ingredients absorb more effectively into the skin. Although it appears on the Agency for Toxic Substances and Disease Registry (ATSDR) list, dermatologists maintain that polyethylene glycol is safe for use because the petrolatum used in its production is of cosmetic-grade quality ^[9].

Polyethylene glycol is considered non-hazardous under the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). Its safety has been evaluated through the Human Repeat Insult Patch Test (HRIPT), where none of the 104 participants exhibited allergic reactions, and only one individual showed minor signs of irritation. Further assessment using the Human Maximisation Test (HMT), which offers a thorough evaluation of a chemical's sensitization potential, also confirmed its safety, as no sensitization was observed among the 24 volunteers tested with 25% and 10% polyethylene glycol concentrations ^[10].

Cetostearyl alcohol is a white, flaky, waxy solid made from a blend of cetyl and stearyl alcohols. It is widely used in the pharmaceutical and cosmetic industries as an emulsion stabilizer, opacifying agent, surfactant-foam booster, and viscosity enhancer, contributing to the texture and stability of many skincare products ^[11]. Its multifunctional properties make it a valuable ingredient in both personal care and pharmaceutical formulations.

The Cosmetic Ingredient Review (CIR) Expert Panel concluded in 1988, and again in 2005, that cetostearyl alcohol is safe for use in cosmetic products. Clinical studies have shown it to have no significant toxicity, no mutagenic effects, and no potential to irritate the skin. The FDA also allows products labeled “alcohol-free” to contain cetostearyl alcohol and lists it as a safe food additive, underscoring its established safety and gentle nature ^[12].

Magnesium ascorbyl phosphate (MAP) is a stable, water-soluble derivative of vitamin C known for delivering consistent antioxidant benefits to the skin. It protects against environmental stressors and free radicals, helping to minimize signs of aging such as fine lines and wrinkles ^[13]. MAP also inhibits melanin production, making it effective for brightening the complexion and reducing hyperpigmentation, while its anti-inflammatory properties help soothe redness and calm irritated skin.

In addition to its protective and brightening effects, magnesium ascorbyl phosphate stimulates collagen production, improving skin elasticity and firmness. It is considered a non-toxic, safe ingredient, tolerated by most skin types, and can be used at concentrations of up to 10% in skincare formulations. Its low potential for side effects, combined with being both vegan and halal-friendly, makes it a versatile and appealing choice for a wide range of cosmetic products ^[14].

Aloe vera is a widely recognized succulent plant valued for its ability to moisturize and soothe the skin. It is biocompatible and possesses antibacterial properties, making it a suitable ingredient for skincare formulations ^[15]. Its anti-inflammatory effects help reduce pain, swelling, and soreness from wounds and injuries, while also promoting collagen production and release ^[16]. Aloe vera contains around 75 active compounds, including vitamins, enzymes, minerals, sugars, lignin, saponins, salicylic acids, and amino acids, all contributing to its broad therapeutic benefits.

In addition to wound healing and hydration, Aloe vera has been shown to protect against radiation-induced skin damage by preventing UV-triggered suppression of delayed-type hypersensitivity ^[17]. Key components such as aloin, emodin, mucopolysaccharides, hyaluronic acid, and flavonoids make it valuable for cosmetic and dermatological uses. In the cosmetics industry, Aloe vera offers whitening, sun protection, antioxidant, anti-aging, and moisturizing effects, making it a powerful ingredient for developing new skincare products and skin treatments ^[18].

2.4 Texture Enhancers and Delivery Agents

Cyclopentasiloxane, also known as decamethylcyclopentasiloxane or D5, is a cyclic dimethyl polysiloxane commonly used in cosmetics as a skin conditioner, emollient, hair conditioner, and solvent ^[19]. It is a clear, odorless, lightweight liquid that enhances the sensory feel and texture of skincare products. By helping deliver active ingredients evenly and evaporating quickly, it leaves the skin with a smooth, silky, and non-greasy finish ^[20].

The Cosmetic Ingredient Review Panel has evaluated cyclopentasiloxane and concluded that the current concentrations used in cosmetics are safe. Its ability to improve product application and overall user experience makes it a popular and trusted ingredient in many personal care formulations.

2.5 Preservatives and Stability Agents

Sodium benzoate is a widely used preservative in cosmetics and personal care products, valued for its ability to prevent bacterial growth and extend shelf life. It appears as an odorless crystalline powder and plays a key role in maintaining the stability and safety of formulations ^[21].

Recognized by the FDA as generally regarded as safe (GRAS), sodium benzoate has been thoroughly studied for its safety profile. In two long-term studies involving rats and mice, no evidence of carcinogenicity was found, further supporting its safe use in cosmetic and personal care products ^[22].

2.6 Colorants and Fragrances

FD&C Blue 1 (Brilliant Blue) and FD&C Red 3 (Erythrosine) are synthetic color additives widely used in cosmetics and personal care products to create vibrant, appealing colors. FD&C Blue 1 is recognized for its bright blue hue and has been certified as safe for use by the U.S. Food and Drug Administration when used within approved concentrations ^[23]. Similarly, FD&C Red 3 imparts a vivid pinkish-red shade and is permitted for external application in products such as makeup and skincare, although its use in foods has some restrictions following earlier safety reviews ^[24]. These artificial colorants are primarily added for aesthetic enhancement to improve the visual appeal of products.

Baby powder fragrance oil is a synthetic fragrance blend formulated to mimic the soft, clean scent traditionally associated with baby powder. It is frequently incorporated into cosmetics, skincare, soaps, and personal care products to evoke a feeling of freshness, comfort, and nostalgia ^[25]. Lavender fragrance oil, whether naturally derived or synthetically produced, is also popular in personal care formulations for its calming floral aroma and its soothing effects on both mood and skin ^[26]. It not only promotes relaxation but may also provide mild antimicrobial and anti-inflammatory benefits, making it both an aromatic and functional ingredient in cosmetics ^[27].

METHODOLOGY

3.1 Cold Process Emulsification and Blending

The preparation of the body wash solution follows a cold process emulsification and blending method to preserve the stability of sensitive ingredients. First, all components were weighed accurately using a precision analytical balance. A clean, sanitized mixing vessel (preferably glass or stainless steel) and a magnetic stirrer or homogenizer were prepared to ensure controlled mixing conditions. In the Mixing Phase, the formulation was divided into distinct phases.

For Phase A (water-soluble ingredients), Deionized Water (65%) was used as the base in a beaker. While stirring continuously, Sodium Benzoate (0.5%) and Phenylpropanol (0.5%) were dissolved completely. Decyl Glucoside (15%) was then added slowly to minimize foaming, followed by Cocamidopropyl Betaine (7%) to enhance foam stability and mildness. Propylene Glycol (3%) was incorporated, and the mixture was stirred for five minutes to ensure uniform dispersion.

For Phase B (oil-soluble ingredients), Cyclopentasiloxane (5%) and Baby Powder Fragrance (0.5%) were blended separately until homogeneous. This oil phase was then gradually introduced into Phase A under gentle stirring to form a stable emulsion.

In Phase C (final additions), Magnesium Ascorbyl Phosphate (3%) was first dissolved in a minimal amount of deionized water before being incorporated into the main batch with continuous stirring. Sodium Chloride (0.5%) was added to fine-tune the viscosity, followed by the careful addition of FD&C Blue 1 (0.01%) to achieve the desired color uniformity. Finally, the entire formulation was homogenized to ensure complete uniformity and stability. Stability and safety assessments were performed before transferring the final product into 15 mL bottles using a pipette or small funnel.

3.2 MATERIALS

1. Beaker
2. Stirring rod
3. Graduated cylinders
4. Pipette
5. Analytical balance
6. Funnel
7. Porcelain spatula

3.3 Stability Tests

3.3.1 Organoleptic Testing

To evaluate the sensory attributes of the solution, such as color, odor, and appearance.

Procedure:

1. Place a small amount of the cream on a clean surface
2. Color: Visually inspect under neutral lighting conditions.
3. Odor: Smell the sample to ensure it aligns with the desired scent.
4. Appearance: Observe for uniformity, lumps, or phase separation.

3.3.2 Determination of pH:

To ensure the solution’s pH is within the range suitable for skin (pH of 4-6).

Procedure:

1. Place a sample of the solution in a beaker.
2. Calibrate the pH meter using standard buffers (pH 4.0 and 7.0).
3. Immerse the pH electrode into the cream solution and record the reading at room temperature.
4. Specification: pH of 4.7 to 5.5

3.3.3. Microbiological Testing

A microbiological test was performed on the sample of body wash using the agar plate streak method to check for bacterial contamination. A diluted sample of the body wash was inoculated onto nutrient agar for total bacterial count. The plates were incubated at appropriate temperatures of 30 degrees Celsius for the required time of 24 hours and 48 hours.

3.3.4. Viscosity Testing

A viscosity test was conducted to determine the flow properties of the non-viscous, No-Rinse Body Wash. The test followed the Brookfield Viscometer to measure the viscosity of thin, free-flowing liquids similar to the consistency of the product. The body wash sample was maintained at a controlled temperature of 25°C, with the usage of an appropriate spindle size (Spindle No. 1) at a rotational speed of 60 rpm. The viscosity was measured in centipoise (cP). Multiple readings were taken, and the average viscosity value was recorded to account for any variation.

Procedure:

1. Measure initial viscosity using a Brookfield viscometer.
2. Store samples under varied conditions.
3. Re-measure viscosity at intervals (7, 14, 30, 60, 90 days).
4. Spindle used: disk LV1; 100 rpm
5. Specification: less than 1,000 cP for non-viscous body wash formulations.

3.3.5 Volatilization

Volatilization is the process by which a chemical substance transitions from a liquid or solid state to a gaseous or vapor state. In this study, 5 mL of each formulation was poured into a petri dish and stored at room temperature and in a hot air oven set to 50°C.

3.3.6 Refractive Index

The refractive index (RI), which measures how much light bends when passing through a medium, is defined as the ratio of the speed of light in a vacuum to its speed in the medium. The formulated body wash primarily consists of deionized water, surfactants, fragrances, and other additives. Since the body wash is predominantly an aqueous solution, its expected RI should be approximately 1.33, similar to water.

RESULTS

1. 1. Organoleptic Testing

Table 4.1.1 presents the organoleptic evaluation of the Lavender and Baby Powder formulations over storage durations of 1 week, 1 month, and 3 months. Both variants had exhibited consistent physical characteristics across all assessed parameters throughout the evaluation period. The Lavender formulation had retained its semi-transparent purple hue, characteristic refreshing and crisp lavender odor, smooth and silky texture with a semi-watery consistency, and a uniform purple appearance. Similarly, the Baby Powder formulation maintained its pastel blue coloration with a misty undertone, clean and subtly sweet fragrance, and consistent texture and appearance.

No observable changes occurred in color, odor, texture, or appearance in either formulation over the course of the study. Specifically, there had been no indications of discoloration, odor deterioration, phase separation, or textural instability. These findings suggest that both products had remained organoleptically stable for a period of at least one month under standard storage conditions. Such stability supports the short-term physical integrity and acceptability of the formulations,

1. 2. Determination of pH

As shown in Table 4.2.1, the pH values of both the Lavender and Baby Powder formulations were assessed across three trials. The Lavender variant had yielded pH values of 4.638, 4.660, and 4.802, resulting in a mean of 4.700. In comparison, the Baby Powder formulation had demonstrated pH readings of 4.680, 4.708, and 4.718, with a calculated mean of 4.702.

These results indicated that both formulations had maintained a slightly acidic pH, which is well within the acceptable range for cosmetic and personal care products. The consistent values observed across the trials suggested that each formulation had exhibited chemical stability, with no significant pH fluctuations during the evaluation period.

1. 3. Microbiological Testing

According to the data presented in Table 4.3.1, a microbiological assessment had been carried out on the formulated body wash to determine the presence of bacterial contamination. The test had employed the agar plate streak method, wherein a diluted sample of the product had been inoculated onto nutrient agar and incubated at 30°C for 24 and 48 hours. Following the incubation periods, no bacterial growth had been detected on the plates.

These findings confirmed that the formulated body wash had complied with microbiological safety standards. The absence of microbial colonies indicated that the product had been free from contamination and that its formulation, preservation system, and handling procedures had effectively inhibited microbial proliferation.

1. 4. Viscosity Testing

As demonstrated in Table 4.4.1 Viscosity measurements of the Baby Powder and Lavender formulations were performed at 7, 14, 30, 60, and 90 days using a disk spindle LV1 at 100 rpm, with the acceptance criterion set at less than 1,000 cP for non-viscous body wash products. The Baby Powder formulation had exhibited stable viscosity values ranging from 680 cP at day 7 to 722 cP at day 90, consistently remaining within the specified limit. In contrast, the Lavender formulation had initially shown an exceptionally high viscosity of 26,100 cP at day 7, which had markedly decreased by day 14 to 734 cP and subsequently stabilized between 732 and 753 cP through day 90, thus conforming to the viscosity specification after the initial adjustment. This initial anomaly in the Lavender sample suggested a transient formulation or measurement inconsistency that resolved early in the storage period.

1. 5. Volatilization

The results of the volatility test conducted at normal temperature were summarized in Table 4.5.1. Both the Baby Powder and Lavender scented formulations initially contained 5 mL of product prior to testing. After a 30-minute exposure period, no change in volume had been observed for either formulation. These findings indicated that both formulations had demonstrated negligible volatility under normal temperature conditions. The retention of volume suggested that the products had maintained their physical integrity without significant evaporation

The results of the volatility test conducted at 50°C using a hot air oven were presented in Table 4.5.2. Both the Baby Powder and Lavender scented formulations initially contained 5 mL of product before exposure. After 30 minutes at elevated temperature, the volume of each formulation had decreased slightly to 4.9 mL. This minimal reduction in volume indicated that both formulations had exhibited limited volatility under accelerated heat conditions. The slight evaporation observed suggested a degree of thermal sensitivity, but the products had largely retained their physical stability

1. 6. Refractive Index

The refractive index (RI) measurements, as presented in Table 4.6.1, had shown that the Standard and Lavender Scent variants had an RI of 1.33586, closely matching the RI of water. This similarity indicated that these formulations had possessed a high water content, with minimal influence from other ingredients on the refraction of light. Conversely, the Baby Powder variant had exhibited a higher RI of 1.36218, suggesting the incorporation of denser or more concentrated components. This elevated optical density was likely attributable to variations in surfactants, oils, or colorants, which had affected the overall composition and light-bending characteristics of the solution. These results had provided insight into the physicochemical differences among the formulations and their potential impact on product properties.