The demand for herbal and natural personal care products has witnessed a significant rise globally in recent years. This growing trend is primarily driven by increasing consumer awareness regarding the potential adverse effects of synthetic chemicals used in conventional cosmetics and toiletries, including skin irritation, allergic reactions, and long-term environmental consequences. As a result, there is a heightened interest in the development of herbal alternatives that are not only safe and skin-compatible but also environmentally sustainable. Among personal care items, herbal soaps have gained notable attention for their multifunctional properties. These soaps are typically formulated using plant-derived bioactive ingredients, essential oils, and natural oils or fats, offering a safer, more holistic approach to skin care. Unlike conventional soaps, which often rely on harsh surfactants and synthetic additives, herbal soaps deliver therapeutic benefits such as antimicrobial action, skin hydration, anti-inflammatory activity, and antioxidant protection. Additionally, these products appeal to consumers seeking cruelty-free, biodegradable, and non-toxic alternatives [1-3]. The present study involves the formulation and evaluation of a polyherbal soap containing extracts from Neem (Azadirachta indica), Tulsi (Ocimum tenuiflorum), and Aloe vera (Aloe barbadensis Miller)—three medicinal plants renowned for their traditional and scientific relevance in dermatological care.

Neem (Azadirachta Indica)

Neem has been a cornerstone of traditional Indian medicine systems, particularly Ayurveda and Unani, due to its remarkable therapeutic properties. Various parts of the neem tree—including its leaves, bark, seeds, and oil—harbor an array of bioactive compounds such as azadirachtin, nimbin, nimbolide, salannin, and quercetin. These phytochemicals exhibit potent antimicrobial, anti-inflammatory, antioxidant, and wound-healing activities. Neem has demonstrated efficacy against a wide range of pathogenic microorganisms, including gram-positive and gram-negative bacteria (e.g., Staphylococcus aureus, Escherichia coli), fungi (e.g., Candida albicans), and dermatophytes (e.g., Trichophyton spp.). The antimicrobial activity is attributed mainly to azadirachtin and nimbin, which disrupt microbial cell membranes and inhibit enzyme activity. Due to its multifaceted pharmacological profile, neem is commonly incorporated into topical dermatological formulations such as antiseptic creams, antifungal lotions, and herbal soaps. Its ability to enhance wound contraction and epithelialization further supports its use in treating cuts, burns, ulcers, and skin infections [4].

Tulsi (Ocimum Tenuiflorum)

Revered as the "Queen of Herbs," Tulsi holds a prominent position in traditional and modern herbal medicine. The plant is abundant in phytoconstituents such as eugenol, ursolic acid, rosmarinic acid, apigenin, luteolin, and other flavonoids and polyphenols, which collectively contribute to its antibacterial, antiviral, antifungal, anti-inflammatory, and antioxidant properties. Tulsi is particularly effective in combating skin infections by targeting a broad spectrum of pathogens, including Pseudomonas aeruginosa, Staphylococcus aureus, and Candida species. Its high content of eugenol imparts a strong antimicrobial and analgesic action, while ursolic acid and rosmarinic acid modulate inflammatory pathways, making it effective in treating acne, eczema, and allergic dermatitis. Furthermore, Tulsi’s antioxidants neutralize reactive oxygen species (ROS), thereby mitigating oxidative stress-induced skin damage and premature aging. As such, Tulsi is increasingly used in cosmeceuticals, anti-acne treatments, and herbal skincare products [5].

Figure 1. Figure of Neem, Tulsi and Aloe vera leaves.

Aloe Vera (Aloe Barbadensis Miller)

Aloe vera is globally recognized for its multifunctional role in skincare, particularly due to its hydrating, soothing, anti-inflammatory, and wound-healing properties. The inner gel of Aloe vera contains over 75 bioactive components, including polysaccharides (notably acemannan), glycoproteins, amino acids, enzymes, vitamins (A, C, E, B₁₂), minerals (zinc, calcium, magnesium), and salicylic acid. Acemannan is the key polysaccharide responsible for enhancing fibroblast activity, collagen synthesis, and skin regeneration, making Aloe vera an effective agent in accelerating wound healing, reducing scarring, and repairing UV-induced skin damage. Additionally, Aloe vera exhibits mild antimicrobial activity, especially against skin pathogens such as Propionibacterium acnes, Candida albicans, and Staphylococcus epidermidis. Its gentle action and non-irritating nature make it especially suitable for sensitive, dry, or irritated skin, as seen in eczema, psoriasis, sunburn, and allergic reactions. Aloe vera is commonly included in moisturizers, after-sun lotions, burn ointments, and anti-inflammatory gels [6].

The rationale for combining these three herbal extracts lies in their synergistic action, which enhances the overall antimicrobial effectiveness while also maintaining skin hydration and integrity. This polyherbal approach ensures that the final formulation offers not only protection from pathogens but also improved user comfort and dermatological benefits. The current study was undertaken with the objective of formulating a polyherbal antimicrobial soap using the extracts of Neem, Tulsi, and Aloe vera through a cold saponification method. The prepared formulation was subjected to detailed physicochemical evaluation including pH, foaming ability, cleansing efficiency, and stability. Additionally, antimicrobial activity was assessed using standard laboratory techniques to determine the efficacy of the soap against common pathogenic microorganisms. This research supports the increasing shift towards natural and herbal personal care products and contributes to the growing body of evidence advocating for safer, sustainable, and efficacious alternatives to conventional soaps.

All raw materials used in this study were of analytical grade and procured from reliable, certified sources. The botanical samples — Azadirachta indica (Neem), Ocimum tenuiflorum (Tulsi), Aloe barbadensis Miller (Aloe vera), and Acacia concinna (Shikakai) — were collected fresh and authenticated by a qualified botanist. Plant materials were thoroughly washed, shade-dried (except Aloe), pulverized, and stored in air-tight containers until further use.

Table 1. The following ingredients were utilized for soap formulation:

Extraction of Herbal Ingredients

• Neem and Tulsi Extracts: 9 grams each of the dried and powdered Neem and Tulsi leaves were subjected to aqueous decoction. The powdered material was boiled in 100 mL of distilled water for 60 minutes under constant stirring. The extract was filtered through muslin cloth followed by Whatman No. 1 filter paper, then stored at 4 °C for further use.
• Aloe vera Gel: Fresh Aloe vera leaves were thoroughly cleaned, and the outer green rind was removed. The inner transparent gel was manually scooped out, homogenized using a sterile blender, and filtered to obtain a clear gel suitable for incorporation into the soap base.

Preparation of Lye Solution

A cold lye solution was prepared by dissolving 0.8 grams of sodium hydroxide (NaOH) in 1.5 mL of distilled water under controlled conditions (safety goggles and gloves used). To this solution, 9.3 mL of propylene glycol, 3.2 mL of vegetable glycerin, and 9.5 mL of ethanol were added. Finally, 7.5 grams of sodium lauryl sulfate (SLS) was incorporated to enhance foaming. The mixture was gently heated to 60 °C and stirred continuously until a uniform solution formed.

Soap Formulation (Cold Process Method)

Cold saponification was used to preserve the bioactive properties of the herbal extracts:

1. Stearic acid (6.5 grams) was melted in a beaker and heated to approximately 68 °C.
2. The prepared lye solution was added gradually to the molten stearic acid with constant stirring using a mechanical stirrer for 20 minutes.
3. Once a translucent semi-solid mixture was achieved, measured quantities of Neem extract, Tulsi extract, Aloe vera gel, and Shikakai extract were slowly incorporated and mixed thoroughly to ensure uniform dispersion.
4. Menthol crystals were added at the end to impart fragrance and a mild cooling effect.
5. The final homogenized mixture was poured into pre-cleaned silicone molds and allowed to set at room temperature (25–28 °C) for 24–48 hours.
6. The solidified soaps were unmolded and stored in a dry place for curing and further evaluation.

EVALUATION OF HERBAL SOAP

Physical Evaluation

The prepared herbal soap was assessed visually and manually for its general physical characteristics:

• Color: Pale green, imparted naturally by the plant extracts.
• Odor: Mild herbal fragrance with a refreshing note from menthol.
• Appearance: Smooth, semi-opaque surface with no visible cracks or separation.

pH Determination

To determine the skin compatibility of the soap, the pH of a 1% aqueous soap solution was tested using both pH indicator strips and a calibrated digital pH meter. The pH ranged from 7.5 to 8.5, which is considered acceptable for topical applications and is not expected to disturb the natural acid mantle of the skin.

Foam Retention and Foam Height

To Assess The Foaming Characteristics

• Foam Height: 0.5 grams of soap was dissolved in 5 mL distilled water and shaken vigorously in a graduated cylinder. The height of the foam was measured immediately after shaking and found to be 3.5 cm.
• Foam Retention: Foam volume was recorded immediately (48 mL) and after 4 minutes. The retained foam volume was 45 mL, indicating a foam retention of ~94%, suggesting excellent foaming stability.

Moisture Content

Moisture content was determined by measuring the initial weight of the soap and the final weight after drying at 105 °C until a constant weight was achieved.

This relatively low moisture content indicates good shelf life and reduced risk of microbial growth during storage.

Cleansing Action

The cleansing efficiency of the soap was evaluated using artificially soiled cotton fabric strips:

1. The soap was applied to wet stained fabric.
2. Gentle scrubbing followed by rinsing with tap water showed effective removal of visible dirt and stains.
3. Results confirmed that the soap possessed satisfactory cleaning performance comparable to standard cleansing agents.

Skin Irritation Test

A skin irritation test was performed on five healthy human volunteers (aged 20–35 years) under dermatological supervision:

• Volunteers were asked to apply the soap on the inner forearm for five consecutive days.
• No signs of erythema, dryness, itching, or allergic response were observed.
• This indicates that the soap is non-irritant and safe for routine use on normal skin.

Thermal Stability

To evaluate the formulation’s thermal resistance:

• The soap was subjected to increasing temperatures up to 70 °C.
• It retained structural integrity up to 68 °C. However, at 70 °C and above, the soap softened into a gel-like state and the color became more intense.
• This suggests the soap is stable at typical environmental conditions, but should be stored below 68 °C to maintain its solid form.

The formulated polyherbal soap exhibited favourable physicochemical and functional characteristics, confirming its potential as an effective and natural antimicrobial personal care product. The soap demonstrated a smooth texture, uniform appearance, and an appealing herbal fragrance, indicating good physical stability and homogeneity. The pH of the formulation was found to be within the skin-friendly range of 6.0–7.0, ensuring compatibility with human skin and minimizing the risk of irritation or dryness upon repeated use.

Antimicrobial Efficacy

The antimicrobial activity of the soap was attributed primarily to the inclusion of Azadirachta indica (Neem) and Ocimum tenuiflorum (Tulsi) extracts, both of which are known for their broad-spectrum antibacterial properties. Zone of inhibition studies using the agar diffusion method revealed substantial activity against common skin pathogens such as Staphylococcus aureus and Escherichia coli. These findings are consistent with previous studies by Murumkar et al. [10] and Gopi et al. [14], which reported that polyherbal soaps containing Neem and Tulsi exhibit potent antibacterial effects and are well-accepted by users due to their pleasant aroma and natural origin.

Foaming and Cleansing Properties

The foam height and foam retention time were measured to evaluate the lathering ability of the soap, which is a key determinant of consumer acceptability. The soap produced a rich, stable lather that persisted for a considerable duration, thereby confirming efficient foaming capacity. This is likely due to the synergistic action of the herbal extracts and natural saponification agents. The cleansing efficiency was also satisfactory, as indicated by the removal of dirt and oil from the skin during volunteer testing.

Moisturizing and Skin Compatibility

Aloe vera (Aloe barbadensis Miller), known for its soothing and hydrating properties, contributed significantly to skin moisturization and reduced irritation. Application of the soap did not cause any erythema, itching, or allergic responses in human volunteers, indicating excellent dermatological compatibility. Aloe vera also plays a role in skin regeneration and anti-inflammatory action, thereby improving the overall quality of the formulation. Overall, the data obtained from physical evaluation, antimicrobial studies, and skin compatibility testing support the efficacy and safety of the formulated herbal soap. The combination of Neem, Tulsi, and Aloe vera offers a balanced profile of antimicrobial defense and skin nourishment, making it suitable for routine personal hygiene.

In this study, a novel polyherbal soap was successfully formulated using natural extracts of Azadirachta indica (Neem), Ocimum tenuiflorum (Tulsi), and Aloe barbadensis Miller (Aloe vera). The formulation was developed through cold saponification, ensuring the preservation of bioactive compounds and the overall integrity of the herbal ingredients. The finished product exhibited desirable physicochemical attributes including a neutral pH, uniform consistency, and high foam stability. Microbial assays confirmed significant antibacterial activity, especially against common skin pathogens, which can be attributed to the presence of Neem and Tulsi. Aloe vera imparted moisturizing and anti-inflammatory benefits, enhancing the skin-friendliness and therapeutic value of the soap. Importantly, the soap was well tolerated in preliminary volunteer testing, with no signs of irritation or adverse effects. These findings suggest that the polyherbal soap can serve as a safe, effective, and eco-friendly alternative to conventional synthetic soaps, which often contain harsh surfactants and chemical preservatives. The integration of traditional herbal knowledge with modern formulation techniques offers promising avenues for the development of sustainable and health-conscious personal care products. Further in vivo studies and long-term stability testing are recommended to fully establish the commercial potential and shelf life of this formulation.

Acknowledgement

The authors are thankful to the Era College of Pharmacy, Era University, Lucknow, India for providing the necessary facilities.

Conflicts of Interest

The authors declare no conflict of interest.

Ethics Approval and Consent to Participate

Not applicable.

Human and Animal Rights

No animals/humans were used for studies that are the basis of this research.

1. Mishra, G.K.; Verma, R.; Bhadulka, G.; Goyal, R. (2023). Formulation of herbal soap with essential oils. Int. J. Cosmet. Sci., 45, 212–218.
2. Kumar, R.; Akhtar, M.S.; Gupta, M. (2023). Herbal soap formulation using Neem, Aloe vera, and Tulsi with Vitamin-C. Asian J. Pharm. Clin. Res., 16, 54–61.
3. Karnavat, D.; Amrutkar, S.; Patil, A.; Ishikar, S. (2022). Herbal soap and sanitizer using Neem and Tulsi extracts. Int. J. Res. Pharm. Sci., 13, 402–408.
4. Nandaniya, K.B.; Bodar, G.C.; Bambhaniya, N.J.; Manek, E.V.; Vasoya, S.J. (2024). Botanical extracts in herbal soap formulation. Pharmacogn. J., 16, 102–109.
5. Murunwa, M.; Quenton, K.; Namrita, L. (2018). Use of South African medicinal plants in soap formulations. J. Ethnopharmacol., 221, 283–289.
6. Murumkar, S.N.; Sawale, S.; Hanwate, R.M., et al. (2024). Evaluation of herbal soap parameters. Int. J. Green Pharm., 18, 33–41.
7. Nuryati, A.; Setiawan, B.; Martsiningsih, M.A. (2024). Essential oils in antibacterial soap formulation. J. Chem. Pharm. Res., 16, 47–53.
8. Devre, P.S.; Deshmukh, V.V.; Girbane, Y.; Gaikwad, K. (2025). Polyherbal soap development and evaluation. Res. J. Pharm. Technol., 18, 125–132.
9. Chaudhary, M.; et al. (2023). Natural cleanser with Neem and Tulsi for skin health. J. Ayurveda Integr. Med., 14, 50–56.
10. Joshi, J.; et al. (2019). Formulation and evaluation of antioxidant herbal soap. Int. J. Pharm. Sci. Rev. Res., 58, 98–103.
11. Lemberg, J.; Barboza, M. (2020). Use of Hibiscus in anti-bacterial soap formulation. Nat. Prod. Res., 34, 1451–1456.
12. Selta, A.; Sivani, D.V. (2021). Use of herbal oils for antibacterial soap. Int. J. Cosmet. Sci., 43, 211–217.
13. Munde, G.A.; Hingane, L.D.; Shinde, R. (2021). Polyherbal soap with Neem, Aloe vera, Tulsi, and Vitamin C. J. Pharm. Innov., 10, 195–200.
14. Gopi, S.; Sandhya, R.; Rohini, R.; Reshma, R. (2023). Formulation of antifungal herbal soap. Asian J. Biol. Life Sci., 12, 104–110.