Formulation and Evaluation of Herbal Deodorant Using Plant Extract

Deodorant sticks are widely used to control body odour and are formulated by blending active ingredients with waxes, oils, and other excipients, then moulding them into a solid stick form. Body odour mainly develops in the underarm region due to the high density of sweat glands. Although sweat is initially odourless, it contains lipids that serve as nutrients for skin microflora. These bacteria metabolize the lipids into volatile compounds such as isovaleric acid, which is responsible for unpleasant odour [1]. Odour control can be achieved through proper hygiene, deodorants, or antiperspirants. Deodorants primarily mask odour or inhibit bacterial growth without affecting sweat production, whereas antiperspirants reduce perspiration by blocking sweat glands, thereby limiting bacterial activity [2]. However, conventional deodorants often contain synthetic chemicals such as parabens, triclosan, and aluminium salts, which may cause skin irritation and have been associated with potential health risks [3,4,5]. In recent years, herbal deodorants have gained significant attention due to their natural origin, safety, and reduced side effects. These formulations utilize plant-based ingredients with antimicrobial, antioxidant, and soothing properties, making them suitable for long-term use [6]. Essential oils such as chamomile, rose, peppermint, and rosemary have demonstrated effective antibacterial activity against odour-causing microorganisms like Staphylococcus epidermidis and Corynebacterium species [7–9]. Chamomile oil, obtained from Matricaria chamomilla, contains active constituents such as αbisabolol and chamazulene, which exhibit antimicrobial, anti-inflammatory, and skinsoothing properties [10]. Rose oil (Rosa damascena) is rich in citronellol and geraniol, providing fragrance along with calming and mild antimicrobial effects [11,12]. Peppermint oil (Mentha piperita) contains menthol, which offers cooling sensation and antibacterial activity by disrupting microbial cell membranes [13]. Rosemary oil (Rosmarinus officinalis) is known for its strong antimicrobial and antioxidant properties, making it effective against odourcausing bacteria [14]. In addition to essential oils, natural base materials such as castor oil, coconut oil, beeswax, and cocoa butter play a crucial role in herbal deodorant formulations. Castor oil exhibits antimicrobial and moisturizing properties, while coconut oil provides skin nourishment. Beeswax and cocoa butter contribute to the structural integrity, stability, and smooth application of the deodorant stick [15,16,18]. Thus, herbal deodorant formulations offer an effective, safe, and eco-friendly alternative to synthetic products by combining antimicrobial activity with skin-friendly properties.

Table 1. Plant profile of ingredients used in herbal deodorant stick

AIM:

Formulation and Evaluation Of Herbal Deodorant Using Plant Extract

OBJECTIVE:

To select suitable medicinal plant extracts possessing antibacterial and antifungal activity. To formulate a stable, safe, and effective herbal deodorant using selected plant extracts with antimicrobial and fragrance properties. To assess antimicrobial activity against odor-causing microorganisms. To evaluate skin irritation potential and safety.

MATERIALS AND METHODS:

List Of Ingredients:

Table 2. List of ingredients used in formulation study

List of Apparatus and Instruments

Table 3. List of Apparatus Used In Formulation

Table 4. list of instruments used in evaluation test

Extraction Of Plant Materials

1. Principle

Hydro-distillation in a Clevenger apparatus relies on co-distillation of the essential oil with steam. Water and plant material are heated together; steam volatilises the essential oil, and the mixture condenses in acooled receiver. The lighter oil separates from the aqueous layer by immiscibility and accumulates in acalibrated graduated tube, from which the yield can be directly read.

2. Apparatus

The Clevenger apparatus consists of: a round-bottomed distillation flask (1000 mL), a vertical condenser,a calibrated oil receiver (graduated tube), and a side overflow return tube that recycles condensed waterback to the flask. The apparatus conforms to the design specified in the European Pharmacopoeia [19].

3. Procedure

Step 1 – Sample Preparation: Accurately weigh 30 g of dried chamomile flowers.Coarsely grind with mortar and pestle to increase surface area, facilitating release of essential oil glands.

Step 2 – Loading: Transfer the ground material into the 1000 mL round-bottomed flask. Add 500 mL of distilled water. Connect the flask to the Clevenger apparatus ensuring all groundglass joints are greased and secured. Fill the graduated receiver tube with water via the overflow tube before beginning distillation.

Step 3 – Distillation: Heat the flask using a heating mantle. Apply a gentle temperature gradient reach a slow rolling boil within 15 minutes. Maintain steady distillation at approximately 2–3 drops/second condensate flow. Continue distillation for 3–4 hours (or until no further increase in oil volume is observed in the graduated tube).

Step 4 – Collection: Allow the apparatus to cool to room temperature. Carefully drain the oil from the calibrated receiver into a pre-weighed amber glass vial. For trace amounts of watersoluble terpenoids, extract the distillation water three times with 10 mL of hexane; combine organic layers and evaporate solvent under reduced pressure at 40°C.

Step 5 – Yield Calculation: Record oil volume (v/v%) and calculate yield: Yield (%) = (Volume of oil collected / Weight of plant material) × 100. A typical chamomile oil yield is 0.3–0.8% v/w.

Step 6 – Storage: Transfer oil to dark amber vials, flush with nitrogen, and store at 4°C until use[20].

4. Quality Assessment of Extracted Oil

The extracted oil was evaluated for refractive index (using Abbe refractometer), specific gravity (using pycnometer), optical rotation (using polarimeter), and colour/odour (organoleptic).

5. Preliminary Phytochemical Screening

Phytochemical screening was performed on aqueous and ethanolic extracts of chamomile flowers and rosemary leaves to identify major classes of phytoconstituents according to standard methods [21,22,23].

6. Preparation of Extracts for Screening

Aqueous Extract: Weigh 5 g of coarsely powdered plant material into a 250 mL beaker. Add 100 mL ofdistilled water. Boil for 15 minutes with stirring, cool and filter through Whatman No.1 filter paper. Use filtrate for tests. Ethanolic Extract: Weigh 5 g of powdered material into a conical flask. Add 100 mL of 95% ethanol. Macerate for 48 hours with intermittent shaking. Filter and use the filtrate for tests.

Method of Preparation of Herbal Deodorant Stick (HDS)

Bees wax and cocoa butter was taken in a china dish and placed into water bath which was set to 75°C, for 4 - 5 minutes. Careful attention was paid to this process to ensure that the temperature is not too high. Quick melting was ensured & to avoid charring. On confirming the complete melting of bees wax and cocoa butter, it is removed from water bath; virgin coconut oil, caster oil, rose oil, rosemary oil, chamomile oil, peppermint oil, were added and mixed well (table ). The solution was poured into the pre lubricated container & allowed to settle for 24hours [24,25,26].

Table 5. Composition of the different formulation

Physicochemical Evaluation Parameters

1. Physical Appearance

Examining a deodorant stick's look, colour, texture, scent, and odour is known as physical observation. A visual examination offers important information about the quality, texture, and look of items, guaranteeing a premium deodorant stick that lives up to customer expectations.

2. pH Measurement

The pH of each formulation was determined by dissolving 1g of the deodorant stick in 10 mL of distilled water with gentle warming, cooling to room temperature, and measuring with a calibrated digital pH meter. The normal skin pH ranges from 4.5 to 6.5; deodorant formulations should ideally maintain a pH within this range to avoid skin irritation [27]. Measurements were taken in triplicate and the mean value was recorded. The pH of F1, F2 & F3, was found to be from 6.92 to 7.10 which are suitable for the human skin and non-irritant upon application (Table 7). The pH of the resulting solution was then determined using a digital pH meter.

3. Breaking point

A laboratory test called the breaking point test, sometimes referred to as the "break test" or "flexural test," is used to assess the mechanical strength and flexibility of solid products like deodorant sticks. A test in which the weight on the stick is gradually increased until it breaks The operation is normally done in a series of weight increases of 10 grams each after every30 seconds. The breaking point is defined as the highest weight that the stick can hold without breaking. This test determines the deodorant stick's strength and stability so that it can sustain typical handling and use without breaking.Breaking point for Herbal Deodorant stick as performed. The prepared herbal deodorant stick can hold 50g of weight for more than 30 seconds [28].

4. Spreadability test

The spreadability test for a deodorant stick evaluates how easily the product spreads on the skin and ensures smooth application. Since sticks are solid, the test is performed using modified semisolid methods. In the parallel plate method, a small scraped sample is placed between two glass plates, a known weight is applied, and the diameter of spread is measured to calculate spreadability using. Another method is the slip and drag (glide) test, where the stick is applied on a surface and the time required to move under weight is measured, reflecting real application performance. Good spreadability indicates proper formulation balance, easy glide, and better consumer acceptability [29].

5. Stability testing

Stability testing of a deodorant stick is carried out to ensure that the product maintains its physical, chemical, and microbiological properties throughout its shelf life. In this test, the deodorant stick is stored under different environmental conditions such as room temperature (25°C) and accelerated conditions (40°C ± 2°C and 75% relative humidity) for a specific period. During storage, the formulation is periodically evaluated for changes in color, odor, appearance, homogeneity, pH, melting point, and spreadability. Chemical stability is assessed by checking the degradation or oxidation of ingredients, while microbiological stability ensures that there is no microbial contamination and that preservatives remain effective. This test helps determine the shelf life, safety, and overall quality of the product and ensures that it remains stable during storage and use. Stability testing is essential to prevent issues like melting, phase separation, unpleasant odor, or reduced effectiveness [30].

6. Antibacterial Activity (Agar-Well Diffusion Method)

The antibacterial activity of all three formulations was evaluated against Escherichia coli and Staphylococcus aureus epidermidis ATCC 12228 using the agar-well diffusion method on Mueller-Hinton agar. Ciprofloxacin (5 µg/disc) was used as the positive control and melted plain base (beeswax + coconut oil without essential oils) as the negative control. The diameter of the zone of inhibition (ZOI) was measured in millimeters after 24 hours incubation at 37°C. All tests were performed in triplicate[31].

RESULT AND DISCUSSION

RESULT

Percentage Yield of Extracts

The essential oil was obtained by hydro-distillation using a Clevenger apparatus. Reported practical yield (based on your method):

Chamomile oil yield ≈ 0.3–0.8% v/w

Evaluation Results of All Batches

1. Physical Appearance

Table 6. Evaluation of physical observation

Physical observation of F1, F 2 and F 3 were studied and the results are tabulated in table no 6. The results indicate that the formulated Deodorant stick 2(F2) had compatible physical observation which was comparable with that of the Deodorant stick 1(F1) and Deodorant stick 3(F3).

2. pH Measurement

Table 7. Evaluation of pH

Fig 2. pH of F2

The pH of F1, F2 & F3, was found to be from 6.92 to 7.10 which are suitable for the human skin and non-irritant upon application (Table 7). The pH of the resulting solution was then determined using a digital pH meter.

3. Breaking point

Table 8. Evaluation Of Breaking Point

Fig 3. Braking point of F1

Breaking point was done to determine the strength of deodorant stick. The weight was gradually increased by a specific value (10 gm) at specific interval of 30 second and weight at which breaks was considered as the breaking point. The result of breaking point is displayed in table 8.

4. Spreadability Test

Table 9. Evaluation of Spreadability Test

Fig 4. Spredability of F2

Spreadability of F2 & F3 was tested and found to have excellent Spreadability which are tabulated in table 9.

5. Stability Test

Table 10. Evaluation of Stability Test

Sweating is an excess of oil or solvent occurred onto the surface of the deodorant sticks. Sweating can be seen clearly if the sample is unstable. Table 10 shows that all the sticks were stable upon storage for 2 weeks at room temperature.

Antibacterial Activity (Agar-Well Diffusion Method)

Table 11. Evaluation of Anti-Microbial Test

Fig 5. Antimicrobial Test