FORMULATION AND EVALUATION OF HERBAL FOOT CARE STICK CONTAINING CINNAMOMUM VERUM AND JUGLANS REGIA

Cosmetics are defined as articles intended to be rubbed, poured, sprinkled or sprayed on, or introduced into, or otherwise applied to, the human body or any part thereof for cleansing, beautifying, promoting attractiveness or altering the appearance and includes any article intended for use as a component of cosmetic.^[1]

The word 'cosmetic' is derived from a Greek word - kosmestikos that means adornment and preparation. Cosmetics refer to all of the products used to care for and clean the human skin and make it more beautiful. The intentions of using cosmetic product is to maintain the body in a good condition, protect it from the effect of the environment and aging process, change the appearance and make the body smell nicer. Cosmetic products are widely used by every socio economic class of human beings to cleanse, perfume, protect and change the appearance of the skin.^[2]Herbal Cosmetics, referred as Products, are formulated, using various permissible cosmetic ingredients to form the base in which one or more herbal ingredients are used to provide defined cosmetic benefits only, shall be called as “Herbal Cosmetics”.^[3]

FOOT SKIN

The skin of the foot is a highly specialized structure designed to support body weight and enable functions such as standing, walking and running. It is particularly thick on the plantar surface (sole) in order to resist continuous friction and pressure. The outermost layer of the foot, known as the epidermis, consists of tightly packed keratinized cells that act as a protective barrier against external damage, microorganisms and dehydration. The stratum corneum of the heel is the thickest in the entire human body and is responsible for providing mechanical strength. Beneath the epidermis lies the stratum lucidum, a layer found only in thick skin such as that of the feet and hands, which contributes to the smooth and tough structure of the sole. Unlike other areas of skin, the plantar region does not contain sebaceous glands or hair follicles, which is why dryness and cracking of heels are common. However, the area is rich in sweat glands that help maintain temperature regulation and moisture levels in the skin.Deeper to the epidermis is the dermis, which is composed of collagen and elastic fibers that give the skin strength, flexibility and durability. This layer contains blood vessels that nourish the outer layers and assist in wound healing. It also houses numerous sensory receptors, making the foot highly sensitive to pressure, vibration and pain. These sensations help maintain balance and alert the body to potential injuries while walking. The deepest layer of the foot skin called the hypodermis or subcutaneous layer, contains thick fatty tissue that serves as a shock absorber. This padding is especially prominent in the heel region and helps protect underlying bones and joints from impact forces experienced during movement.

Overall, the unique structure of foot skin ensures effective protection, cushioning and support to the body. However, because it is constantly exposed to stress and lacks natural oil secretion. it is prone to common conditions such as callus formation, fissures, blisters and fungal infections. Proper foot care, including hydration and hygiene is essential to maintain healthy skin and prevent discomfort or disease. The specialized anatomy of the foot skin highlights its vital role in mobility, stability and overall quality of life.^[4]

Foot skin has 3 main layers:

Figure1: Structure of Foot Skin

HERBAL FOOTCARE STICK

A herbal foot care stick is a convenient topical formulation designed to nourish, protect and repair the skin of the feet using natural plant-derived ingredients. Since the skin of the heel and sole is the thickest and usually prone to dryness, cracks, callus formation and fungal infections due to absence of oil glands. The formulation aims to provide intense moisturization and restorative action. This type of product typically contains herbal oils, plant extracts, waxes and natural emollients that create a protective barrier to prevent water loss and soften hardened skin. The herbal constituents often possess anti-bacterial, anti-fungal and anti-inflammatory properties that help maintain healthy feet, reduce odour and support healing of minor wounds and fissures. Herbal foot care sticks are easy to apply due to their solid stick form and allow targeted application without the need for direct hand contact making them hygienic and travel-friendly. They offers a combined effect of hydration, soothing and antimicrobial protection. The presence of waxes such as beeswax helps in providing the product its solid consistency and enhances its adherence to the skin, which is beneficial for long-lasting moisture retention. Regular application of a herbal foot care stick improves the texture, smoothness and elasticity of foot skin, preventing cracking and discomfort while restoring overall foot health.^[8]

Since the product is based on natural herbal ingredients, it reduces the risk of irritation and side effects associated with synthetic chemicals, making it suitable for long-term personal care. Due to increasing preference for natural cosmetics and easy-to-use solid formulations, herbal foot care sticks are gaining importance in both cosmetic and therapeutic foot care. Their role becomes essential in maintaining soft, healthy  and well-protected feet in daily life.

The herbal foot care stick formulated with cinnamon extract and walnut works by deeply moisturizing, protecting and repairing the thick and dry skin of the feet. Cinnamon contains active compounds such as cinnamaldehyde, polyphenols and essential oils that show strong antibacterial, antifungal  and anti-inflammatory properties. When applied to the heel and sole, cinnamon extract helps to inhibit the growth of common foot pathogens including fungi responsible for athlete’s foot and bad odour. Its mild warming effect improves local blood circulation, which enhances nutrient supply to the damaged tissues and promotes faster skin regeneration and healing of cracks and calluses. Cinnamon also supports exfoliation of dead cells, helping to smoothen rough surfaces on pressure areas of the feet.^[7][8]

Walnut contributes nourishment in the form of omega-3 fatty acids, proteins, vitamins (E & B complex) and minerals that restore the skin barrier and help retain moisture in the stratum corneum. The presence of antioxidant compounds protects the skin from oxidative stress caused by friction and environmental exposure. Walnut has natural emollient and softening action, which reduces dryness, prevents fissure formation and improves the overall elasticity of the heel pad. When both cinnamon and walnut ingredients penetrate the skin, they synergistically provide hydration, antimicrobial protection  and rejuvenation. Additionally, waxes and lipids in the stick form a protective occlusive layer, reducing water loss and shielding the skin from further mechanical damage. With consistent application, this formulation leads to visibly softer, smoother and healthier feet with reduced cracking, pain  and infection risks.^[7]

Advantages

• Made from natural herbal ingredients, reducing the risk of irritation and side effects.
• Cinnamon provides strong antibacterial and antifungal action, preventing foot infections and odour.
• Improves blood circulation in heel and sole, promoting faster healing of cracks.
• Walnut offers deep moisturization due to omega fatty acids and vitamin E.
• Helps restore the skin barrier and prevents dryness and fissure formation.
• Antioxidants in walnut protect the skin from damage and support regeneration.
• Stick form allows clean, easy and targeted application without using hands.
• Forms a protective film over the skin to retain moisture for a longer time.
• Reduces callus formation and softens rough skin.^[7]

MATERIALS AND METHODS

Materials

Methyl Paraben (Loba Chemie, Mumbai), Beeswax (Oxford Lab, Maharashtra), Castor Oil (Isochem Laboratory,Kochi), Paraffin Wax (Finar Ltd Ahmedabad) ,Cetosteryl Alcohol(Loba Chemie Mumbai).

Methods

Plants Used:  

a) Cinnamon (Cinnamomum verum)

Cinnamomum verum, commonly known as True Cinnamon or Ceylon Cinnamon belongs to the family Lauraceae. It is a small evergreen tree native to Sri Lanka and Southern India. The bark of the plant is widely used in traditional and modern systems of medicine. It possess numerous therapeutic properties such as antibacterial, antifungal, antioxidant^[5] and anti-inflammatory effects due to the presence of active constituents like Cinnamaldehyde, Eugenol  and Cinnamic acid. These properties make cinnamon a valuable ingredient in cosmetic and pharmaceutical formulations aimed at promoting skin health and protection. It is commonly used as spices  and widely cultivated for its aromaticity.^[9]

b) Walnut (Juglans regia)

Juglans regia, commonly known as Walnut belongs to the family Juglandaceae. It is a large deciduous tree native to Central Asia and the Himalayan regions. The fruit (nut) and oil extracted from walnuts are rich in polyunsaturated fatty acids, tocopherols, phenolic compounds  and essential vitamins. These components are responsible for its moisturizing, nourishing  and antioxidant properties. In cosmetic applications, walnut oil and powder are used to soften rough skin, prevent dryness and provide gentle exfoliation, making it suitable for foot-care preparations.^[9]

Collection of Bark and Seeds.

The cinnamon bark and walnut seeds were procured from a local herbal raw material supplier. Both raw materials were authenticated and examined for quality. The collected plant materials were cleaned, shade-dried and finely powdered using a mechanical grinder. The powders were stored in airtight containers for further use in the formulation.^[9]

Preparation of Herbal Extracts.

The Cinnamon extract were prepared by weighing 10g of dried bark, powdered mechanically and soaked in 100ml of ethanol overnight. After 24hrs the extract were filtered using funnel and filter paper and used for the preparation of herbal foot care stick.The walnut milk extract was prepared by weighing 10g of walnut kernels, which were cleaned and soaked in 100ml of warm distilled water for 8-10hrs.The soaked kernels were then blended mechanically into a smooth mixture and filtered through a muslin cloth to obtain the milk extract .The filtrate (walnut milk) was stored in an airtight container and used for the preparation of herbal foot care stick.^[10]

Figure no.2: Extract of Cinnamon and Walnut

Formulation of Herbal Foot care stick

The herbal foot care stick was formulated using a conventional Hot fusion method. Initially, Beeswax and paraffin wax were placed in a china dish and melted on a water bath at 60-65? until a clear, homogeneous oil phase was obtained. Castor oil was then incorporated slowly into the molten wax base with gentle stirring  and heating was continued to maintain uniformity. Cinnamon extract and walnut milk were mixed separately in a glass beaker, followed by the addition of Cetostearyl alcohol to aid proper dispersion of the active ingredients. This mixture was gradually added to the molten base under continuous stirring. Methyl paraben was introduced into the formulation at approximately 60?

The herbal foot care stick was prepared by the following ingredients given in the table no.1

Table no.1:Formula for the preparation of herbal foot care stick

Figure no. 3: Formulated footcare stick

4.Phytochemical Screening of the extract.

The ethanolic extract of Cinnamomum verum and Juglans regia milk was subjected to the following qualitative test to reveal the presence of carbohydrates, alkaloids, glycosides,  flavonoids, terpenoids, phenolic compounds, tannins and saponins.^[11][13]

i. Test for Alkaloids

• To 0.1ml of Mayer’s reagent, 0.5ml of extract solution was added and mixed in a test tube and looked for any precipitates. A pale-yellow precipitate indicates the presence of alkaloids.
• Equal volume of Dragendroff’s reagent and extract solution was mixed on a clean test tube. Formation of orange, brown precipitate shows the presence of alkaloids.

ii. Test for Carbohydrate

• Molisch test

2ml of extract was added into the test tube and few drops of Molisch reagent was added to extract. To this 2ml of concentrated H2SO4 was dropped out from the walls of test tube. Formations of a violet colour ring at the junction of two liquids indicates the presence of carbohydrate.

• Fehling's test

1ml of the extract was boiled with lml each of Fehling solution A and B on water bath. Appearance of a red or brick precipitate indicates the presence of sugar.

iii. Test for Glycosides

• Legal test

A small quantity of extract was heated with dilute HCl to the hydroxylate 2ml of pyridine and 2ml of sodium nitroprusside solution was added. Formation of pink red colour indicates the presence of glycosides.

• Borntrager's test

A small portion of the extract was boiled with dil.H2SO4 and filtered while hot. The filtrate was cooled and 5ml of solvent ether was added and shaken well. Ether layer was separated and treated with equal volume of ammonia solution. Rose pink in the ammonical layer shows the presence of anthraquinone glycoside.

iv. Test for Saponins

• Foam test

A few ml of extract was mixed with 20ml of distilled water in a 100ml measuring cylinder and shaken for 15mins. 1cm of foam indicate the presence of saponins. About 3ml of extract solution was mixed with lead sub acetate solution. Formation of precipitate indicates the presence of saponin.

v. Test for Flavonoids

• One drop of extract was caught on a filter paper and was exposed to ammonia.

    Yellow spots show the presence of flavonoids.

• Extract was treated with a few drops of lead acetate solution. Formation of yellow colour precipitate indicates the presence of flavonoids.

vi. Test for Tannins and Phenolic compounds

• To 1ml of Gelatin solution add 10% NaCl and 1ml extract, precipitation occurs if tannins are present.
• To 2ml of aqueous solution of the extract, 0.5ml of ferric chloride solution was added. Blue colour indicated the presence of phenolic compounds.

vii. Test for Proteins and Amino acids

• Xanthoproteic test

The extract was treated with few drops of concentrated nitric acid solution. Formation of  yellow colour indicates the presence of protein.

• Ninhydrin test

To the extract 0.25% of Ninhydrin reagent was added and boiled for few minutes. Formation of blue colour indicates the presence of amino acids.

viii. Test for Terpenoid

• 2.0ml of chloroform was added with the 5 ml aqueous plant extract and evaporated on the water path and then boiled with 3 ml of H2SO4 concentrated. A grey colour formed which showed the entity of terpenoids.^[11][13]

EVALUATION OF HERBAL FOOT CARE STICK

To evaluate the prepared formulation, Various evaluation test are performed to determine the physiochemical parameters.

i. Physical Appearance: 

Visual inspection of the herbal foot care stick was performed. The colour, odour and homogeneity  of the herbal foot care stick were checked.

ii. Determination of the pH:

In 100 ml of petroleum ether,1g of herbal foot care stick was mixed. The pH of the mixture was examined using a previously standardized digital pH metre.^[14]

iii. Spreadability:

The spreadability was expressed in terms of time in seconds taken by two slides to slip off from the foot care stick, placed in between the slides, under certain load. Lesser the time taken for separation of the two slides better the spreadability. Good spreadability ranges from 5 to 7cm. Two sets of glass slides of standard dimension were taken. Then one slide of suitable dimension was taken and the stick formulation was placed on that slide. Then the other slide was placed on top of the formulation. Then a weight or certain load was placed on the upper slide so that the stick formulation between the two slides was pressed uniformly to form a thin layer. The excess of formulation adhering to the slides was scrapped off. The upper slide was allowed to slip of freely by the force of weigh placed over it. The time taken by the slide to slip off was noted.^[17]

Spreadability = ml/t

Where,  m= standard weight which is placed over the upper slide (100g)

              l= length moved by the slide 

              t= time taken in seconds

iv. Melting Point

Determination of melting point is important as it is an indication of the limit of safe storage. The melting point of formulated foot care stick was determined by Capillary tube method. The capillary tube and thermometer was fitted in a Burette and is immersed in beaker containing Paraffin wax and is then gently heated. The product in the test tube was slowly melted, The temperature at this point was observed. Melting point of each formulation was determined.^[11]

Figure no. 4: Melting point apparatus

v. DPPh Assay for Antioxidant study:

The DPPh (2,2-diphenyl-1-picrylhydrazyl) assay is a widely used method for evaluating the antioxidant activity of plant extracts, compounds and foods. The assay measures the ability of antioxidants to scavenge the stable free radical DPPh, which is a stable nitrogen-centered radical with a deep purple colour. The reduction of DPPh by an antioxidant results in a colour change from purple to yellow, which can be measured spectrophotometrically at 517 nm. The DPPh assay is a simple, rapid and sensitive method for assessing antioxidant activity, making it a popular choice for screening and evaluating the antioxidant potential of various samples

To evaluate the antioxidant property using DPPH assay, follow steps are followed;

• Prepare DPPH Solution: To prepare 100 ml of 0.1 mM, Dissolve 0.0034 g(3.94 mg)in 100 ml ethanol.
• Preparation of standard ascorbic acid:  Dissolve 10 mg Ascorbic acid in 10 ml ethanol. Prepare serial dilutions for standard curve(50,100,150mg/ml).
• Prepare Sample: Prepare a series of concentrations of the sample (50,100,150mg ) in ethanol.
• Mix DPPH and Sample & Test: Mix 3 ml of DPPH solution with 1,1.5,2 ml of sample And Test solution.
• Make up to 10 ml in a standard flask.
• Incubate: Incubate the mixture in the dark for 30 minutes.
• Measure Absorbance: Measure the absorbance at 517 nm using a spectrophotometer.
• Calculate IC50: Calculate the IC50 value, which is the concentration of sample required to scavenge 50% of DPPH radicals.

Formula:

% Inhibition = (A₀ – A₁) / A₀ x 100

A₀ = Absorbance of DPPH solution without sample

A₁ =Absorbance of DPPH solution with sample.^[12][17]

vii. Microbial study:

The antimicrobial efficiency of optimized formulation (F3) was studied using Escherichia coli. The inhibitory effect of formulation on the studied microorganisms was evaluated using Agar well diffusion method. All the glass wares required to conduct the test were sterilized by dry heat method using hot air oven. Nutrient agar medium was prepared and sterilized by autoclaving under aseptic conditions. Nutrient agar medium was inoculated with 0.1ml of fresh overnight nutrient broth culture of bacterium in flasks and poured into sterile petri plates. Allow them to solidify. After solidification cups were made on each plate with the help of sterile borer of 6mm diameter and poured appropriate amount of formulation to the cup. Incubate the plates for 24hrs at 37°C. After the incubation period, the plates were examined for inhibition of bacterial growth around the wells. The plates were examined for inhibition of bacterial growth around the wells. Alcohol was used as the control, while ciprofloxacin served as the standard antimicrobial agent. The plates were then incubated at 37°C for 24 hours. After the incubation period, the plates were observed for the presence of zones of inhibition around the wells, indicating antimicrobial activity of the formulation.^{[ [18]}

RESULTS

Preliminary phytochemical screening

Preliminary phytochemical screening was evaluated and the results are given in the table no. 2

Table no.2:Preliminary Phytochemical Screening

+ present,-absent

The following evaluation test were performed on formulated Herbal footcare stick.

i. Physical Appearance: 

 The colour ,odour of the formulated herbal foot care stick were inspected and determined.

Table no.3:Table showing characteristics of formulation

The homogeneity of the formulated foot care stick was judged by the visual appearance and touch. The appearance and touch of the foot care stick was good.

ii. Determination of pH

The pH of the prepared formulations were determined using digital pH meter and the pH of the prepared formulations are shown in the table no.4,the pH of these formulations are compatible with Foot skin, thus cause no irritation.

Table no.4:pH of formulations

iv.Spreadability

Spreadability of the formulated herbal foot care stick were determined by using the Slip and Drag method. The time taken for the movement of upper slide is given in the following table no.5

Table no.5: Spreadability of formulations

Satisfactory spreadability of formulated herbal foot care stick was found to be F3.

vi. Melting point

Melting point of all the footcare stick formulations was found in between 47-59°C. Thus all the formulation possess typical stick property. Moderate melting property of stick prevents its melting during storage and promotes ease of application on the foot. The melting point results were depicted in table no 6.

Table no.6:Melting point of formulations

v. Antioxidant study

The DPPH method measures the ability of a compound scavenge free radicals. The ability of antioxidants is related to the ability of compound components to donate electrons or hydrogen. A molecule can donate electron or hydrogen will react to DPPH. The mechanism will change the colour solution from purple to yellow. We got a yellow coloured solution while adding DPPH solution and the percentage inhibition found to be shown in table no.6Antioxidant activity is the ability of a compound or an extract to inhibit oxidation reaction which can be expressed by the presentation of DPPH absorption.Extract exhibit percentage inhibition that they possess a good antioxidant activity from the table no.7

Table no.7 percentage inhibition

 T₁= Test Sample 1

T₂= Test Sample 2

T₃= Test Sample 3

T₄= Test Sample 4

T₅= Test Sample 5

T₆= Test Sample 6

S₁=Standard Sample 1

S₂=Standard Sample 2

S₃=Standard Sample 3

Selection of best formulation

Out of the five formulations prepared, one formulation is selected as the best formulation based on the following evaluation parameters

• pH
• Spreadability
• Melting point
• DPPh assay

Formulation F3 was selected as the best formulation which showed a pH 6.5, spreadability of 5.5g.cm/sec and showed a better antioxidant activity.

The selected formulation F3 was then evaluated for antibacterial activity.

vii. Antimicrobial study

The Antimicrobial study of herbal foot care stick was done using E.coli. The Best formulation F₃ was studied and it showed a satisfactory antimicrobial property.

Figure no.5: Microbial Test for the Formulation F3Figure no.6: Microbial test of control and standard

DISCUSSION

The present study demonstrates the successful formulation and evaluation of a herbal foot care stick containing Cinnamomum verum and Juglans regia. Phytochemical screening confirmed the presence of flavonoids, glycosides, terpenoids and phenolic compounds, which are known to contribute to antioxidant and antimicrobial activities. Among the five formulations, F3 exhibited optimal physicochemical properties, including acceptable pH close to skin neutrality, good homogeneity  and satisfactory spreadability, making it suitable for topical application. The antioxidant activity evaluated by the DPPH assay showed significant free radical scavenging ability, indicating the protective potential of the formulation against oxidative stress. Furthermore, the antimicrobial study against Escherichia coli confirmed the inhibitory effect of the optimized formulation, supporting the traditional use of cinnamon for microbial control. Overall, the findings suggest that the developed herbal foot care stick is stable, safe and effective for managing dry, cracked and infection-prone foot skin, highlighting its potential as a natural cosmetic foot care product.