Development of A Herbal Transdermal Patch for Cracked Heels: A Novel Approach

Prachiti Sahane , Sakshi Bhosale, Kalyani Shelar, Kaustubh Shelar, Diksha Shinde , Gauri Mahajan , Nikita Pagare,

doi:10.5281/zenodo.16418586

Research Paper | Open Access
Volume 03 | Issue 07 | Article Id IJPS/250307338

Development of A Herbal Transdermal Patch for Cracked Heels: A Novel Approach
Prachiti Sahane * Sakshi Bhosale Kalyani Shelar Kaustubh Shelar Diksha Shinde Gauri Mahajan Nikita Pagare
Department of Pharmaceutics, Shivajirao S. Jondhle College of Pharmacy, Asangaon, Thane.

Abstract

Cracked heels, or heel fissures, are a common issue caused by dryness, pressure, and poor foot care. Conventional treatments often offer limited relief and may cause irritation. This study explores the development of a transdermal patch using Datura metal (Datura) and Brassica juncea (mustard oil), known for their anti-inflammatory, healing, and emollient properties. The paper outlines the phytochemical profiles, formulation techniques, evaluation parameters, and challenges in transdermal delivery. This herbal-based approach aims to provide a safe, effective alternative for managing cracked heels through the integration of traditional medicine with modern drug delivery systems.

Keywords

Transdermal patch, Datura (Datura metal), Mustard oil, Cracked heels, Herbal formulation, Wound healing, Drug delivery system

Introduction

Cracked heels are partial-thickness wounds caused by dryness and skin thickening, common in high-pressure areas like the heel edge¹. They can lead to pain, infection, and ulcers, especially in the elderly or diabetics. If untreated, they may progress to serious complications like cellulitis or amputation. Common symptoms include pain, bleeding, itching, and emotional distress due to their appearance. These occur due to imbalances in skin hydration, lipid content, pH, and keratin production. This study aims to develop a herbal transdermal patch that combines traditional remedies with modern delivery methods for effective management of cracked heels^2,3.Datura and mustard oil both offer valuable therapeutic benefits, especially in traditional medicine. Datura is known for its anti-inflammatory, analgesic, and antispasmodic properties, making it useful for relieving pain and swelling. It has been used topically to ease muscle and joint discomfort⁴. Mustard oil, on the other hand, is widely recognized for its warming effect, which promotes blood circulation. It also has antibacterial, antifungal, and anti-inflammatory actions, making it helpful in treating skin conditions, soothing cracked heels, and reducing localized pain⁵. Together, they can support healing and provide relief in topical applications. The present study aimed to develop and evaluate a herbal transdermal patch containing Datura metal and mustard oil for the effective treatment of cracked heels by enhancing healing, reducing inflammation, and improving skin hydration.

MATERIALS AND EQUIPMENTS:

The materials used in this study included the active pharmaceutical ingredients Datura extract and mustard oil. The excipients comprised polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), propylene glycol, glycerine, distilled water, and rose oil. The equipment utilized during the formulation and evaluation process included a Soxhlet apparatus for extraction, a hot air oven for drying, a magnetic stirrer for mixing, and a desiccator for storage and drying under controlled conditions.

Experimental Work:

Extraction of Datura seeds^6,7:

Detoxification (Shodhna process) of datura seeds⁸: The seeds were first soaked in cow’s urine for 2 hours, followed by thorough washing with distilled water to remove impurities. They were then boiled in 100 mL of milk for 1 hour to further purify and soften them⁹. After boiling, the seeds were dried completely and ground into a fine powder for use in the formulation ¹⁰.

Datura seed extraction (maceration method): For the preparation of the extract, Datura seeds were first dried for 7–10 days and then crushed into a coarse powder. A total of 50 g of this crushed seed powder was added to a jar containing 250 mL of an ethanol-water mixture for solvent extraction. The jar was sealed and stirred every 6–8 hours for a period of 48 hours at room temperature to allow maceration. After maceration, the mixture was filtered using Whatman filter paper or muslin cloth to separate the liquid extract. The solvent from the filtrate was then evaporated using a water bath maintained at 50°C or by air-drying. The final concentrated extract was stored in amber-coloured bottles to protect it from light and maintain its stability11.

2. Extraction of Mustard oil (Soxhlet method)

Mustard seeds were first dried and ground into a coarse powder for sample preparation. The powdered seeds were then placed in a thimble, and either n-hexane or petroleum ether was used as the extraction solvent. The solvent was heated, evaporated, and condensed repeatedly to extract the oil over a period of 4–6 hours using a Soxhlet apparatus. After extraction, the solvent was distilled off to obtain the pure mustard oil. Finally, the extracted oil was dried and stored in an airtight container to preserve its quality and prevent contamination12.

Fig 5: Soxhlet Extraction

Preliminary tests for active constituents

datura¹³

a. Organoleptic Evaluation Parameters:

Colour- greenish brown
Smell- pungent
Taste- bitter, slightly acidic

b. Phytochemical Tests:

Table 1: preliminary tests for active constituents- datura extract

Tests	Procedure	Observation	Inference
Wagner’s Test	To 2 ml of extract, add 1 ml of Wagner’s reagent	Reddish brown ppt formed	Alkaloid present	Fig6: Wagner’s Test
Salkowski’s Test (Steroid & Terpenoid Test	Mix 2 ml of extract with 2 ml of chloroform. Carefully add 2 ml of concentrated sulphuric acid along the sides of the test tube.	Reddish-brown colour formation	Steroid & Terpenoid Present	Fig7: Salkowski’s Test
Shinoda Test (Flavonoid Test)	To 2 ml of extract, add a few magnesium ribbon pieces and then add 1 ml of concentrated hydrochloric acid.	Red colour formation	Flavonoid Present	Fig 8: Shinoda Test
Ferric Chloride Test (Phenols & Tannins)	To 2 ml of extract, add 2-3 drops of 5% ferric chloride solution.	No change observed	Phenols & Tannins absent	Fig 9: Ferric Chloride Test
Foam Test (Saponins)	Shake 5 ml of extract with 10 ml of distilled water in a test tube vigorously for 30 seconds. Let it stand for 15 minutes.	Foam appears	Saponin present	Fig 10: Foam Test
Keller-Killiani Test (Cardiac Glycosides)	To 2 ml of extract, add 1 ml of glacial acetic acid and 1 drop of 2% ferric chloride solution. Then, carefully add 1 ml of concentrated sulphuric acid along the sides of the tube.	Reddish-brown ring formation at junction	Glycoside present	Fig11: Keller-Killiani Test

c. IR Spectroscopy

Mustard oil¹⁴

Organoleptic Tests:

Colour- yellow to dark brown colour
Odour- pungent
Taste- strong, pungent, slightly bitter

B. Specific gravity:

Table 2: Specific Gravity

Test

Procedure

Calculated value

Standard value

Specific gravity

Take 25 mL specific gravity bottle.
Fill with mustard oil, weigh.
Empty, clean, and fill with distilled water, weigh.

0.9226

0.91-0.92

Fig12: Specific Gravity

C. Adulteration Tests:

Table 3: Adulteration Tests

Test	Procedure	Observation	Inference
Nitric acid test	5 mL oil is mixed with 5 mL concentrated nitric acid	No colour change observed	No argemone oil adulteration
Turbidity Test	5 mL oil is mixed with 5 mL alcohol and 5 mL water	No turbidity appears	Mineral oil is absent

D. Saponification Value:

Table 4: Saponification Test

Test

Procedure

Calculated value

Standard value

Saponification test

About 2 g oil is refluxed with 25 mL alcoholic KOH for 30 minutes, cooled, and titrated with 0.5 N HCl

190.38 mg KOH/gm

190-198 mg KOH/gm

Fig14: Saponification test

E. Solubility Test

Table 5: Solubility Test

Test

Procedure

Observation

Inference

Soluble in ether

1ml oil mixed with 5ml ether

Mixed with ether

Soluble

Fig15: Solubility Test in Ether and Water

Soluble in water

1ml oil mixed with 5ml water

Doesn’t mixed with water

Insoluble

F. IR Spectroscopy

Formulation of Transdermal Patches:

Table 6: Formulation of Transdermal Patch

Ingredients	F1	F2	F3	F4	F5	F6
Datura Seed Extract	0.5 ml	0.5 ml	0.3 ml	0.2 ml	0.5 ml	0.1 ml
Mustard Oil	0.1 ml	0.2 ml	0.5 ml	0.4 ml	0.3 ml	0.4 ml
Polyvinyl Pyrrolidine (PVP)	1 gm	1 gm	1 gm	1 gm	1 gm	1 gm
Polyvinyl Alcohol (PVA)	1 gm	1 gm	1 gm	1 gm	1 gm	1 gm
Propylene glycol (PEG -400)	0.5 ml	0.5 ml	0.5 ml	0.5 ml	0.5 ml	0.5 ml
Glycerol	0.5 ml	0.5 ml	0.5 ml	0.5 ml	0.5 ml	0.5 ml
Distilled Water	10 ml	10 ml	10 ml	10 ml	10 ml	10 ml

The transdermal patch was prepared using the solvent casting technique. Initially, 1 gram each of Polyvinyl Alcohol (PVA) and Polyvinyl Pyrrolidone (PVP) were accurately weighed. These polymers were separately added to a beaker containing 10 mL of distilled water. The mixture was gently heated in a water bath while stirring continuously with a glass rod to ensure complete dissolution without forming bubbles. Once the polymers dissolved completely, the solution was taken off the heat and allowed to cool down to room temperature (around 25°C). Subsequently, the powdered leaf extract (active drug) was introduced into the cooled polymer solution, with constant stirring to achieve a uniform blend. Following this, plasticizers including 0.3 mL of propylene glycol and 1 mL of glycerol, along with mustard oil, PEG 400, and DMSO, were added to the mixture. The final homogeneous solution was poured into a Petri dish pre-coated lightly with glycerine to prevent adhesion. The Petri dish was then placed in a hot air oven for 2 to 4 hours to remove any trapped air bubbles. After baking, the patch was left to dry at room temperature for 20 hours, covered with a funnel to minimize rapid evaporation. Finally, the dried patch was gently peeled off from the Petri dish using a sharp blade15.

Evolution of Transdermal Patches:

Before advancing to further testing, the transdermal patches underwent an initial inspection to identify any physical defects. This included checking for air bubbles, uneven thickness, inconsistent weight, or irregular drug content. Patches showing any of these flaws were excluded to maintain uniformity and ensure the quality of the samples used in later evaluations.

Organoleptic Evaluation

The physical appearance and characteristics of the patches were assessed through organoleptic (sensory) evaluation:

Shape and Size: The patches were originally prepared in a circular form and later trimmed to the required dimensions.
Colour: Their colour varied from pale yellow to light brown.
Clarity: The patches were transparent, indicating a uniform formulation without visible signs of air pockets or crystallization.
Flexibility: They showed good flexibility, which reflects suitable mechanical strength for easy application to the skin.
Surface Texture: The surface felt smooth, suggesting an even distribution of the polymer across the patch¹⁶.

Fig 17: F1-F6 Patches

2) Thickness of the Patch:

The thickness of the transdermal patch was measured using a digital micro meter to ensure uniformity. The average thickness was approximately 0.05 mm for all batches, indicating a consistent and evenly spread matrix suitable for controlled drug delivery¹⁷.

3)Surface pH:

The surface pH of the patch was measured to ensure skin compatibility and avoid irritation. After allowing the patch to swell in 1 mL of distilled water at room temperature for 2 hours, pH indicator paper was placed on its surface. The observed pH ranged from 5.0 to 6.5, which is close to the natural pH of human skin. This indicates that the patch is skin-friendly and suitable for topical use¹⁸.

Fig 18: PH Determination Test

Swelling Index: -

Weight Increase due to Swelling:

A 1×1 cm² patch was weighed, placed in phosphate buffer (pH 7.4), and reweighed at 5-minute intervals up to 30 minutes. The increase in weight was calculated to determine water absorption.

Area Increase due to Swelling:

The patch was placed on graph paper beneath a petri dish with buffer. Swelling was measured visually. All patches showed slight swelling, with F5 and F6 showing optimal, uniform expansion¹⁹.

Fig 19: Swelling Index

5) Moisture content: -

Moisture content is an important factor that influences the flexibility and shelf life of transdermal patches. To assess this, the patch was first weighed, then stored in a desiccator containing fused calcium chloride for 24 hours at room temperature. Afterward, it was reweighed, and the percentage of moisture content was calculated using the formula:

% Moisture Content = [(Initial Weight – Final Weight) / Initial Weight] × 100²⁰

Fig 20: Moisture Content

6) Folding Endurance:

The mechanical strength and flexibility of the patch were evaluated by performing a folding endurance test. This involved folding the patch repeatedly at the same spot until it showed visible cracks or broke21.

Fig 21: Folding Endurance

7) Thumb tack test:

Tackiness of the transdermal patch was evaluated using a qualitative thumb tack test, where the thumb was gently pressed onto the adhesive surface and then lifted to assess stickiness²².

RESULT:

The transdermal patch formulated with Datura extract and Mustard Oil was evaluated for its physicochemical properties, stability, and effectiveness in healing cracked heels. The following results were obtained:

Table 7: Evaluation of transdermal patches

Test	F1	F2	F3	F4	F5	F6	Inference
Color	Light Yellow	Yellow	Pale Yellow	Light Yellow	Light Yellow	Pale Yellow	All patches showed similar shades. F1 and F5 had ideal appearance.
Clarity	Slightly Transparent	Transparent	Opaque	Transparent	Slightly Transparent	Transparent	F2, F4, and F6 had better clarity.
Flexibility	Good	Good	Fair	Good	Excellent	Good	F5 showed best flexibility.
pH	5.8	6.0	5.5	6.2	6.1	5.7	All were within acceptable range. F5 closest to skin pH.
Swelling Index	45.2%	50.1%	60.4%	70.3%	78.6%	52%	F5 showed the best swelling, making it the most suitable formulation
Folding Endurance	260	220	180	230	266	200	F1 and F5 showed highest endurance.
Moisture Content	3.2%	3.8%	4.0%	3.5%	3.3%	3.4%	F2 and F5 showed ideal moisture balance.

CONCLUSION:

Among the six prepared formulations (F1–F6), Formulation F5 demonstrated the most favourable characteristics for transdermal patch development. It achieved an ideal combination of Datura extract and mustard oil, ensuring efficient drug delivery, enhanced skin absorption, and adequate moisturization. The consistent concentrations of film-forming polymers (PVA and PVP) and plasticizers (PEG-400 and glycerol) across all formulations contributed to the uniform flexibility and adhesive nature of the patches. Therefore, Formulation F5 is considered the most promising for further investigation and possible clinical use. The herbal-based transdermal patch, formulated using PVA and PVP as the base polymers, exhibited good stability, safety, and effectiveness in managing cracked heels. It offered sustained release of active ingredients and provided multiple therapeutic benefits. Additionally, it served as a non-greasy, biodegradable, and eco-friendly option compared to conventional topical products, indicating the need for extended clinical evaluation to confirm its applicability in human use.

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