Formulation and Evaluation of Herbal Cream for Psoriasis Management

Psoriasis is a chronic inflammatory skin disorder that affects millions of people worldwide and is recognized as one of the most common immune-mediated dermatological diseases. It is characterized by the formation of erythematous, thickened, and scaly plaques that commonly appear on the scalp, elbows, knees, and lower back. The disease develops due to abnormal hyperproliferation and differentiation of keratinocytes accompanied by excessive activation of the immune system. Psoriasis not only affects the physical appearance of the skin but also significantly influences the emotional, psychological, and social well-being of patients. Persistent itching, pain, discomfort, and cosmetic disfigurement often lead to anxiety, depression, low self-esteem, and reduced quality of life.

The skin is the largest organ of the human body and acts as the first protective barrier against environmental hazards, microorganisms, and ultraviolet radiation. Structurally, the skin consists of three major layers: epidermis, dermis, and hypodermis. The epidermis is primarily composed of keratinocytes that undergo continuous division and shedding in a regulated cycle. Under normal physiological conditions, the regeneration cycle of skin cells takes approximately 28 days. However, in psoriasis, this cycle becomes abnormally accelerated and is completed within 3–5 days, resulting in accumulation of immature keratinocytes on the skin surface. This rapid turnover leads to formation of thick, dry, and silvery scales that are characteristic of psoriatic lesions.

The pathogenesis of psoriasis involves complex interactions between genetic, immunological, and environmental factors. It is now widely recognized as a T-cell-mediated autoimmune disease. In psoriasis, dendritic cells activate T-helper cells, particularly Th1 and Th17 cells, which release inflammatory cytokines such as TNF-α, IL-17, and IL-23. These cytokines stimulate excessive proliferation of epidermal cells and maintain a chronic inflammatory cycle. The inflammatory response also causes dilation of blood vessels and infiltration of immune cells into the dermis, leading to redness, swelling, and scaling of the skin. Genetic predisposition plays a major role in disease development, and several genes including HLA-Cw6 and IL-23 receptor genes have been associated with psoriasis susceptibility. Environmental triggers such as infections, stress, trauma, smoking, alcohol consumption, and certain medications may further precipitate disease onset or exacerbate symptoms.

Clinically, psoriasis presents in different forms, including plaque psoriasis, guttate psoriasis, pustular psoriasis, inverse psoriasis, and erythrodermic psoriasis. Plaque psoriasis is the most common type and is characterized by sharply demarcated erythematous plaques covered with silvery-white scales. Patients commonly experience itching, burning sensation, dryness, and cracking of the skin. In severe cases, bleeding and secondary infections may occur. Nail involvement is frequently observed and may include pitting, discoloration, thickening, and separation of the nail plate. Some patients also develop psoriatic arthritis, a chronic inflammatory joint disease associated with pain, stiffness, and swelling. Psoriasis is therefore considered a systemic inflammatory condition rather than merely a skin disorder.

Conventional treatment strategies for psoriasis include topical corticosteroids, coal tar preparations, vitamin D analogues, retinoids, immunosuppressive agents, biologics, and phototherapy. Although these therapies are effective in controlling symptoms, prolonged use is often associated with several adverse effects such as skin atrophy, irritation, hepatotoxicity, nephrotoxicity, immune suppression, and tachyphylaxis. In addition, high treatment costs and frequent recurrence limit patient compliance and long-term therapeutic success. Consequently, there is a growing interest in safer, economical, and naturally derived alternatives for psoriasis management.

Herbal medicines have been traditionally used in various systems of medicine for treating skin disorders due to their wide range of pharmacological activities and better safety profile. Medicinal plants such as turmeric, neem, manjistha, aloe vera, and guduchi possess potent anti-inflammatory, antioxidant, antimicrobial, antiproliferative, and wound-healing properties.

MATERIAL AND METHODOLOGY

Materials

The materials used in the preparation of the polyherbal cream were selected based on their therapeutic properties, compatibility, safety, and suitability for topical application. Herbal extracts such as turmeric, neem, manjistha, aloe vera, and guduchi were used as active ingredients due to their anti-inflammatory, antioxidant, antimicrobial, and wound-healing activities which are beneficial in the management of psoriasis. These medicinal plants have been traditionally used in Ayurvedic and herbal medicine for the treatment of various skin disorders.

Turmeric (Curcuma longa) contains curcumin, which possesses strong anti-inflammatory and antioxidant properties. Neem (Azadirachta indica) is known for its antimicrobial and immunomodulatory effects. Manjistha (Rubia cordifolia) acts as a blood purifier and exhibits anti-inflammatory activity. Aloe vera (Aloe barbadensis) provides soothing, moisturizing, and wound-healing effects, while guduchi (Tinospora cordifolia) contributes immunomodulatory and antioxidant actions.

Different solvents such as distilled water and ethanol were used for extraction of phytoconstituents from plant materials. Ethanol acts as an effective solvent for extraction of both polar and moderately non-polar compounds, whereas distilled water is mainly used for extraction of water-soluble constituents.

The cream base was prepared using pharmaceutical excipients including beeswax, stearic acid, cetyl alcohol, liquid paraffin, glycerin, triethanolamine, methyl paraben, propyl paraben, and distilled water. Beeswax and stearic acid were used as stiffening and emulsifying agents to provide suitable consistency to the cream. Cetyl alcohol acted as an emollient and stabilizer, while liquid paraffin served as a moisturizing agent. Glycerin was added as a humectant to maintain skin hydration. Triethanolamine was used for pH adjustment and emulsion stabilization. Methyl paraben and propyl paraben were incorporated as preservatives to prevent microbial contamination and improve shelf life. Buffer solutions of pH 5.5–7.4 were used for pH adjustment and evaluation studies.

Various laboratory apparatus and instruments were used during the preparation and evaluation of the herbal cream formulation. The apparatus included mortar and pestle, beakers, measuring cylinders, glass rods, spatulas, thermometers, and filter papers. These tools were mainly used for grinding plant materials, measuring ingredients, mixing formulations, filtration, and monitoring temperature during preparation.

A mortar and pestle is a traditional laboratory apparatus used for crushing and grinding dried herbal materials into fine powder to increase the surface area for extraction. Beakers and measuring cylinders were used for measuring and mixing solvents and ingredients accurately. Glass rods and spatulas assisted in stirring and transferring materials during formulation.

Different laboratory instruments were also utilized to ensure precision and uniformity in the formulation process. A digital analytical balance was used for accurate weighing of herbal extracts and excipients. The balance works on the principle of electromagnetic force compensation and provides highly accurate measurements necessary for pharmaceutical formulations.

A hot plate and water bath were used to provide controlled heating during preparation of the oil and aqueous phases. The water bath ensures uniform and gentle heating without direct exposure to flame, thereby preventing decomposition of heat-sensitive ingredients. A magnetic stirrer was used to achieve continuous and uniform mixing during extraction and emulsification processes.

A pH meter was employed to determine the acidity or alkalinity of the prepared cream. Maintaining suitable pH is important to ensure compatibility with skin and to avoid irritation. A thermometer was used to monitor temperature during extraction and cream preparation to maintain process accuracy and stability of ingredients.

METHODOLOGY

1. Extraction of Herbal Materials

Extraction is an important step in herbal formulation development because it separates the biologically active constituents from crude plant materials. The solvent used for extraction is called the menstruum. Selection of a suitable solvent depends on the nature of phytoconstituents and the polarity of compounds to be extracted. Polar solvents such as water, methanol, and ethanol are commonly used for extraction of polar compounds, while non-polar solvents like hexane are used for non-polar constituents.

In the present study, the maceration method was employed for extraction of herbal drugs. Maceration is a simple and economical extraction technique in which plant materials are soaked in suitable solvents for a specific period to dissolve active constituents. This method is especially suitable for heat-sensitive compounds because extraction occurs at room temperature without exposure to high heat.

Preparation of Plant Materials

The collected herbal materials were first cleaned thoroughly to remove dust, impurities, and foreign particles. The plant materials were then shade dried at room temperature to preserve heat-sensitive phytoconstituents. After drying, the materials were powdered using a mechanical grinder and stored in airtight containers until further use. Powdering increases the surface area of plant materials and improves extraction efficiency.

Extraction of Manjistha

Powdered roots of manjistha were subjected to maceration using methanol as solvent. The powdered material was soaked in methanol and kept for extraction until the solvent became colorless, indicating complete extraction of active compounds. The extract obtained was filtered and dried for further use in formulation.

Extraction of Turmeric

Turmeric extract was prepared by cold maceration using ethanol as extracting solvent. The powdered turmeric material was mixed with ethanol and continuously stirred using a magnetic stirrer at controlled speed. After extraction, the mixture was filtered using filter paper and the filtrate was concentrated using a rotary evaporator at controlled temperature. The final concentrated extract was stored under refrigerated conditions to maintain stability.

Extraction of Neem

Fresh and dried neem leaves were cut into small pieces, powdered, and mixed separately with different solvents such as ethanol, methanol, ether, acetone, and distilled water. Continuous grinding and mixing were carried out to facilitate extraction. The mixtures were filtered, and the filtrates were concentrated using a rotary evaporator before storage at low temperature.

Extraction of Guduchi

Guduchi plant materials were washed thoroughly, shade dried, and powdered. The aqueous extraction method was used in which powdered material was soaked in distilled water and kept at room temperature for several hours with occasional shaking. The extract was then filtered using Whatman filter paper and stored for formulation studies.

2. Preparation of Polyherbal Cream

The polyherbal cream was prepared by the emulsification method using oil and aqueous phases. The formulation process was carried out carefully to ensure uniformity, stability, and smooth texture of the cream.

Preparation of Oil Phase

The oil phase was prepared by taking beeswax, stearic acid, cetyl alcohol, and liquid paraffin in a clean beaker. The ingredients were heated on a water bath at a temperature of about 70–75°C until complete melting occurred. Continuous stirring was maintained to obtain a homogeneous oily mixture.

Preparation of Aqueous Phase

In another beaker, distilled water was taken and preservatives such as methyl paraben and propyl paraben were added. The aqueous phase was heated separately to the same temperature as the oil phase to ensure proper emulsification.

Emulsification Process

The heated aqueous phase was slowly added to the oil phase with continuous stirring. Stirring was maintained using a glass rod or mechanical stirrer to form a stable oil-in-water emulsion. Proper temperature and stirring speed were maintained throughout the process to avoid phase separation.

Cooling and Addition of Herbal Extracts

After emulsification, the prepared cream base was allowed to cool gradually while stirring continuously. Once the temperature dropped below 40°C, the herbal extracts including turmeric, neem, manjistha, guduchi, and aloe vera were added. These extracts were mixed thoroughly to ensure uniform distribution throughout the formulation.

Homogenization and Storage

The prepared cream was further homogenized to obtain a smooth texture and uniform consistency. Homogenization helps in reducing particle size and improving stability of the cream. Finally, the formulation was transferred into clean and dry containers, properly labeled, and stored in a cool and dry place for further evaluation studies.

The prepared polyherbal cream was expected to provide anti-inflammatory, moisturizing, soothing, and healing effects suitable for the management of psoriasis. The combination of different herbal extracts in a topical cream base may enhance therapeutic effectiveness while minimizing side effects associated with synthetic medications.

3. Evaluation Parameters

a) pH Test

The pH of the prepared herbal cream was determined to evaluate its compatibility with skin. A small quantity of cream was dispersed in distilled water, and the pH was measured using a calibrated digital pH meter. The pH values obtained for formulations F1, F2, and F3 were found to be 5.9, 6.1, and 6.3 respectively. These values are close to the normal skin pH range, indicating that the formulation is suitable for topical application and is less likely to cause irritation or dryness to the skin.

Result:

F1 – 5.9

F2 – 6.1

F3 – 6.3

Inference:

The formulations were found to be skin compatible and safe for external application.

b) Spreadability Test

Spreadability is an important parameter that determines the ease of application of cream on the skin surface. The test was performed using a wooden block and pulley apparatus. A fixed amount of cream was placed between two glass slides, and weight was applied to form a uniform layer. The time required for the upper slide to move under the influence of weight was measured. The prepared herbal cream showed good spreadability with smooth texture and uniform spreading characteristics.

Result:

The cream exhibited good spreadability and smooth application.

Inference:

The formulation can be easily applied and distributed uniformly over the affected skin area.

c) Washability Test

Washability determines how easily the cream can be removed from the skin surface after application. In this test, a small quantity of cream was applied on the skin and washed with lukewarm water. The prepared cream was removed easily without leaving excessive oily residue on the skin.

Result:

The cream was easily washable with lukewarm water in all batches.

Inference:

The formulation is non-greasy, user-friendly, and suitable for regular topical use.

d) Irritancy Test

The irritancy test was carried out to evaluate the safety of the herbal cream on the skin. A small area of approximately 1 cm² on the dorsal surface of the hand was selected, and the cream was applied to the marked area. The site was observed at regular intervals for 24 hours for any signs of irritation such as redness, erythema, edema, itching, or swelling.

Result:

No signs of irritation, redness, edema, or itching were observed after application.

Inference:

The prepared herbal cream was found to be non-irritant and safe for topical application on the skin

Formulation table