Formulation And Evaluation of Herbal Aromagel Against Steroid-Induced Adverse Effects in Asthma

Asthma is a chronic inflammatory respiratory disorder commonly treated with inhaled corticosteroids such as Beclomethasone, Budesonide, and Fluticasone. Although effective, prolonged use of these drugs may lead to adrenal suppression and immune suppression, resulting in fatigue, stress intolerance, and increased susceptibility to infections.

Asthma is a long-term condition marked by persistent inflammation in the airways. Various types of immune and structural cells, such as mast cells, eosinophills, T cells,  macrophages, neutrophills, and epithelial cells, are involved in the disease process. In individuals who are susceptible, this inflammation leads to repeated episodes of symptoms like wheezing, shortness of breath, chest tightness, and coughing, especially during the night or early morning hours. These flare-ups are commonly linked to widespread but changeable narrowing of the airways, which can typically improve either on its own or with medical intervention. The underlying inflammation also increases the sensitivity of the airways to different triggers. While many individuals experience full reversal of airflow limitation, in some cases, this reversal may be only partial.

Adverse effects of inhaled corticosteroids and their causes:

Inhaled corticosteroids used in asthma, such as beclomethasone dipropionate can produce both local and systemic adverse effects due to their pharmacological action and site of deposition. Local airway irritation may occur when drug particles deposit on the trachea, bronchi, and larynx, causing cough, throat irritation, hoarseness, and sometimes paradoxical bronchospasm due to reflex activation of airway sensory nerves. Local immunosuppression in the oral and pharyngeal mucosa reduces host defense mechanisms, leading to infections such as oral candidiasis and increased susceptibility to respiratory infections. Deposition of corticosteroids on the laryngeal muscles can result in steroid-induced myopathy, causing voice changes and dysphonia. With long-term or high-dose use, a portion of the drug may be systemically absorbed, suppressing the hypothalamic pituitary adrenal axis through negative feedback inhibition of cortisol secretion, which can lead to adrenal suppression and reduced stress response.Although effective, long-term corticosteroid therapy is associated with adverse effects including throat irritation, immune suppression, adrenal suppression, mucosal dryness, cough, and paradoxical bronchospasm. These side effects reduce patient compliance and quality of life.

Herbal Aromagel

An aromagel is a semi-solid topical gel formulation containing volatile aromatic compounds and herbal extracts, designed to release therapeutic vapors for inhalation while also allowing local transdermal absorption. It combines the advantages of aromatherapy and gel-based drug delivery.

Herbal aromatherapy offers a complementary approach by delivering volatile bioactive compounds through inhalation and topical absorption, producing rapid local and systemic effects. Medicinal plants such as Thyme, Menthol, Ginger, Licorice, Ginseng, Basil (Tulsi) and bioactive compounds like Asperuloside and Eriodictyol possess anti-inflammatory, bronchodilatory, antioxidant, immunomodulatory, and mucoprotective properties. Incorporating these agents into a herbal aromatherapy gel may help counteract corticosteroid-induced adverse effects while supporting respiratory health.

These bioactive compounds interact with multiple cellular and molecular targets, modulating signaling pathways involved in inflammation, oxidative stress, and immune responses. The inhaled volatile agents directly affect the airway mucosa and smooth muscle, promoting bronchodilation and reducing inflammation, while the transdermally absorbed compounds contribute to systemic immunomodulation and tissue repair. Additionally, the antioxidant properties of these compounds help neutralize reactive oxygen species generated during respiratory diseases or corticosteroid therapy, thereby protecting lung tissues from oxidative damage. The synergistic action of diverse herbal constituents in the gel matrix not only supports respiratory function but also offers a complementary approach to counteract the adverse effects of long-term corticosteroid use, such as mucosal thinning and immune suppression. Theoretically, aromagels represent an innovative platform that integrates phytochemical complexity with advanced drug delivery principles, optimizing therapeutic efficacy while minimizing systemic side effects. Through controlled vapor release and skin absorption, aromagels provide a holistic and multifaceted means to support respiratory health, reduce inflammation, and enhance overall well-being.

MATERIAL AND METHODOLOGY

Materials

Eriodictyol and asperuloside were used as primary active phytoconstituents. The herbal materials selected included ginger (Zingiber officinale), ginseng (Panax ginseng), licorice (Glycyrrhiza glabra), basil (Ocimum basilicum), and thyme (Thymus vulgaris), based on their reported anti-inflammatory, bronchodilatory, and antioxidant properties.

Carbopol 940 was used as a gelling agent, Polysorbate 20 as a solubilizing agent, and propyl paraben as a preservative. Purified water was used as the vehicle. All chemicals and reagents used were of analytical grade and obtained from authenticated suppliers.

Methodology

1. Preparation of Herbal Extracts

The crude plant materials were washed, shade-dried, and coarsely powdered. The powdered drugs were subjected to maceration using hydroalcoholic solvent (ethanol:water, 70:30) for 48-72 hours with occasional stirring. The extracts were filtered using muslin cloth followed by Whatman filter paper and concentrated using a water bath at controlled temperature (40-50°C). The concentrated extracts were stored in airtight containers for further use.

2. Preparation of Carbopol Gel Base

Carbopol 940 was pre-wetted with a small amount of glycerin to prevent clumping and then dispersed in purified water under continuous stirring. The dispersion was allowed to hydrate completely to form a uniform gel base. Air bubbles entrapped during mixing were removed by gentle sonication. The gel base was stored in a closed container to prevent contamination.

3. Incorporation of Herbal Extracts and Essential Oils

The prepared herbal extracts and essential oils were added gradually to the gel base with continuous gentle stirring to ensure uniform distribution. Compatibility of ingredients was confirmed by observing any phase separation or precipitation. Care was taken to avoid excessive stirring to prevent foam formation.

4. Final Adjustment and Homogenization

The formulation was homogenized using a mechanical homogenizer to obtain a smooth and uniform consistency. The pH of the gel was adjusted and maintained within the suitable range (6.5-7.0). The formulation was evaluated for uniformity and absence of aggregates.

5. Filling and Packaging

The final gel was filled into suitable containers under hygienic conditions. Proper packaging materials were selected to protect the formulation from light, moisture, and contamination. The containers were labeled with batch number, manufacturing date, expiry date, and storage instructions, and stored under controlled condition

6. Preformulation Studies

Preformulation studies of herbal extracts were carried out to determine:

• Organoleptic properties (color, odor, appearance)
• Solubility in various solvents
• pH of extract solution
• Compatibility with excipients
• These studies ensured stability and compatibility of ingredients before formulation.

Ingredients of Herbal Aromagel

Table 1 : Ingredients used in Herbal aromagel

Formulation of Herbal Aromagel

Table No 2 : Formulation Table

Evaluation Parameters

Evaluation Parameters

1. Organoleptic character

Table No. 3 : Evaluation parameter

2. pH Measurment

The pH of the formulated aromagel was measured using a calibrated pH meter and found to be

6.5.

The ideal pH of skin is 5.5 to 7.0.

Figure No 1 : pH Test

3. Spreadability

The herbal aromagel demonstrated excellent spreadability, allowing it to be evenly and smoothly applied over the skin surface with minimal effort. When a small amount of gel was placed between two glass slides, it spread uniformly without breaking or forming lumps, indicating good flow properties. This facilitated easy coverage of the affected area, enhancing user comfort and ensuring efficient delivery of the herbal actives. The balanced viscosity and non-sticky nature of the gel contributed to its superior spreadability, making it suitable for regular topical use.

Procedure:

1. A fixed amount of gel is placed between two glass slides.
2. weight is placed on the top slide for 5 minutes to  compress the gel ito a thin layer.
3. The weight is then removed  and see the difference.

Figure No 2 : Spreadability Test

4. Washability

Washability refers to how the gel can be removed from the skin using water. This is important for user convenience and hygiene especially for products used multiple times a da or over large skin areas.

Procedure:

1. A small quantity of gel is applied to a marked area on the skin.
2. It is allowed to sit for a few minutes.
3. The area then rinsed with water.

Before wash                                                             After wash

Figure No 3 : Washability Test