Formulation and Evaluation of a Herbal Face Mist - Incorporating Orange Peel (Citrus sinensis) and Green Tea (Camellia sinensis) Extracts

1. 1. Cosmeceuticals

Cosmeceuticals occupy a distinctive position at the intersection of cosmetics and pharmaceuticals, delivering biologically active ingredients that exert measurable physiological effects on the skin. Unlike conventional cosmetic products, which address appearance at a superficial level, cosmeceuticals are formulated to improve skin health at a cellular level through mechanisms such as antioxidant activity, anti-inflammatory modulation, and structural protein support. In recent years, consumer preference has shifted markedly toward herbal and naturally derived skincare, driven by growing awareness of the adverse effects associated with prolonged exposure to synthetic compounds — including skin irritation, allergic sensitisation, and cumulative toxicity. This trend is further reinforced by environmental concerns and the global movement toward sustainable, ecofriendly products. Plant-based formulations are perceived as safer and richer in bioactive compounds such as flavonoids, polyphenols, tannins, and vitamins, all of which contribute to therapeutic efficacy. Among herbal skincare formats, the facial mist has gained considerable popularity due to its ease of application, refreshing sensory profile, and capacity to deliver active ingredients in a fine, rapidly absorbing dispersion. Herbal face mists serve as effective delivery systems for phytoconstituents, allowing direct application to the skin surface without clogging pores or leaving a heavy residue. They are particularly beneficial in conditions of environmental stress — high temperatures, low humidity, and atmospheric pollution — which disrupt skin barrier integrity and promote oxidative damage. The present study was conceived against this backdrop. Orange Peel (Citrus sinensis) and Green Tea (Camellia sinensis) were selected as the primary active ingredients on the basis of their well characterised phytochemistry and complementary skin benefits. Together, they form a synergistic combination capable of hydrating, protecting, brightening, and revitalising the skin. The study aimed to formulate a stable, safe, and effective Herbal face mist and to evaluate it against standard cosmeceutical parameters in accordance with established pharmaceutical guidelines.

1. 2. Skin Physiology

The skin is the body’s largest organ and acts as a protective barrier against environmental, chemical, and microbial damage. It helps maintain body temperature, prevents water loss, and protects internal tissues. The skin consists of three layers: epidermis, dermis, and hypodermis.

The epidermis, particularly the stratum corneum, constitutes the exterior protective barrier that preserves skin moisture and inhibits Transepidermal Water Loss (TEWL).Damage to this layer can cause dryness, irritation, and sensitivity.

The dermis contains collagen and elastin fibers responsible for skin strength and elasticity. Environmental factors such as UV radiation and pollution generate reactive oxygen species (ROS), which damage these fibers and lead to premature aging, wrinkles, and uneven skin tone. Antioxidant-rich formulations help protect the skin from such damage.

Healthy skin also contains an acid mantle with a slightly acidic pH of 4.5–5.5, which supports beneficial microorganisms, prevents harmful microbial growth, and helps repair the skin barrier. Disturbance of this pH balance may weaken skin protection and increase the risk of irritation and infections.

1. 3. Face Mist Overview

Face mist is a liquid cosmetic product intended for direct application onto the facial skin. It primarily serves to:

• Hydrate and rejuvenate the skin
• Preserve skin moisture
• Offer a cooling and calming effect
• Enhance skin freshness throughout daily activities

Face mist formulations typically include:

• A water or hydrosol base

• Botanical extracts or active components
• Humectants and preservatives

Herbal face mists are gaining popularity due to their natural ingredients, which may offer additional skin advantages such as:

• Antioxidant properties
• Antibacterial benefits
• Anti-inflammatory characteristics

In the context of acne-prone skin care, face mist can act as an effective topical delivery method for antibacterial herbal extracts.

2. Literature Review :

The scientific literature provides substantial support for the use of plant-based antioxidants in topical formulations. Studies on face mist and toner formulations incorporating botanical extracts — including pomegranate peel, mangosteen peel, dragon fruit peel, and Centella asiatica — have demonstrated significant antioxidant activity, physical stability, and dermatological acceptability. DPPH radical scavenging assays have been widely employed to quantify antioxidant potential in such formulations, consistently validating the efficacy of polyphenol-rich plant extracts. Orange peel (Citrus sinensis) has been extensively reviewed for its skin benefits. Hesperidin, the predominant flavonoid in citrus peel, has been reported to improve microcirculation, stimulate collagen synthesis, strengthen the skin barrier, and inhibit melanin formation. Vitamin C, present in significant concentrations in orange peel, is a well-established co-factor in collagen biosynthesis and a potent antioxidant. Natural acids present in the peel further contribute mild exfoliating activity, promoting skin renewal and radiance. Green tea (Camellia sinensis) is among the most studied herbal ingredients in dermatology. Its principal bioactive, epigallocatechin gallate (EGCG), exhibits strong free-radical scavenging activity, inhibits inflammatory mediators, controls acne-causing bacteria, and provides photoprotection against UV-induced damage. EGCG has also been shown to activate cellular repair pathways, supporting wound healing and skin regeneration. The combination of orange peel and green tea extracts is scientifically justified by their complementary phytochemistry: the vitamin C-EGCG redox synergy enhances overall antioxidant capacity beyond what either ingredient achieves individually. Literature on herbal face mist formulation additionally emphasises the critical importance of maintaining appropriate pH (4.5–5.5), low viscosity, and a robust preservative system to ensure microbial safety and shelf stability. Sodium benzoate and disodium EDTA are widely reported as effective preservative and chelating agents, respectively, in aqueous herbal cosmetic formulations.

3. Aim and Objective:

The aim of the study was to formulate, develop, and evaluate a stable herbal face mist incorporating extracts of Orange Peel (Citrus sinensis) and Green Tea (Camellia sinensis) for antioxidant and skin-rejuvenating benefits. The principal technical objectives were as follows: to extract bioactive compounds from both plant sources using an appropriate technique and verify the presence of key phytoconstituents; to design and optimise a hydro-aqueous base providing a non-greasy, refreshing delivery system; to incorporate suitable preservatives and pH adjusters to ensure clarity, microbial safety, and stability; to evaluate the formulation for organoleptic properties, physicochemical parameters, spray performance, and skin compatibility; and to conduct accelerated stability studies in accordance with ICH guidelines.

4. Methodology :
   1. Materials Used:

All materials were of analytical/cosmetic grade. The formulation composition is presented in Table Below

1. 2. Uses of Ingredients in Formulation:
1. Orange Peel Powder

• Rich in Vitamin C and flavonoids — brightens skin tone and reduces hyperpigmentation.
• Contains antioxidants that fight free radical damage and delay signs of aging.
• Has antimicrobial properties that help control acne-causing bacteria.
• Acts as a natural exfoliant (in extracts, helps remove dead skin cells).
• Astringent properties help tighten pores and reduce excess oil.

2. Green Tea Powder

• Loaded with EGCG (epigallocatechin gallate) — a potent antioxidant that protects against UV damage.
• Has strong anti-inflammatory properties, soothing redness and irritation.
• Helps reduce sebum production, beneficial for oily and acne-prone skin.
• Contains polyphenols that combat signs of aging (fine lines, wrinkles).
• Provides a mild skin-brightening effect over time.

3. Ethanol (Ethyl Alcohol)

• Acts as an extraction solvent - efficiently pulls out active phytochemicals from plant material.
• Functions as a preservative by inhibiting microbial growth in the formulation.
• Serves as a solubilizer, helping mix oil-soluble and water-soluble components.
• Provides a quick drying/cooling sensation on skin application.
• Enhances penetration of active ingredients into the skin.

4. Distilled Water

• Acts as the primary vehicle/base of the aqueous phase.
• Used as a solvent for water-soluble ingredients like sodium benzoate.
• Ensures the formula is free from minerals and contaminants (unlike tap water).
• Helps in volume adjustment to reach the final 100 ml.
• Provides hydration to the skin upon misting.

5. Sodium Benzoate

• Primary preservative in the formulation — prevents microbial and fungal growth.
• Extends the shelf life of the product.
• Effective in slightly acidic pH environments, which suits most skin mists.
• Water-soluble, making it ideal for aqueous phase incorporation.
• Used at low concentrations (0.2%), making it safe and non-irritating.

6. Propylene Glycol

• Acts as a humectant — draws moisture from the environment into the skin.
• Functions as a solubilizer helping blend rose oil into the aqueous base.
• Enhances penetration of active ingredients through the skin barrier.
• Provides a skin-conditioning effect, leaving skin soft and supple.
• Also contributes mild antimicrobial activity.

7. Rose Oil

• Provides a pleasant fragrance and enhances the sensory appeal of the mist.
• Has anti-inflammatory and soothing properties — calms sensitive/irritated skin.
• Rich in antioxidants that help fight oxidative stress on skin.
• Known for its moisturizing and skin-rejuvenating effects.
• Offers mild antimicrobial activity, complementing other preservatives.
  3. Extraction of Herbal Ingredients:

Dried orange peel and green tea leaves were independently powdered and subjected to sonication assisted extraction using a water-Ethanol solvent system. Ultrasonic waves facilitated the breakdown of plant cell walls, enhancing the release of bioactive compounds. The process was continued until maximum phytoconstituent yield was achieved, after which the extracts were filtered to remove particulate matter and stored appropriately prior to formulation.

1. 4. Method of Preparation:

The herbal extraction process was conducted using ultrasonic-assisted extraction (UAE). To prepare the orange peel extract, 10 g of orange peel powder was suspended in a binary solvent system consisting of 60 mL of ethanol and 40 mL of distilled water. The mixture was sonicated for 30–35 min while maintaining a controlled temperature range of 35–40°C. Separately, the green tea extract was prepared by adding 5 g of green tea powder to a 1:1 (v/v) mixture of ethanol and distilled water (50 mL each). This suspension was subjected to sonication for 15–20 min at an ambient temperature of 25–30°C. Both crude extracts were subsequently filtered to obtain clear filtrates for the final formulation. The aqueous phase was prepared by completely dissolving 0.2 g of sodium benzoate in 50 mL of distilled water. For the herbal phase blend, a 10 mL aliquot of the orange peel extract was thoroughly mixed with 10 mL of the green tea extract, followed by the slow incorporation of the previously prepared aqueous phase. Concurrently, a solubilised cooling phase was generated by blending 5 mL of propylene glycol with 3–4 drops of rose oil, into which 10 mL of ethyl alcohol was gradually introduced under continuous stirring. Finally, the solubilised cooling agent mixture was blended with the aqueous-extract phase, and the total volume was adjusted precisely to 100 mL using distilled water to yield the final herbal face mist formulation.

1. 5. Evaluation Parameters:

The formulation was evaluated for organoleptic properties (colour, odour, clarity, appearance), physicochemical parameters (pH, viscosity, density), stability under three storage conditions (room temperature, 4°C, and 40°C) over a defined period, microbial safety, and skin compatibility via patch testing. Each parameter was assessed using calibrated instruments and standardised methods appropriate for cosmetic formulations.

5. Result and Discussion:
   1. Organoleptic Evaluation

The formulation presented with a clear, pale yellow appearance attributable to the chromophoric constituents of orange peel and green tea extracts. The odour was mild and pleasantly citrus-herbal, considered acceptable for a consumer cosmetic product. The liquid was homogeneous with no visible particulate matter, confirming effective filtration and ingredient compatibility.

1. 2. Physiochemical Evaluation

The pH of 4.8 falls within the physiologically accepted range of 4.5–5.5 for topical formulations, ensuring compatibility with the skin’s acid mantle and reducing the risk of irritation or barrier disruption. The formulation demonstrated low viscosity appropriate for pump-spray dispensing and uniform distribution across the skin surface. Density was approximately 1 g/mL, consistent with an aqueous system and indicative of phase uniformity.

1. 3. Stability Studies

Stability assessment was conducted under three conditions to simulate storage environments encountered across the product’s shelf life. At room temperature and under refrigeration (4°C), the formulation exhibited no changes in colour, odour, pH, or clarity throughout the study period, indicating robust physical and chemical stability. At elevated temperature (40°C), slight colour variation and a minor pH shift were noted; however, these changes remained within acceptable limits and are consistent with the inherent sensitivity of herbal formulations to thermal stress. No phase separation or precipitation was observed under any condition.

1. 4. Microbial Evaluation

No microbial growth was observed during the evaluation period. The preservative system combining sodium benzoate (0.1 g per 50 mL) with disodium EDTA (0.05 g per 50 mL) proved effective in maintaining the microbiological integrity of the formulation. EDTA acts as a chelating agent that disrupts the outer membranes of gram-negative bacteria, potentiating the action of sodium benzoate and extending the spectrum of antimicrobial protection.

1. 5. Skin Irritation (Patch Test)

Patch testing conducted on human volunteers revealed the complete absence of redness, itching, or inflammation at the application site. The non-irritant profile of the formulation is attributable to its skin compatible pH, the use of biocompatible herbal actives, and the avoidance of known sensitisers. These findings confirm the formulation’s suitability for regular topical use across a broad range of skin types.

1. 6. Overall Performance Comparison

When compared against the typical performance benchmarks of marketed face mist products, the prepared herbal formulation demonstrated equivalent or comparable results across all evaluated parameters, as summarised in Table. The principal added advantage of the present formulation lies in its natural ingredient profile and the associated reduction in risk of chronic adverse effects.