Formulation and Evaluation of Herbal Face Serums as a Cosmeceutical Applications

Skin is the largest organ of the human body and serves as the first protective barrier against environmental pollutants, microorganisms, harmful chemicals, and ultraviolet radiation. Continuous exposure to dust, pollution, stress, sunlight, and chemical-based cosmetic products can damage the skin and lead to various problems such as dryness, acne, hyperpigmentation, premature aging, wrinkles, and dullness. [1,2]

Today, consumers are increasingly aware of skincare needs and are increasingly preferring herbal cosmetic products because of their natural origin and reduced side effects. Herbal ingredients are rich in vitamins, antioxidants, minerals, and bioactive compounds that help nourish and protect the skin naturally. Ingredients such as aloe vera, licorice, green tea, cucumber, amla, guava, and essential oils are widely used in cosmetic formulations due to their moisturizing, soothing, anti-inflammatory, anti-aging, and skin-brightening properties. [3,4,5]

A face serum is a lightweight skincare product formulated to deliver active ingredients efficiently into the skin. Unlike heavy creams, serums are lightweight and easily absorbed, making them highly effective in improving skin hydration, elasticity, smoothness, and radiance. They are commonly used for moisturizing, anti-aging, acne control, brightening, and skin rejuvenation. [2,6,7]

Herbal face serums combine the benefits of natural ingredients with advanced cosmetic technology to provide multifunctional skincare benefits. This study focuses on the formulation and evaluation of different herbal face serum formulations prepared using natural plant extracts and oils as they are proven safe and are being used as home remedies. [8,9,10,11,12]

Types of Serums:

Hydrating Serums

Hydrating serums are formulated to improve the moisture content of the skin. Ingredients such as glycerin and hyaluronic acid help attract and retain moisture, making these serums suitable for dry and dehydrated skin.

Anti-Aging Serums

Anti-aging serums help reduce signs of aging such as wrinkles, fine lines, and sagging skin. They usually contain antioxidants, vitamins, peptides, and herbal extracts that promote collagen production and improve skin elasticity.

Brightening Serums

Brightening serums are used to improve skin tone and reduce pigmentation, dark spots, and dullness. Ingredients like licorice, vitamin C, orange peel, and niacinamide help provide a radiant and glowing complexion.

Acne-Fighting Serums

These serums help control acne, pimples, and excess oil production. Ingredients such as salicylic acid, tea tree oil, and green tea extract help reduce inflammation and prevent bacterial growth.

Calming Serums

Calming serums are beneficial for sensitive and irritated skin. Herbal ingredients such as aloe vera, cucumber, chamomile, and green tea help soothe redness and skin irritation.

Exfoliating Serums

Exfoliating serums contain ingredients that help remove dead skin cells and promote skin renewal. These serums improve skin texture and brightness.

Firming Serums

Firming serums help improve skin elasticity and tighten loose skin. They are commonly used for mature skin to reduce sagging and improve firmness.

Oil-Control Serums

Oil-control serums help regulate sebum production and reduce excessive oiliness without causing dryness. They are suitable for oily and combination skin types.

ADVANTAGES OF FACE SERUM:

Face serums have several advantages, making them a popular choice in skincare routines. Here are some key benefits:

• Face serums contain a high concentration of active ingredients.
• They are lightweight and quickly absorbed into the skin.
• They help improve skin hydration and moisture retention.
• Serums reduce signs of aging such as wrinkles and fine lines.
• They help brighten the skin and reduce pigmentation.
• Serums penetrate deeper into the skin compared to creams.
• Herbal serums generally produce fewer side effects.
• They provide multifunctional skincare benefits such as moisturizing, anti-aging, and rejuvenation.

DISADVANTAGES OF FACE SERUM

Face serums can be great for targeting specific skin concerns, but there are a few potential downsides to consider:

• Some active ingredients may cause irritation in sensitive individuals.
• Certain herbal formulations may show phase separation or stability issues.
• Preservatives are often required to prevent microbial contamination.
• Overuse may lead to dryness or redness.
• Natural ingredients may reduce product shelf life.
• Highly concentrated formulations may not suit extremely sensitive skin.

MATERIALS AND METHODS

The materials used in the study were represented as tabular form in table 1, for their composition and use in serum along with their biological or chemical names. Many of them were used as age old home made remedies and proven tested as safe.   

Table 1: List of Materials Used Along with Category and Function

FORMULATION OF HERBAL FACE SERUMS

SERUM 1 FORMULATION:

Serum 1 was formulated using Aloe vera gel, lemon oil, castor oil, coconut oil, and jasmine oil to provide moisturizing, antioxidant, soothing, and skin-brightening effects. The formulation was designed as a lightweight herbal serum with enhanced hydration and nourishment properties.

Working formula:

The formulation combines natural oils and herbal ingredients that help improve skin softness, hydration, and overall skin appearance while providing antioxidant protection [8,10]

SERUM 2 FORMULATION:

Serum 2 was prepared using Aloe vera gel, jojoba oil, sandalwood oil, and glycerine to obtain a soothing and moisturizing herbal serum suitable for dry and sensitive skin.

Working formula:

The selected ingredients provide skin nourishment, hydration, and calming effects, making the formulation suitable for maintaining healthy and soft skin. [6,9]

SERUM 3 FORMULATION:

Serum 3 was formulated using Aloe vera gel, licorice extract, lemon oil, and coconut oil to develop a herbal serum with anti-hyperpigmentation, antioxidant, and skin-brightening properties.

Working formula:

The formulation contains active herbal ingredients that help reduce pigmentation, improve skin radiance, and provide antioxidant protection against environmental damage. [13,14]

SERUM 4 FORMULATION:

Serum 4 was prepared using carrot extract, amla extract, olive oil, and sandalwood oil to obtain a serum rich in antioxidants and vitamins for anti-aging and skin rejuvenation purposes.

Working formula:

The formulation provides antioxidant and nourishing effects that help improve skin texture, brightness, and overall skin rejuvenation. [15,9]

SERUM 5 FORMULATION:

Serum 5 was formulated using green tea extract, Aloe vera juice, cucumber juice, and salicylic acid to develop a refreshing serum with antioxidant, cooling, and anti-acne properties.

Working formula:

The ingredients present in the formulation help soothe the skin, reduce acne, control excess oil, and provide hydration and antioxidant protection. [15,20]

SERUM 6 FORMULATION:

Serum 6 was prepared using banana leaf extract, jojoba oil, rose oil, and sandalwood oil to formulate a nourishing herbal serum with moisturizing and rejuvenating properties

Working formula:

The formulation provides skin hydration, nourishment, and soothing effects while improving skin texture and softness.[16]

SERUM 7 FORMULATION:

Serum 7 was formulated using orange peel extract, Aloe vera gel, rose water, and glycerine to prepare an herbal serum with skin-brightening and moisturizing properties.

Working formula:

The formulation exhibited good moisturizing and antioxidant properties, helping improve skin brightness and overall appearance. [17,10]

SERUM 8 FORMULATION:

Serum 8 was prepared using guava fruit extract, almond oil, Aloe vera gel, and sandalwood oil to obtain a nourishing herbal serum with antioxidant and anti-aging activity.

Working formula:

The formulation contains antioxidant-rich herbal ingredients that help improve skin nourishment, hydration, and protection against premature aging. [18,19]

PREPARATION OF FACE SERUM:

The herbal face serum formulations were prepared by the trituration method. Initially, the oil phase containing ingredients like oils, essential oils, and emulsifying agents was prepared separately by continuous mixing.

At the same time, the aqueous phase containing ingredients like aloe vera gel, herbal extracts, glycerin, rose water, cucumber juice, and distilled water was prepared separately with continuous stirring until a homogeneous mixture was obtained.

The oil phase was then added slowly into the aqueous phase with continuous trituration to form a primary emulsion. The remaining aqueous phase was added gradually while stirring continuously to obtain a smooth and homogeneous serum formulation.

Plant extracts such as licorice, guava, orange peel, carrot, banana leaf, and amla were prepared by maceration using suitable solvents followed by filtration before incorporation into the formulation. Finally, the prepared formulations were transferred into airtight containers and stored at room temperature for further evaluation.

EVALUATION OF SERUM FORMULATIONS:

The prepared herbal face serum formulations were evaluated using various physicochemical and performance parameters to determine their quality, stability, safety, and suitability for skin application. The evaluation procedures are described below.

1. Organoleptic Evaluation (colour, odour, appearance)

The prepared serum formulations were visually examined for their colour, odour, appearance, and overall acceptability. A small quantity of each serum was taken in a transparent container and observed under normal daylight conditions. The characteristic fragrance of the serum was also noted. This evaluation helped determine the aesthetic appeal and consumer acceptability of the formulations. [6,8,9]

2. Texture Evaluation

The texture of each serum was evaluated by applying a small amount onto the skin and gently rubbing it between the fingers. The formulations were examined for smoothness, consistency, stickiness, and ease of application. A good serum should possess a smooth and pleasant texture without leaving an excessively greasy residue. [6,10,11]

3.  Determination of pH

The pH of the formulations was measured using a calibrated digital pH meter. Approximately 1 g of serum was dispersed in 10 mL of distilled water, and the electrode was immersed in the sample. The pH value was recorded after stabilization. Maintaining a pH close to that of the skin is essential to avoid irritation and ensure user comfort. [8,13,24]

4. Spreadability Test

Spreadability was determined to assess the ease with which the serum could be applied to the skin. A known quantity of serum was placed between two glass slides, and a standard weight was applied over the upper slide. After 2 min, the diameter or area of spread was measured and recorded. Higher spreadability indicates better ease of application and uniform distribution on the skin surface. [9,10,21]

5. Washability Test

Washability was evaluated by applying a small amount of serum onto the skin and subsequently washing the area with water. The ease with which the formulation could be removed was observed. The formulations were considered satisfactory if they could be washed off easily without leaving excessive residue. [8,13,24]

6. Irritability Test

A skin patch test was performed to evaluate the safety of the serum formulations. A small quantity of serum was applied to a limited area of skin, usually on the forearm, and observed for 24 hours. Any signs of redness, itching, swelling, burning sensation, or allergic reaction were noted. The absence of such reactions indicated that the formulation was non-irritating and safe for topical use. [9,13,20]

7. Phase Separation Study

The physical stability of the formulations was assessed by observing them for any signs of phase separation during storage. The serum samples were stored in suitable containers at room temperature and examined periodically. The appearance of separate oil and aqueous layers indicated instability, whereas formulations showing no phase separation were considered physically stable. [6,10,22]

8. Homogeneity Evaluation

The homogeneity of the formulations was assessed through visual inspection. Each serum was examined for uniformity, smoothness, and the absence of lumps or coarse particles. A homogeneous formulation indicates proper mixing and uniform distribution of ingredients throughout the serum. [9,11,21]

9. Stability Study

The prepared formulations were subjected to stability testing at room temperature ranging from 25 to 35°C on bench top away from direct sunlight. The stored samples were observed periodically for changes in colour, odour, texture, pH, and phase separation for 1 month. The stability study helped determine the ability of the serums on bench top to maintain their quality and effectiveness during storage. [6,8,10,22]

10. Skin Compatibility Evaluation

The compatibility of the serum with the skin was assessed through topical application. The formulations were applied to the skin and monitored for comfort, hydration, smoothness, and any adverse reactions. This evaluation confirmed the suitability of the serum for routine skincare use. [2,13,20]

11. Microbial contamination Test

The mixed culture was obtained from 1 gm of leaf litter compost pile and serially diluted directly in tubes of 20 ml liquid agar medium. The sterile nutrient agar medium, 20 ml, was maintained in a liquid state at a temperature of 45? and mixed well with 1 ml of mixed culture to allow thorough distribution of the inoculum. The inoculated agar medium was transferred into sterile petri plates, allowed to solidify and incubated as a positive standard. In a negative control test 1 ml of sterile water mixed in 20 ml of sterile nutrient agar medium at 45? was transferred into sterile petri plates and allowed to solidify. 1 ml of test serum formulation mixed in 20 ml of nutrient agar medium at 45?. The nutrient agar medium was shaken and poured in a sterile petri plate, cooled to solidify and incubated at 37°C for 24 hours. [8,10,20]

RESULTS AND DISCUSSIONS:

The prepared serum formulations were evaluated for various physicochemical parameters such as color, odor, texture, washability, irritability, phase separation, pH, and spreadability and performance characteristics. The evaluation results of formulations S1–S4 were presented in Table No. 2

Table No. 2: Evaluation results data of Herbal Serums (S1–S4)

Formulations S2 and S3 showed better homogeneity and absence of phase separation compared to S1 and S4. All formulations exhibited suitable pH and non-irritant characteristics for topical application.

Further evaluation of formulations S5–S8 was carried out to determine their physical stability, spreadability, washability, and skin compatibility.

The results obtained are shown in Table No. 3

Table No. 3: Evaluation of Herbal Dual-Phase Face Serum (S5–S8)