Formulation and Evaluation of Nano Emulsion from Curcumin for Anti-Inflammatory Treatment

Curcumin is a natural polyphenolic compound primarily sourced from Curcuma longa Linn. and exhibits strong anti-inflammatory properties when administered either orally or topically. Research has shown that curcumin can inhibit the metabolism of arachidonic acid, as well as affect cyclooxygenase, lipoxygenase, pro-inflammatory cytokines, and the activation of nuclear factor-kB.¹ It is characterized by very low intrinsic toxicity, even when taken in significantly large doses. Curcumin's poor solubility in water at acidic or neutral pH levels, coupled with its extensive degradation in alkaline conditions, limits its applicability. Additionally, curcumin experiences rapid first-pass metabolism, converting it into inactive metabolites that result in low bioavailability within systemic circulation.² Consequently, various strategies have been explored to enhance the biological effectiveness of curcumin, including chemical modifications, formation of complexes or interactions with macromolecules, and the use of nanotechnology-based drug delivery systems.³ Curcumin is a vibrant yellow compound naturally present in turmeric (Curcuma longa), a plant from the ginger family (Zingiberaceae). It is the key ingredient responsible for turmeric’s characteristic color, taste, and numerous health benefits. Known scientifically as Curcuma longa L., the plant originates from southern Asia and is now widely grown in temperate climates. Turmeric is derived from the plant’s rhizomes, either fresh or dried, and contains a group of active substances called curcuminoids. The major components include curcumin (about 77%), desmethoxycurcumin (around 17%), and bisdemethoxycurcumin (approximately 3–6%). These natural polyphenols give turmeric its bright color and powerful biological effects. Curcumin is well known for its anti-inflammatory and antioxidant properties and has been studied for its potential in preventing and treating cancer. It also supports brain health, protects the heart, and provides natural pain relief, making it a valuable compound in both traditional and modern medicine.⁴ Nanoemulsions encapsulating curcumin are designed to address the major limitations of curcumin's therapeutic use, particularly its poor solubility and low bioavailability. By significantly increasing the aqueous solubility of curcumin, nanoemulsions enhance its absorption in the gastrointestinal tract. This improved solubility, along with the nanoemulsion's ability to protect curcumin from rapid degradation, leads to greater systemic bioavailability. Furthermore, nanoemulsions can be engineered for targeted delivery, allowing curcumin to accumulate at inflamed tissues where it is most needed, thereby enhancing its anti-inflammatory effectiveness. These systems also offer controlled and sustained release, maintaining therapeutic levels of curcumin over extended periods, which supports consistent anti-inflammatory action. Additionally, by improving the efficiency of delivery, nanoemulsions reduce the need for high doses, thereby minimizing potential side effects and making curcumin therapy safer and more effective.⁵

Fig.1. Particle of Nano emulsion

Collection of Plant material:

Curcumin that was identified and collected from the Koregaon Bhima, Pune. Maharashtra, India-412216 neighbourhood. The curcumin was cleaned, dried in room temperature, transfer into moderately coarse powder and stored in well closed container before the extraction.

Preparation of Curcumin Extract:

The preparation of turmeric extract begins with washing and drying the turmeric rhizomes, which are then ground into a fine powder. Approximately 50 grams of this turmeric powder is weighed and placed into a thimble, which is inserted into a Soxhlet extractor. Around 250–300 ml of ethanol or methanol is added to a round-bottom flask attached to the Soxhlet apparatus. The setup is then gently heated to allow the solvent to reflux, initiating the extraction process, which is typically continued for 2 to 4 hours. Once the extraction is complete, the mixture is filtered to remove any plant residues. The solvent is then evaporated using a rotary evaporator or a water bath at a temperature range of 40–60°C to obtain the concentrated extract. The final extract is collected from the round-bottom flask, filtered again if necessary, and stored in a well-sealed container. For preservation, the extract should be kept in a cool, dry place away from direct sunlight to maintain its stability and effectiveness.

The figure shows how extraction process will conduct:

All process of extraction is conduct in Delight College of Pharmacy, Koregaon Bhima, Pune, Maharashtra, India.

Fig.2.Powder of Curcumin                                           

Fig.3.Process of extraction

Fig.4.Collection of extract  

Fig.5.Filtration of extract

Fig.6.Extracted liquid

Table 1: Method for the Preparation of Nano emulsion from Curcumin

Step-by-Step Preparation Method:

Step 1: Preparation of oil Phase

1. Weigh the oil phase and heat it to 40-50°C.
2. Add the curcumin extract to the oil phase and stir until dissolved.

Step 2: Preparation of Aqueous Phase

1. Weigh the aqueous phase and heat it to 40-50°C.
2. Add the surfactant and co-surfactant to the aqueous phase and stir until dissolved.

Step 3: Nano emulsion Formation

1. Slowly add the oil phase to the aqueous phase under high-speed homogenization at 4000 rpm for 10-15 minutes.
2. Continue homogenization until the mixture is uniform and stable.

Step 4: Ultrasonication

1. Transfer the nano emulsion to an ultrasonic bath and sonicate for 10-15 minutes to reduce practice size.

Step 5: Addition of Glycerine

1. Add glycerine to the nano emulsion and stir until dissolved.

Step 6: pH Adjustment

1. Adjust the pH of the nano emulsion to the desired range using a pH adjuster. 

Step 7: Storage

1. Store the nano emulsion in cool and dry place to protected from light.

Fig.7.Nano emulsion Formulation

Evaluation Parameter for Nano emulsion from Curcumin:

Physical Evaluation:

1.Appearance and colour:

Appearance refers to the overall visual characteristics of a formulation or substance and includes several factors. It encompasses clarity, which can be clear, translucent, or opaque, and consistency, such as whether the formulation is fluid, gel-like, creamy, or another texture. Additionally, appearance involves assessing phase separation to determine if the formulation is homogeneous or if there is any separation of oil and water layers. The presence of particles or sediment within the formulation is also an important aspect of appearance. Colour, on the other hand, describes the visual hue of the formulation, which can range from colourless to various shades depending on the ingredients used, such as oils, surfactants, and active drugs. The colour can also be influenced by the presence of dyes or pigments, as well as any oxidation or degradation that may occur over time, potentially altering the original hue.

2.Odour and Texture:

Odour refers to the smell or scent of a substance, detected through the olfactory system, and is an important qualitative characteristic. It plays a significant role in user acceptance, especially for cosmetics and topical products, and can also indicate the purity or spoilage of a product—for example, a rancid smell in oils. Consistency of odour across different batches is important for maintaining product quality. Common odour descriptors include terms like odourless, mild, pleasant, medicinal, herbal, or fishy. Texture, on the other hand, describes the physical feel or tactile sensation of a product when touched or applied. It encompasses attributes such as viscosity (whether the product is thin, thick, or runny), smoothness (silky, gritty, greasy, or sticky), spreadability (how easily the product spreads over skin or surfaces), and residue (whether it leaves a film or is fully absorbed). Texture is especially critical in topical and cosmetic formulations such as ointments, creams, lotions, and emulsions, as it strongly influences consumer preferences and overall product acceptability.

3. Particle Size and Polydispersity Index (PDI):

Dynamic Light Scattering (DLS) analysis revealed that the nano emulsion had a particle size distribution extending up to127.01 ± 2.34, suggesting good stability and suitability for potential biomedical use."

 4. Zeta Potential: Transfer the diluted sample into a zeta potential cell (clear disposable folded capillary cell). Insert the cell into the Zetasizer. Set measurement condition (e.g., temperature a 25°C, dispersant viscosity and dielectric constant).

5. pH Measurement:

Dilute 1 ml nano emulsion in 10 ml distilled water. Measure using a calibrated pH meter.

6. Viscosity:

Allow the nano emulsion sample to equilibrate to room temperature (25°C). Pour a suitable amount (~50 ml) into the sample container. Use the Brookfield viscometer.

7. Centrifugation Test: Centrifuge at 3000- 5000 rpm for 30 minutes.

8. Stability Testing:

The temperature stability test involves storing the nano emulsion at different temperatures 4°C (refrigerator), 25°C (room temperature), and 40°C (accelerated stability conditions) for a period of one month. During this time, key parameters such as pH, viscosity, and appearance are regularly monitored to assess any changes. This test helps evaluate the nano emulsion stability under various storage conditions, ensuring that its physical and chemical properties remain consistent and that the formulation maintains its effectiveness over time.

RESULT AND DISCUSSION:

The evaluation of the nano emulsion formulation was conducted through a series of physicochemical and stability tests. In terms of appearance and colour, the formulation exhibited a uniform yellow colour with no signs of creaming, sedimentation, or turbidity, indicating good physical stability and suitability for topical application. The odour was mild and pleasant with a slightly herbal or spicy note, while the texture was smooth, non-greasy, and easily spreadable—attributes that are desirable for consumer-friendly dermal products. Particle size analysis using dynamic light scattering (DLS) revealed an average size of approximately 127.01 ± 2.34 nm, which falls well within the nano range (20–200 nm), suggesting a stable formulation with potential for enhanced bioavailability. The zeta potential, measured over a three-month period, ranged from -38.8 mV to -34.9 mV, indicating strong electrostatic stability, as values more negative than -30 mV typically reflect good long-term stability. pH measurements remained stable between 5.8 and 6.0 over three months, a slightly acidic range suitable for skin application and indicating chemical stability. The viscosity of the nano emulsion was recorded at 48.6 ± 1.5 cP at 20 rpm, demonstrating low viscosity that allows for smooth application and spreadability. The centrifugation test, conducted at 3000–5000 rpm for 30 minutes, showed no phase separation or creaming, further supporting the physical robustness of the formulation under stress. Finally, the temperature stability test, involving storage at 4°C, 25°C, and 40°C for three months, revealed only slight, non-significant changes in particle size and no visual separation, confirming the nano emulsion stability across varied temperature conditions.

Table 2:  Observation of Odour and Texture

Table 3: Result and Observation of Zeta Potential (mv)

                                                Table 4: Result and Observation of pH Measurement

Table 5: Result and Observation of Viscosity

Table 6: The Curcumin Nono emulsion remained stable over 3 months, even when the temperature increased or decreased

Fig. 8. Zeta Potential