INTRODUCTION:

Topical medications like creams, lotions, and ointments have several drawbacks, including stickiness, instability, and low spreading coefficient, making the use of transparent gels popular in cosmetic and pharmaceutical preparations. Emulgels, which are a combination of gels and emulsions, have significant potential as drug delivery vehicles, improving permeation efficacy, reducing side effects, increasing drug absorption, and preventing enzymatic breakdown in the stomach. Therefore, the pharmaceutical industry is currently focusing on emulgel systems for drug delivery.^1,2 Wound may be defined as breaking or loss of anatomic and cellular or functional connection of living tissue. It is an unavoidable part of the human life which is caused by chemical, physical, thermal, immunological or microbial damages to the tissue. Wound healing is natural process, obtained through four highly programmed stages: hemostasis, inflammation, proliferation and remodeling ¹⁴. Emulgels are dual control release systems that combine the properties of both emulsions and gels. Topical gels, like the emulgel, offer a range of benefits, such as being greaseless, easily spreadable, easily removed, emollient, and water-miscible. This makes them an excellent choice for topical applications. Incorporating gel into an emulsion has been proven to significantly enhance the stability and penetration ability of the emulsion through its thixotropic behavior.² This approach allows for controlled release of active compounds, ensuring prolonged skin contact and desired outcomes.³

Factors Affecting Topical Drug Delivery System:⁴

1. Skin condition

2. Lipid content

3. Blood flow

4. Skin hydration

Physiochemical factor:

1. Partition coefficient

2 Molecular weight

3. Drug concentration

4. Effect on vehicles

Types of Herbal Emulgel:

1 Macro-emulsion gel

2 Nano-emulgel

3 Micro-emulsions based emulgel

Emulgel Is Made Up of Two Components

1. Emulsion: An emulsion is a biphasic system made up of two immiscible liquids, which is one of finely and consistently propagated as globules throughout the other to form an emulsion.

2. Gel: According to the U.S.P., gels are semisolid systems made up of a dispersion whether large organic molecules or small inorganic particles that are encased and penetrated by liquid.⁴

Composition of Herbal Emulgel:

1. Aqueous material

2. Oils

3. Emulsifying Agents

4. Gelling Agent

5. Preservatives

6. pH adjusting agent⁴

Topical delivery is the application of a drug-containing formulation to the skin to limit the drug's pharmacological or other effects on the skin's surface or deeper layers to treat cutaneous conditions like psoriasis or the cutaneous manifestations of more widespread illnesses like acne. 2 Since the mid-1980s, emulsion gels have been picking up significance in pharmaceutical topical semisolid dosage forms.⁵In light of the numerous advantages associated with gels, the development of emulgels has emerged as a strategic solution. Emulgels have been crafted in a manner that harnesses the unique attributes of hydrophobic substances for therapeutic purposes. Emulgels, when applied to the skin, exhibit a host of favorable characteristics, including emollient properties, non-staining attributes, extended shelf life, non-greasiness, ease of spreadability, and eco-friendliness.⁶

Emulgel is the name given to the product created when an emulsion is combined with a gel and exhibits dual control release properties. Emulgel is used to relieve aches and pains, including backaches, and muscle aches. The purpose of the proposed research is to Formulated Developed and Evaluated of Topical Herbal Emulgel of Turmeric for its in vitro anti-inflammatory activity.⁷The combination of emulsion and gel, known as Emulgel, has thus been appreciated as a novel modified strategy to solve this issue and used for dermatological purposes. They have several advantageous properties, including being thixotropic, greaseless, easily spreadable, easily removable, emollient, non-staining, long shelf-life, transparent, pleasing appearance, compatible with various excipients, and water-soluble/miscible.⁸

Emulgel has several advantages, like greasiness, ease of spreadability, easiness of removal, emollient characteristics, and transparency. Emulgel are often used to deliver analgesics, anti-inflammatory, anti-fungal and anti-acne drugs, as well as a variety of cosmetic compositions. Emulgel was created in order to improve patient compliance and bioavailability.⁹Emulgels with advantage of both gels and emulsion act as a controlled drug delivery system for topically applied drugs. They are emulsion of either oil in water type or water in oil type which are gelled by mixing with a gelling agent. Gels have extended the contact period of medication over the skin due to mucoadhesive property. Both water-in-oil and oil-in-water type of emulsion are used in topical preparation as water washable preparation & emollients for dry skin respectively.¹⁰

The general ways to improve drug penetration through skin is to facilitate the use of penetration enhancers in topical formulations. The interaction of the enhancers with the polar head groups of the lipids is the possible way to increase the permeation of drug molecules. Permeation enhancer’s increases the content of free water molecules between the bilayer, which cause to an augmentation of the cross-section for polar drug diffusion.¹¹Topical formulations should be simple and acceptable to use, and they should mainly penetrate the skin and permeate sufficiently to the skin to exercise a therapeutic effect into the target areas.¹²

Emulgels provide dual control release in the form of emulsion as well as gel. The use of polymers that have phase transition from solution to gel upon alterations in physicochemical properties of drug. Herbal formulations have become popular due to their natural origin and are used in wound healing. Therefore, main aim of this study to prepared a sustained release topical emulgel containing turmeric and investigation the influence of type of gelling agent, emulsifying agent and the type of oil phase on extrudability, spreadability, drug content and evaluate the rheological behavior and their wound healing potential of the prepared formulations.^13,15

MATERIALS AND METHODS:

Materials:

Turmeric was obtained from local market in jamner. And all the ingredients such as olive oil, oleic acid, methyl salicylate, propylene glycol, Ceto stearyl alcohol, span-80, tween-20, Carbopol-934, propyl paraben, methyl paraben, triethanolamine were collected from SSJIPER, Jamner.

Methods:

Preparation of Emulgel:

Emulgel preparations were involved in two processes. In step I, the gel phase was prepared and in step II, prepared gel phase was combined with an oily phase in order to give the final Emulgel. (Table-1).

Gel Phase:

In order to create a homogeneous gel base, Carbopol 934 was individually dispersed in 30ml distilled water using a magnetic stirrer. After adjusting pH with a 5% m/m triethanolamine solution, further air bubbles were eliminated using ultrasonic water bath for 1h.

Emulgel:

Using a thermostatic water bath, the oil and water phases were heated independently to 65°C before being combined using a magnetic stirrer. After an emulsion was formed, the prepared gel phase was introduced gradually while being continuously stirred.

Evaluation Parameters of Emulgel:

Pre-Formulation Parameter:

1) Standard Calibration Curve of Turmeric:

The stock solution (1mg/ml) was prepared by weighed accurately 10mg of turmeric emulgel and transferred to a 50ml volumetric flask then makeup the final volume with phosphate buffer Ph 7.4. Different concentrations (2, 4, 6, 8, and10µg/ml) of solutions were prepared from the stock and measure the absorbance at 225nm by using UV-Visible spectrophotometer and blank reagent. Graphs were plotted taking concentration on X-axis and absorption on Y-axis to give linear curve and the method obeyed Beer's law.

Post-Formulation Parameter:

1) Physical appearance:^2,6,8,16,18

The emulgel formulations were visually assessed for physical appearance, color, and consistency. The formulation exhibiting desirable results underwent further examination and characterization.

2) pH determination:^2,5,7,8,9

The pH values were measured using a calibrated meter at room temperature. 1g of emulgel was distributed in 100 ml of distilled water. Digital pH meter was used to determine the dispersion's pH value.

3) Viscosity determination:^{1,2,5,7,14,17}

A Brookfield digital viscometer with a suitable sample adaptor was used to measure the viscosities of the Carbopol gel in cps. All the measurements were conducted using spindle no.6 using about 100 ml sample volume at 50 RPM. Direct multiplication of the dial readings with factors given in the Brookfield Viscometer catalogue gave the viscosity in centipoises.

Table no. 1: Formulation Batches of Herbal Emulgel of Turmeric

Sr. No.	Ingredients	Formulation Batches
Sr. No.	Ingredients	TRM1	TRM2	TRM3	TRM4	TRM5
1.	Turmeric	0.6	0.6	0.6	0.6	0.6
2.	Olive Oil	6	6	6	6	6
3.	Oleic Acid	10	10	10	15	10
4.	Methyl Salicylate	10	10	8	10	8
5.	Propylene Glycol	2.5	5	2.5	5	2.5
6.	Ceto stearyl Alcohol	4	6	4	6	4
7.	Span-80	1	1	0.5	1	0.5
8.	Tween-20	3	3	3	4.2	3.2
9.	Carbopol-934	1.8	1.8	1.5	2.5	1.8
10.	Distilled Water	Q.S.	Q.S.	Q.S.	Q.S.	Q.S.
11.	Propyl Paraben	0.02	0.02	----	0.02	----
12.	Methyl Paraben	----	----	0.02	0.02	0.02
13.	Triethanolamine	Adjust PH in between 6.5-6.9

(All ingredients were taken in %)

4) Procedure to conduct skin irritation test (patch test):¹¹

The primary skin irritation test was performed on healthy albino rabbits, weighing between 2.0kg. The gel formulation film was prepared and used as test patches, while adhesive tape (USP) was used as control. The test was conducted on unbraided skin of the rabbits. The control and test patches were placed on the left and right dorsal surfaces of the rabbits respectively. The patches were removed after 24hours with the help of alcohol swab and the skin was examined for erythema and edema

5) Extrudability Study of Topical Emulgel (Tube Test):^10,16

It is usual empirical test to measure the force required to extrude the material from tube. The method applied for determination of applied shear in the region in the rheogram corresponding to shear rate exceeding the yield value and exhibiting consequent plug flow. In present study, the method adopted for evaluating emulgel formulation for extrudability is based upon the quantity in percentage of emulgel and emulgel extruded from lacquered aluminum collapsible tube on application of weight in grams required to extrude at least 0.5 cm ribbon of emulgel in 10 seconds. More quantity extruded better is extrudability. The measurement of extrudability of each formulation is in triplicate and the average vales are presented. The extrudability is than calculated by using the following formula:

Extrudability = Applied weight to extrude emulgel from tube (in gm) / Area (in cm2)

6) Spreadability determination:^{2,5,6,10,14,18}

The spreadability apparatus is a device which specifically designed to measure the spreadability of transdermal preparations. 1g of emulgel was taken with the combination between two horizontal glass slides (25 × 25cm), 500gm load was applied for a minute and spreadability was calculated using the formula:

Spreadability = Mass (g) × Length (cm)/Time (Sec).

7) Centrifugation test:^2,8

To evaluate stability, emulgel formulations undergo a centrifugal test. Both formulations were subjected to 5000 rpm for 10 min at 25°C. After the process, the products were visually inspected for signs of phase separation or creaming.

8) Drug content:^2,8,10,15,17

1 gram of emulgel was dissolve in 1 ml of methanol. Dilute the resulting solution and measure its absorbance by UV spectrometer at 261nm. The formula was used to find the amount of drug present in each formulation. The formulation with the most drug content was taken for further examination and characterization.

Drug content = (concentration × dilution factor × volume taken) ×conversion factor

RESULTS AND DISCUSSION:

Pre-Formulation Parameters:

1) Preparation of Calibration Curve:

Table 2: Calibration Curve of turmeric in Phosphate Buffer pH 7.4

Sr. No.	Concentration (µg/ml)	Absorbance (nm.)
1.	2	0.063
2.	4	0.139
3.	6	0.222
4.	8	0.308
5.	10	0.398

Fig. no. 1: - Calibration Curve of Turmeric

Post- Compression Parameter:

Physical appearances:

Table no. 3: Physical appearances of Emulgel

Batch No.	Colour	Homogeneity	Consistency
TRM1	Yellowish	Homogenous	Smooth
TRM2	Yellowish	Homogenous	Smooth
TRM3	Yellowish	Homogenous	Smooth
TRM4	Yellowish	Homogenous	Smooth
TRM5	Yellowish	Homogenous	Smooth

DISCUSSION:

The herbal turmeric emulgel was meticulously evaluated for its physical properties such as color, homogeneity and consistency. The result was found to be a yellowish color of herbal emulgel that boasts excellent uniformity and consistency, providing a smooth and even application. After a month of development, best formulation (TRM4) showed no signs of change or deterioration, proving to be a reliable and long-lasting product.

Measurement of pH:

Table no. 4: pH of Emulgel

Batch No.	PH
TRM1	5.35±0.07
TRM2	5.98±0.05
TRM3	6.47±0.07
TRM4	6.49±0.12
TRM5	6.38±0.09

All the values are expressed as mean ± SD, n=3

DISCUSSION:

pH of the best formulation (TRM4) was adjusted with triethanolamine and measured between 6.49±0.12. It was revealed that the formulation has an optimum pH which is required for topical delivery of drug from emulgel (5.5-6.5).

Viscosity measurement:

Table no. 5: Rheological study data

Batch No.	Viscosity (cp.)
TRM1	1860±10
TRM2	1930±10
TRM3	2257±15.0
TRM4	3140±10
TRM5	2349±12.5

All the values are expressed as mean±SD, n=3

DISCUSSION:

Viscosity of the best formulation (TRM4) was measured between 3140±10 cps. It was observed that on increasing the concentration of gelling agent (Carbopol), the viscosity of the formulation was increased as the gelling agent was responsible to reduce interfacial as well as surface tension the flow of gel and thereby increases the viscosity.

Skin irritation test:

Table no. 6: - skin irritation test (patch test) of Emulgel

Batch No.	Irritation Test
TRM1	No irritation was observed
TRM2	No irritation was observed
TRM3	No irritation was observed
TRM4	No irritation was observed
TRM5	No irritation was observed

DISCUSSION:

Skin irritation test was carried out as per the procedure no. 4, there was no irritation such as erythema and edema and any kind of reaction, redness or irritation appeared on rabbits. Thus, the gel was found to be safer for topical use.

Extrudability:

Table no. 7: Data of Extrudability

Batch No.	Extrudability (cm²)
TRM1	16.9±0.50
TRM2	15.8±0.55
TRM3	17.5±0.5
TRM4	19.9±0.55
TRM5	15.3±0.55

All the values are expressed as mean ± SD, n=3

DISCUSSION:

The extrudability of emulgel shows its behavior while coming out of the container tube. The gels were filled into collapsible tubes after formulating them in that out of all the formulation. The TRM4 was give the great extrudability.

Spreadability:

Table no. 8: Spreadability

Batch No.	Time (Sec.)	Length (cm.)	Weight (gm.)
TRM1	39	7.0	500
TRM2	44	7.0	500
TRM3	40	7.0	500
TRM4	33	7.0	500
TRM5	42	7.0	500

DISCUSSION:

Spreadability of the best formulation (TRM4) was found to be 33 seconds. Emulgel treatment effectiveness is determined by its spread. Emulgels prepared for topical application must meet the optimal quality for topical application, improving patient compliance and have high spreadability. Table 6 displays the results of spreadability study.

Centrifugation test:

Table no. 9: - Centrifugation Test

Batch No.	Centrifugation
TRM1	No phase separation was observed
TRM2	No phase separation was observed
TRM3	Phase separation was observed
TRM4	No phase separation was observed
TRM5	Phase separation was observed

Discussion:

After conducting the visual centrifugation test, it was confirmed that all formulations were stable. No phase separation was observed, indicating excellent stability.

Drug content:

Table no 10: - Drug Content Determination

Batch No.	Drug Content (%)
TRM1	94.43±0.35
TRM2	95.56±0.71
TRM3	89.67±0.08
TRM4	98.34±0.17
TRM5	92.46±0.36

All the values are expressed as mean ± SD, n=3

DISCUSSION:

Drug content of best formulation (TRM4) was found to be 98.34±0.17%. The drug content of each formulation of turmeric herbal emulgel has been listed in table no. 8.

CONCLUSION:

The present work deals with the formulation development and evaluation of topical herbal emulgel of turmeric using gelling agent like Carbopol 934 in different concentrations and all the excipients are of standard grad as supplied by manufacturer. In this study increases the concentration of gelling agent as well as increases in the rheological studies and extrudability of formulation. The spreadability of formulations within 33 seconds. The higher drug content determination in emulgel TRM4 are 98.34 %. Topical gel formulation was prepared by using Carbopol 934 in different concentrations the formulated five batches (TRM1-TRM5) show yellowish in appearance. Best batch TRM4 shows yellowish in appearance. pH of all five batches was found between 5.35–6.49 PH of best batch TRM4 was found 6.49 which lies in normal PH of skin. Viscosity is important parameter for characterizing the gels as it affects spreadability, extrudability and drug content, all the formulated batches should increase viscosity as the concentration of gelling agent increased best batch TRM4 show ideal viscosity is 3140 cp. Emulgel with high consistency may not extrude from the tube easily, where as low viscous gel may show quickly extrudability of emulgel. Best batch TRM4 show better extrudability than other four batches. Formulation with less concentration of gelling agent was found to be good and with high concentration of gelling agent it was satisfactory. All the prepared emulgel formulations showed uniformity of emulgel content. Hence the best formulation may be used to treat the topical wound healing and inflammation.

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Received on 17.12.2024 Revised on 04.01.2025

Accepted on 20.01.2025 Published on 03.03.2025

Available online from March 10, 2025

Res. J. Pharma. Dosage Forms and Tech.2025; 17(1):1-6.

DOI: 10.52711/0975-4377.2025.00001

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