Formulation and in Vitro Evaluation of Herbal Emulgel

1. Introduction

Drugs can be administered by many routes to human body namely oral, sublingual, rectal, parental etc. Topical drug delivery is an attractive route for local and systemic treatment.

The main advantage of the topical delivery system is to bypass first pass metabolism. The most popular products are semisolid preparation.

Among the semisolid preparations, the transparent gels are used both in cosmetics and in pharmaceutical preparations.

Gel formulations generally show better drug release than ointments and creams When gels and emulsion are mixed together emulgel is formed. It also shows good penetration through the skin.

Emulgels with properties such as being thixotropic, greaseless, easily spreadable, easily removable, emollient, water soluble, longer shelf life.

1.1. Advantages:

•  Avoidance of first pass metabolism.

•   More selective to a specific site.

•  Suitability for self-medication.

•  Drug with short biological half-life and narrow therapeutic window.

•  Convenient and easy to apply.

1.2. Disadvantages:

• Skin irritation on contact dermatitis.

• Possibility of allergenic reactions

1.3. Application of Emulgel in Drug Delivery System

• Emulgel preparation is short and simple.

• There are no specialized instruments needed for the production of emulgels.

• Patient compliance

• They are less greasy and easy to apply.

• Better stability

1.4. Constituents of Emulgel

• Aqueous Material: This forms the aqueous phase of the emulsion. Commonly used agents are water, alcohols.

• Oils: Mineral oils, either alone or combined with soft or

hard paraffin

• Emulsifiers: They are used to maintain stability of a preparation during its shelf life.. e.g. Span 80, Tween 80.

• Gelling Agent: It is used to improve the consistency of any dosage form and also used as a thickening agent. E.g. carbopol 940

• Permeation Enhancers: They are used to improve the absorption of drugs. Commonly used penetration enhancers are oleic acid, lecithin, clove oil, menthol etc.

Curcumin which is obtained from dried rhizome of Curcuma longa is well known plant extract used to treat inflammation. Curcumin showed anti-inflammatory action by inhibiting enzymes like cyclooxygenase 2 (COX-2) and lipoxygenase (LOX).

2.Review of Literature

2.1.Past work on Emulgel:

Jaise Thomas, et al. Topical drug delivery system can be defined as a direct effect of drug containing medication to the skin to get the effect of drug or to cure disorders. Major disadvantage of gel is the delivery of hydrophobic drug1.

Anil R.Phad, et al. In comparison with the other semisolid preparations, the use of gels has been emerged both in cosmetics and pharmaceutical preparations2.

Abhijeet Ojha, et al. Gels are the preferable dosage forms for topical delivery of drugs in present days, but their use is not suitable for drugs with hydrophobic nature3.

2.2. Past work on Curcuma longa:

Jaggi Lal, et al. Turmeric is a very important spice in India, which is obtained from rhizomes of plant Curcuma longa, a member of the Zingiberaceae (ginger) family.

Abraham A, et al. to evaluate Curcuma longa rhizome by pharmacognostic and phytochemical analysis and standardize one of its formulations by HPLC.

Ghasem D. Najafpour, et al. in this study, extraction of curcumin, the bioactive compound of turmeric (Curcuma longa L.), through different extraction methods was investigated.

3. Drug Profile for Herbal Emulgel (Curcuma Longa)

Kingdom: Plantae
Family : Zingiberaceae
Genus : Curcuma
Species: Longa

Scientific name: Curcuma longa

Figure 1: Curcuma longa.

3.1.Chemical constituents

Curcuminoids are phenolic compounds which are the main active constituents

Other constituents of turmeric include terpenes, steroids and fatty acids, which contribute to its aromatic taste and smell4.

3.2. Applications:

• Curcuma longa rhizome is important as it is a commonly used spice and a widely used ingredient of herbal and ayurvedic formulations.

• The volatile oils and curcumin and exhibit potent anti-

inflammatory effects.

• Constituents of turmeric exert several protective effects on the gastrointestinal tract.

• Turmeric lower serum cholesterol levels.

• Constituents of turmeric block the replication of HIV. Stimulate muscle regeneration.

4.  Excipient Profile for Herbal Emulgel

4.1. Carbopol: Carbopol is a water-soluble polymer, used as an emulsifying, stabilizing, suspending, thickening and gelling agent.

4.2.Liquid Paraffin: Liquid paraffin is highly refined mineral oil used in cosmetics and for medicinal purposes.

4.3.   Methyl Paraben: Methyl Paraben is an antimicrobial agent, Flavoring agent and Preservative.

4.4. Poly Sorbate 80: Polysorbate 80 is a hydrophilic nonionic surfactant. In pharmaceutical products, it can acts as an emulsifier, solubilizer, antimicrobial, preservative and disinfectant.

4.5. Menthol

•  Menthol is widely used as a natural product in cosmetics.

•  Menthol is used as traditional medicine for a number of ailments including infections, insomnia.

4.6.Propylene Glycol: Propylene glycol is used as an organic solvent and diluent in pharmaceuticals and many other industrial applications.

4.7. SPAN 20: Sorbitan laurate is an emulsifier in cosmetic creams and lotions as well as a stabilizer5.

4.8. Triethylamine

•  Tri ethylamine is commonly employed in organic synthesis as a base.

•  It is useful as an intermediate for manufacturing medicines, pesticides.

•  Triethyl amine is the active ingredient of fly Nap.

5. Materials for Emulgel

Table 1: List of chemicals used in Emulgel.

6. Methods For Emulgel

6.1. selection of Herb

• Curcuma longa (Family-Zingerberaceae) chemically known as diferouloul methane has been reported to possess antioxidant, anti-inflammatory.

•  It undergoes extensive first pass metabolism and hence is a

suitable candidate for topical emulgel formulation.

6.2. Preparation of Extract: Maceration process of Curcuma longa

6.3. Preparation of 6.8 pH Buffer

6.4.Determination of Wave Length: Curcumin was examined in the range 200-600nm by using 3µg/ml solution.

6.5. Construction of calibration curve for Curcumin

• Preparation of stock solution

• Preparation of working standard

• Preparation of Dilutions

6.6. Evaluation Tests for Extract

• Tests for carbohydrates: Molisch test, Fehling test.

• Tests for terpenoids: Salkowski test

• Tests for alkaloids: Mayer’s reagent test, Hager’s reagent test, Wagner’s reagent test

• Tests for glycosides: Legal’s test

• Tests for flavonoids: Aqueous sodium hydroxide test, Concentrated sulphuric acid test

• Tests for polyphenols: Ferric chloride test.

     
6.7. Preparation of Emulgel

Figure 2: Curcuma Longa Herbal Emulgels.
6.8. Evaluation of Emulgel

• Physical appearance: The Emulgel is checked for their color, homogeneity, consistency.

• Spreadability.

• Skin Irritation Test (Patch Test).

• Drug Diffusion.
7. Results and Discussions

Table 2: Composition of all formulations of Herbal Emulgel.

• Curcuma longa (Family-Zingerberaceae) is selected for this work. Curcumin is chemically known as diferouloul methane has been reported to possess antioxidant, anti- inflammatory.

• In the present work, studies were carried out on herbal emulgel by employing pharmaceutically acceptable excipients like carbopol, methyl parabin, propylene glycol, liquid paraffin etc…with a main objective to control the drug release and to improve bioavailability.

• Curcumin is extracted from Curcuma longa by maceration process.

7.1. Preparation of Emulgel

• Herbal emulgel of Curcuma longa formulated with different concentrations (0.5, 1, and 1.5%) of carbopol and with different excipients like liquid paraffin, propylene glycol, Tween 20, span 80, menthol, Triethylamine.

• Then these prepared emulgels were evaluated for various physical parameters such was texture, appearance, Spreadability, irritability, and diffusion studies.

7.2. Physical parameters of herbal emulgel of Curcumin longum

The herbal emulgel has good texture without having any lumps. It has good appearance with acceptable color and fragrance, it also has good Spreadability character because it evenly spread in applied area. It has good consistency and overall acceptability. (Table 3) (Figure 3)

Table 3: Calibration data of Curcumin in 6.8 PH Buffer.

Figure 3: Calibration curve of Curcumin in 6.8 pH Buffer.

7.3. Determination of Wave Length: Curcumin was examined in the range 200-600nm by using 3µg/ml solution, it shows absorption maxima at 426 nm.

7.4. Preparation of calibration curve of curcumin: An analytical method used in the present work for the estimation of curcumin was UV spectrophotometric method. This method was adopted for the estimation of above drug in the herbal emulgel and in vitro diffusion studies. The method obeyed Beer’s law in concentration range of 1-4(µg/ml) (Table 4).

Curcuma longa was analyzed for presence of carbohydrates, proteins, glycosides, tannins, saponins, polyphenols and flavonoids by using general identification tests. It composed of mono and sesquiterpenes6. (Table 5) (Figure 4)

7.5. Invitro drug release studies: Curcumin release from the emulgel was evaluated by invitro diffusion studies. % Drug release from emulgel depends on concentration of gelling agent. Gelling agent increases release of drug decreases. In F1, F2, F3 formulations concentration of carbopol is 0.5%, 1%, 1.5% respectively. Based on the release rate, the order of drug release from the three formulations was F1>F2>F3. The invitro release data was presented in table.

Table 4: Phyto Chemical Analysis of Curcuma Longa Extract.

Table 5: Cumulative % Drug release from Emulgel formulations at different time intervals.

Figure 4: Comparative in vitro drug release plots of curcumin.

8.  Conclusion
The following conclusion were made from these experimental results.

1. Emulgel was prepared with herbal drug.
2. Curcuma longa is selected for preparation of Emulgel.
3. Maceration is used for extraction of curcuma longa,
4. Extract was evaluated by phyto chemical analysis like presence of carbohydrates, proteins, glycosides, s polyphenols and flavonoids.
5. Emulgel was evaluated by Physical appearance, Spreadability, Skin irritation test, Drug diffusion.
6. And it has evaluated by invitro drug diffusion studies. % Drug release from emulgel depends on concent gelling agent. Gelling agent increases release of drug decreases.

9.  References

1. Jaise Thomas, Kuppuswamy S, Sahib AA, et al. Emulgel as a Current Trend in Topical Drug Delivery System. Ijppr Human Journals, 2017;9(3): 273-281.
2. Anil RP, Dilip NT, Ganapathy S. Emulgel: A Comprehensive Review for Topical Delivery of Hydrophobic Drugs. Asian Journal of Pharmaceutics, 2018;12(2): 382-393.
3. Shambhvi S, Indu S. Evolving Implementation of Emulgel as a Topical Drug Delivery System: A Systematic Review. Current Research in Pharmaceutical Sciences, 2022;12(3): 121-131.
4. Thakur S, Thakur N, Ghosh NS. Formulation and in-vitro evaluation of Polyherbal Micro-emulgel containing Tinospora cordifolia and Curcumin for treatment of Arthritis. International Journal of Pharmaceutical Sciences and Drug Research, 2016;8(5): 259-264.
5. Pakhare AV, et al. Design and Development of Emulgel Preparation Containing Diclofenac Potassium. Asian Journal of Pharmaceutics, 2017;11(4): 712-716.
6. Haneef KPM, et al. Emulgel: An advanced review. J Pharm Sci and Res, 2013;5(12): 254-258.