Formulation and Evaluation of Herbal Anti-Inflammatory Emulgel of Boswellia serrata

(The figure 1 shows the various layers of skin involved in the delivery of topical drug using emulgel formulation. The emulgel, when applied on the skin surface, comes in contact with the stratum corneum, the outermost protective barrier, which increases hydration and drug permeation. The active ingredients diffuse through the epidermis to the dermis where therapeutic effects such as anti-inflammatory activity occur. Deeper penetration may reach the hypodermis in some cases and give longer lasting localised action. The emulgel system improves the spreadability, absorption and effective delivery of herbal active ingredients)

In the Indian medical system known as Ayurveda, Boswellia serrata, Linn F (Burseraceae) is frequently employed as an anti-inflammatory, analgesic, anti-arthritic, and anti-proliferative agent . According to clinical research, the Boswellia serrata plant may help individuals with inflammatory bowel disease experience less diarrhoea . In terms of macrophage activation, a biopolymeric fraction of the plant has demonstrated a dose-dependent immunostimulatory effect.(7) Strong analgesic, anti-inflammatory, and anti-arthritic properties have been demonstrated in the gum of the Boswellia serrata tree, which grows throughout India. B. serrata contains β-configured pentacyclic triterpene acids, which are significant components of the extract. These acids include 11-keto-β-boswellic acid (KBBA), 3-acetyl-11-keto-β-boswellic acid (AKBBA), 3-acetyl-β-boswellic acid (ABBA), and β-boswellic acid (BBA).(8) According to both in vitro and in vivo research, formulations containing Boswellia serrata may block inflammatory pathways linked to the development of OA and reduce the catabolic activities of important inflammatory mediators in the early stages of the disease. In particular, Boswellia serrata extract's 3-O-Acetyl-11-keto-beta-boswellic acid (AKBA) inhibits 5-lipoxygenase, a major source of pro-inflammatory leukotrienes, to produce anti-inflammatory actions .Boswellia serrata extract is safe and beneficial for OA patients, according to a recent meta-analysis (2020).(9)Vesicles are cells, and phyto denotes plant. A lipophilic form of the medication is produced by phospholipids utilised to generate phytovesicles bound with the plant extract. It improves the anti-inflammatory properties of the Boswellia serrata gum extract by penetrating the skin efficiently due to its high lipid profile. Phytovesicles have many benefits and applications as compared to the traditional formulation.  Herbal anti-inflammatory gels that use herbal extracts to increase patient compliance while being non-toxic, safe, and effective would be very acceptable.(10)More than 25 species, including Boswellia carteri, Boswellia sacra, and Boswellia papyrifera, are cultivated all over the world. BS is frequently grown in Gulf nations like Saudi Arabia and East Africa. It is extensively grown in the Indian states of Orissa, Bihar, Madhya Pradesh, Uttar Pradesh, Rajasthan, and Gujarat.The oleo gum resin is the dry exudate from the bark of Boswellia plants. Several extraction techniques, including solvent extraction, can be used to extract a specific pharmacological active ingredient. The extraction procedure, solvent extraction, and hydrodistillation. This extraction needs a variety of plant components, including the base, stem, leaves, and even a entire Boswellia plant. Several ailments can be treated with this substance. Inflammatory conditions including ulcers from colitis and Crohn’s disease. Essential oils and extracts are both utilised as mouth antiseptics. Cleaning and cough care for asthma.(11)

(Table 1: Taxonomical Hierarchy of Boswellia serrata)

(Table 2: Morphological characteristics of boswellia serrata)

Advantages(12,13):

• Increased patient acceptability and Distribute medications in a specified way.
• Boost bioavailability such that modest dosages can still be beneficial when compared to other treatments.
• Low-cost preparation and production viability.released under control.
• Increase adherence to treatment.
• Including hydrophobic medications.
• Increased capacity for loading.

Disadvantages(12,14):

• High particle size medications are more difficult for the skin to absorb.
• Certain drugs are poorly absorbed via the skin.
• High molecular weight drugs cannot be administered by Emulgel.

• Large-particle drug molecules are difficult for the skin to absorb.
• Contact dermatitis may cause skin irritation or an allergic reaction.

Rastinale of emulgel:

Certain medications that are applied to the skin or mucous membrane either pharmacologically alter an action in the tissues or enhance or restore a fundamental skin function. These products are referred to as dermatological or topical products.Often used topical medicines, ointments, creams, and lotions have a number of disadvantages. They have stability problems, a low spreading coefficient that necessitates rubbing, and a sticky character that makes patients uncomfortable when applied. All of these factors under the primary category of semisolid preparations have led to an increase in the use of transparent gels in pharmaceutical and cosmetic preparations. Hydrophobic medication delivery is a serious drawback of gels, despite their many benefits. In order to overcome this limitation and successfully integrate and administer even a hydrophobic medicinal ingredient through gels, an emulsion-based approach is being used.(15)

MATERIAL AND METHOD:

Material:

1) Boswellia serrata :

Synonym: Salai/Salai guggul,

Bio-source: Boswellia serrata is dried oleo-gum-resion obtained from stem bark of Boswellia serrata Roxb.

Family: Burseraceae

Boswellia serrata gum (Shallaki) used in this project was procured from the Commercial herbal supplier Value Life Essentials (100 g pack).boswellia is a tree with moderate to big branches that grows in arid mountainous areas of the Middle East, Northern Africa, and India.Two With 17 genera and 600 species scattered throughout all tropical climates, the Burseraceae family is represented in the plant kingdom.(16) In the full Freund's adjuvant-induced animal model of rheumatoid arthritis, Boswellia serrata exhibits effects on acute inflammatory parameters and tumour necrosis factor-α (Kumar, R. et al., 2019). According to Lee DM and Weiblatt M.E. (2011), rheumatoid arthritis (RA) is an inflammatory disease of synovial tissue that causes pain and joint deterioration. Constant inflammation of this tissue causes deformity by loosening joint ligaments and joint deterioration by eroding surrounding bones and cartilage (Matsumoto, I. et al., 2002). Nonsteroidal anti-inflammatory medications, corticosteroids, and disease-modifying anti-rheumatic medications are currently used to treat RA, however they all have negative side effects. It has been reported that the natural medication Boswellia serrata has anti-inflammatory properties.(17)

2) HPMC(Hydroxypropylmethyl cellulose):

HPMC is a semi-synthetic gelling agent made from cellulose that is stable at pH 3–11 and resistant to phenol. This polymer produces a clear and neutral gel and has a stable viscosity on long-term storage . Film coating solutions using aqueous solvents employ low-viscosity HPMC, whereas.Organic solvents use high viscosity levels. Depending on the viscosity grade, the concentration.The film-forming solution for the film-coated tablet is made of 2–20% w/w (6). HPMC-based films  has the qualities of a consistent, light, non-greasy coating with a pleasing texture, does not interact strongly with other components and water-absorbing surfactants, making it simple to spread, to offer lubrication, and to feel comfortable when applied in an occlusive state to the skin.(18)

3) Liquid Paraffin:

In semi-solid formulations, liquid paraffin is utilised as an emollient with a moisturising action that keeps skin from drying out by raising the skin's water content.(19) In addition to being a basis for lotions and ointments, liquid paraffin softens the skin.(20)

4) Glyceryl Monostearate:

Glyceryl monostearate comes in a wide range of forms and is utilised in food, pharmaceutical, and cosmetic applications as nonionic emulsifiers, stabilisers, emollients, and plasticisers. It serves as a mutual solvent for polar and nonpolar substances that can create water-in-oil or oil-in-water emulsions, acting as an efficient stabiliser.Because of these characteristics, it can also be used as a solvent for phospholipids like lecithin or as a dispersion agent for colours in oils or solids in fats..(21)

5) Spaan 80:

Pharmaceutical and cosmetic formulations employ Span 80 (Sorbitan monooleate), a non-ionic surfactant, as an emulsifying agent. Because of its low HLB value (4.3), it is mostly utilised to make water-in-oil (W/O) emulsions. It enhances the stability of formulations and offers good emulsifying, wetting, and dispersion qualities.(22)

6) Propylene glycol:

Pharmaceutical and cosmetic compositions frequently use propylene glycol as a humectant and solvent. It aids in moisture retention, enhances the formulation's texture, and makes the active chemicals more soluble. Propylene glycol improves the pH, viscosity, and clarity of gel formulations. Additionally, it helps make topical formulations more stable and spreadable.(23)

7) Methyl and Propyl paraben:

The parabens are one of the most commonly utilised classes of medicinal preservatives. They are the carboxylic esters of 4-hydroxybenzoic acid. Methyl paraben (MP) (E218) and propyl paraben (PP) are the most often used parabens.(E216), the corresponding sodium salts. The alkyl’s lengthChain, the less soluble it is in water. Therefore, a co-solvent like ethanol is typically needed.To make them more soluble, and it should be mentioned that sodium salts are less common in variousFormulations. They are typically regarded as manufactured substances, although in recent years, numerous.There were natural sources. The pharmaceutical and cosmetic industries favour them. due to their broad spectrum of antibacterial activity, excellent chemical stability across a wide pH range, and odourless and tasteless qualities. (24)

8)Triethanolamine:

Triethanolamine is widely used in topical pharmaceutical formula-tions, primarily in the formation of emulsions. When. combined with a fatty acid in equimolar amounts, like stearic acid or oleic acid, triethanolamine forms an anionic soap having a pH of roughly 8, which might be applied as an emulsifying agent to produce fine-grained, stable oil-in-water emulsions. Concentrations that are typically used for emulsification are 2–4% v/v of 2–5 times that of fatty acids and triethanolamine. When it comes to mineral oils, 5% v/v of triethanolamine will be needed, with suitable rise in the quantity of fatty acid utilised. Getting Ready that contain triethanolamine soaps tend to darken on storage. However, discoloration may be reduced by avoiding exposure to light as well as metal and metal ion interaction. Additionally, triethanolamine is utilised in topical analgesic treatments and salt production for injectable solutions. It is also used in sunscreen preparations. Triethanolamine is used as an intermediate in the manufacturing of waxes, polishes, herbicides, textile specialities, surfactants, petroleum demulsifiers, toilet goods, cement additives, and cutting oils. Triethanolamine is also claimed to be used for the production of lubricants for the textile and rubber glove industries. Other general uses are as buffers, solvents, and polymer plasticizers, and as A humectant.(21)

9) Distilled water:

Distilled water, the formulation's solvent, supplies the aqueous phase needed for hydration. It ensures that the mixture is pure and free of impurities that could jeopardise the stability and moisturiser efficacy.Vaporised water that has been boiled and then transformed back into a liquid in a different container is referred to as distilled water. The initial Parts of the water are still in the container. that do not boil below the boiling point of water. Thus, distilled water is a type of purified water. Purified water is essentially free. of substances and microbes. Osmosis in reverse (moving water across a membrane to extract substances, minerals, and microbes), Ionisation is the process of employing an ioniser rather than a chemical to sanitise water).(25)

Method of preparation (26,27,28,29):

1. Boswellia serrata Resin Extraction

To extract the active ingredients, the Boswellia serrata resin was precisely weighed and steeped in ethanol for 24 to 48 hours.The concentrated extract was obtained by filtering the mixture and evaporating the solvent.For future formulation, the extracted material was appropriately kept.

2. Gel Phase Preparation

Using a magnetic stirrer, the necessary amount of HPMC was gradually distributed in distilled water while being continuously stirred.For the dispersion to properly expand and create a smooth gel, it was set aside.

3. Oil Phase Preparation

A beaker was filled with liquid paraffin and additional oil-soluble substances. A homogenous oil phase was created by gradually heating the mixture while stirring constantly.

4. Aqueous Phase Preparation

In a different beaker, water-soluble components were dissolved in distilled water. The aqueous phase was supplemented with the produced Boswellia serrata extract. The combination was gradually heated until it reached the same temperature as the oil phase.

5. Emulsion Preparation

To create a stable emulsion, the aqueous phase was gradually introduced to the oil phase while being continuously stirred with a magnetic stirrer.

6. Emulgel preparation

With constant stirring, the produced gel phase was gradually added to the emulsion.Until a homogenous Boswellia serrata emulgel was achieved, stirring was continued.For additional assessment research, the created emulgel was put into appropriate containers and maintained appropriately.

(Figure 2. Method of preparation )

FORMULATION TABLE:

EVALUATION PARAMETERS (30,31,32,33,34,35,36):

1. Physical appearance:

This is mostly used to assess the colour, stability, texture, and smell of the emulgel.

2. pH measurement:

Every prepared emulgel's pH is measured using a digital pH meter. Prior to employing a standard buffer solution, the pH meter is calibrated. After dissolving 1 gram of the formulation in distilled water to create a homogenous solution, it is set aside for two hours. The glass electrode is submerged in the suspension for two hours, and the pH is then determined.

3. Viscosity:

The Brookfield Viscometer was used to measure the gel’s viscosity.

4. Spreadability :

A wooden block with a glass slide attached to it and another glass slide with a fixed weight attached to it were used to test the emulgel's spreadability. One gram of emulgel was placed in the center of a circle with a diameter of two centimetres on the glass slide that is fastened to the wooden block. With a fixed weight of 200 g on the slide for five minutes, the second glass slide was carefully positioned above it. It was observed that the emulgel's diameter had increased.

5. Washability:

A little amount of the produced formulation was applied to the skin, and it was then rinsed with water to establish the washability test. The skin was treated with a little amount of prepared formulations (gels) and then cleaned with warm water. The compositions ought to be easily cleaned.

6. Egg albumin test:

In a clean beaker, 0.2 ml of egg albumin (fresh hen's egg) and 2.8 ml of phosphate buffer solution (ph.7,4) are added to create a reaction mixture.Two millilitres of the test extract at different concentrations (20, 40, 60, 80, and 100 μg/mL) were added to separate test tubes containing this prepared solution. Additionally, distilled water was used in place of the test extract to provide a control solution. Every reaction mixture was thoroughly mixed and adjusted to the necessary volume. To enable interaction between the protein and the test extract, the resultant reaction mixture was incubated at 37ºC for 15 minutes. and then cooked for five minutes to 70ºC.The samples were heated and then allowed to cool to room temperature. A UV-visible spectrophotometer was used to test each sample's absorbance at 660 nm.By comparing the absorbance of the test samples with that of the control, the percentage inhibition of protein denaturation was determined.

7. Irritancy test:

The produced emulgel was applied to the previously designated 1 square centimetre region on the dorsal surface of the left hand, and the time was noted. After that, the skin was checked for irritation, erythema, and oedema (if any) at regular intervals for up to 24 hours.

8. Stability:

According to ICH guidelines, the gel was stored at 30°C±2°C/60% ±5% RH and 40°C±2°C/75% ±5% RH for the stability research. The formulation was evaluated for changes in viscosity, spreadability, pH, and physical appearance.

RESULT:

1. Physical apperance:

Emulgel formulation were light yellow preparation with smoothy and non – greasy apperance . Result have been shown in table 3.

(Table:3 Physical appearance of emulgel formulation)

2. pH measurement:

A pH meter was used to determine the prepared formulations' pH. The formulations' pH was between 5.0 and 7.0, which is regarded as appropriate to reduce the risk of skin irritation when applied to the skin.

(Table:4  pH measurement of emulgel formulation)

3. Viscosity test:

The Brook-field viscometer was used to conduct the testing.Result are given in table 5

(Table:5  viscosity test of emulgel formulation)

4. Spredability test:

The spreadability of three formulation are shown in table 6.

(Table:6 Spreadability test of emulgel formulation)

5. washability test:

The prepared emulgel showed good washability and was easily removed with water.Result are given in table 7.

(Table:7 Washability test of emulgel formulation)

6. Egg albumin test:

The prepared Boswellia serrata emulgel showed good anti-inflammatory activity by inhibiting egg albumin denaturation.Result were given in table 8.

(Table:8 Egg albumin test of emulgel formulation)