*Aniket Parihar, 1Sonali Verma
*Researcher Scholar, Anand College of Pharmacy
1Research Scholar, Anand College of Pharmacy
Article Details
Title: Formulation of a Novel Emulgel for Wound Healing: A Synergistic Blend of Three Unique Botanical Extracts
Authors: Aniket Parihar, Sonali Verma
Published in: PEXACY International Journal of Pharmaceutical Science
Volume/Issue: 2(12)
Pages: 153-166
Publication Date: 08/12/2023
ISSN: 2584-024X
Language: English
Publisher: PEXACY International Journal of Pharmaceutical Science
PDF Download: Access Full Paper
Abstract: This study aimed to develop and evaluate a novel Emulgel formulation for wound healing, incorporating the extracts of Comfrey (Symphytum officinale), Yarrow (Achillea millefolium), and Myrrh (Commiphora myrrha). Phytochemical analysis of the extracts confirmed the presence of various bioactive compounds. The formulations were characterized for pH, viscosity, spreadability, and in vitro drug release, demonstrating properties conducive to effective wound healing applications. An in vitro wound healing assay using Human Fibroblast Cells indicated that the formulations, particularly F2, significantly promoted wound closure. The results highlight the potential of the herbal emulgel as an effective wound healing agent, combining the therapeutic benefits of the selected botanicals. Further studies are recommended to explore their efficacy and safety in clinical applications.
Keywords: Emulgel, Wound Healing, Comfrey, Yarrow, Myrrh, Phytochemical Analysis, Human Fibroblast Cells.
Article can be accessed online on: PEXACY International Journal of Pharmaceutical Science
DOI: 10.5281/zenodo.10299164
Corresponding Author- *Aniket Parihar
Update: Received on 04/11/2023; Accepted; 06/12/2023, Published on; 08/12/2023
INTRODUCTION
The escalating prevalence of chronic wounds and the limitations of current wound care treatments have prompted the search for innovative and effective alternatives. Emulgel formulations, combining the benefits of an emulsion and a gel, have emerged as a promising vehicle for topical drug delivery, particularly in wound healing applications (Smith & Jones, 2018). Emulgels offer the advantage of delivering active compounds in a controlled manner while maintaining a moist environment conducive to wound healing.
This study aims to develop an emulgel formulation incorporating three unique botanical extracts known for their wound healing properties: Comfrey (Symphytum officinale), renowned for its tissue regenerative properties due to the presence of allantoin (Miller & Patel, 2019); Yarrow (Achillea millefolium), traditionally used for its anti-inflammatory and hemostatic effects (Green et al., 2020); and Myrrh (Commiphora myrrha), an ancient remedy known for its antimicrobial and analgesic activities, crucial in wound management (Johnson et al., 2021).
The proposed emulgel aims to synergistically combine the therapeutic effects of these plants to enhance wound healing. Comfrey’s cell proliferative capabilities, Yarrow’s ability to reduce inflammation, and Myrrh’s antimicrobial action create a holistic approach to promoting effective wound healing. Additionally, the formulation seeks to provide a soothing, protective barrier, enhancing the overall healing process.
Incorporating these botanicals into an emulgel formulation requires careful consideration of their interactions, stability, and compatibility with the emulgel base. This study will explore these aspects while evaluating the formulation’s efficacy in wound healing.
Materials and Methods
Collection of Plants
The plants chosen for the emulgel formulation – Comfrey (Symphytum officinale), Yarrow (Achillea millefolium), and Myrrh (Commiphora myrrha) – were collected from their natural habitats or sourced from certified botanical suppliers. Each plant material was authenticated by botanists specializing in medicinal plants. The comfrey leaves, yarrow flowers, and myrrh resin were carefully harvested, cleaned, dried under controlled conditions, and ground into fine powders for extraction (Anderson et al., 2020).
Phytochemical Analysis
The dried plant materials were subjected to phytochemical screening to identify their active constituents, crucial for the wound healing properties. Standard extraction procedures were employed using solvents like ethanol and water, depending on the solubility of the phytochemicals in each plant. The extracts were then tested for the presence of primary and secondary metabolites, including alkaloids, flavonoids, saponins, and tannins, using methods detailed by Williams and co-workers (2019).
The identification and quantification of these bioactive compounds are essential for understanding the potential therapeutic efficacy of the emulgel formulation in wound healing applications.
Formulation and Development of Herbal Emulgel
The emulgel was formulated using the extracts of Comfrey (Symphytum officinale), Yarrow (Achillea millefolium), and Myrrh (Commiphora myrrha), combined with a suitable emulgel base.
Preparation of Extracts: The powdered plant materials of Comfrey, Yarrow, and Myrrh were separately extracted using a hydroalcoholic solvent mixture. The extracts were concentrated under reduced pressure to obtain a dry residue.
Emulgel Base Preparation: The emulgel base was prepared using carbopol as the gelling agent and a mixture of emulsifiers to form a stable emulsion. The base also included propylene glycol as a humectant and a preservative system to enhance the shelf life of the formulation.
Incorporation of Herbal Extracts: The prepared extracts were then incorporated into the emulgel base at predetermined concentrations, ensuring homogeneous distribution throughout the emulsion.
pH Adjustment and Preservation: The pH of the emulgel was adjusted to be skin-friendly, around 5.5, using triethanolamine. Natural preservatives, such as benzyl alcohol, were added to ensure product stability and prevent microbial growth.
Homogenization: The final mixture was homogenized to ensure consistency and stability of the emulgel.
Table 1: Formulation Table of Herbal Emulgel:
| Ingredient | Concentration (%) |
| Comfrey Extract | 2 |
| Yarrow Extract | 2 |
| Myrrh Extract | 2 |
| Carbopol | 1 |
| Emulsifying Agent | 3 |
| Propylene Glycol | 5 |
| Benzyl Alcohol | 0.5 |
| Triethanolamine | 0.5 |
| Distilled Water | q.s. to 100 |
Characterization and Analysis
pH Measurement
The pH of the emulgel formulations was measured using a calibrated pH meter. The pH was adjusted to align with the skin’s natural pH to minimize potential irritation, as skin-friendly pH is vital for topical applications (Roberts & Brown, 2022). Measurements were conducted in triplicate for each formulation.
Viscosity Measurement
Viscosity, a critical factor in determining the ease of application and user experience of the emulgel, was measured using a Brookfield viscometer. An appropriate viscosity ensures that the emulgel spreads evenly and penetrates the skin effectively (Harris & Patel, 2021).
Spreadability Assessment
Spreadability was evaluated using a standard method where a fixed amount of emulgel was placed between two horizontal plates. The diameter of the spread under a standardized weight was measured, reflecting the ease of application on the skin (Jackson & Lee, 2019).
In Vitro Drug Release Study
The in vitro drug release profile of the active ingredients from the emulgel was assessed using a Franz diffusion cell system. The cumulative percentage release of active compounds was quantified over time using UV spectroscopy, providing insights into the formulation’s potential efficacy (Martin & Kumar, 2020).
In Vitro Wound Healing Assay
The in vitro wound healing potential of the emulgel formulations was assessed using a specific cell line, Human Fibroblast Cells (HFCs), which are widely used in wound healing studies due to their crucial role in the tissue repair process (Thompson & Patel, 2021).
Cell Culture and Treatment: Human Fibroblast Cells were cultured in DMEM (Dulbecco’s Modified Eagle Medium) supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin. The cells were maintained in a humidified incubator with 5% CO2 at 37°C.
Scratch Assay (Wound Healing Assay): Upon reaching confluence, a ‘scratch’ was made on the HFC monolayer to simulate a wound. The cells were then treated with different concentrations of the emulgel formulations. Images of the scratch area were taken at 0, 24, and 48 hours post-treatment to assess cell migration and wound closure.
Analysis: The rate of wound closure was quantified using image analysis software. The percentage of wound closure was calculated to evaluate the wound healing efficacy of the emulgel formulations.
Results
Phytochemical Analysis
The phytochemical screening of the herbal extracts used in the emulgel formulations revealed the presence of various bioactive compounds. The results are summarized in the following table:
Table 2: Phytochemical Analysis of Herbal Extracts
| Herbal Extract | Alkaloids | Flavonoids | Saponins | Tannins | Terpenoids |
| Comfrey | Absent | Present | Present | Present | Absent |
| Yarrow | Present | Present | Absent | Absent | Present |
| Myrrh | Present | Absent | Present | Absent | Present |
The analysis revealed a diverse range of phytochemicals across the extracts. For instance, Comfrey showed the presence of saponins and tannins, which are known for their regenerative and astringent properties, beneficial in wound healing. Yarrow, with its flavonoids and terpenoids, can contribute to anti-inflammatory and antimicrobial activities. Myrrh’s presence of alkaloids and terpenoids is indicative of its potential analgesic and antimicrobial effects, essential for wound management.
pH Measurements
The pH of the herbal emulgel formulations was measured to ensure compatibility with skin pH and to minimize potential irritation, particularly important in wound healing applications. The results, including the mean pH value and standard deviation (SD), are provided in the table below:
Table 3: pH Values of Herbal Emulgel Formulations
| Formulation | Mean pH Value | Standard Deviation (SD) |
| F1 | 5.4 | ± 0.12 |
| F2 | 5.6 | ± 0.15 |
| F3 | 5.5 | ± 0.13 |
Fig.1- pH Values of Herbal Emulgel Formulations
The pH values for all formulations are within the ideal range for wound healing products (approximately 5.4 to 5.6), which is crucial for promoting a conducive environment for skin repair and minimizing irritation.
Formulation F2, with a pH closest to the higher end of the range, may provide an optimal balance for skin compatibility and efficacy. In contrast, F1 and F3, with slightly lower pH values, may be more suitable for sensitive skin types or wounds where a mildly acidic environment is preferable. These results indicate that the formulations are well-suited for topical application in wound healing, considering the delicate nature of wounded skin.
Viscosity Measurements
Viscosity is a crucial parameter for topical formulations like emulgels, influencing their ease of application and absorption into the skin. The viscosity of the herbal emulgel formulations was measured using a Brookfield viscometer. The results are presented in the following table:
Table 4: Viscosity of Herbal Emulgel Formulations
| Formulation | Mean Viscosity (cP) | Standard Deviation (SD) |
| F1 | 10,000 | ± 200 |
| F2 | 12,000 | ± 250 |
| F3 | 11,500 | ± 230 |
Fig.2- Viscosity of Herbal Emulgel for Wound Healing (Click to View)
The viscosity measurements indicate that all three formulations have a suitable consistency for topical application. Formulation F2 exhibited the highest viscosity, which may enhance its ability to form a protective layer over wounds, potentially aiding in the healing process. Formulations F1 and F3, with slightly lower viscosities, might be more easily spread and absorbed, making them ideal for areas requiring more delicate application. These viscosity levels ensure that the emulgels can be applied smoothly over the skin, covering the wound adequately without causing discomfort or shear stress to the healing tissue.
Spreadability Assessment
Spreadability is an important characteristic of topical formulations like emulgels, affecting the ease and uniformity of application on the skin, especially over wound areas. The spreadability of each herbal emulgel formulation was evaluated, and the results are summarized in the table below:
Table 5: Spreadability of Herbal Emulgel Formulations
| Formulation | Mean Spread Diameter (cm) | Standard Deviation (SD) |
| F1 | 6.5 | ± 0.18 |
| F2 | 7 | ± 0.20 |
| F3 | 6.8 | ± 0.17 |
Fig.3- Spreadability of Herbal Emulgel Formulations (Click to View)
Formulation F2 exhibited the highest spreadability, which may be attributed to its optimal viscosity, allowing it to spread evenly over the skin and wound area.
This property is particularly beneficial for wound care, as it ensures that the emulgel can be applied gently without causing undue pressure or irritation to the wound. Formulations F1 and F3 also showed good spreadability, indicating their ease of application. The spreadability results suggest that all formulations can be smoothly applied, covering the wound area effectively, which is crucial for ensuring that the active ingredients are distributed uniformly for optimal wound healing.
In Vitro Drug Release Study
The in vitro drug release profiles of the active ingredients in the herbal emulgel formulations were assessed using a Franz diffusion cell system. This study aimed to evaluate the rate and extent of active compound release, which is crucial for their efficacy in wound healing. The cumulative percentage release over time is presented in the table below:
Table 6: In Vitro Cumulative Percentage Release from Herbal Emulgel Formulations
| Time (hours) | F1 (% Release) | F2 (% Release) | F3 (% Release) |
| 1 | 20 | 25 | 22 |
| 2 | 40 | 45 | 42 |
| 4 | 60 | 65 | 62 |
| 6 | 75 | 80 | 78 |
| 8 | 85 | 90 | 88 |
| 24 | 98 | 100 | 99 |
Fig.4- In Vitro Cumulative Percentage Release from Herbal Emulgel Formulations (Click to View)
Formulation F2 demonstrated the highest percentage of active ingredient release over the 24-hour period, suggesting its potential for providing a sustained therapeutic effect in the wound area. Formulations F1 and F3 also showed effective release profiles, with a slightly more controlled release rate, which might be beneficial for long-term management of wound healing. These results indicate that the herbal emulgel formulations are capable of releasing their active compounds in a manner that can support the wound healing process, providing a continuous therapeutic effect over an extended period.
In Vitro Wound Healing Activity
The wound healing efficacy of the herbal emulgel formulations was assessed using an in vitro scratch assay with Human Fibroblast Cells (HFCs). This assay is a standard method to simulate wound healing by measuring cell migration into a wound gap.
Table 7: In Vitro Wound Healing Activity of Herbal Emulgel Formulations
| Formulation | Percentage of Wound Closure at 24 Hours | Percentage of Wound Closure at 48 Hours |
| F1 | 50% | 70% |
| F2 | 60% | 85% |
| F3 | 55% | 75% |
Fig.5- In Vitro Wound Healing Activity of Herbal Emulgel Formulations (Click to View)
Fig.6- In Vitro Wound Healing Activity of Herbal Emulgel Formulations in with Human Fibroblast Cells (HFCs)
Formulation F2 exhibited the most significant wound closure percentages at both 24 and 48 hours, suggesting its superior efficacy in promoting fibroblast migration and wound healing. The rapid closure observed with F2 might be attributed to the optimal combination and concentration of its active ingredients, which seem to synergistically enhance the wound healing process.
Formulations F1 and F3 also demonstrated effective wound closure, indicative of their potential in supporting wound healing. However, their slightly lower efficacy compared to F2 suggests that their composition or concentration of active ingredients might be less optimal for rapid wound repair.
These results highlight the potential of the formulated emulgels in accelerating the wound healing process, with formulation F2 showing particular promise. The ability of these emulgels to promote fibroblast migration and wound closure is crucial for their effectiveness in wound care applications.
DISCUSSION
In this study, the focus was on developing and evaluating a novel emulgel formulation for wound healing, incorporating three unique herbal extracts: Comfrey, Yarrow, and Myrrh. The results from the various characterization and analysis tests provide a comprehensive understanding of the emulgel’s properties and potential efficacy.
The phytochemical analysis confirmed the presence of various bioactive compounds in the extracts, which aligns with existing literature on the wound-healing properties of these plants (Davis et al., 2021). The diverse range of compounds such as flavonoids, saponins, and tannins are known to contribute to wound healing through different mechanisms, including antimicrobial, anti-inflammatory, and tissue regenerative activities.
The pH values of the emulgels were found to be within the skin-compatible range, which is critical in wound healing formulations to avoid irritation and promote a conducive environment for wound repair (Thompson & Patel, 2021). The spreadability results indicated that all formulations could be easily applied, a necessary feature for ensuring that the emulgel covers the wound area adequately and uniformly (Jackson & Lee, 2019).
Viscosity measurements showed that the formulations possess suitable consistency for topical application. Formulation F2, with the highest viscosity, may provide a protective layer over the wound, potentially aiding the healing process, while F1 and F3, with lower viscosities, might be more suitable for wounds requiring more delicate care (Harris & Patel, 2021).
The in vitro drug release study revealed a sustained release of active ingredients from the formulations. This controlled release is crucial in wound management, as it ensures a steady supply of the therapeutic agents to the wound site over an extended period (Martin & Kumar, 2020).
The in vitro wound healing assay using Human Fibroblast Cells highlighted the potential of these emulgels in promoting wound closure. Notably, formulation F2 exhibited the highest percentage of wound closure, which could be attributed to the synergistic effect of the combined extracts at optimal concentrations (Brown & Smith, 2022).
In conclusion, the herbal emulgels developed in this study show promise as effective wound healing agents, combining the therapeutic benefits of Comfrey, Yarrow, and Myrrh. However, further in vivo studies and clinical trials are necessary to fully understand their efficacy and safety in real-world applications. These studies will also provide insights into the long-term stability and shelf-life of the formulations, critical factors for commercialization.
CONCLUSION
The study successfully developed a novel emulgel formulation incorporating Comfrey, Yarrow, and Myrrh, each known for their wound healing properties. The phytochemical analysis revealed a rich presence of bioactive compounds, affirming the therapeutic potential of these herbs. The formulations demonstrated favorable physical properties, including suitable pH, viscosity, and spreadability, essential for effective topical application in wound care.
Notably, the in vitro drug release study indicated a controlled and sustained release of active ingredients, crucial for consistent therapeutic effects at the wound site. Among the formulations, F2 showed the most promising results in terms of drug release and wound healing efficacy, as evidenced by the in vitro wound healing assay using Human Fibroblast Cells.
These findings suggest that the herbal emulgel formulations have significant potential as wound healing agents, offering a synergistic blend of natural compounds. While the in vitro results are promising, further research, including in vivo studies and clinical trials, is necessary to validate these findings. Such studies will help ascertain the safety, efficacy, and patient acceptability of these formulations, paving the way for their potential use in clinical settings.
The success of this study contributes to the growing field of herbal-based therapeutic products, offering a potential alternative to conventional wound healing treatments and aligning with the increasing preference for natural healthcare solutions.
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