Formulation, Characterization and Evaluation of Ethosomal Gel of Azathioprine for the Treatment of Vitiligo

The CurrentInvestigation focuses on developing and evaluating an ethosomal gel formulation of azathioprine for topical treatment  of vitligo. Administration of topical medications allows for higher drug concentrations at the site of action compared to systemic therapy. The Efficiency of topical treatments can be enhanced using delivery systems such as liposomes, proliposomes, and ethosomes. Ethosomes are phospholipid- based vesicularsystems with high alcohol content, which enhances the transport of hydrophilic and lipophilic substances both dermally and transdermally. In this research,ethosomes were produced using phospholipid, ethanol, and distilled water through a mechanical dispersion method. The ethosomes will be assessed for vesicle size, shape, microscopy, and entrapment efficiency. Carbopol 934 was used as a gelling agent to formulate the gel.

Vesicles are tiny structures with a bilayer arrangement comparable to the natural bilipid layer structure of our body's membrane. They are particularly effective at encapsulating pharmaceuticals with varying physicochemical properties. The Skin (SC) is regarded as the most significant barrier to good transdermal medication penetration and is easily overcome by these vesicular structures (Cevc, 2004) . The amphiphilic character of vesicles permits lipophobic and lipophilic medicines to their respective destinations with reasonable ease (Tyagi LK, 2013) . Liposomes had earlier been established as apioneer model in vesicular delivery systems.

Vesicles providesignificant contributions to both cellular communication and particle movement. Researchers have stated there that the form of vesicles helps them to deliver medications in an efficient manner, and Vesicles are marked for cell specificity, producing a targeted effect. The liposomes were additionally changed for superior features, resulting in the ethosomes, which will lead to significant progression and benefit in vesicularresearch.(W., 2001)

Advantages:

More permeability through the dermis can be achieved via ethosomes, which is perfectfor transdermal and intercellular drug administration. They aid in the more effective and efficient distribution of bigger componentgroups, such as peptides and proteins. With respect, to alternative physical methods like iontophoresis and sonophoresis, the approach is comparatively easier to use. There are advantages to using non-toxic raw materials, and as a non-toxicusing a passive and intrusive method It might be commercially utilized and is immediately marketable. Compared to many other methods, it offers superiorcompliance by patients with increased stabilityand solubility.

Additionally, size of particle is decreased to allowable limits. Another crucial component is the simplicity in industrial scale-up, which makes proprietary technology more appealing overall since it makes it simple to create vast amounts of ethosomes without complex machinery or technology. As a result, they are more beneficial in the biotechnology, pharmaceutical, cosmetic, and veterinary industries. Medications that are hydrophilic or lipophilic can be added to vesicles to facilitate the transport of most drugs that are not soluble or permeable.The vesicle can improve focused and more effective therapy by increasing a strong medication at thelocation of action since it resemblesthe skin's bilipid structure

Limitations:

When ethosomes are not prepared correctly, the yield can occasionally be low. The drug loss while the shifting is very significant. In, some cases, shell locking can cause coalescence and the loss of vital stability. The medication that will be loaded must have a reasonable molecular size; otherwise, the procedure cannot deliver all drug kinds. They may occasionally be irritating to wear or uncomfortable, which would reduce their usefulness. Another significant obstacle is the unprofitable part of their price.

Fig: Advantages and Limitations of Ethosomes

Literature Review

1.E.Toutiou et.al(2000)[5] this article describes about the ethosomal systemcomposed of phospholipids,ethanol,and water which is novelcarrier for enhanced skin delivery. In terms of quantity and depth, ethosomal systems were far more effective than liposomes or hydroalcoholic solutions in delivering a fluorescent probe to the skin.This researcharticle describes the ethosomal system, a new carrier for improved skin delivery that is made of phospholipid, ethanol, and water. When it came to both amount and depth of delivery of a probe with a to the skin, ethosomal systems outperformed hydroalcoholic solution and liposomes. By using electron microscopy, it was demonstrated that ethosomal systemsconsisting of 2% soy phosphatidylcholine, 30% ethanol, and water had multilamellar vesicles.P-NMR analyses verified the lipids' bilayer structure. When compared to liposomes produced without ethanol, calorimetry and fluorescence tests indicated that the vesicular bilayers are flexible and have a comparatively low Tm and fluorescence anisotropy. According to dynamic light scattering tests, the vesicles acquireda negative charge from the ethanol.

Fang YP et al.(2008)[22] Its foundationis topical photodynamic therapy (PDT), which is an alternate treatmentfor a variety of skin malignancies other than melanomathat uses 5- aminolevulinic acid (ALA).However , the main drawbackof this treatment is that ALA has a low permeability through the skin’s stratumcorneum (SC) .

Zhang JP et al (2012) [29] the purpose of was to compare the skin penetration of Terbinafine Hydrochloride (TH) under non –occlusive settingsby ethosomes, binary ethosomes and transferosomes.These lipid vesicles were made, and their size, shape, zeta –potential, and entrapment effectiveness were assessed. .Franz diffusion cells and confocallaser scanning microscopy (CLSM) were used to study percutaneous absorption.In comparison to conventional liposomes (control), the amount of medication in the skin from ethosomes, binary ethosomes (ethanol to propylene glycol weight ratio: 7:3, ethanol-PG=7:3,w/w), and transfeorsomes all hadskin deposition rates of 3.34(p<0>

demonstrated that Rhodamine B from binary ethosomes had a significantly higher fluorescence intensity and penetration depth than that of ethosomes and transferosmes. According to these finding, transferosomes made it simplestfor drugs to concentrate in the skin , while binary ethosomes(ethanol-PG=7:3,w/w)most successfully allowed drug penetration throughskin.

With more improvement in skin penetration than in skin deposition, ethosomesenhanced medication delivery

Zhu X et al.(2013)[28]’s the goal was to prepare lidocainebase ethosomes by employing the injection- sonication– filter technique. High performance liquid chromatography and a zetasizerwere used to assess size, loading efficiency, encapsulation efficiency in the orthogonal test , Formulation was ascertained. A Franz-type diffusioncell experiment was used to examine the percutaneous penetration efficiency in vitro. The pinpricktest was used to assess in vivo effectiveness. White guinea pigs underwent cutaneous irritancy testing,which were followed by histopathologic examination. The outcomes were contrasted between lidocaine administrated in a hydroethanolic          solution     and                lidocaine   liposomes.                       Egg                phosphatidyl                        choline (5%w/w),35%w/wEthanol, 0.2% w/w cholesterol, and 5%w/w) are the constituents of lidocaine base ethosomes When compared to lidocaine base liposome base liposomes or lidocaine administered in a hydroethanolic solution, lidocaine base     ethosomes demonstrated a quicker onset time and a longer endurance in vivo. Ethosomesare potential transporters of local anaesthetics over the skin and may be applicable for other percutaneous medicines that requirequick onset.

Shen S. et al.’s (2015)[34] Developing a novel antimalarial agent is the main goal of investigation.The purpose of this work was to create ethosomal cataplasm, a novel chemicalantimalarial transdermal   nanosystem, and to examine it’s properties and effectiveness as wellas methodically research the mechanisms that facilitate ethosomal cataplasm’s penetration. Both febrifugine and artesunate – loaded ethosomes were made made, and their properties were assessed. The compound anti- malarial ethosomes cataplasm was created by integrating drug- loaded ethosomes into the cataplasmic matrix. The cumulative permeation quantity of artesunate increased dramatically with the use of ethosomal technology at 8 hours post –administration;this rise was 1.57 times more than that of conventionalcataplasm. A significant amount anti malarial medication could swiftly pass through the epidermis following injection because to the ethosomal cataplasm, and theremaining drug in the ethosomal cataplasm could be steadily released

Moghal.Roohi Shabreen (2020) [13] Several uses of ethosomes, such as the delivery of antibiotics NSAIDS, anti- cancer, anti- fungal, anti-acne, and skin cancer, will be covered in this review. Drugs including fluconazole (an antibiotic), clotrimazole (an antifungal), raloxifene

HCl (an anti-cancer agent), and indomethacin (a NSAID’s)are among those found in ethosomes.

In this review ,the preparation techniques for ethosomes – such as the cold ,hot,injection, mechanical dispersion, and classic methods – are explained. The ethosomes conduct evaluation tests such as size analysis, zeta potential , FT-IR research , stability studies , drug entrapment efficiency, permeation properties and HPLC assay.The composition ethosomes included the use of several penetration enhancers including Labrasol,Transcutol and Terpens .Increase the amount of medication that permeates the stratum corneum[SC] and reaches deeper levelsof the

Skin far more successfully than liposomes. Ethosomes         have a wide range of uses in the biotechnological, cosmetics and pharmaceutical industries as well as the abilityto transpory a huge and diverse range of medications with various physicochemical characteristics. The utilization of an ethosomaltransporter to facilitate the transfer of bioactive compoundsacross cellular membranes and the skin presents a multiple of opportunities and challenges for future Study and development of enhanced therapeutics. Ethosomes formulation has a brightfuture in efficient transdermal or dermal administration of bioactive compounds.

Conclusion

The formulation and evaluation of ethosomes loaded with azathioprine represent a promisingadvancement in the treatment of vitiligo. Ethosomes, with their lipid-based structure and ethanol content, offer enhanced transdermal administration of azathioprine, potentially improving its therapeutic effectiveness in contrast to traditional formulations. The successful development of ethosomes involves optimizing the phospholipid and ethanol concentrations, ensuring high entrapment efficiency, and achieving a desirable release profile of azathioprine.