Transferosomal Niacinamide: A Novel Approach for Hyperpigmentation and Melasma Treatment

Skin is the largest body organ which protects our body from many injuries and many microorganisms. There are many things which affect our skin layer and can cause many diseases like skin cancer, Hyperpigmentation, Melasma, Rashes etc. Many factors have different roles in skin issues. [1] When it comes to setting health priorities, skin conditions are sometimes viewed as minor players in the global league of illnesses when contrasted with illnesses that have a high death rate, such tuberculosis, HIV/AIDS, and community-acquired pneumonias. However, in tropical regions, skin conditions are typically among the most prevalent illnesses observed in basic care settings. [2] The Global Burden of Disease (GBD) 2013 Study examined the global disability and mortality rate from skin diseases. More than 1000 professionals from around the world have joined forces to build the GBD, which aims to develop an internally consistent, quantifiable, and systematic source of health information. [3] Furthermore, numerous drugs and dietary pollutants may trigger skin toxicity. [1] Early detection of the skin infection allows for the implementation of a recommended treatment plan that can cure the condition. A dermatologist's visual check and a comprehensive examination based on established clinical practice are typically used to make an appropriate diagnosis of the skin illness. Skin infections typically have a variety of reasons, and it is essential to recognize them as soon as possible. Inadequate care, poor hygiene habits, UV exposure, and bacterial or viral infections are among the common causes of skin infections. Since it is crucial to identify and treat skin infections as soon as possible, various diagnostic techniques have been investigated in the body of extant research. [4], [5].

(Fig:1) Shows the skin anatomy and physiology and what are present beneath our skin or into our skin layer.

Numerous pathogens or microorganisms can cause various skin disorders; autoimmune disorders or drug toxicity may additionally be the cause; few examples of Skin Diseases are;

? Acne: it is caused by the bacteria or when skin pores get clogged with dirt and sweat. Acne vulgaris (AV) is a common chronic disorder that impacts over 85% of teenagers and young adults globally and contributes to between 15 and 20 percent of all skin disease cases. After dermatitis, it is quickly rising to the position of the second most prevalent dermatological condition. AV is an inflammatory condition that primarily affects the back, chest, and face.

? Psoriasis:Thick, red areas covered with silvery scales are the result of the rapid growth of skin cells in psoriasis, a chronic inflammatory condition. Although the occurrence might appear in many body parts, the lower back, elbows, scalp, and other skin areas are given special attention. [6]

? Eczema: The most prevalent chronic inflammatory skin condition, eczema (also known as atopic dermatitis, or AD) affects 15–30% of children and 2–10% of adults globally. [7]

Eczema typically shows up as evenly spread lesions around the body, which can display a variety of illness symptoms, including dryness and redness, with differing degrees of severity. Due to time restrictions, family practitioners still find it difficult to determine the severity of eczema. [8]

? Skin Cancer: Skin cancer is a global epidemic and a diverse group of cancers. There are two subtypes of cancer Melanoma skin cancer (MSC) and non-melanoma skin cancers (NMSCs). Approximately 90% of skin cancer are of this type. Skin cancer, of which NMSCs are the most prevalent, accounts for one out of every three malignancies diagnosed globally. [9] MSC is a malignant tumor that develops from defective and improperly proliferating melanocytes. Malignant melanoma or cutaneous melanoma are other names for it. Melanocytes, or pigment-producing cells, are derived from the neural crest. They create the brown pigment known as melanin, which gives skin its color and protects it from the sun's damaging rays. [10]

? Hyperpigmentation: Millions of people worldwide suffer from hyperpigmentation, a skin condition marked by uneven skin tone, mainly in the facial skin areas, which can have serious negative psychological and social effects. [11] Excessive melanin production by melanocytes and enhanced transfer of the melanosome, which stores melanin, from melanocytes to the keratinocytes of the epidermal melanin unit are the causes of skin hyperpigmentation. [12]

? Melasma: The most frequent cause of facial melanosis is melasma, which is characterized by the development of hyperpigmented macules on the face. When these macules are exposed to sunshine, they become more noticeable. [13] Melasma typically manifests as symmetrical, irregularly shaped macules and patches on the face. It primarily affects the face, though it can also occasionally affect the neck and forearms. [14]

2. Hyperpigmentation and Melasma:

Here we discuss one of the most common skin diseases Hyperpigmentation and Melasma. Although both are quite different from each other but yet have similarities. Millions of people worldwide suffer from hyperpigmentation, a skin condition marked by uneven skin tone, mainly in the facial skin areas, which can have serious negative psychological and social effects. Excessive melanin production by melanocytes and enhanced transfer of the melanosome, which stores melanin, from melanocytes to the keratinocytes of the epidermal melanin unit are the causes of skin hyperpigmentation. [11], [12]. This hyperactivity is affected by endocrine and autocrine mechanisms and has a strong correlation with excessive UV exposure. The distinctive hue of melanin is produced by combining two distinct pigments, pheomelanin and eumelanin. Tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2) are the three enzymes that synthesize these two colors [15]. For the reaction to take place, TYR needs to exist. It catalyzes the conversion of tyrosine to dopaquinone, the reaction's rate-limiting step, because of its monophenolase and diphenolase activity. The presence of MITF (Microftalmia Transcription Factor) initiates the manufacture of these three enzymes. A number of routes control the synthesis of enzymes necessary for the synthesis of melanin by activating or inhibiting MITF expression [16], [17].

Melasma is the type of hyperpigmentation, characterized by the development of hyperpigmented macules on the face. When these macules are exposed to sunshine, they become more noticeable. Melasma typically manifests as symmetrical, irregularly shaped macules and patches on the face. It primarily affects the face, though it can also occasionally affect the neck and forearms. Women and those with darker skin tones—particularly those with Fitzpatrick skin types IV–VI—are more likely to have this disorder. [13], [14]. According to several studies, between 1% and 50% of the general population is thought to have melasma. Furthermore, in 55% to 64% of cases, a positive family history has been documented. Several common risk factors have been found, including heredity, exposure to ultraviolet light, pregnancy, and the use of oral contraceptives or drugs like phenytoin, even if the precise etiology of melasma is still unknown [14], [18].

2.1 Pathology of Hyperpigmentation:

The overproduction of melanin or aberrant melanin deposition in the epidermis or dermis after inflammation causes post inflammatory hyperpigmentation, also known as hypermelanosis. Melanocyte hypertrophy and activity are triggered by inflammatory mediators, which raises the epidermis's production of melanin. Damage to basal keratinocytes causes them to emit a lot of melanin in deeper processes that reach the dermis. The skin becomes permanently discolored in a blue-gray hue as a result of the phagocytosed and deposited melanin. Compared to dermal hyperpigmentation, epidermal hyperpigmentation has a higher chance of clearing up. [19] [20] In other words, hyperpigmentation occur due to excess amount of melanin production into dermis layer of the skin, these melanin production can be enhanced due to UV ray (sun exposure), little tan is not hyperpigmentation as it occur on the outer layer of skin, aging, changes in hormones, and inflammation or damage to the skin. For example, exposure to the sun can result in solar lentigines, also referred to as sun spots or age spots, and hormonal factors can produce melasma, which is characterized by brown patches that are frequently observed in pregnant women or those on contraceptives. These are few common examples of how hyperpigmentation occurs.

2.2 Pathology of Melasma:

Melasma has a complex pathogenesis that is not fully understood. Melasma is more common in women as compare to the men because of the pregrancy, abortion or by using any kind of contraceptive pills, there appears to be a clear correlation between female hormonal activity and melasma. In fact, pregnancy is when half of melasma instances first appear. Furthermore, it seems that melasma lesions have an up-regulated expression of estrogen receptors. [21] [22]

There is ongoing research over the potential significance of hormone levels in the development of male melasma. Certain cosmetics, minor ovarian malfunction, and photosensitizing drugs are additional factors linked to the pathophysiology of melasma. Certain involved drugs are often the source of ochronosis, an exogenous form of melasma. Given that a substantial risk factor for the development of melasma is a family history of the condition, there is undoubtedly a role for genetic predisposition as well. Between 55 and 64 percent of melasma patients have a family history of the illness. [23] [24]. Sunlight exposure is the most significant element in the development of melasma. UV light causes the skin to produce reactive oxygen species, which in turn encourages melanogenesis. It is also known that ultraviolet (UV) radiation increases the production of [corticotropin, alpha-melanocyte-stimulating hormone, interleukin 1, and endothelin 1] , all of which help intraepidermal melanocytes produce more melanin. Melasma may also be caused by fibroblasts found in the skin's dermal layer; melasma lesions have been found to overexpress the tyrosine kinase receptor c-kit and certain stem cell factors, which are thought to promote melanogenesis. Without rigorous sun protection, melasma treatments that might work are doomed to fail. [25] [26]

2.3 Treatment for Hyperpigmentation and Melasma:

Some treatments are very costly or clinical and others are affordable for the treatment of hyperpigmentation and melasma. Although there are few ways which can prevent this from happening.

a) Topical; in this chemical or any drug applied over layer to let it absorb rapidly into the skin to show the action on target site.

b) Laser therapy; is a medical treatment that uses a highly focused, monochromatic beam of light to treat various skin and health conditions.

c) Sunscreen; this helps to prevent or reflect the UV ray from the skin so they can’t enter into the skin and harm it.

d) Microneedling; Using small needles to cause micro-injuries, microneedling improves product absorption and encourages the creation of collagen. Microneedling can help lighten pigmentation and enhance skin texture; it is frequently used in conjunction with tranexamic acid or vitamin C.

e) Oral Drugs; Tranexamic Acid Tablets: Melasma, especially hormonally driven instances, has been successfully treated with oral tranexamic acid. It is often administered under a doctor's supervision and for brief durations of time. Polypodium Leucotomos Extract: An oral antioxidant that might lessen hyperpigmentation and shield skin from UV rays.

2.3.1 Topical:

2.3.2 Laser Therapy:

2.3.3 Chemical Peel:

The vesicular carrier systems that have drawn the most attention in recent decades as a transdermal medication delivery method are liposomes and niosomes. The characteristics of vesicle architectures have been understood by researchers in order to tag the vesicles for cell specificity and improve drug administration within their cavities. Vesicles are used in transdermal drug delivery because of their composition, which enhances penetration and acts as a drug carrier to transport entrapped drug molecules over the skin. A tailored transdermal medication delivery method uses transferosomes as its carrying body. These particular liposomes are made up of an edge activator and phosphatidylcholine. Phospholipid vesicles are also used by this technology as a transdermal medication delivery device. It enters the stratum corneum by the creation of an "osmotic gradient" either intracellularly or transcellularly. Transferosomes provide several benefits, including a broad spectrum of solubilities, improved penetration, and biocompatibility and biodegradability. Transferosome benefits include oxidative degradation, cost, etc [27] The conventional rotary evaporation sonication procedure was used to create the transfersomes. It has surfactant, phospholipids, and the medication that was made. The following are the transferosome evaluation parameters: Vesicle shape, entrapment efficiency, drug content, turbidity measurement, degree of deformability or permeability measurement, vesicle size distribution and zeta potential, Occlusion effect, penetration ability, charge density and surface charge, Physical stability, in vitro skin penetration studies, and in vitro drug release. Transferosomes can be used for transdermal vaccination, target delivery to peripheral subcutaneous tissues, controlled release, and the transportation of big molecules and weight substances. [27] The word Tranfersomes is made of two different words in Latin ‘tranferre’ refers to ‘to carry across’ and in Greek ‘soma’ refers to ‘the body’ which translates to ‘carrying body’. The active ingredient is contained within the core or between the bilayers, depending on its lipophilicity. When applied topically, transferosomes have a greater ability than liposomes to reach deeper, whole skin regions [28].

(Fig:3) Structure of Tranferosomes

Extremely adaptable and resilient under stress, these are a complex aggregate. The vesicle's local composition and bilayer form independence allow it to be both self-regulating and self-optimizing. This makes it possible for transferosomes to effectively pass through a number of transport barriers before serving as a drug carrier for targeted, non-invasive medication delivery and prolonged release of therapeutic agents. [30]

Tween80, span80, sodium cholate, sodium deoxycholate, and other edge activators are frequently used in this kind of drug delivery system to promote flexibility, and soy phosphatidylcholine, egg lecithins, cholesterol, and other phospholipids are frequently utilized for vesicle formation. [31]

Few Examples of Transferosomes:

1. Egg Phosphatidyl CholineSoya Phosphatidyl choline, dipalamitoylphosphatidyl choline: it belongs to class phospolipids and used as vesicle forming component.

2. Ethanol, methanol, isopropyl alcohol, chloroform: it belongs to class solvents and used as solvent.

3. Sod. Cholate, Sod. Deoxycholate, Tween-80, Span 80, Tween 20: it lies under Edge Activators category (surfactant vesicles forming component)

4. Saline phosphate buffer (pH 6.4), Phosphate buffer pH 7.4: belongs to class buffer agent used as As a hydrating medium

5. Rhodamine-123 Rhodamine –DHPE Fluorescein –DHPE Nile-red: it belongs to class dye used a For CSLM study.

3.1 Advantages of Transferosomes: [27], [28], [29], [30], [31], [32], [33], [34],

1. The only drug delivery method that can transport therapeutic substances across a broad range of solubility is transferosomal carriers, which are composed of both hydrophilic and hydrophobic units.

2. Transferosomes are able to pass through narrow skin barrier constrictions, which are 5–10 times smaller than vesicle size, due to their ultra-deformability and elastic properties.

3. High vesicle deformability can be used for both topical and systemic therapy, allowing drugs to pass through the skin without significantly destroying vesicles.

4. These carriers are incredibly versatile and effective at holding a variety of agents, regardless of their size, shape, molecular weight, or polarity.

5. Natural phospholipids and edge activators are used in the preparation of these units. They are both biocompatible and biodegradable.

6. Just like other active substances, transferosomes are used to transport many proteins and peptides, insulins, cortico-steriods, anesthetics, NSAIDS, antitumor drugs and herbal treatment. Transferosomes are the best option for achieving both an expected and prolonged duration of activity and a sustained drug release.

7. These can improve the site sele 9 activity of bioactive agents and increase transdermal flow.

3.2 Limitations of Transferosomes:

1. The chemical instability of transferosome formulations is caused by their susceptibility to oxidative stress. The oxidation of transferosmes is significantly decreased when aqueous solutions are degassed and purged using inert gases like argon and nitrogen.

2. Getting pure natural phospholipids, which is hard to make, is another problem with employing transferosomes as drug delivery vehicles. Therefore, artificial phospholipids could be utilized as an alternative.

3.3 Composition and Mechanism of Action of Transferosomes:

A transferosome is a mixed lipid aggregate which is optimized and self-adapting.

As "edge activators," the surfactant molecules provide the transferosomes ultra-deformability, apparently allowing them to move through stratum corneum channels that are less than a tenth of the transferosome's width. The researchers who created them suggest that transferosomes up to 500 nm in size can naturally squeak across and penetrate the stratum corneum barrier in circumstances when liposomes are too big to fit through pores smaller than 50 nm. [35] Researchers hypothesize that the "transdermal gradient," resulting from the variations in water content between the fluid viable epidermis (almost 100%) and the almost dry epidermal surface (roughly 20% water), is what accelerates penetration into the skin. The proper proportion of surface-active agent is used to make transferosomes deformable. The formulation of transferosomes depends upon the concentration of the surface-active agent since these substances give vesicle membranes flexibility at sublytic concentrations and eliminate vesicles at larger concentrations. [44] When compelled against or forced into a small pore, the ultra-deformable transferosomes may modify their membrane composition locally and reversibly because to the consequent flexibility of the transferosomal membrane, which additionally minimizes the chance of complete vesicle rupture in the skin. This significantly reduces the energetic cost of membrane deformation and enables the very flexible particles that result to enter the pores and then swiftly and effectively flow through them. [46] At least one amphiphat (such as phosphatidylcholine) that self-resembles a lipid bilayer in an aqueous solvent and closes into a simple lipid vesicle makes up the carrier aggregation. [45] The flexibility and permeability of lipid bilayers are significantly enhanced by the inclusion of at least one bilayer softening component (such as an amphiphilic medicine or a biocompatible surfactant). Therefore, the transferosome vesicles can quickly and readily conform to their ambient shape by maximizing the ensuing flexibility and permeability. As a result, they can also modify the local concentration of each bilayer component in accordance with the bilayer's local stress. These vesicles' fundamental structure is largely comparable to that of liposomes. [47] The enhanced ability of transferosomes to bind and retain water is another advantageous effect of strong bilayer deformability. Avoiding dehydration is always the goal of an ultradeformable, highly hydrophilic vesicle; this may include a transport mechanism that is similar to but distinct from forward osmosis. In order to provide proper hydration, a transferosome vesicle put to an open biological surface, such as non-occluded skin, has a tendency to cross its barrier and move into the deeper strata that are rich in water. For the underlying hydration affinity and gradient to remain in place, barrier penetration requires reversible bilayer deformation, but neither the vesicle integrity nor the barrier characteristics must be unacceptable compromised. The transferosome must locate and enforce its own path through the organ because it is too big to diffuse through the skin. Therefore, the use of transferosomes in drug delivery depends on the carrier's capacity to enlarge and penetrate the hydrophilic pores in the skin or another barrier. The drug molecules can then spread and eventually bind to their target thanks to the drug carrier's following, progressive agent release. Unless the vesicle is actively taken up by the cell through a process known as endocytosis, drug transport to an intracellular action site may also include the fusing of the carrier's lipid bilayer with the cell membrane. [48] [49] [50]

Mechanism of Action of Transferosomes (Penetration):

Under the right circumstances, transferosomes can spread 0.1 mg of lipid every hour and square centimeter across healthy skin. Compared to the value usually influenced by the transdermal concentration gradients, this value is significantly higher. Naturally occurring "transdermal osmotic gradients," or another, much more pronounced gradient across the skin, are the cause of this high flux rate. Water loss via the skin is prevented by the osmotic gradient created by the skin penetration barrier, which also keeps the water activity difference between the virtually dry stratum corneum near the skin surface (15% water content) and the viable portion of the epidermis (75% water content). [51]  [52] [53]

Even when the transdermal water loss is abnormally large, surrounding air acts as a perfect sink for the water molecule, which makes this gradient extremely stable. Every polar lipid contains some water. This results from the hydrophilic lipid residues' energetically advantageous interaction with their proximal water. Therefore, the majority of lipid bilayers naturally withstand an induced dehydration. As a result, every lipid vesicle derived from polar lipid vesicles migrates from a more arid area to one where the concentration of water is high enough. Lipid vesicles sense this "osmotic gradient" and attempt to avoid total drying by traveling along it when a lipid suspension (transferosome) is applied to the skin surface that has been partially dehydrated due to water evaporation loss. [54] Because surfactant-based transferosomes have better rheological and hydration characteristics than the vesicles that give them their greater deformability, they can only accomplish this if they are sufficiently deformable to fit through the skin's narrow pores. Standard liposomes and other less deformable vesicles are restricted to the skin's surface, where they completely dehydrate and fuse, giving them less penetration power than the transferosome. This allows transferosomes to be as flexible as possible, allowing them to fully use the transepidermal osmotic gradient (water concentration gradient). Transferosomes squeeze themselves along the intracellular sealing lipids of the stratum corneum to get past the barrier to skin penetration. [55] Researchers still not found the mechanism to enhance the delivery of the active substances across the skin. Two mechanisms of action have been proposed:

1. After penetrating the skin, transferosomes stay intact and function as drug vectors.

2. By upsetting the stratum corneum's highly ordered intercellular lipids, transferosomes serve as penetration enhancers, promoting the drug molecule's entry into and passage through the stratum corneum.

Mechanism of Transferosomes on Skin:

Transfersomes are very advanced phospholipid vesicles in transdermal drug delivery systems. Depending on the approach of administration or application, they can deliver the medicine to or through the skin in a reproducible and highly successful manner because of their self-optimized and ultra-flexible membrane properties. Vesicular transfersomes are appropriate for skin penetration because they are more porous than regular liposomes. Transfersomes squeeze along the intracellular locking lipid of the stratum corneum to get beyond the barrier of skin penetration. Because of the increased vesicle deformability that permits entry due to the surrounding mechanical stress, these are self-adapting characteristics of transfersomes. The combination of suitable surface-active chemicals with phospholipids regulates the transfersome membrane's flexibility. When used in a non-occlusive setting, the ensuing transfersome membrane flexibility allows transfersomes to follow the natural water gradient across the epidermis and reduces the risk of entire skin vesicle rupture. There are two internal lipid pathways via which transfersomes might spontaneously penetrate the intact stratum corneum, and the properties of their bilayers differ. According to confocal microscopy research, undamaged liposomes remain on the upper stratum corneum layer rather than penetrating the granular layer of the epidermis. The rate of drug release and deposition to the target site can be modified by altering the vesicular composition or surface properties. [56] [57] [58] [59] [60]

As you can see the Fig 4:

3.4 Preparation Methods of Transferosomes:

There are various methods by which you can prepare transfersomes:

1. Ethanol Injection Method

2. Thin Film Layer Method

3. Rotary Film Evaporation Method

4. Reverse Phase Evaporation Method

5. Freeze Thaw Method

3.4.1 Ethanol Injection Method:

A straightforward and popular approach for making transfersomes is the ethanol injection method. It involves infusing an ethanol-dissolved lipid solution into an aqueous phase, which causes vesicles to form on their own. [36] [37] [38] [39]

Material Required: