*Article* **Babchi Oil-Based Nanoemulsion Hydrogel for the Management of Psoriasis: A Novel Energy Economic Approach Employing Biosurfactants**

**Aftab Alam 1,\* , Mohammed H. Alqarni <sup>1</sup> , Ahmed I. Foudah <sup>1</sup> , Mohammad Raish <sup>2</sup> and Mohamad Ayman Salkini <sup>1</sup>**


**Abstract:** The current research aimed to assess the Babchi oil nanoemulsion-based hydrogel prepared using biosurfactants through a low-energy emulsification process for the topical management of psoriasis. The emulsification capacity and solubilities of many nanoemulsion constituents such as surfactants, co-surfactants, and oil were considered to determine the range of concentration of the constituents. Pseudoternary phase diagrams were created using the method of titration. Nanoemulgel structure, morphology, micromeritics, conductivity, and viscosity were all optimized. The assessment of the Babchi oil nanoemulgel included particle size, polydispersity index (PDI), drug content, pH, spreadability, rheological management, ex vivo drug study, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, in vitro drug release, release kinetics, and dermatokinetics. The selected ratios of the surfactant mixture (Smix) taken were 3:1. The entrapment efficiency estimated was 91.298%. The zeta potential of Babchi oil was observed to be −24.93 mV at 25 ◦C with water as a dispersant, viscosity as 0.887 cP, and material absorption as 0.01 nm. The size distribution of the particle was 108 nm by the intensity and the conductivity observed was 0.03359 mS/cm. The cumulative amount of Babchi oil penetrated and fluxed by nanoemulgel was considered larger (*p* ≤ 0.05) than the conventional formulations. Skin retention was observed to be good with decreased lag time. The formulation followed the Higuchi Korsmeyer for Fickian Peppas model for in vitro drug release studies. The oil was most effective on the epidermal layer of the skin for treatment. It was established that the Babchi oil nanoemulgel formulation had superior permeability capabilities for topical and transdermal administration and is a viable alternative to traditional formulations.

**Keywords:** Babchi oil; nanoemulsion-based hydrogel; nanoemulgel; low energy emulsification; psoriasis

### **1. Introduction**

Psoriasis is an inherited skin condition that presents with persistent non-contagious intense itching. Symptoms of this condition include deformation, inflammation, and scaly and thickened skin [1]. The global statistics of recorded cases of psoriasis are about two to five percent [2–4]. The condition progresses in many ways, and its differentiation is noted by the undergoing inflammation, rash localization, irritation of the local area, intensity of other traits, and its occurrence. This condition is classified into four types: erythroderma, pustular, and guttate, along with a persistent plaque. It manifests during the early forties and is observed equally in both genders [5,6]. Longer periods of therapy are required to treat psoriasis as it is a chronic disorder. Cyclosporines, methotrexate, and retinoids are the commonly used anti-psoriatic medications. Still, several adverse effects occur due to these drugs that include renal and liver dysfunction, loss of hair, stomach discomfort, and inflammation of lips [1,7].

**Citation:** Alam, A.; Alqarni, M.H.; Foudah, A.I.; Raish, M.; Salkini, M.A. Babchi Oil-Based Nanoemulsion Hydrogel for the Management of Psoriasis: A Novel Energy Economic Approach Employing Biosurfactants. *Gels* **2022**, *8*, 761. https://doi.org/ 10.3390/gels8120761

Academic Editor: Shige Wang

Received: 29 October 2022 Accepted: 21 November 2022 Published: 23 November 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

Approved topical therapies for the treatment of psoriasis, such as dithranol, emollients, and coal tar, are usually safe; however, they are minimally effective. Medical advancements are exploring several methods for the treatment of this condition, such as steroidal lotions, oral and injectable medications, etc. Although these medications provide momentary relief, they do not treat the symptoms as a whole because they lack a secure and optimum vehicle that can properly transport the anti-psoriatic properties of the drug for maximum treatment benefit [4,8]. To overcome the limits of traditional therapies, researchers have turned to nanoscience and nanomedicines to improve the effectiveness and lessen the undesirable adverse effects of anti-psoriatic medications. These medicines have become valuable because of their increased bioavailability, low prescription doses, and nanosized delivery of drugs. Similar to these methods, nanoemulsion is also the technique that employs a colloidal approach to administering nanosized particles of active drug moieties to the afflicted skin areas as the drugs have large surface areas.

A nanoemulsion is a transparent, stable kinetic dispersion of two insoluble phases of oil and water in the presence of surfactant particles ranging in size from 5 to 200 nm [9,10]. The usage of nanoemulsion as a vehicle for anti-psoriatic medications is favourable since it does not exhibit flocculation, internal creaming, deposition, or coarsening, which are prevalent in macroemulsions [11]. The ability to permeate is strong in nanoemulsions, along with increased drug-loading potential when used topically [4,12]. The choice of the right surfactants and oils is critical for an optimum nanoemulsion. The potential usage of biosurfactants in substitution of synthesized equivalents is considered better in regards to expense and price, durability, and compatibility with the environment. Biosurfactants are agents that are active on the surface and provide a natural alternative to their chemical equivalents. These are less harmful and also perform well during high temperature and pH conditions. Biosurfactants are significantly durable as bacterial growth is quick, and the source is numerous and producible [13]. Hydrogels are a potential type of material made from natural or artificial polymer that has three-dimensional network structures with large water content [14]. It is the most ideal biomaterial for the creation of surface coatings in the prevention and treatment of multi-drug resistant infections due to their high hydrophilicity, complex three-dimensional network, cell adhesion, and distinctive biocompatibility [15–20].

Plant-derived essential oils are fragrant liquids that have high volatility. Their abundant chemicals, such as hydrocarbons, terpenoids, coumarins, and phenols, are observed and used for their range of therapeutic properties [21]. Babchi oil produced from *P. coryfolia* (*Psoralea coryfolia* L.) is widely recognized among essential oils for its antioxidant, antibacterial, anticancer, immunomodulatory, anti-inflammatory, and antifungal effects [22]. The herb is found to grow annually in warm climates in countries such as China, India, South Africa, and Pakistan. It has become a standard treatment in the Chinese and Ayurveda fields of therapy [23].

Babchi has been used to treat a range of skin ailments, including psoriasis, leukoderma, and leprosy [24]. Isopsoralen, psoralen, and bakuchiol are the main components obtained from Babchi oil and are recognized for their various properties. Although the benefits of Babchi oil are abundant, it has poor physical qualities such as degradation susceptibility, sensitivity to light, hydrophobicity, and extreme viscosity, which has reduced the practical usage of the oil and has been confined to medicines. Recent trends in using Babchi oil include formulations such as emulgel [25] and other forms; however, formulation of the oil into a nanoemulsion-based hydrogel has not been reported. This study aims to investigate Babchi oil nanoemulsion-based hydrogel or nanoemulgel with low energy emulsification method for the management of psoriasis.

### **2. Results and Discussion** *2.1. Component Screening*

#### *2.1. Component Screening* For development of the system for nanoemulsion for delivering the drug transder‐

**2. Results and Discussion**

For development of the system for nanoemulsion for delivering the drug transdermally, certain factors, such as the solubility of the drug and its components, are required for the drug to reach and permeate within the skin. The solubility of Babchi oil was investigated. mally, certain factors, such as the solubility of the drug and its components, are required for the drug to reach and permeate within the skin. The solubility of Babchi oil was inves‐ tigated.

### *2.2. The Behavior of Phase and Nanoemulsion Optimization 2.2. The Behavior of Phase and Nanoemulsion Optimization*

*Gels* **2022**, *8*, x FOR PEER REVIEW 3 of 21

Constructing diagrams for pseudoternary phases is required because they help in finding the existing nanoemulsion ranges. Diagrams of the phase represent the translucent regions of nanoemulsion. Visual observation of the other regions on the diagram of the phases is of traditional and turbid type [26]. Separate ratio diagrams for the surfactant to co-surfactant of the pseudoternary phase were constructed to determine the regions of O/W of nanoemulsion and its formulations for optimization as shown in Figure 1. Constructing diagrams for pseudoternary phases is required because they help in finding the existing nanoemulsion ranges. Diagrams of the phase represent the translu‐ cent regions of nanoemulsion. Visual observation of the other regions on the diagram of the phases is of traditional and turbid type [26]. Separate ratio diagrams for the surfactant to co‐surfactant of the pseudoternary phase were constructed to determine the regions of O/W of nanoemulsion and its formulations for optimization as shown in Figure 1.

**Figure 1.** Pseudoternary phase diagrams displaying the area of nanoemulsion of Smix. (**a**) 3:1 (Se‐ lected ratio for Smix). (**b**) 4:1. (**c**) 5:1. (**d**) 2:1. (**e**) 1:0. (**f**) 1:1. **Figure 1.** Pseudoternary phase diagrams displaying the area of nanoemulsion of Smix. (**a**) 3:1 (Selected ratio for Smix). (**b**) 4:1. (**c**) 5:1. (**d**) 2:1. (**e**) 1:0. (**f**) 1:1.

### *2.3. Characterization: Structure and Morphology 2.3. Characterization: Structure and Morphology*

Nanoemulsion appeared to be dark around the other light surroundings when ob‐ served positively under a TEM (transmission electron microscope). The average size of the droplet was smaller than that of 100 nm from the sample. The droplets were observed Nanoemulsion appeared to be dark around the other light surroundings when observed positively under a TEM (transmission electron microscope). The average size of the droplet was smaller than that of 100 nm from the sample. The droplets were observed to be within the range of ≤200 nm of nanosize, and therefore the emulsion that was prepared was considered to be nanoemulsion. Figure 2 shows the TEM of the spreadability of Babchi oil nanoemulgel.

**Figure 2.** TEM measurement (scale set at 50 nm). **Figure 2.** TEM measurement (scale set at 50 nm).

### *2.4. Micromeritics 2.4. Micromeritics*

of Babchi oil nanoemulgel.

To determine the effective and safer dose, it is crucial to characterize the nanoemul‐ sion sizes [27]. It was found that the current formulations fell into the nanosize range. This was also observed through the decreased values of the index of polydispersity. The index for polydispersity is defined as the SD (standard deviation) ratio to the mean size of drop‐ lets and denotes the homogeneity of the size inside the formulation. To determine the effective and safer dose, it is crucial to characterize the nanoemulsion sizes [27]. It was found that the current formulations fell into the nanosize range. This was also observed through the decreased values of the index of polydispersity. The index for polydispersity is defined as the SD (standard deviation) ratio to the mean size of droplets and denotes the homogeneity of the size inside the formulation.

to be within the range of ≤200 nm of nanosize, and therefore the emulsion that was pre‐ pared was considered to be nanoemulsion. Figure 2 shows the TEM of the spreadability

### *2.5. Determination of Conductance and Viscosity 2.5. Determination of Conductance and Viscosity*

cous enough to be dermally administered.

The nanoemulsion viscosities were determined to be minimal, with a range of 9.8 ± 0.42 to 36.1 ± 0.63 mPaS. This behaviour of nanoemulsions demonstrated that they were unsuitable for topical applications. Therefore, it justified the integration of nanoemulsion within the matrix of gel,resulting in a high viscosity value in the formulated nanoemulgel. The nanoemulsion conductance was observed to be high with a value of 48.2 ± 0.03 to 161.1 ± 0.13 S/cm which resulted in the formulation being of the nanoemulsion O/W cat‐ egory. The nanoemulsion viscosities were determined to be minimal, with a range of 9.8 ± 0.42 to 36.1 ± 0.63 mPaS. This behaviour of nanoemulsions demonstrated that they were unsuitable for topical applications. Therefore, it justified the integration of nanoemulsion within the matrix of gel, resulting in a high viscosity value in the formulated nanoemulgel. The nanoemulsion conductance was observed to be high with a value of 48.2 ± 0.03 to 161.1 ± 0.13 µs/cm which resulted in the formulation being of the nanoemulsion O/W category.
