Design, Formulation, and Characterization of Valsartan Nanoethosomes for Improving Their Bioavailability

Ethosomes as a carrier for transdermal drug delivery system: methodology and recent developments

Transdermal drug delivery systems (TDDS) have received significant attention in recent years. TDDS are flexible systems that transport active components to the skin for either localized or systemic delivery of drugs through the skin. Among the three main layers of skin, the outermost layer, called the stratum corneum (SC), prevents the entry of water-loving bacteria and drugs with a high molecular weight. The challenge lies in successfully delivering drugs through the skin, which crosses the stratum corneum. The popularity of lipid-based vesicular delivery systems has increased in recent years due to their ability to deliver both hydrophilic and hydrophobic drugs. Ethosomes are specialized vesicles made of phospholipids that can store large amounts of ethanol. Ethosome structure and substance promote skin permeability and bioavailability. This article covers ethosome compositions, types, medication delivery techniques, stability, and safety. In addition to this, an in-depth analysis of the employment of ethosomes in drug delivery applications for a wide range of diseases has also been discussed. This review article highlights different aspects of ethosomes, such as their synthesis, characterization, marketed formulation, recent advancements in TDDS, and applications.

Development and optimization of kaempferol loaded ethosomes using Box-Behnken statistical design: In vitro and ex-vivo assessments

Kaempferol (KMP) belong to flavonoid class have developed in ethosomal formulation and were evaluated for their potential to treat diabetic foot ulcers. Even though ethosomes are highly deformable, they can pass through human skin intact. KMP ethosomes were formulated using the cold method and optimized by Box-Behnken design (BBD) (three-factor, three-level (33 )). The formulation variables used for optimization are drug concentration of KMP, soylecithin content, and ethanol percentage. The optimized formulation was examined using transmission electronic microscopy (TEM), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, in-vitro release, ex-vivo permeation studies, and storage stability. The optimized KMP ethosomes was found to have vesicle size (VS) of 283 ± 0.3 nm and zeta potential (ZP) of -29.67 ± 0.3 mV, polydispersity index (PDI) of 0.36, % entrapment efficiency (%EE) of 91.02 ± 0.21%, drug loading (%) of 46.23 ± 2.5% followed by good storage stability at 4°C/60 ± 5% RH. In vitro drug release of optimized KMP ethosomes was 88.2 ± 2.75%, which was approximately double when compared with pure KMP release, that is 49.9 ± 1.89%. The release kinetics for optimized KMP ethosomes follows the Korsmeyer-Peppas model. An apparent permeation coefficient of 356.25 ± 0.5 μg/cm2 was determined and compared with pure KMP (118.46 ± 0.3 μg/cm2 ) for 24 h. According to the study, ethosomes can be a cutting-edge strategy that offers a new delivery method for prolonged and targeted distribution of KMP in a variety of dosage forms including oral, topical, transdermal, and so forth.

Engineering nanosystems for transdermal delivery of antihypertensive drugs

To control hypertension, long-term continuous antihypertensive therapeutics are required and five classes of antihypertensive drugs are frequently involved, including diuretics, β-blockers, calcium channel blockers, angiotensin II receptor blockers, and angiotensin-converting enzyme inhibitors. Although with demonstrated clinical utility, there is still room for the improvement of many antihypertensive drugs in oral tablet or capsule dosage form, in terms of reducing systemic side effects and first-pass hepatic drug uptake. Meanwhile, nanocarrier-mediated transdermal drug delivery systems have emerged as a powerful tool for various disease treatments. With benefits such as promoting patient compliance for long-time administration, enhancing skin permeability, and reducing systemic side effects, these systems are reasonably investigated and developed for the transdermal delivery of multiple antihypertensive drugs. This review aims to summarize the literature relating to nanosystem-based transdermal antihypertensive drug delivery and update recent advances in this field, as well as briefly discuss the challenges and prospects of engineering transdermal delivery nanosystems for hypertension treatment.

Preparation and Characterization of Transethosome Formulation for the Enhanced Delivery of Sinapic Acid

Sinapic acid (SA) is a bioactive phenolic acid; its diverse properties are its anti-inflammatory, antioxidant, anticancer, and antibacterial activities. The bioactive compound SA is poorly soluble in water. Our goal was to formulate SA-transethosomes using thin-film hydration. The prepared formulations were examined for various parameters. In addition, the optimized formulation was evaluated for surface morphology, in-vitro penetration studies across the Strat M®, and its antioxidant activity. The optimized formulation (F5) exhibited 74.36% entrapment efficacy. The vesicle size, zeta potential, and polydispersity index were found to be 111.67 nm, -7.253 mV, and 0.240, respectively. The surface morphology showed smooth and spherical vesicles of SA-transethosomes. In addition, the prepared SA-transethosomes exhibited enhanced antioxidant activity. The SA-transethosomes demonstrated considerably greater penetration across the Strat M® membrane during the study. The flux of SA and SA-transethosomes through the Strat M® membrane was 1.03 ± 0.07 µg/cm2/h and 2.93 ± 0.16 µg/cm2/h. The enhancement ratio of SA-transethosomes was 2.86 ± 0.35 compared to the control. The SA-transethosomes are flexible nano-sized vesicles and are able to penetrate the entrapped drug in a higher concentration. Hence, it was concluded that SA-transethosome-based approaches have the potential to be useful for accentuating the penetrability of SA across the skin.

Improved skin permeation of transferosomes containing Eulophia macrobulbon extract

Eulophia macrobulbon (EM) extract-loaded transferosomes represent an advanced approach for enhancing skin permeation of bioactive compounds. The formulations improving skin permeation and characterizations of transferosomes were studied, including morphology, entrapment efficiency (EE), vesicle size, polydispersity index (PDI), zeta potential, and skin permeation in the Strat-M® synthetic membrane. Vesicle size increased with increasing transition temperature (Tm) of phosphatidylcholine and the hydrophilic-lipophilic balance (HLB) of the surfactant used as an edge activator. EM extract-loaded transferosomes with varying amounts of phosphatidylcholine, surfactants, and EM extract showed non-significant differences in EE, PDI, and zeta potential. The results demonstrated that the EM extract-loaded transferosomes improved membrane permeability better than the EM solution. The EM solution exhibited a shorter lag time. Considering the advantages of the EM extract-loaded transferosomes and EM solutions, a combination of both formulations was developed in this study. The results showed that the lag time decreased and membrane permeation increased. This study highlights a novel system combining EM extract-loaded transferosomes and an EM solution, exhibiting considerable improvement in skin permeation and presenting the potential for an efficient transdermal drug delivery system for natural bioactive compounds.

Enhancement of Valsartan Oral Bioavailability by Preparing a Microwave-Irradiated Inclusion Complex with Sulfobutyl Ether β-Cyclodextrin Using a Central Composite Face Design for Optimising Process Parameters

The purpose of the study is to investigate the influence of sulfobutyl ether β-cyclodextrin (SBE₇-β-CD) on the bioavailability of valsartan. Phase solubility investigations showed an A_L type curve. The estimated apparent stability constant for valsartan SBE₇-β-CD is 427 ± 0.32 M^-1. Inclusion complexes of valsartan SBE₇-β-CD in equal molar ratio were prepared by microwave irradiation technique. The process parameters were optimised with a central composite face design. Response surface graphs and contour plots showed how process factors affected drug content. The inclusion complexes prepared by optimising process variables are characterised. The DSC and X-ray diffraction confirm the formation of inclusion complexes and the drug's transition from a crystalline to an amorphous state. FTIR suggests hydrogen bonding between valsartan and SBE₇-β-CD. SEM showed changes in drug morphology and shape. The dissolution rate of the prepared SBE₇-β-CD complex using microwave irradiation was 2.85 times that of pure valsartan. The inclusion complex was formulated into tablet dosage forms F₁ to F₄. Furthermore, oral bioavailability studies in rats with tablet formulation F₃ were carried out and compared to the marketed Diovan® tablet as a reference standard. The F₃ tablet formulation exhibited significantly higher values of AUC_0-∞ and C_max than the reference. Finally, the microwave-irradiated valsartan SBE₇-β-CD inclusion complex converted into tablet dosage form may be a promising approach to increasing valsartan oral bioavailability.

Formulation Development, Optimization by Box-Behnken Design, and In Vitro and Ex Vivo Characterization of Hexatriacontane-Loaded Transethosomal Gel for Antimicrobial Treatment for Skin Infections

There are many different infections and factors that can lead to skin illnesses, but bacteria and fungi are the most frequent. The goal of this study was to develop a hexatriacontane-loaded transethosome (HTC-TES) for treating skin conditions caused by microbes. The HTC-TES was developed utilizing the rotary evaporator technique, and Box-Behnken design (BBD) was utilized to improve it. The responses chosen were particle size (nm) (Y1), polydispersity index (PDI) (Y2), and entrapment efficiency (Y3), while the independent variables chosen were lipoid (mg) (A), ethanol (%) (B), and sodium cholate (mg) (C). The optimized TES formulation with code F1, which contains lipoid (mg) (A) 90, ethanol (%) (B) 25, and sodium cholate (mg) (C) 10, was chosen. Furthermore, the generated HTC-TES was used for research on confocal laser scanning microscopy (CLSM), dermatokinetics, and in vitro HTC release. The results of the study reveal that the ideal formulation of the HTC-loaded TES had the following characteristics: 183.9 nm, 0.262 mV, -26.61 mV, and 87.79% particle size, PDI, and entrapment efficiency, respectively. An in vitro study on HTC release found that the rates of HTC release for HTC-TES and conventional HTC suspension were 74.67 ± 0.22 and 38.75 ± 0.23, respectively. The release of hexatriacontane from TES fit the Higuchi model the best, and the Korsmeyer-Peppas model indicates the release of HTC followed a non-Fickian diffusion. By having a higher negative value for cohesiveness, the produced gel formulation demonstrated its stiffness, whereas good spreadability indicated better gel application to the surface. In a dermatokinetics study, it was discovered that TES gel considerably increased HTC transport in the epidermal layers (p < 0.05) when compared to HTC conventional formulation gel (HTC-CFG). The CLSM of rat skin treated with the rhodamine B-loaded TES formulation demonstrated a deeper penetration of 30.0 µm in comparison to the hydroalcoholic rhodamine B solution (0.15 µm). The HTC-loaded transethosome was determined to be an effective inhibitor of pathogenic bacterial growth (S. aureus and E. coli) at a concentration of 10 mg/mL. It was discovered that both pathogenic strains were susceptible to free HTC. According to the findings, HTC-TES gel can be employed to enhance therapeutic outcomes through antimicrobial activity.

Development, Optimization, and In Vitro/In Vivo Evaluation of Azelaic Acid Transethosomal Gel for Antidermatophyte Activity

Treatment of dermatophytosis is quite challenging. This work aims to investigate the antidermatophyte action of Azelaic acid (AzA) and evaluate its efficacy upon entrapment into transethosomes (TEs) and incorporation into a gel to enhance its application. Optimization of formulation variables of TEs was carried out after preparation using the thin film hydration technique. The antidermatophyte activity of AzA-TEs was first evaluated in vitro. In addition, two guinea pig infection models with Trichophyton (T.) mentagrophytes and Microsporum (M.) canis were established for the in vivo assessment. The optimized formula showed a mean particle size of 219.8 ± 4.7 nm and a zeta potential of -36.5 ± 0.73 mV, while the entrapment efficiency value was 81.9 ± 1.4%. Moreover, the ex vivo permeation study showed enhanced skin penetration for the AzA-TEs (3056 µg/cm²) compared to the free AzA (590 µg/cm²) after 48 h. AzA-TEs induced a greater inhibition in vitro on the tested dermatophyte species than free AzA (MIC₉₀ was 0.01% vs. 0.32% for T. rubrum and 0.032% for T. mentagrophytes and M. canis vs. 0.56%). The mycological cure rate was improved in all treated groups, specially for our optimized AzA-TEs formula in the T. mentagrophytes model, in which it reached 83% in this treated group, while it was 66.76% in the itraconazole and free AzA treated groups. Significant (p < 0.05) lower scores of erythema, scales, and alopecia were observed in the treated groups in comparison with the untreated control and plain groups. In essence, the TEs could be a promising carrier for AzA delivery into deeper skin layers with enhanced antidermatophyte activity.