Niosomes as carriers for tretinoin. III. A study into the in vitro cutaneous delivery of vesicle-incorporated tretinoin

Quality by design for Niosome-Based nanocarriers to improve transdermal drug delivery from lab to industry

Niosomes are essentially multilamellar or unilamellar vesicles based on non-ionic surfactants. They consist of surfactant macromolecules arranged in a bilayer, which surrounds an aqueous solute solution. Amphiphilic, biodegradable, biocompatible, and environmentally friendly materials are utilized for encapsulating the drugs in vesicles that enhance the bioavailability, therapeutic efficacy, penetration of drug via the skin, and drug release in a controlled or sustained manner, and are employed to target the anticipated area via modifying composition that acts to minimize undesirable effects. With cholesterol as the lipid, Tween 20, Span 60, and Tween 60 are mostly employed as surfactants. Many medications, including Glibenclamide for diabetic kidney disease and anti-cancer medications including gemcitabine, cisplatin, and nintedanib, have been effectively encapsulated into niosomes. The traditional approach for creating niosomes at the lab scale is a thin film hydration process. The ideal ratio between primary components as well as critical manufacturing process parameters is key component in creating the best niosomal formulations with substantial drug loading and nanometric form. Utilizing the Design of Experiments (DoE) and Response Surface Methodology (RSM) in conjunction with Quality by design (QbD) is essential for comprehending how these variables interact both during lab preparation and during the scale-up process. Research on the development of anti-aging cosmetics is being done by Loreal. Niosomal preparations like Lancome are sold in stores. An overview of niosomes, penetration mechanisms, and quality by design from laboratory to industrial scale is provided in this article.

Augmented glycerosomes as a promising approach against fungal ear infection: Optimization and microbiological, ex vivo and in vivo assessments

In the current study, voriconazole (VCZ) augmented glycerosomes were optimized for topical otomycosis management according to a 23 factorial design, employing a thin film hydration method. By optimizing Glycerol volume, limonene: VCZ ratio and Span® 60: soybean phosphatidyl choline (PC) ratio, glycerosomes with maximum percentage entrapment efficiency (%EE) and zeta potential (ZP) and minimum vesicle size (VS) and polydispersity index (PDI) were to be obtained. An optimal augmented glycerosomal formula (OAG) that contained 10 mg VCZ, 150 mg PC, and 3 mL glycerol, comprising 2.5: and 0.92:1 ratios of the latter two independent variables, was proposed via numerical optimization. OAG exhibited high %EE and ZP values and acceptable low values for VS and PDI (84.3 ± 2.0 %, -38.8 ± 1.8 mV, 191.0 ± 1.1 nm, and 0.192 ± 0.01, respectively). Extensive in vitro testing of OAG revealed the entrapment of VCZ within OAG, biphasic in vitro release profile, stability for up to 3 months at 2-8 °C and spherical morphology of OAG with VS like that obtained via zetasizer. OAG demonstrated higher permeated amounts of VCZ and flux values than VCZ suspension, leading to an enhancement ratio of 2.56 in the ex vivo permeation study. The deeper penetration ability of OAG demonstrated by Confocal Laser Scanning Microscopy and its superior in vitro antifungal activity confirmed the validity of the ex vivo study. Also, the histopathological study confirmed the safety of OAG for topical use, suggesting that VCZ OAG was a promising topical antimycotic formula.

Topical retinoids: Novel derivatives, nano lipid-based carriers, and combinations to improve chemical instability and skin irritation

BACKGROUND

Retinoids, defined as synthetic or natural derivatives of vitamin A, have been extensively studied as anti-aging molecules that are widely applied in cosmetics. However, due to their physicochemical property, retinoids are highly unstable and extremely sensitive to light, oxygen, and temperature. Moreover, topical application of retinoids often leads to cutaneous irritation. These instabilities and irritant properties of retinoids limit their application in cosmetic and pharmaceutical products.

AIM

Our study aimed to provide a systematic review to summarize the mechanisms underlying the instability and irritant properties of retinoids, as well as recent developments in addressing these challenges.

METHODS

A comprehensive PubMed search was conducted using the following keywords: retinoids, chemical instability, skin irritation, retinoid derivatives, nano lipid-based carriers, liposomes, penetration-enhancer vesicles, ethosomes, niosomes, nanoemulsions, solid lipid nanoparticles, vitamins, soothing and hydrating agents, antioxidants and metal chelator and retinol combinations. Relevant researches published between 1968 and 2023 and studies related to these reports were reviewed.

RESULTS

The development of new retinoid derivatives, the utilization of new delivery systems like nano lipid-based carriers and the combination with other compounds like vitamins, soothing agents, antioxidants and metal chelator have been explored to improve the stability, bioavailability, and toxicity of the retinoid family.

CONCLUSIONS

Through advancements in formulation techniques, structure modification of retinoid derivatives and development of novel nano lipid-based carriers, the chemical instability and skin irritation of retinoids has been mitigated, ensuring their efficacy and potency over extended periods.

How the designed processing parameters affect the liquid mixture density and viscosity of the tretinoin-loaded niosomes at different temperatures?

The current study was conducted to present novel thermophysical data on tretinoin-loaded niosomes paired with a combination of span 60 and tween 80. Measurements were carried out to analyze the liquid mixture density and viscosity of the mentioned multilayered structures for the first time, with consideration given to the diverse molecular weights of surfactants and various stabilizers at different temperatures. Through the application of equations of state, this study has the ability to set the stage for thermodynamic modeling of solutions that involve niosomes, presenting a promising avenue for further research. So, tretinoin-loaded formulations were prepared by investigating the effects of different co-surfactants, including cholesterol or dodecanol, as well as the impact of surfactant molecular weight limited to 650.525-1090.175 g mol-1. This novel investigation was conducted to assess the superior stabilizing capabilities of dodecanol in comparison to cholesterol, with a specific emphasis on optimized vesicle size, highest incorporation efficiency, and lowest zeta potential. In particulars, the response surface methodology (RSM) was applied to optimize the operative factors and the number of experiments. The experimental evidence clearly indicates that the use of dodecanol in the manufacturing process significantly improves the stability of niosomes, while the inclusion of cholesterol leads to higher liquid mixture density and viscosity in the prepared niosomes.

Multilayered collagen-lipid hybrid nanovesicles for retinol stabilization and efficient skin delivery

Lipid-based nanocarriers have been extensively utilized for the solubilization and cutaneous delivery of water-insoluble active ingredients in skincare formulations. However, their practical application is often limited by structural instability, leading to premature release and degradation of actives. Here we present highly robust multilamellar nanovesicles, prepared by the polyionic self-assembly of unilamellar vesicles with hydrolyzed collagen peptides, to stabilize all-trans-retinol and enhance its cutaneous delivery. Our results reveal that the reinforced multilayer structure substantially enhances dispersion stability under extremely harsh conditions, like freeze-thaw cycles, and stabilizes the encapsulated retinol. Interestingly, these multilamellar vesicles exhibit significantly lower cytotoxicity to human dermal fibroblasts than their unilamellar counterparts, likely due to their smaller particle number per weight, minimizing potential disruptions to cellular membranes. In artificial skin models, retinol-loaded multilamellar vesicles effectively upregulate collagen-related gene expression while suppressing the synthesis of metalloproteinases. These findings suggest that the robust multilamellar vesicles can serve as effective nanocarriers for the efficient delivery and stabilization of bioactive compounds in cutaneous applications.

Niosomes: A Smart Drug Delivery System for Brain Targeting

Niosomes are lipid-based nanovesicles that have the potential to act as drug-delivery vehicles for a variety of agents. They are effective drug delivery systems for both ASOs and AAV vectors, with advantages such as improved stability, bioavailability, and targeted administration. In the context of brain-targeted drug delivery, niosomes have been investigated as a drug delivery system for brain targeting, but more research is needed to optimize their formulation to improve their stability and release profile and address the challenges of scale-up and commercialization. Despite these challenges, several applications of niosomes have demonstrated the potential of novel nanocarriers for targeted drug delivery to the brain. This review briefly overviews the current use of niosomes in treating brain disorders and diseases.

A Comprehensive Review on Niosomes as a Tool for Advanced Drug Delivery

Over the past few decades, advancements in nanocarrier-based therapeutic delivery have been significant, and niosomes research has recently received much interest. The self-assembled nonionic surfactant vesicles lead to the production of niosomes. The most recent nanocarriers, niosomes, are self-assembled vesicles made of nonionic surfactants with or without the proper quantities of cholesterol or other amphiphilic molecules. Because of their durability, low cost of components, largescale production, simple maintenance, and high entrapment efficiency, niosomes are being used more frequently. Additionally, they enhance pharmacokinetics, reduce toxicity, enhance the solubility of poorly water-soluble compounds, & increase bioavailability. One of the most crucial features of niosomes is their controlled release and targeted diffusion, which is utilized for treating cancer, infectious diseases, and other problems. In this review article, we have covered all the fundamental information about niosomes, including preparation techniques, niosomes types, factors influencing their formation, niosomes evaluation, applications, and administration routes, along with recent developments.

Recent Advances in Nanocarrier-based Approaches to Atopic Dermatitis and Emerging Trends in Drug Development and Design

Atopic dermatitis (AD), commonly known as Eczema, is a non-communicable skin condition that tends to become chronic. The deteriorating immunological abnormalities are marked by mild to severe erythema, severe itching, and recurrent eczematous lesions. Different pharmacological approaches are used to treat AD. The problem with commercial topical preparations lies in the limitation of skin atrophy, systemic side effects, and burning sensation that decreases patient compliance. The carrier-based system promises to eliminate these shortcomings; thus, a novel approach to treating AD is required. Liposomes, microemulsions, solid lipid nanoparticles (SLNs), nanoemulsions, etc., have been developed recently to address this ailment. Despite extensive research in the development method and various techniques, it has been challenging to demonstrate the commercial feasibility of these carrier- based systems, which illustrates a gap among the different research areas. Further, different soft wares and other tools have proliferated among biochemists as part of a cooperative approach to drug discovery. It is crucial in designing, developing, and analyzing processes in the pharmaceutical industry and is widely used to reduce costs, accelerate the development of biologically innovative active ingredients, and shorten the development time. This review sheds light on the compilation of extensive efforts to combat this disease, the product development processes, commercial products along with patents in this regard, numerous options for each step of computer-aided drug design, including in silico pharmacokinetics, pharmacodynamics, and toxicity screening or predictions that are important in finding the drug-like compounds.

Optimization, characterization, and follicular targeting assessment of tretinoin and bicalutamide loaded niosomes

Acne vulgaris, a prevalent skin disorder among teenagers and young adults, can have numerous psychological consequences. Topical treatment of acne would be advantageous by reducing the risk of systemic adverse drug reactions. However, the major challenge would be skin penetration through the stratum corneum. Therefore, during this study, tretinoin (TRT) and bicalutamide (BCT) loaded niosomes with follicular targeting potential were fabricated through the thin film hydration technique. Formulation optimization was performed using the Design-Expert software and optimum formulation was characterized in terms of particle size, zeta potential, transmission electron microscopy, drug loading, and differential scanning calorimetry. In vivo follicular targeting was assessed using rhodamine B-loaded niosomes to follow the skin penetration pathways. The results showed that, the optimum formulation was spherical in shape and had an average diameter of 319.20 ± 18.50 nm and a zeta potential of - 29.70 ± 0.36 mV. Furthermore, entrapment efficiencies were 94.63 ± 0.50% and > 99% and loading capacities were 1.40 ± 0.01% and 1.48 ± 0.00% for BCT and TRT, respectively. According to the animal study results, the prepared niosomes with an average diameter of about 300 nm showed significant accumulation in hair follicles. It seems that the designed niosomal BCT-TRT co-delivery system would be promising in acne management with follicular targeting potential.

Eco-friendly preparation, characterization, evaluation of anti-melanogenesis/antioxidant effect and in vitro/in vivo safety profile of kojic acid loaded niosome as skin lightener preparation

In the current study, an ultrasonic approach (as green method) was utilized to prepared kojic acid niosome (kojisome) which aimed to increase the dermal delivery and improving anti-melanogenesis properties. The study's findings demonstrated that increasing cholesterol enhanced the mean particle size from 68.333 ± 5.686 nm to 325.000 ± 15.099 nm and entrapment efficiency 0% to 39.341 ± 4.126% of the kojisome. Cholesterol may enhance the number and rigidity of bilayers that induced a size enhancement and entrapment efficiency. The skin permeability test revealed that kojisome gel had more kojic acid in dermal layers (437.563 ± 29.857 μg/cm2 or 16.624 ± 1.379%) than kojic acid plain gel (161.290 ± 14.812 μg/cm2 or 6.128 ± 0.672%). The niosome's lipophilicity allowed for gradual penetration, possibly due to better contact with the skin layers. Also, the extended-release behavior of improved kojisome exhibited high safety profile and low side effect in In vitro cytotoxicity assay, dermal irritation test, and Histo-pathological evaluation. Furthermore, optimum kojisome inhibited melanin formation (53.093 ± 2.985% at 1000 µM) higher than free kojic acid (62.383 ± 1.958%) significantly (p < 0.05). In addition, Kojisome 6 inhibited L-dopa auto-oxidation greater extent (94.806 ± 2.411%) than pure kojic acid solution (72.953 ± 2.728%). Kojisome by delivering and targeting large amount of kojic acid on specific site causes high efficacy in inhibition of melanin synthesis. The observations of this study revealed that the produced kojisome might be used as a potential nano-vehicle for kojic acid dermal administration, thereby opening up innovative options for the treatment of hyperpigmentation problems.

Exploring the use of niosomes in cosmetics for efficient dermal drug delivery

Dermal drug delivery has emerged as a promising alternative to traditional methods of drug administration due to its non-invasive nature and ease of use. However, the stratum corneum, the outermost layer of the skin, presents a significant barrier to drug penetration. Niosomes, self-assembled vesicular structures composed of nonionic surfactants and cholesterol, have been extensively investigated as a means of overcoming this barrier and improving the efficacy of dermal drug delivery. This review summarizes the current state of research on the use of niosomes in dermal drug delivery in cosmetics, with a particular focus on their formulation, characterization, and application in the delivery of various drug classes. The review highlights the advantages of niosomes over conventional drug delivery methods, including improved solubility and stability of drugs, controlled release, and enhanced skin permeation. The review also discusses the challenges associated with niosome-based drug delivery, such as their complex formulation and optimization, and the need for further studies on their long-term safety and toxicity.

Effect of nanovesicular surface-functionalization via chitosan and/or PEGylation on cytotoxicity of tamoxifen in induced-breast cancer model

AIMS

The effect of surface-modification of Tamoxifen (Tam)-loaded-niosomes on drug cytotoxicity and bio-distribution, via functionalization with chitosan and/or PEGylation, was investigated.

MATERIALS AND METHODS

Tam-loaded hybrid-nanocarriers (Tam-loaded niosomes, chitosomes, PEGylated niosomes, and PEGylated chitosomes) were formulated and characterized.

KEY FINDINGS

Chitosanization with/without PEGylation proved to selectively enhance Tam-release at the cancerous-acidic micromilieu. Cytotoxic activity study showed that Tam-loaded PEGylated niosomes had a lower IC₅₀ value on MCF-7 cell line (0.39, 0.35, and 0.27 times) than Tam-loaded PEGylated chitosomes, Tam-loaded niosomes, and Tam-loaded chitosomes, respectively. Cell cycle analysis showed that PEGylation and/or Chitosanization significantly impact Tam efficiency in inducing apoptosis, with a preferential influence of PEGylation over chitosanization. The assay of Annexin-V/PI double staining revealed that chitosanized-nanocarriers had a significant role in increasing the incidence of apoptosis over necrosis. Besides, PEGylated-nanocarriers increased apoptosis, as well as total death and necrosis percentages more than what was shown from free Tam. Moreover, the average changes in both Bax/Bcl-2 ratio and Caspase 9 were best improved in cells treated by Tam-loaded PEGylated niosomes over all other formulations. The in-vivo study involving DMBA-induced-breast cancer rats revealed that PEGylation made the highest tumor-growth inhibition (84.9 %) and breast tumor selectivity, while chitosanization had a lower accumulation tendency in the blood (62.3 ng/ml) and liver tissues (103.67 ng/ml). The histopathological specimens from the group treated with Tam-loaded PEGylated niosomes showed the best improvement over other formulations.

SIGNIFICANCE

All these results concluded the crucial effect of both PEGylation and chitosan-functionalization of Tam-loaded niosomes in enhancing effectiveness, targetability, and safety.

Ozonated Olive Oil: Enhanced Cutaneous Delivery via Niosomal Nanovesicles for Melanoma Treatment

Ozonated olive oil (OL) combines the therapeutic effects of both ozone and olive oil. However, it suffers from limited water solubility and poor transdermal permeation, which hinder its application in melanoma treatment. Nanocarrier host molecules, such as niosomes, were used to improve the water solubility, transdermal permeation, and anticancer effect of hydrophobic compounds. This study aims to design and optimize a niosomal vesicular nanoplatform loaded with OL (OL/NSs) to improve OL’s skin permeation and anti-melanoma effect. In this regard, OL was prepared and characterized by evaluating its chemical properties (acid, peroxide, and iodine values) and fatty acid composition using gas chromatography. Then, OL/NSs were developed using the thin film hydration method employing cholesterol, Span 60, and Tween 60 at five different molar ratios. The optimized niosomes had an average diameter of 125.34 ± 13.29 nm, a surface charge of −11.34 ± 4.71 mV, and a spherical shape. They could entrap 87.30 ± 4.95% of the OL. OL/NSs showed a 75% sustained oil release over 24 h. The skin permeation percentage of OL/NSs was 36.78 ± 3.31 and 53.44 ± 6.41% at 12 and 24 h, respectively, three times higher than that of the free OL (11.50 ± 1.3 and 17.24 ± 2.06%, at 12 and 24 h, respectively). Additionally, the anticancer activity of the developed niosmal formulation, when tested on human melanoma cells (A375), was double that of the free OL; the IC50 of the OL/NSs was 8.63 ± 2.8 μg/mL, and that of the free OL was 17.4 ± 3.7 μg/mL. In conclusion, the encapsulation of ozonated olive oil in niosomes enhanced its water solubility, skin permeation, and anticancer activity and thus may represent potent natural chemotherapy in treating melanoma.

Venlafaxine HCl Encapsulated in Niosome: Green and Eco-friendly Formulation for the Management of Pain

The goal of this experimentation was to increase the cutaneous absorption of venlafaxine HCl (VFX) encapsulated in a niosome (venlasosme) produced by an ultrasonic approach. The impact of the cholesterol:surfactant (Chol:Surf) proportion was examined to modify the venlasosme properties. Photon correlation spectroscopy, powder X-ray diffraction (PXRD), SEM, DSC, and ATR-FTIR spectroscopy were utilized to investigate the solid-state and morphology of VFX in the venlasosme. The studies revealed that increasing the level of Chol in the venlasosme increased the size of the particles. Alterations in the Chol to surfactant ratios (when Chol decreased from 2.5 to 0%) caused the zeta potential enhancement from 7.37 ± 0.67 to 15.53 ± 1.47 mV. The venlasosme with the highest cholesterol concentration (2.5%) had the highest encapsulation efficiency (approximately 63%). PXRD results revealed that VFX in venlasosme was in the amorphous form. The levels of VFX in the cutaneous layers and the receiver compartment were higher for the venlasosme gel than for VFX simple gel in the cutaneous permeability study and showed no cutaneous irritancy in rats. Furthermore, the venlasosme gel demonstrated significant antinociceptive and anti-inflammatory responses when compared to the control groups (VFX simple gel and diclofenac gel). The topical administration of the venlasosme gel also considerably increased the tail-flick and hot-plate response time when compared to the VFX simple gel, control groups, and diclofenac gel (p < 0.05). These findings suggest that niosomes can improve VFX efficacy as an antinociceptive and anti-inflammatory substance by improving the medicaments delivery to the specified site.

Brij Niosomes as Carriers for Sustained Drug Delivery─A Fluorescence-Based Approach to Probe the Niosomal Microenvironment

Niosomes were prepared using a triad of polyoxyethylene alkyl ether surfactants. The focus was to elucidate the effects of varying alkyl chain length and varying hydrophilic headgroups on the structure of the niosomes, with an aim to design niosomes for efficient encapsulation and release of both hydrophobic and hydrophilic drugs. The phase transitions of the surfactants were ascertained by differential scanning calorimetry. It was found that the headgroup has a profound influence on the niosomal bilayer. Fluorescent probes Coumarin 153 (C-153) and 1,6-diphenyl-1,3,5-hexatriene were used to probe the structural integrity of the niosomal bilayer under stress conditions. Other aspects of the niosomes were probed by following the aggregation of the dyes fluorescein (FL) and Nile Red, red edge excitation shift, and fluorescence resonance energy transfer (FRET) between them. Fluorescence lifetime imaging microscopy provides proof of the exact location of the donor and acceptor dyes in the niosomes under FRET condition. It was also shown that the niosomes are efficient "carriers" for entrapment and controlled release of the chemotherapeutic drug 5-fluorouracil. It was found that a rigid niosomal bilayer leads to controlled drug release. The present work is relevant for the future use of these niosomes for cargo entrapment.

D-optimal mixture design for optimization of topical dapsone niosomes: in vitro characterization and in vivo activity against Cutibacterium acnes

This study aimed to illustrate the use of D-optimal mixture design (DOMD) for optimization of an enhancer containing Dapsone niosomal formula for acne topical treatment. Mixture components (MixCs) studied were: Span 20, Cholesterol, and Cremophor RH. Different responses were measured. Optimized formula (OF) was selected to minimize particle size and maximize absolute zeta potential and entrapment efficiency. Optimized formula gel (OF-gel) was prepared and characterized. OF-gel in vivo skin penetration using confocal laser scanning microscopy and activity against Cutibacterium acnes in acne mouse model were studied. Based on DOMD results analysis, adequate models were derived. Piepel and contour plots were plotted accordingly to explain how alteration in MixCs L-pseudo values affected studied responses and regions for different responses’ values. The OF had suitable predicted responses which were in good correlation with the actually measured ones. The OF-gel showed suitable characterization and in vivo skin penetration up to the dermis layer. In vivo acne mouse-model showed that OF-gel-treated group (OF-gel-T-gp) had significantly better recovery (healing) criteria than untreated (UT-gp) and Aknemycin^®-treated (A-T-gp) groups. This was evident in significantly higher reduction of inflammation percent observed in OF-gel-T-gp than both UT-gp and A-T-gp. Better healing in OF-gel-T-gp compared with other groups was also verified by histopathological examination. Moreover, OF-gel-T-gp and A-T-gp bacterial loads were non-significantly different from each other but significantly lower than UT-gp. Thus, DOMD was an adequate statistical tool for optimization of an appropriate enhancer containing Dapsone niosomal formula that proved to be promising for topical treatment of acne.

Design and Optimization of Cationic Nanocapsules for Topical Delivery of Tretinoin: Application of the Box-Behnken Design, In Vitro Evaluation, and Ex Vivo Skin Deposition Study

Cationic nanocapsules represent a promising approach for topical delivery purposes. We elaborated on a novel formulation based on the cationic nanocapsules to enhance the pharmacodynamic efficacy, user compliance, and photostability of tretinoin (TTN). To achieve this goal, TTN nanocapsules were prepared by the nanoprecipitation method. In order to statistically optimize formulation variables, a Box-Behnken design, using Design-Expert software, was employed. Three independent variables were evaluated: total weight of the cationic acrylic polymer (X ₁), oil volume (X ₂), and TTN amount (X ₃). The particle size and encapsulation efficiency percent (EE%) were selected as dependent variables. The optimal formulation demonstrated spherical morphology under scanning electron microscopy (SEM), optimum particle size of 116.3 nm, and high EE% of 83.2%. TTN-loaded nanocapsules improved photostability compared to its methanolic solution. The in vitro release study data showed that tretinoin was released in a sustained manner compared to the free drug. The ex vivo skin permeation study demonstrated that greater drug deposition into the epidermal region rather than the deep skin was observed with a gel containing TTN-loaded nanocapsules than that of drug solution, respectively. The skin irritation test revealed that the nanoencapsulation of the drug decreased its irritancy compared to the free drug. These results revealed the promising potential of cationic nanocapsules for topical delivery of tretinoin.

Preparation and Characterization of Curcumin Nanoemulgel Utilizing Ultrasonication Technique for Wound Healing: In Vitro, Ex Vivo, and In Vivo Evaluation

Hydrogels being a drug delivery system has great significance particularly for topical application in cutaneous open wound. Its specific physicochemical properties such as non-adhesiveness, moisture retention, exudate absorption, and gas permeability make them ideal as a drug delivery vehicle for wound healing application. Further, curcumin (a natural bioactive) was selected as a therapeutic agent to incorporate into the hydrogel system to design and develop nanogel pharmaceutical products for wound healing. Although, curcumin possesses remarkable anti-inflammatory, antioxidant, and anti-infective activity along with hastening the healing process by acting over the different stages of the wound healing process, but its poor biopharmaceutical (low aqueous solubility and skin penetrability) attributes hamper their therapeutic efficacy for skin applications. The current investigation aimed to develop the curcumin-loaded nanogel system and evaluated to check the improvement in the therapeutic efficacy of curcumin through a nanomedicine-based approach for wound healing activity in Wistar rats. The curcumin was enclosed inside the nanoemulsion system prepared through a high-energy ultrasonic emulsification technique at a minimum concentration of surfactant required to nanoemulsify the curcumin-loaded oil system (Labrafac PG) having droplet size 56.25 ± 0.69 nm with polydispersity index 0.05 ± 0.01 and negatively surface charge with zeta potential −20.26 ± 0.65 mV. It was observed that the impact of Smix (surfactant/co-surfactant mixture) ratio on droplet size of generated nanoemulsion is more pronounced at lower Smix concentration (25%) compared to the higher Smix concentration (30%). The optimized curcumin-loaded nanoemulsion was incorporated into a 0.5% Carbopol^® 940 hydrogel system for topical application. The developed curcumin nanoemulgel exhibited thixotropic rheological behavior and a significant (p < 0.05) increase in skin penetrability characteristics compared to curcumin dispersed in conventional hydrogel system. The in vivo wound healing efficacy study and histological examination of healed tissue specimen further signify the role of the nanomedicine-based approach to improve the biopharmaceutical attributes of curcumin.

Cholesterol-Based Nanovesicles Enhance the In Vitro Cytotoxicity, Ex Vivo Intestinal Absorption, and In Vivo Bioavailability of Flutamide

Critical adverse effects and frequent administration, three times per day, limit the use of flutamide (FLT) as a chemotherapeutic agent in the treatment of prostate cancer. Therefore, our research aimed to develop new cholesterol-based nanovesicles for delivering FLT to malignant cells in an endeavor to maximize its therapeutic efficacy and minimize undesired adverse effects. Draper–Lin small composite design was used to optimize the critical quality attributes of FLT-loaded niosomes and ensure the desired product quality. The influence of the selected four independent variables on mean particle size (Y₁), zeta potential (Y₂), drug entrapment efficiency (Y₃), and the cumulative drug release after 24 h (Y₄) was examined. The optimized nanovesicles were assessed for their in vitro cytotoxicity, ex-vivo absorption via freshly excised rabbit intestine as well as in vivo pharmacokinetics on male rats. TEM confirmed nanovescicles’ spherical shape with bilayer structure. Values of dependent variables were 748.6 nm, −48.60 mV, 72.8% and 72.2% for Y₁, Y₂, Y₃ and Y₄, respectively. The optimized FLT-loaded niosomes exerted high cytotoxic efficacy against human prostate cancer cell line (PC-3) with an IC₅₀ value of 0.64 ± 0.04 µg/mL whilst, it was 1.88 ± 0.16 µg/mL for free FLT. Moreover, the IC₅₀ values on breast cancer cell line (MCF-7) were 0.27 ± 0.07 µg/mL and 4.07 ± 0.74 µg/mL for FLT-loaded niosomes and free FLT, respectively. The permeation of the optimized FLT-loaded niosomes through the rabbit intestine showed an enhancement ratio of about 1.5 times that of the free FLT suspension. In vivo pharmacokinetic study displayed an improvement in oral bioavailability of the optimized niosomal formulation with AUC and C_max values of 741.583 ± 33.557 μg/mL × min and 6.950 ± 0.45 μg/mL compared to 364.536 ± 45.215 μg/mL × min and 2.650 ± 0.55 μg/mL for the oral FLT suspension. With these promising findings, we conclude that encapsulation of FLT in cholesterol-loaded nanovesicles enhanced its anticancer activity and oral bioavailability which endorse its use in the management of prostate cancer.

Innovative topical niosomal gel formulation containing diclofenac sodium (niofenac)

The purpose of this research was to enhance the transdermal delivery of diclofenac sodium niosomal formulations. To characterise the obtained niosomes, SEM, XRPD, DSC and ATR-FTIR were employed. The size of the niosomes increased from 158.00 ± 6.17 to 400.87 ± 4.99 nm when cholesterol was incorporated into the formulations. It was observed that the zeta potential of niofenac varies from -25.40 ± 1.352 to -43.13 ± 1.171 mV when the cholesterol percentage decreased from 2% to 0.2%. The higher entrapment efficiency percentage (63.70 ± 0.18%) was obtained for the formulations with larger particle sizes and higher cholesterol content. The optimised niofenac formulation showed a controlled release fashion where 61.71 ± 0.59% of the drug released within 24 h. The results showed that the value of permeated diclofenac sodium through the skin layers was higher for the niofenac gel formulation (242.3 ± 31.11 µg/cm²) compared to simple gel formulation (127.40 ± 27.80 µg/cm²). Besides, niofenac formulation outperformed the anti-inflammatory activities in the formalin test compared to the control and diclofenac simple gel group. The licking time was significantly lower in both early (40.2 ± 7.3 s) and late stages (432.4 ± 31.7 s) for niofenac compared to conventional formulation (early stage 130.4 ± 8.73 s and late stage 660.6 ± 123.73 s). This study indicates that niosomal formulations can improve drug therapeutic effects by increasing drug delivery to specific sites.

Thymoquinone Loaded Topical Nanoemulgel for Wound Healing: Formulation Design and In-Vivo Evaluation

Thymoquinone is a natural bioactive with significant therapeutic activity against multiple ailments including wound healing. The poor aqueous solubility and low skin permeability limit its therapeutic efficacy. The present investigation aimed to improve the biopharmaceutical attributes of thymoquinone to enhance its topical efficacy in wound healing. A nanoemulsion-based hydrogel system was designed and characterized as a nanotechnology-mediated drug delivery approach to improve the therapeutic efficacy of thymoquinone, utilizing a high-energy emulsification technique. The black seed oil, as a natural home of thymoquinone, was utilized to improve the drug loading capacity of the developed nanoemulsion system and reduced the oil droplet size to <100 nm through ultrasonication. The influence of formulation composition, and the ultrasonication process conditions, were investigated on the mean globule size and polydispersity index of the generated nanoemulsion. Irrespective of surfactant/co-surfactant ratio and % concentration of surfactant/co-surfactant mixture, the ultrasonication time had a significant (p < 0.05) influence on the mean droplet size and polydispersity index of the generated nanoemulsion. The developed nanoemulgel system of thymoquinone demonstrated the pseudoplastic behavior with thixotropic properties, and this behavior is desirable for topical application. The nanoemulgel system of thymoquinone exhibited significant enhancement (p < 0.05) in skin penetrability and deposition characteristics after topical administration compared to the conventional hydrogel system. The developed nanoemulgel system of thymoquinone exhibited quicker and early healing in wounded Wistar rats compared to the conventional hydrogel of thymoquinone, while showing comparable healing efficacy with respect to marketed silver sulfadiazine (1%) cream. Furthermore, histopathology analysis of animals treated with a developed formulation system demonstrated the formation of the thick epidermal layer, papillary dermis along with the presence of extensive and organized collagen fibers in newly healed tissues. The outcome of this investigation signifies that topical delivery of thymoquinone through nanoemulgel system is a promising candidate which accelerates the process of wound healing in preclinical study.

Efficacy assessments of tretinoin-loaded nano lipid carriers in acne vulgaris: a double blind, split-face randomized clinical study

Here, we assessed the efficacy and safety of Nano lipid carrier (NLC) drug delivery system containing tretinoin (NLC-TRE) in comparison with the conventional 0.05% tretinoin cream (TRE cream) in mild to moderate acne vulgaris. A stable and appropriate NLC-TRE formulation was prepared using a high-pressure homogenizer and particle characterization and physicochemical properties were evaluated under accelerated conditions. Efficacy assessment was performed via a split-face clinical study, by comparing the number of acne lesions, porphyrin production and skin biophysical parameters in both sides of the face randomly treated with NLC-TRE and TRE cream. Plasma concentration of tretinoin after topical application of NLC-TRE was measured for primary safety evaluation. We acquired a stable, spherical nanoparticles with particle size of 118.5 nm, PI equal to 0.485 and ZP of - 44.7 mV. The rate of decrease of acne lesions was significantly higher in NLC- TRE side (p value < 0.001). The size and intensity of porphyrin production in pilosebaceous follicles were significantly reduced only on NLC-TRE side (p value < 0.01). The plasma concentration of the tretinoin, after 8 weeks' application remained lower than the toxic levels. The NLC-TRE formula provides better efficiency and good loading capacity of TRE in the drug delivery system.

Assessment of the in vitro activity of azithromycin niosomes alone and in combination with levofloxacin on extensively drug-resistant Klebsiella pneumoniae clinical isolates

BACKGROUND AND AIM

Extensively drug-resistant (XDR) Klebsiella pneumoniae represent a major threat in intensive care units. The aim of the current study was to formulate a niosomal form of azithromycin (AZM) and to evaluate its in vitro effect on XDR K. pneumoniae as a single agent or in combination with levofloxacin.

MATERIAL AND METHODS

Forty XDR K. pneumoniae isolates (23 colistin-sensitive and 17 colistin-resistant) were included in the study. Formulation and characterization of AZM niosomes were performed. The in vitro effect of AZM solution/niosomes alone and in combination (with levofloxacin) was investigated using the checkerboard assay, confirmed with time-kill assay and post-antibiotic effect (PAE).

RESULTS

The AZM niosome mean minimal inhibitory concentration (MIC) (187.4 ± 209.1 μg/mL) was significantly lower than that of the AZM solution (342.5 ± 343.4 μg/mL). AZM niosomes/levofloxacin revealed a 40% synergistic effect compared to 20% with AZM solution/levofloxacin. No antagonistic effect was detected. The mean MIC values of both AZM niosomes and AZM solution were lower in the colistin-resistant group than in the colistin-sensitive group. The mean PAE time of AZM niosomes (2.3 ± 1.09 h) was statistically significantly longer than that of the AZM solution (1.37 ± 0.5 h) (p = 0.023).

CONCLUSION

AZM niosomes were proved to be more effective than AZM solution against XDR K. pneumoniae, even colistin-resistant isolates.

Liver targeting of ledipasvir via galactosylated chitosan-coated spanlastics: chemical synthesis, statistical optimization, in vitro, and pharmacokinetic evaluation

INTRODUCTION

Ledipasvir is an effective direct acting antiviral agent used in the treatment of hepatitis C virus. The high price of ledipasvir was a reason for its limited provision to wide population of HCV patients.

OBJECTIVES

Our objective is the formulation of liver targeted drug delivery system that can increase the amount of ledipasvir delivered to liver and prolong its liver residence in an attempt to reduce its recommended dose and its costing in the treatment of HCV.

METHODS

Different ledipasvir-loaded spanlastic formulations were prepared using the ethanol injection method and evaluated with respect to the particle size, zeta potential, polydispersity index, and entrapment efficiency %. Using Design-Expert ® software, the optimum spanlastics formulation was selected; then, it was coated by synthesized galactosylated chitosan. A pharmacokinetic study was carried out to evaluate the ability of the prepared galactosylated chitosan-coated spanlastics formulation to enhance ledipasvir liver bioavailability when it was administrated via the oral route.

RESULTS

The pharmacokinetic study revealed that the optimized galactosylated chitosan-coated spanlastics exhibited significantly higher liver peak concentration (Cmax) and area under liver concentration versus time curve (AUC0-72 h) and significant prolongation in the liver terminal half life (t½) and mean residence time (MRT) compared to the free ledipasvir dispersion with values of 6270 ng/g, 61,706.3 ng.h/g, 15.85 h, and 24.66 h, respectively.

CONCLUSIONS

Enhanced liver bioavailability of ledipasvir has been accomplished using the developed galactosylated chitosan-coated spanlastics which can be a base for probable reduction in the required dose of ledipasvir in HCV treatment.

Optimization of transdermal atorvastatin calcium - Loaded proniosomes: Restoring lipid profile and alleviating hepatotoxicity in poloxamer 407-induced hyperlipidemia

In an attempt to optimize the anti- hyperlipidemic effect and reduce statins induced hepatotoxicity, Atorvastatin Calcium (ATC) transdermal proniosomal gel (PNG) was developed. Different non-ionic surfactants (NISs) (Spans, Tweens, Cremophor RH 40 and Brij 52) were incorporated in the vesicle's lipid bilayer, in combination with lecithin. PNG formulae were characterized for encapsulation efficiency percent (% EE), vesicle size, polydispersity index (PDI) and zeta potential (ZP). Ex-vivo permeation study was performed using full thickness rat skin measuring drug flux and skin permeability coefficients. The pharmacodynamic performance of optimized transdermal ATC- PNG on both lipid profile and liver biomarkers was assessed and compared to oral ATC administration in poloxamer 407-induced hyperlipidemic rats. The liver tissues were subjected to histological examination as well. The results revealed nano-size range vesicles with relatively high ATC entrapment efficiency. Ex-vivo results demonstrated the permeation superiority of ATC proniosomes over free drug. Pharmacodynamic study revealed that transdermal administration of ATC- PNG succeeded in retaining the anti-hyperlipidemic efficacy of orally administered ATC without elevating liver biomarkers. The histological examination signified the role of optimized ATC-PNG in hindering statin- induced hepatocellular damage. The obtained results suggested a promising, easy-to-manufacture and effective ATC proniosomal gel for safe treatment of hyperlipidemia.

The Challenge of Nanovesicles for Selective Topical Delivery for Acne Treatment: Enhancing Absorption Whilst Avoiding Toxicity

Acne is a common skin disease that affect over 80% of adolescents. It is characterized by inflammation of the hair bulb and the attached sebaceous gland. To date, many strategies have been used to treat acne as a function of the disease severity. However, common treatments for acne seem to show several side effects, from local irritation to more serious collateral effects. The use of topical vesicular carriers able to deliver active compounds is currently considered as an excellent approach in the treatment of different skin diseases. Many results in the literature have proven that drug delivery systems are useful in overcoming the toxicity induced by common drug therapies, while maintaining their therapeutic efficacy. Starting from these assumptions, the authors reviewed drug delivery systems already realized for the topical treatment of acne, with a focus on their limitations and advantages over conventional treatment strategies. Although their exact mechanism of permeation is not often completely clear, deformable vesicles seem to be the best solution for obtaining a specific delivery of drugs into the deeper skin layers, with consequent increased local action and minimized collateral effects.

Static and dynamic properties of decane/water microemulsions stabilized by cetylpyridinium chloride cationic surfactant and octanol cosurfactant

Molecular dynamics simulation (MD) is used to study the static and dynamic properties of positively charged decane/water microemulsions, for various volume fractions Φ (2.8%, 6.98%, 14%, and 26.5%). An effective hybrid potential combining three potentials, namely the hard-sphere repulsive potential, the van der Waals attractive potential, and the Yukawa repulsive potential, is used to describe the microemulsion interactions. The microemulsion shape is determined using the renormalized spectra in Porod representation. The appropriate potential parameters are tested using the Ornstein-Zernike integral equation approach with the Hypernetted Chain (HNC) closure relation by a comparison between the structure factor calculated from HNC and that obtained from Small Angle Neutron Scattering experiments (SANS). Thus, the micro arrangements of microemulsions have been analyzed using the pair correlation function g(r) and the structure factor S(q) obtained from HNC, SANS, and MD simulation using these parameters. The microemulsion dynamic properties were discussed using the mean-square displacement (MSD) and the diffusion coefficient D c calculated from MD simulations.

Assessments of in vitro and in vivo antineoplastic potentials of β-sitosterol-loaded PEGylated niosomes against hepatocellular carcinoma

β-sitosterol (BS), a phytosterol, exhibits ameliorative effects on hepatocellular carcinoma (HCC) due to its antioxidant activities. However, its poor aqueous solubility and negotiated bioavailability and short elimination half-life is a huge limitation for its therapeutic applications. To overcome these two shortcomings, BS-loaded niosomes were made to via, film hydration method and process parameters were optimized using a three-factor Box-Behnken design. The optimized formulation (BSF) was further surface-modified with polyethylene glycol (PEG). The resulting niosomes (BSMF) have spherical shapes, particle sizes, 219.6 ± 1.98 nm with polydispersity index (PDI) and zeta potential of 0.078 ± 0.04 and -19.54 ± 0.19 mV, respectively. The drug loading, entrapment efficiency, and drug release at 24 h of the BSMF were found to be 16.72 ± 0.09%, 78.04 ± 0.92%, and 75.10 ± 3.06%, respectively. Moreover, BSMF showed significantly greater cytotoxic potentials on Hep G2 cells with an enhanced cellular uptake relative to pure BS and BSF. The BSMF also displayed potentially improved curative property of HCC in albino wistar rat. Thus, the BSMF could be one of the promising therapeutic modalities for HCC treatment in terms of targeting potential resulting in enhanced therapeutic efficacy.

Potential of Nanoparticles as Permeation Enhancers and Targeted Delivery Options for Skin: Advantages and Disadvantages

The topical route of administration has many advantages for the treatment of various skin disorders as well as cosmeceutical purposes. This route bypasses hepatic first-pass effect and systemic availability of many pharmaceuticals is limited to skin organelles such as hair follicles and so could avoid unwanted adverse reactions and increase the localized therapeutic effect. Despite such attributed advantages of the topical route, the most important challenge is skin barrier characteristics that should be overcome to obtain dermal or trans-dermal drug delivery. Different approaches have been recruited to overcome this barrier. In this review, different types of nanoparticles for skin permeation enhancement and targeted delivery to skin organelles are discussed. The potential mechanisms of each nanocarrier in permeation enhancement and dermal delivery are considered and finally, the most important advantages and disadvantages of each group are summarized.

Development and Statistical Optimization of Solid Lipid Nanoparticle Formulations of Fluticasone Propionate

OBJECTIVES

The aim of this study was to develop fluticasone propionate (FP)-loaded solid lipid nanoparticle (SLN) formulations by using factorial design approach.

MATERIALS AND METHODS

Tristearin percentages (X1) (1%, 2%, and 4%) and homogenization cycles (X2) (2, 4, and 8 cycles) were selected as independent variables in the factorial design. SLN formulations were optimized by multiple linear regression (MLR) to evaluate the influence of the selected process and formulation independent variables on SLNs' characteristics, namely as encapsulation efficiency (Q1) and particle size (Q2). The polydispersity index and surface charge of the SLNs were also evaluated in this research. Moreover, transmission electron microscopy, differential scanning calorimetry, and in vitro drug release studies were carried out on the optimum SLN formulation.

RESULTS

The MLR analysis indicated that as the homogenization cycle (X2) increased in the production process, the mean particle size decreased.

CONCLUSION

This research showed that FP-encapsulated SLNs with desired characteristics can be produced by varying the production and content variables of the formulations.

Lipid vesicles: A versatile drug delivery platform for dermal and transdermal applications

Topical and transdermal application of active pharmaceutical ingredients to the skin is an attractive strategy being explored by formulation scientists to treat disease conditions rather than the oral drug delivery. Several approaches have been attempted, and many of them have emerged with significant clinical potential. However, the delivery of drugs across the skin is an arduous task due to permeation limiting barriers. It, therefore, requires the aid of external agents or carrier systems for efficient permeation. Lipid-based vesicular systems are carriers for the transport of drugs through the stratum corneum (dermal drug delivery) and into the bloodstream for systemic action (transdermal drug delivery) overcoming the barrier properties. This review article describes the various vesicular systems reported for skin delivery of actives with relevant case studies. The vesicular systems presented here are in the order of their advent from conventional systems to the advanced lipid vesicles. The design and development of drugs in vesicular systems have brought a new dimension to the treatment of disease conditions overcoming the permeation limiting barriers, thus improving its efficacy.

Evaluations of Quality by Design (QbD) Elements Impact for Developing Niosomes as a Promising Topical Drug Delivery Platform

Topical corticosteroids are used to treat a variety of skin conditions such as allergic reactions, eczema, and psoriasis. Niosomes are a novel surfactant-based delivery system that may be used to deliver desoximetasone via topical product application in order to mitigate common side effects associated with traditional oral delivery routes. The aim of this research was to identify the critical material attributes (CMAs) and critical process parameters (CPPs) that impact key characteristics of drug-loaded niosomes using a systematic quality by design (QbD) approach. An organic phase injection method was developed and used to manufacture the niosomes. The CMAs were identified to be drug amount, concentrations of surfactant and cholesterol, and types of lipids. The CPPs were phase volumes, temperature, mixing parameters, and addition rate based on previous research. The quality attributes measured were entrapment efficiency, particle size distribution, PDI, and zeta potential. These were used to determine the quality target product profile (QTPP) of niosomes. The experimental data indicate that the critical impacting variables for niosomes are: surfactant and cholesterol concentrations, mixing parameters, and organic-phase addition rate. Based on the experimental results of this study methanol:diethyl ether (75:25) as the organic system, drug:surfactant:cholesterol in 1:2:1 concentration, stearic acid as the charge-inducing material, 20 mL external phase and 10 mL internal phase volume, 65 °C external phase temperature, 60 min mixing time, 650 RPM mixing speed and 1 mL/ml addition rate is the ideal combination to achieve desirable desoximetasone niosomes with optimum entrapment efficiency and particle size for topical application.

Nanocrystals of Fusidic Acid for Dual Enhancement of Dermal Delivery and Antibacterial Activity: In Vitro, Ex Vivo and In Vivo Evaluation

With the alarming rise in incidence of antibiotic-resistant bacteria and the scarcity of newly developed antibiotics, it is imperative that we design more effective formulations for already marketed antimicrobial agents. Fusidic acid (FA), one of the most widely used antibiotics in the topical treatment of several skin and eye infections, suffers from poor water-solubility, sub-optimal therapeutic efficacy, and a significant rise in FA-resistant Staphylococcus aureus (FRSA). In this work, the physico-chemical characteristics of FA were modified by nanocrystallization and lyophilization to improve its therapeutic efficacy through the dermal route. FA-nanocrystals (NC) were prepared using a modified nanoprecipitation technique and the influence of several formulation/process variables on the prepared FA-NC characteristics were optimized using full factorial statistical design. The optimized FA-NC formulation was evaluated before and after lyophilization by several in-vitro, ex-vivo, and microbiological tests. Furthermore, the lyophilized FA-NC formulation was incorporated into a cream product and its topical antibacterial efficacy was assessed in vivo using a rat excision wound infection model. Surface morphology of optimized FA-NC showed spherical particles with a mean particle size of 115 nm, span value of 1.6 and zeta potential of −11.6 mV. Differential scanning calorimetry and powder X-ray diffractometry confirmed the crystallinity of FA following nanocrystallization and lyophilization. In-vitro results showed a 10-fold increase in the saturation solubility of FA-NC while ex-vivo skin permeation studies showed a 2-fold increase in FA dermal deposition from FA-NC compared to coarse FA. Microbiological studies revealed a 4-fofd decrease in the MIC against S. aureus and S. epidermidis from FA-NC cream compared to commercial Fucidin cream. In-vivo results showed that FA-NC cream improved FA distribution and enhanced bacterial exposure in the infected wound, resulting in increased therapeutic efficacy when compared to coarse FA marketed as Fucidin cream.

Niosome-Based Approach for In Situ Gene Delivery to Retina and Brain Cortex as Immune-Privileged Tissues

Non-viral vectors have emerged as a promising alternative to viral gene delivery systems due to their safer profile. Among non-viral vectors, recently, niosomes have shown favorable properties for gene delivery, including low toxicity, high stability, and easy production. The three main components of niosome formulations include a cationic lipid that is responsible for the electrostatic interactions with the negatively charged genetic material, a non-ionic surfactant that enhances the long-term stability of the niosome, and a helper component that can be added to improve its physicochemical properties and biological performance. This review is aimed at providing recent information about niosome-based non-viral vectors for gene delivery purposes. Specially, we will discuss the composition, preparation methods, physicochemical properties, and biological evaluation of niosomes and corresponding nioplexes that result from the addition of the genetic material onto their cationic surface. Next, we will focus on the in situ application of such niosomes to deliver the genetic material into immune-privileged tissues such as the brain cortex and the retina. Finally, as future perspectives, non-invasive administration routes and different targeting strategies will be discussed.

Development of Topical Nanocarriers for Skin Cancer Treatment Using Quality by Design Approach

BACKGROUND

One of the most compelling medical challenges of this century is the treatment of cancer and among them, skin cancer is the most common type. Thus, current treatments need to be renewed continuously to handle this challenge.

OBJECTIVE

This review presents considerations which can be employed during the development of nanosized formulations dedicated to the topical treatment of skin cancer. We aimed to collect and organize literature data on the treatment options for skin cancer in order to determine the required quality attributes of an effective dermal anticancer formulation.

METHOD

With the consideration of the Quality by Design (QbD) approach related to the development of new pharmaceutical formulations, a cost-saving process ensuring a high-quality product taking into account patient expectations, industrial and regulatory aspects can be achieved. Furthermore, this concept is highly recommended by regulatory agencies.

RESULTS

Our work discusses the current therapies, active agents, drug carrier systems, and evaluation methods in connection with the treatment of skin cancer and outlines Critical Quality Attributes which need to be considered during the development of a nanosized dermal anticancer formulation.

CONCLUSION

The first part of this review summarizes the most important topical treatment therapies for skin cancer and highlights the future therapeutic perspectives, focusing on the benefits of nanotechnology and dermal administration. The second part outlines the critical points of nanosized dermal anticancer formulation development in the view of QbD approach. Our research emphasizes the application of QbD method for a rationalized and more effective anticancer formulation development process.

Liquid chromatography method to assay tretinoin in skin layers: validation and application in skin penetration/retention studies

A liquid chromatography (LC) method for the quantification of tretinoin (TTN) in different matrices (adhesive tape, cotton and porcine skin layers, stratum corneum, viable epidermis, and dermis) was validated and applied in in vitro porcine skin penetration/retention studies. This study proposes, for the first time, a method for assaying TTN in separated porcine skin layers (stratum corneum, viable epidermis, and dermis). The skin studies were carried out using tape stripping and cutaneous retention techniques. The procedures for the extraction of TTN from dermatological formulations (creams and gels) and biological and non-biological matrices used with the tape stripping and retention techniques were also evaluated. The LC method consisted of a mobile phase composed of a mixture of methanol, water, and glacial acetic acid (85:15:1, v/v); a C18 column used as the stationary phase; a flow rate of 1.0 mL min⁻¹; an injection volume of 100 μL; and TTN detection at 342 nm. The method was linear in the range of 0.05–15.00 μg mL⁻¹ (r = 0.9999), and it was precise and accurate. The limit of detection (LOD) and limit of quantification (LOQ) were 0.0165 μg mL⁻¹ and 0.0495 μg mL⁻¹, respectively. TTN was extracted from different matrices, showing good precision [relative standard deviation (RSD) of <5%] and accuracy (89.4–113.9%). This method was successfully applied in the evaluation of TTN skin retention/permeation from dermatological formulations (cream and gel). A higher penetration of TTN through the skin was achieved with the gel rather than the cream, showing the influence of the dosage form. Therefore, the developed method can easily be applied in porcine skin penetration/retention studies of dermatological formulations containing TTN, and it is able to discriminate the behaviours of the different formulations.

Targeted Topical Delivery of Retinoids in the Management of Acne Vulgaris: Current Formulations and Novel Delivery Systems

Acne vulgaris is a common inflammatory pilosebaceous condition that affects 80-90% of adolescents. Since the introduction of tretinoin over 40 years ago, topical retinoid products have been a mainstay of acne treatment. The retinoids are very effective in addressing multiple aspects of the acne pathology as they are comedolytic and anti-inflammatory, and do not contribute to antibiotic resistance or microbiome disturbance that can be associated with long-term antibiotic therapies that are a common alternative treatment. However, topical retinoids are associated with skin dryness, erythema and pain, and may exacerbate dermatitis or eczema. Thus, there is a clear need to target delivery of the retinoids to the pilosebaceous units to increase efficacy and minimise side effects in surrounding skin tissue. This paper reviews the current marketed topical retinoid products and the research that has been applied to the development of targeted topical delivery systems of retinoids for acne.

Recent advances in non-ionic surfactant vesicles (niosomes): Fabrication, characterization, pharmaceutical and cosmetic applications

Development of nanocarriers for drug delivery has received considerable attention due to their potential in achieving targeted delivery to the diseased site while sparing the surrounding healthy tissue. Safe and efficient drug delivery has always been a challenge in medicine. During the last decade, a large amount of interest has been drawn on the fabrication of surfactant-based vesicles to improve drug delivery. Niosomes are self-assembled vesicular nano-carriers formed by hydration of non-ionic surfactant, cholesterol or other amphiphilic molecules that serve as a versatile drug delivery system with a variety of applications ranging from dermal delivery to brain-targeted delivery. A large number of research articles have been published reporting their fabrication methods and applications in pharmaceutical and cosmetic fields. Niosomes have the same advantages as liposomes, such as the ability to incorporate both hydrophilic and lipophilic compounds. Besides, niosomes can be fabricated with simple methods, require less production cost and are stable over an extended period, thus overcoming the major drawbacks of liposomes. This review provides a comprehensive summary of niosomal research to date, it provides a detailed overview of the formulation components, types of niosomes, effects of components on the formation of niosomes, fabrication and purification methods, physical characterization techniques of niosomes, recent applications in pharmaceutical field such as in oral, ocular, topical, pulmonary, parental and transmucosal drug delivery, and cosmetic applications. Finally, limitations and the future outlook for this delivery system have also been discussed.

Synthesis of Nitrogen Containing Biocompatible Non-ionic Surfactants and Investigation for Their Self-Assembly Based Nano-Scale Vesicles

Nonionic surfactants are increasingly interesting because of the solubility and release of drugs. Here, a synthesis of four nonionic nitrogen-containing surfactants is reported. In the synthesis, sulfonamide was reacted with alkyl halides of different lipophilicity. The synthesized nonionic surfactants were characterized by 1H NMR and mass spectroscopy. Their critical micelle concentration (CMC) was determined with a UV spectrophotometer. The self-assembly of surfactants to form drug-loaded, niosomal vesicles with Simvastatin as model drug was investigated. The resulting niosoaml vesicles were characterized by atomic force microscope (AFM), zeta-sizer, and UV spectrophotometer for shape, size, polydispersity index, zeta potential, and drug inclusion efficiency. Their biocompatibility has been determined by blood hemolysis and cell toxicity tests. The synthesized surfactants showed low CMC values and were able to form nano-sized round niosomal vesicles with a homogeneous population and surface negativity. Depending on the lipophilicity, they absorbed an increased amount of drug. The biocompatibility studies show that the surfactants are hemocompatible and non-toxic. The results of the study confirm that the synthesized nonionic surfactants are suitable for the solubilization and release of hydrophobic drugs as efficient novel biocompatible carriers.