A synergistic approach of adapalene-loaded nanostructured lipid carriers, and vitamin C co-administration for treating acne

A central composite design-based targeted quercetin nanoliposomal formulation: Optimization and cytotoxic studies on MCF-7 breast cancer cell lines

This study aimed to enhance the efficacy of quercetin (QT) by formulating it into a liposomal drug delivery system utilizing the concept of central composite design. The drug:lipid ratio, cholesterol concentration, and sonication time were selected as independent variables in the study. The vesicle and percentage entrapment efficiency were selected as the dependent variables. Quercetin nanoliposomes (QT-NLs) were prepared via a combination of ethanol injection and thin film hydration. The vesicle size and entrapment efficiency of all formulations were within the ranges of 100 nm and >80 %, respectively. The zeta potential value indicated the stability of the optimized formulation. The contour plots were used to select the desired batch range. SEM studies revealed an imperfect crystalline morphology without any unwanted agglomeration. MTT assays on VERO cell lines indicated the safety of the developed formulation. MTT assays of MCF-7 cells revealed IC50 values of 5.8 μM and 7.9 μM for QT-NLs and QT, respectively. In our study, the optimized formulation exhibited late and early apoptosis and necrosis when used to treat MCF-7 cells. S and G2/M cell cycle phases of MCF-7 cell arrest were confirmed by the cell cycle report. At sub-G0/G1 phase, 2.10 ± 1.1 %; G0/G1 phase, 34.13 ± 1.9 %; S phase, 34.55 ± 0.98 %; and G2/M phase, 26.24 ± 1.7 % of cell arrest were observed. The results demonstrated the effectiveness of the proposed design for the development of corn starch-coated QT-NLs and their activity in breast cancer cell lines.

Enhanced Antibacterial Activity of Clindamycin Using Molecularly Imprinted Polymer Nanoparticles Loaded with Polyurethane Nanofibrous Scaffolds for the Treatment of Acne Vulgaris

Acne vulgaris, a prevalent skin condition, arises from an imbalance in skin flora, fostering bacterial overgrowth. Addressing this issue, clindamycin molecularly imprinted polymeric nanoparticles (Clin-MIP) loaded onto polyurethane nanofiber scaffolds were developed for acne treatment. Clin-MIP was synthesized via precipitation polymerization using methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), and azoisobutyronitrile (AIBN) as functional monomers, crosslinkers, and free-radical initiators, respectively. MIP characterization utilized Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) before being incorporated into polyurethane nanofibers through electrospinning. Further analysis involved FTIR, scanning electron microscopy (SEM), in vitro release studies, and an ex vivo study. Clin-MIP showed strong antibacterial activity against S. aureus, with inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 0.39 and 6.25 μg/mL, respectively. It significantly dropped the bacterial count from 1 × 108 to 39 × 101 CFU/mL in vivo and has bactericidal activity within 180 min of incubation in vitro. The pharmacodynamic and histopathology studies revealed a significant decrease in infected animal skin inflammation, epidermal hypertrophy, and congestion upon treatment with Clin-MIP polyurethane nanofiber and reduced pro-inflammatory cytokines (NLRP3, TNF-α, IL-1β, and IL-6) conducive to acne healing. Consequently, the recently created Clin-MIP polyurethane nanofibrous scaffold. This innovative approach offers insight into creating materials with several uses for treating infectious wounds caused by acne.

Understanding the Novel Approach of Nanoferroptosis for Cancer Therapy

As a new form of regulated cell death, ferroptosis has unraveled the unsolicited theory of intrinsic apoptosis resistance by cancer cells. The molecular mechanism of ferroptosis depends on the induction of oxidative stress through excessive reactive oxygen species accumulation and glutathione depletion to damage the structural integrity of cells. Due to their high loading and structural tunability, nanocarriers can escort the delivery of ferro-therapeutics to the desired site through enhanced permeation or retention effect or by active targeting. This review shed light on the necessity of iron in cancer cell growth and the fascinating features of ferroptosis in regulating the cell cycle and metastasis. Additionally, we discussed the effect of ferroptosis-mediated therapy using nanoplatforms and their chemical basis in overcoming the barriers to cancer therapy.

Quercetin-loaded solid lipid nanoparticles exhibit antitumor activity and suppress the proliferation of triple-negative MDA-MB 231 breast cancer cells: implications for invasive breast cancer treatment

BACKGROUND

Quercetin (QC) is a naturally occurring flavonoid found in abundance in fruits and vegetables. Its anti-cancer and anti-inflammatory properties have been previously demonstrated, but its low bioavailability hampers its clinical use. Triple-negative breast cancer is a subtype of breast cancer with a poor response to chemotherapy. This study investigates the anti-cancer effects of quercetin-solid lipid nanoparticles (QC-SLN) on the triple-negative breast cancer cell line MDA-MB231.

MATERIALS AND METHODS

MCF-7 and MDA-MB231 cells were treated with 18.9 µM of QC and QC-SLN for 48 h. Cell viability, apoptosis, colony formation assay, and the anti-angiogenic effects of the treatment were evaluated.

RESULTS

QC-SLN displayed optimal properties (particle size of 154 nm, zeta potential of -27.7 mV, encapsulation efficiency of 99.6%, and drug loading of 1.81%) and exhibited sustained release of QC over 72 h. Compared to the QC group, the QC-SLN group showed a significant decrease in cell viability, colony formation, angiogenesis, and a substantial increase in apoptosis through the modulation of Bax and Bcl-2 at both gene and protein levels. The augmentation in the proportion of cleaved-to-pro caspases 3 and 9, as well as poly (ADP-ribose) polymerase (PARP), under the influence of QC-SLN, was conspicuously observed in both cancer cell lines.

CONCLUSIONS

This study showcases quercetin-solid lipid nanoparticles (QC-SLN) as a promising therapy for triple-negative breast cancer. The optimized QC-SLN formulation improved physicochemical properties and sustained quercetin release, resulting in reduced cell viability, colony formation, angiogenesis, and increased apoptosis in the MDA-MB231 cell line. These effects were driven by modulating Bax and Bcl-2 expression, activating caspases 3 and 9, and poly (ADP-ribose) polymerase (PARP). Further in vivo studies are needed to confirm QC-SLN's efficacy and safety.

Vitamin C fortification: need and recent trends in encapsulation technologies

The multifaceted role of vitamin C in human health intrudes several biochemical functions that are but not limited to antioxidant activity, homoeostasis, amino acid synthesis, collagen synthesis, osteogenesis, neurotransmitter production and several yet to be explored functions. In absence of an innate biosynthetic pathway, humans are obligated to attain vitamin C from dietary sources to maintain its optimal serum level (28 μmol/L). However, a significant amount of naturally occurring vitamin C may deteriorate due to food processing, storage and distribution before reaching to the human gastrointestinal tract, thus limiting or mitigating its disease combating activity. Literature acknowledges the growing prevalence of vitamin C deficiency across the globe irrespective of geographic, economic and population variations. Several tools have been tested to address vitamin C deficiency, which are primarily diet diversification, biofortification, supplementation and food fortification. These strategies inherit their own advantages and limitations. Opportunely, nanotechnology promises an array of delivery systems providing encapsulation, protection and delivery of susceptible compounds against environmental factors. Lack of clear understanding of the suitability of the delivery system for vitamin C encapsulation and fortification; growing prevalence of its deficiency, it is a need of the hour to develop and design vitamin C fortified food ensuring homogeneous distribution, improved stability and enhanced bioavailability. This article is intended to review the importance of vitamin C in human health, its recommended daily allowance, its dietary sources, factors donating to its stability and degradation. The emphasis also given to review the strategies adopted to address vitamin c deficiency, delivery systems adopted for vitamin C encapsulation and fortification.

Solid Lipid Nanoparticles Embedded Hydrogels as a Promising Carrier for Retarding Irritation of Leflunomide

Leflunomide (LEF), a disease-modifying anti-rheumatic drug, has been widely explored for its anti-inflammatory potential in skin disorders such as psoriasis and melanoma. However, its poor stability and skin irritation pose challenges for topical delivery. To surmount these issues, LEF-loaded solid lipid nanoparticles (SLNs) integrated with hydrogels have been developed in the present investigation. SLNs developed by microemulsion techniques were found ellipsoidal with 273.1 nm particle size and -0.15 mV zeta potential. Entrapment and total drug content of LEF-SLNs were obtained as 65.25 ± 0.95% and 93.12 ± 1.72%, respectively. FTIR and XRD validated the successful fabrication of LEF-SLNs. The higher stability of LEF-SLNs (p < 0.001) compared to pure drug solution was observed in photostability studies. Additionally, in vitro anti-inflammatory activity of LEF-SLNs showed good potential in comparison to pure drugs. Further, prepared LEF-SLNs loaded hydrogel showed ideal rheology, texture, occlusion, and spreadability for topical drug delivery. In vitro release from LEF-SLN hydrogel was found to follow the Korsmeyer-Peppas model. To assess the skin safety of fabricated lipidic formulation, irritation potential was performed employing the HET-CAM technique. In conclusion, the findings of this investigation demonstrated that LEF-SLN hydrogel is capable of enhancing the photostability of the entrapped drug while reducing its skin irritation with improved topical delivery characteristics.

Nanocrystals as an emerging nanocarrier for the management of dermatological diseases

Skin conditions are amongst the most prevalent health issues in the world and come with a heavy economic, social, and psychological burden. Incurable and chronic skin conditions like eczema, psoriasis, fungal infections are linked to major morbidity in the manner of physical pain and a reduction in quality life of patients. Several drugs have difficulties for penetrating the skin due to the barrier mechanism of the skin layers and the incompatible physicochemical characteristics of the drugs. This has led to the introduction of innovative drug delivery methods. Currently, formulations depend on nanocrystals have indeed been researched for topical administration of drugs and have resulted in enhanced skin penetration. This review focuses on skin penetration barriers, modern methods to enhance topical distribution, and the use of nanocrystals to overcome these barriers. By means of mechanisms such as adherence to skin, creation of diffusional corona, targeting of hair follicles, and the generation of a greater concentration gradient throughout the skin, nanocrystals could enhance transport across the skin. Scientists working on product formulations incorporating chemicals that are "challenging-to-deliver" topically may find the most current findings to be of relevance.

Co-Encapsulation of Drugs for Topical Application-A Review

Achieving the best possible outcome for the therapy is the main goal of a medicine. Therefore, nanocarriers and co-delivery strategies were invented to meet this need, as they can benefit many diseases. This approach was applied specifically for cancer treatment, with some success. However, these strategies may benefit many other clinical issues. Skin is the largest and most exposed organ of the human body, with physiological and psychological properties. Due to its exposition and importance, it is not difficult to understand how many skin diseases may impact on patients' lives, representing an important burden for society. Thus, this review aims to summarize the state of the art in research concerning nanocarriers and co-delivery strategies for topical agents' applications targeting skin diseases. The challenge for the medicine of the future is to deliver the drug with spatial and temporal control. Therefore, the co-encapsulation of drugs and the appropriate form of administration for them are so important and remain as unmet needs.

An insight into photodynamic therapy towards treating major dermatological conditions

Photodynamic therapy (PDT), as the name suggests is a light-based, non-invasive therapeutic treatment method that has garnered immense interest in the recent past for its efficacy in treating several pathological conditions. PDT has prominent use in the treatment of several dermatological conditions, which consequently have cosmetic benefits associated with it as PDT improves the overall appearance of the affected area. PDT is commonly used for repairing sun-damaged skin, providing skin rejuvenation, curbing pre-cancerous cells, treating conditions like acne, keratosis, skin-microbial infections, and cutaneous warts, etc. PDT mediates its action by generating oxygen species that are involved in bringing about immunomodulation, suppression of microbial load, wound-healing, lightening of scarring, etc. Although there are several challenges associated with PDT, the prominent ones being pain, erythema, insufficient delivery of the photosensitizing agent, and poor clinical outcomes, still PDT stands to be a promising approach with continuous efforts towards maximizing clinical efficacy while being cautious of the side effects and working towards lessening them. This article discusses the major skin-related conditions which can be treated or managed by employing PDT as a better or comparable alternative to conventional treatment approaches such that it also brings about aesthetic improvements thereof.

A Mini-Review on Solid Lipid Nanoparticles and Nanostructured Lipid Carriers: Topical Delivery of Phytochemicals for the Treatment of Acne Vulgaris

Acne vulgaris (acne) is one of the most common dermatological problems affecting adolescents and young adults. Although acne may not lead to serious medical complications, its psychosocial effects are tremendous and scientifically proven. The first-line treatment for acne is topical medications composed of synthetic compounds, which usually cause skin irritation, dryness and itch. Therefore, naturally occurring constituents from plants (phytochemicals), which are generally regarded as safe, have received much attention as an alternative source of treatment. However, the degradation of phytochemicals under high temperature, light and oxygen, and their poor penetration across the skin barrier limit their application in dermatology. Encapsulation in lipid nanoparticles is one of the strategies commonly used to deliver drugs and phytochemicals because it allows appropriate concentrations of these substances to be delivered to the site of action with minimal side effects. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are promising delivery systems developed from the combination of lipid and emulsifier. They have numerous advantages that include biocompatibility and biodegradability of lipid materials, enhancement of drug solubility and stability, ease of modulation of drug release, ease of scale-up, feasibility of incorporation of both hydrophilic and lipophilic drugs and occlusive moisturization, which make them very attractive carriers for delivery of bioactive compounds for treating skin ailments such as acne. In this review, the concepts of SLNs and NLCs, methods of preparation, characterization, and their application in the encapsulation of anti-acne phytochemicals will be discussed.

Azelaic acid and Melaleuca alternifolia essential oil co-loaded vesicular carrier for combinational therapy of acne

Aim: Azelaic acid (AzA), a comedolytic, antibacterial, anti-inflammatory anti-melanogenic agent, prescribed against acne vulgaris is safe on skin. Its combination with another widely used anti-acne agent, tea tree oil (EO) whose delivery is limited by volatility, instability and lipophilicity constraints was attempted. Method: Solvent injection was used to prepare AzA-EO integrated ethosomes. Result: Ethosomes were transformed into carbopol hydrogel, which exhibited pseudo-plastic properties with appreciable firmness, work of shear, stickiness and work of adhesion. The hydrogel showed better permeation and retention characteristics vis-a-vis commercial formulation (AzidermTM), when evaluated in Wistar rat skin. Further, ethosome hydrogel composite was better tolerated with no side effects. Conclusion: The findings suggests that the aforementioned strategy could be a potential treatment used for acne management.

Lipid Nanoparticulate Drug Delivery Systems: Recent Advances in the Treatment of Skin Disorders

The multifunctional role of the human skin is well known. It acts as a sensory and immune organ that protects the human body from harmful environmental impacts such as chemical, mechanical, and physical threats, reduces UV radiation effects, prevents moisture loss, and helps thermoregulation. In this regard, skin disorders related to skin integrity require adequate treatment. Lipid nanoparticles (LN) are recognized as promising drug delivery systems (DDS) in treating skin disorders. Solid lipid nanoparticles (SLN) together with nanostructured lipid carriers (NLC) exhibit excellent tolerability as these are produced from physiological and biodegradable lipids. Moreover, LN applied to the skin can improve stability, drug targeting, occlusion, penetration enhancement, and increased skin hydration compared with other drug nanocarriers. Furthermore, the features of LN can be enhanced by inclusion in suitable bases such as creams, ointments, gels (i.e., hydrogel, emulgel, bigel), lotions, etc. This review focuses on recent developments in lipid nanoparticle systems and their application to treating skin diseases. We point out and consider the reasons for their creation, pay attention to their advantages and disadvantages, list the main production techniques for obtaining them, and examine the place assigned to them in solving the problems caused by skin disorders.

Nanotechnology-based formulations toward the improved topical delivery of anti-acne active ingredients

Introduction: Acne vulgaris is a chronic inflammatory skin disorder that affects an extremely concerning percentage of teenagers (ca. 85%), gathering serious negative impacts on the social life and psychological well-being of individuals. Conventional topical formulations for acne show low tolerability and side effects, such as skin irritation, leading to a decrease in the user's adherence to therapy. Nanotechnology-based formulations were developed as new strategies for topical acne management, particularly to overcome the difficulties associated with conventional treatments.Areas covered: This paper presents a critical analysis of reviewed nanosized anti-acne technological strategies, strongly supporting controlled active ingredient release, improved skin permeation, and lower skin irritation. An updated regulatory framework, considering the promising applications in nanomedicine, and the toxicity of these nanosystems are also addressed.Expert opinion: Nanosystems evidence several advantages, attending to the possibility of controlled active ingredient release, better skin permeation, and lower skin irritation. However, novel nanotechnological strategies for acne treatment and care can lead to new side effects, but also environmental nano pollution. Little is known about the toxicology of these nanotechnology-based formulations, therefore, as future trends, more studies should be conducted to assure the consumers' health and environmental safety.

An Overview on Topical Administration of Carotenoids and Coenzyme Q10 Loaded in Lipid Nanoparticles

Carotenoids and coenzyme Q10 are naturally occurring antioxidant compounds that are also found in human skin. These bioactive compounds have been the focus of considerable research due to their antioxidant, anti-inflammatory, and photoprotective properties. In this review, the current state of the art in the encapsulation of carotenoids and coenzyme Q10 in lipid nanoparticles to improve their bioavailability, chemical stability, and skin absorption is discussed. Additionally, the main findings are highlighted on the cytotoxic and photoprotective effects of these systems in the skin.

Lipid-Based Nanostructures for the Delivery of Natural Antimicrobials

Encapsulation can be a suitable strategy to protect natural antimicrobial substances against some harsh conditions of processing and storage and to provide efficient formulations for antimicrobial delivery. Lipid-based nanostructures, including liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid nanocarriers (NLCs), are valuable systems for the delivery and controlled release of natural antimicrobial substances. These nanostructures have been used as carriers for bacteriocins and other antimicrobial peptides, antimicrobial enzymes, essential oils, and antimicrobial phytochemicals. Most studies are conducted with liposomes, although the potential of SLNs and NLCs as antimicrobial nanocarriers is not yet fully established. Some studies reveal that lipid-based formulations can be used for co-encapsulation of natural antimicrobials, improving their potential to control microbial pathogens.

Design, Preparation, and Characterization of Effective Dermal and Transdermal Lipid Nanoparticles: A Review

Limited permeability through the stratum corneum (SC) is a major obstacle for numerous skin care products. One promising approach is to use lipid nanoparticles as they not only facilitate penetration across skin but also avoid the drawbacks of conventional skin formulations. This review focuses on solid lipid nanoparticles (SLNs), nanostructured lipid nanocarriers (NLCs), and nanoemulsions (NEs) developed for topical and transdermal delivery of active compounds. A special emphasis in this review is placed on composition, preparation, modifications, structure and characterization, mechanism of penetration, and recent application of these nanoparticles. The presented data demonstrate the potential of these nanoparticles for dermal and transdermal delivery.

Recent Advances in Nanomaterials for Dermal and Transdermal Applications

The stratum corneum, the most superficial layer of the skin, protects the body against environmental hazards and presents a highly selective barrier for the passage of drugs and cosmetic products deeper into the skin and across the skin. Nanomaterials can effectively increase the permeation of active molecules across the stratum corneum and enable their penetration into deeper skin layers, often by interacting with the skin and creating the distinct sites with elevated local concentration, acting as reservoirs. The flux of the molecules from these reservoirs can be either limited to the underlying skin layers (for topical drug and cosmeceutical delivery) or extended across all the sublayers of the epidermis to the blood vessels of the dermis (for transdermal delivery). The type of the nanocarrier and the physicochemical nature of the active substance are among the factors that determine the final skin permeation pattern and the stability of the penetrant in the cutaneous environment. The most widely employed types of nanomaterials for dermal and transdermal applications include solid lipid nanoparticles, nanovesicular carriers, microemulsions, nanoemulsions, and polymeric nanoparticles. The recent advances in the area of nanomaterial-assisted dermal and transdermal delivery are highlighted in this review.

Dermal delivery and follicular targeting of adapalene using PAMAM dendrimers

Acne is a chronic dermatological disease of pilosebaceous units existing in the form of hair follicles (HFs) and accompanying sebaceous glands. In topical acne treatment, localisation of drug substance at the target site, in pilosebaceous units, especially in HFs is essential. The aims of this study were to develop and optimise adapalene (ADA)-loaded PAMAM dendrimer-based nanocarriers for topical acne treatment and to prepare gel formulations of the selected nanocarriers and to characterise their rheological properties and spreadability. ADA accumulation in HFs and in the skin from PAMAM dendrimers' aqueous colloidal formulations and their gel formulations were quantitatively determined using punch biopsy technique. Follicular targeting efficiency from PAMAM dendrimers and their gel formulation was compared with the commercial gel product, Differin^® Gel. The localisation of fluorescently labelled PAMAM dendrimers was visualised using a confocal microscope, which confirmed a successful delivery of the carrier system to the HFs. It was also quantified that PAMAM dendrimers improved follicular localisation and skin deposition of ADA. PAMAM dendrimers' gel formulation including lower ADA doses compared with the commercial product exhibited efficient performance in terms of drug accumulation in HFs. In vitro cell viability studies showed the relative safety of G2-PAMAM dendrimers which could be considered to possibly be well tolerated by the skin. Overall, PAMAM dendrimers' potential to selectively target drugs to the site of action, reduce dose administrated, therefore minimise side effects and provide efficiency in topical treatment of dermatological diseases such as acne was shown.

Preparation and evaluation of adapalene nanostructured lipid carriers for targeted drug delivery in acne

Adapalene (ADA) is believed to be one of the topical treatments utilized commonly in case of acne. Nanostructured lipid carriers (NLCs) have been established as an effective carrier system with certain advantages, for instance increased solubility, drug targeting, controlled drug release, and stability of ADA. This study was conducted to obtain the formulation with a good therapeutic property. All formulations were formed by probe sonicator and its characterizations were analyzed. Finally, the therapeutic effects of 0.1% ADA-loaded nanostructured lipid carriers (NLC-ADA) were evaluated. This formulation had a great entrapment efficiency (EE) that illustrated a controlled drug release profile. A pilot clinical evaluation conducted on 15 patients (age 25.23 ± 12.24 years) with mild to moderate acne vulgaris lesions. The results demonstrated significant reduction in acne severity index and the number of inflammatory and noninflammatory lesions after 12 weeks of treatment (P-value .02, .04, and .01, respectively). Subjective results were confirmed with significant improvement in size and intensity of porphyrin production in pilosebaceous follicles (P-value = .03). The study demonstrated that the formulation was safe and revealed the proper improvement rate of acne lesions after 12 weeks.

Analytical tools and evaluation strategies for nanostructured lipid carrier-based topical delivery systems

INTRODUCTION

The inception of nanostructured lipid carriers (NLCs) proved to be a revolutionary step toward the treatment of dermatological disorders. To uncover its true potential, it is imperative that the system be characterized and evaluated comprehensively.

AREAS COVERED

The present review has been written to furnish an in-depth account of analytical tools and evaluation procedures under one roof. Besides discussing the challenges of topical delivery and benefits of NLCs, the paper elaborates on their physicochemical characterization. Further, in vitro evaluation of NLCs for dermatological benefits, followed by their evaluation in a hydrogel/cream base is covered. Lastly, disease-specific evaluation of NLC-based formulations is presented.

EXPERT OPINION

The research endeavors for NLCs have largely focused on the fabrication of NLCs for different bioactives. However, scientific efforts should be aimed toward the lesser explored realm of NLCs, i.e. exploitation of analytical techniques, such as Parelectric spectroscopy, Electron Spin Resonance, and Nuclear Magnetic Resonance spectroscopy. NLCs have been proven for their potential to foster the therapeutic modalities applicable to cutaneous disorders. More attention needs to be devoted to their evaluation for disease-specific parameters. The futuristic steps must involve clinical studies, to lay the path for their commercialization.

Recent Advances Regarding the Therapeutic Potential of Adapalene

Adapalene (ADP) is a representative of the third retinoids generation and successfully used in first-line acne treatment. ADP binds to retinoic acid nuclear receptors. The comedolytic, anti-inflammatory, antiproliferative, and immunomodulatory are the known ADP effects. Its safety profile is an advantage over other retinoids. ADP recently was found to be effective in the treatment of several dermatological diseases and photoaging besides the utility in the treatment of acne vulgaris. New biological effects of adapalene with therapeutic potential are highlighted in this review paper. Thus, adapalene could be a valuable therapeutic drug into the treatment of several types of cancer. Additionally, some neurodegenerative diseases could be treated with a suitable formulation for intravenous administration. The antibacterial activity against methicillin-resistant Staphylococcus aureus of an analogue of ADP has been proven. In different therapeutic schemes, ADP is more effective in combination with other active substances. New topical combinations with adapalene include ketoconazole (antifungal), mometasone furoate (anti-inflammatory corticosteroid), nadifloxacin (fluoroquinolone), and alfa and beta hydroxy acids. Combination with oral drugs is a new trend that enhances the properties of topical formulations with adapalene. Several studies have investigated the effects of ADP in co-administration with azithromycin, doxycycline, faropenem, isotretinoin, and valganciclovir. Innovative formulations of ADP also aim to achieve a better bioavailability, increased efficacy, and reduced side effects. In this review, we have highlighted the current studies on adapalene regarding biological effects useful in various treatment types. Adapalene has not been exploited yet to its full biological potential.

Triamcinolone acetonide loaded-cationic nano-lipoidal formulation for uveitis: Evidences of improved biopharmaceutical performance and anti-inflammatory activity

Topical administration of corticosteroids is the cornerstone treatment of anterior uveitis, but poor corneal penetration and retention cause hindrance in their therapeutic utility. The conventional eye drops are less valuable in conditions where inflammation reaches deeper regions of the eye. Therefore, there is a clear need for an effective drug delivery system, which can increase corticosteroid penetration after topical application. To address this, cationic nanostructured lipid carriers of the drug triamcinolone acetonide (cTA-NLC) were prepared. The cTA-NLC were prepared by a hot microemulsion method and evaluated for drug release, permeation, cell uptake, cytotoxicity, anti-inflammatory activity and ocular irritancy. The cTA-NLC are nanometric in size (< 200 nm), with a zeta potential of about +35 mv and % drug EE of 88 %. The nanocarriers exhibited slow and sustained release of around 84 % in 24 h and transcorneal drug permeation of 51 % in 8 h. The nanocarriers exhibited no cytotoxicity (% cell viability of>90 %). The cell uptake study showed that nanocarriers could retain inside the cells for 24 h. The developed formulation could significantly reduce the TNF-α level in LPS induced inflamed cells. The studies indicated that cTA-NLC could be a promising option for the topical treatment of uveitis.

SLN and NLC for topical, dermal, and transdermal drug delivery

Introduction: From a biopharmaceutical standpoint, the skin is recognized as an interesting route for drug delivery. In general, small molecules are able to penetrate the stratum corneum, the outermost layer of the skin. In contrast, the delivery of larger molecules, such as peptides and proteins, remains a challenge. Nanoparticles have been exploited not only to enhance skin penetration of drugs but also to expand the range of molecules to be clinically used.Areas covered: This review focus on Solid lipid nanoparticles (SLN) and Nanostructured lipid carriers (NLC) for skin administration. We discuss the selection criteria for lipids, surfactants, and surface modifiers commonly in use in SLN/NLC, their production techniques, and the range of drugs loaded in these lipid nanoparticles for the treatment of skin disorders.Expert opinion: Depending on the lipid and surfactant composition, different nanoparticle morphologies can be generated. Both SLN and NLC are composed of lipids that resemble those of the skin and sebum, which contribute to their enhanced biocompatibility, with limited toxicological risk. SLN and NLC can be loaded with very chemically different drugs, may provide a tunable release profile, can be produced in a sterilized environment, and be scaled-up without the need for organic solvents.

Development and Investigation of Vitamin C-Enriched Adapalene-Loaded Transfersome Gel: a Collegial Approach for the Treatment of Acne Vulgaris

Adapalene-loaded transfersome gel containing vitamin C as a combination therapy for the management of acne vulgaris was developed in the present study. The transfersome was prepared by reverse-phase evaporation, and the effect of various process parameters were investigated by the Design of Experiment (DOE) approach and optimized based on the particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE). The selected tranfersomes were further evaluated for their thermal behavior and morphology by transmission electron microscopy and turbidity measurements and incorporated into a gel with/without vitamin C. The gel was evaluated and compared with the marketed product (Adiff gel) for various physicochemical parameters, and in vivo studies in testosterone-induced rat models of acne. The prepared transfersomes had PS in the range of 280 to 400 nm, PDI values of 0.416 to 0.8, ZP of - 38 to - 20 mV, and % EE of 32 to 70%. DSC studies confirmed a positive interaction of the components in the transfersome. Surface morphology confirmed that the vesicles were spherical, unilamellar, and discrete. A relative deformability study showed higher elasticity of the transfersomes compared with Adiff aqs gel. Ascorbyl-6-palmitate in adapalene-loaded transfersome gel containing vitamin C (ADVTG) was found to have a good antioxidant free radical-scavenging activity. An in vitro drug release study showed that the sustained release of the transfersomal formulations was attributed to the flexibility of the vesicles by which penetration was increased. ADVTG was found to be promising in treating acne compared with the marketed product. Graphical Abstract.

Topical Drug Delivery of Anti-infectives Employing Lipid-Based Nanocarriers: Dermatokinetics as an Important Tool

BACKGROUND

The therapeutic approaches for the management of topical infections have always been a difficult approach due to lack of efficacy of conventional topical formulations, high frequency of topical applications and non-patient compliance. The major challenge in the management of topical infections lies in antibiotic resistance which leads to severe complications and hospitalizations resulting in economic burden and high mortality rates.

METHODS

Topical delivery employing lipid-based carriers has been a promising strategy to overcome the challenges of poor skin permeation and retention along with large doses which need to be administered systemically. The use of lipid-based delivery systems is a promising strategy for the effective topical delivery of antibiotics and overcoming drug-resistant strains in the skin. The major systems include transfersomes, niosomes, ethosomes, solid lipid nanoparticles, nanostructured lipid carriers, microemulsion and nanoemulsion as the most promising drug delivery approaches to treat infectious disorders. The main advantages of these systems include lipid bilayer structure which mimics the cell membrane and can fuse with infectious microbes. The numerous advantages associated with nanocarriers like enhanced efficacy, improvement in bioavailability, controlled drug release and ability to target the desired infectious pathogen have made these carriers successful.

CONCLUSION

Despite the number of strides taken in the field of topical drug delivery in infectious diseases, it still requires extensive research efforts to have a better perspective of the factors that influence drug permeation along with the mechanism of action with regard to skin penetration and deposition. The final objective of the therapy is to provide a safe and effective therapeutic approach for the management of infectious diseases affecting topical sites leading to enhanced therapeutic efficacy and patient-compliance.

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.

Oral Administration of Resveratrol-Loaded Solid Lipid Nanoparticle Improves Insulin Resistance Through Targeting Expression of SNARE Proteins in Adipose and Muscle Tissue in Rats with Type 2 Diabetes

In the current study, we developed resveratrol (RES)-loaded solid lipid nanoparticle (SLN-RES) in order to improve insulin resistance through the upregulation of SNARE protein complex in rats with type 2 diabetes. The SLN-RES characteristics include the following: the average size of 248 nm, the zeta potential of - 16.5 mV, and 79.9% RES entrapment efficiency. The release profile of SLN-RES showed an initial burst followed by a sustained release in natural condition. Infrared spectroscopy results revealed good incorporation of RES into core SLN. Spherical nanoparticle with less aggregation was observed under electronic microscopic examination. Oral administration of SLN-RES prevented weight loss and showed better hypoglycemic effect than RES. Serum oxidative stress status was restored to the normal level by SLN-RES. Furthermore, expression of synaptosomal-associated protein 23 (Snap23), syntaxin-4 (Stx4), and vesicle-associated membrane protein 2 (Vamp2) as the major elements of SNARE protein complex were reduced by SLN-RES more significantly than RES treatment in muscle tissue. However, SLN-RES has a similar effect to RES treatment in adipose tissue. Taken together, our results revealed SLN-RES could be a modern and interestingly therapeutic approach for the improvement of insulin resistance through targeting the expression of Snap23, Stx4, and Vamp2 in adipose and muscle tissues.

Effects of Quercetin-Loaded Nanoparticles on MCF-7 Human Breast Cancer Cells

Background and objectives: Previous studies have shown anti-tumor activity of quercetin (QT). However, the low bioavailability of QT has restricted its use. This study aimed to assess the toxic effect of QT encapsulated in solid lipid nanoparticles (QT-SLNs) on the growth of MCF-7 human breast cancer cells. Materials and Methods: MCF-7 and MCF-10A (non-tumorigenic cell line) cell lines treated with 25 µmol/mL of QT or QT-SLNs for 48 h. Cell viability, colony formation, oxidative stress, and apoptosis were evaluated to determine the toxic effects of the QT-SLNs. Results: The QT-SLNs with appropriate characteristics (particle size of 85.5 nm, a zeta potential of −22.5 and encapsulation efficiency of 97.6%) were prepared. The QT-SLNs showed sustained QT release until 48 h. Cytotoxicity assessments indicated that QT-SLNs inhibited MCF-7 cells growth with a low IC₅₀ (50% inhibitory concentration) value, compared to the free QT. QT-SLNs induced a significant decrease in the viability and proliferation of MCF-7 cells, compared to the free QT. QT-SLN significantly increased reactive oxygen species (ROS) level and MDA contents and significantly decreased antioxidant enzyme activity in the MCF-7 cells. Following QT-SLNs treatment, the expression of the Bcl-2 protein significantly decreased, whereas Bx expression showed a significant increase in comparison with free QT-treated cells. Furthermore, The QT-SLNs significantly increased apoptotic and necrotic indexes in MCF-7 cells. Viability, proliferation, oxidative stress and apoptosis of MCF-10A cells were not affected by QT or QT-SLNs. Conclusions: According to the results of this study, SLN significantly enhanced the toxic effect of QT against human breast cancer cells.

Beta-carotene-Encapsulated Solid Lipid Nanoparticles (BC-SLNs) as Promising Vehicle for Cancer: an Investigative Assessment

Beta-carotene (BC), a red-colored pigment found in plants and animals, is one of the most extensively investigated carotenoids due to its provitamin-A, antioxidant, and anticancer properties. The anticancer activity of BC through oral administration is severely affected due to its low bioavailability and oxidative degradation. The present study aimed to formulate and characterize solid lipid nanoparticles (SLNs) of BC for enhanced bioavailability and therapeutic efficacy. Beta-carotene-loaded solid lipid nanoparticles (BC-SLNs) were prepared employing different combinations of glyceryl monostearate and gelucire. The characterization studies were performed for particle size, morphology, release behavior, and stability. BC-SLNs were also studied for in vitro cytotoxicity in human breast cancer cell lines (MCF-7) and pharmacokinetic studies in Wistar rats. The cytotoxicity studies confirmed that encapsulation of BC within the lipid bilayers of nanoparticles did not affect its anticancer efficacy. An improved anticancer activity was observed in BC-SLNs as compared to the free BC. BC-SLNs enhanced the bioavailability of BC on oral administration by sustaining its release from the lipid core and prolongation of circulation time in the body. Similarly, area under the curve (AUC_total) enhanced 1.92-times more when BC was incorporated into SLNs as compared to free BC. In conclusion, solid lipid nanoparticles could be an effective and promising strategy to improve the biopharmaceutical properties of carotenoids for anticancer effects.

Beta carotene-loaded zein nanoparticles to improve the biopharmaceutical attributes and to abolish the toxicity of methotrexate: a preclinical study for breast cancer

Beta carotene (βC) loaded nanoparticles of zein (βC-NPs) were developed using modified phase separation technique. βC-NPs were prepared using different zein concentration and optimized formulation was selected on the basis of micromeritics properties and entrapment efficiency. Further, βC-NPs were evaluated for in vitro release, in vitro cell-survival, cellular localization and apoptosis induced in MCF-7 cells. The combined effect of the βC and its nanoparticulate counterpart with MTX was evaluated thereafter for cytotoxicity and apoptotic activity in MCF-7 cells. In comparison to free βC, the βC-NPs demonstrated noteworthy improvement in various biopharmaceutical attributes viz C_max (∼2.3-folds), AUC_total (2.7-folds), t_1/2 (∼1.5 folds) and MRT (∼1.5 folds), further indicating the remarkable increment in oral bioavailability of βC after incorporation in zein nanoparticles. The anti-tumour potential of prepared βC-NPs and effects of free βC and βC-NPs were investigated upon anticancer efficacy of methotrexate (MTX) in experimentally induced breast cancer rat model. Protective role of βC on MTX-associated hepatic toxicity in wistar rats was also determined using haematological and histopathological approaches. In a nutshell, zein nanoparticles improved the cellular uptake, cytotoxicity and exhibited enhanced oral biopharmaceutical performance of βC. This combination regimen could also be promising platform to facilitate the therapeutic benefits of anticancer agents.

Selective delivery of adapalene to the human hair follicle under finite dose conditions using polymeric micelle nanocarriers

Drug delivery systems that target the pilosebaceous unit (PSU) selectively could improve the clinical management of diseases that originate in the hair follicle. The aims of this study were (i) to prepare polymeric micelles using d-α-tocopheryl polyethylene glycol succinate diblock copolymer that incorporated adapalene (ADA), a retinoid indicated for Acne vulgaris, and (ii) to investigate the feasibility of delivering ADA preferentially to the PSU under finite dose conditions - thereby better approximating actual conditions of use by patients. Incorporation of ADA into spherical micelles (d_n <20 nm) increased aqueous solubility by ∼50 000-fold (from <4 ng mL^-1 to 0.2 mg mL^-1). Optimized micelle solution and gel formulations (0.02% ADA) were stable after storage for 4 weeks at 4 °C. Finite dose experiments using full-thickness porcine and human skin revealed that ADA delivery efficiency from micelle solution and gel formulations was equivalent and was >2- and 10-fold higher than that from Differin® gel and Differin® cream (products containing ADA at 0.1% (w/w)). Follicular delivery studies in human skin, using a punch biopsy technique to extract the intact PSU, demonstrated that the micelle solution and gel formulations did indeed enable preferential delivery of ADA to the PSU (4.5- and 3.3-fold higher, respectively, than that to PSU-free skin biopsies). Confocal laser scanning microscopy provided visual corroboration that ADA was uniformly distributed in the hair follicles. In conclusion, the results confirmed that polymeric micelle nanocarriers enabled selective, targeted drug delivery to the PSU under finite dose conditions and so might improve therapy of follicular diseases and decrease off-site side-effects.

Formulations based on solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) for cutaneous use: A review

Cutaneous use of lipid nanoparticles (solid lipid nanoparticles, SLN and nanostructured lipid carriers, NLC) has been showing promising results. These systems consist of low viscosity aqueous dispersions, being usually employed by means of semi-solid formulations with adequate consistency for skin application. This review addresses the cutaneous use of lipid nanoparticles for therapeutic and cosmetic applications. Initially, general information related to pharmaceutical semi-solid formulations is presented. Afterwards, the effects of SLN and NLC on the skin, and technological aspects related to semi-solid systems based on SLN or NLC are described. Finally, the most relevant studies related to the formulations based on SLN and NLC, for cosmetic and therapeutic applications, are reported. Notwithstanding the cutaneous use of SLN and NLC has been proposed for both local and transdermal delivery, the reported studies show promising results only for local application. In this sense, more research is required to better understanding the interaction mechanisms of lipid nanoparticles with skin lipids. Furthermore, the development of standard methods for skin experiments with nanoparticles is necessary.

Anticancer Effects of Resveratrol-Loaded Solid Lipid Nanoparticles on Human Breast Cancer Cells

In this study, resveratrol-loaded solid lipid nanoparticles (Res-SLNs) were successfully designed to treat MDA-MB-231 cells. The Res-SLNs were prepared using emulsification and low-temperature solidification method. The Res-SLNs were spherical, with small size, negative charge, and narrow size distribution. Compared with free resveratrol, the Res-SLNs displayed a superior ability in inhibiting the proliferation of MDA-MB-231 cells. In addition, Res-SLNs exhibited much stronger inhibitory effects on the invasion and migration of MDA-MB-231 cells. Western blot analysis revealed that Res-SLNs could promote the ratio of Bax/Bcl-2 but decreased the expression of cyclinD1 and c-Myc. These results indicate that the Res-SLN may have great potential for breast cancer treatment.

Methotrexate and beta-carotene loaded-lipid polymer hybrid nanoparticles: a preclinical study for breast cancer

Aim: This work was intended to investigate the targeting potential of fructose-tethered lipid-polymeric hybrid nanoparticles (F-BC-MTX-LPHNPs) co-loaded with beta carotene (BC) and methotrexate (MTX) in breast cancer therapeutics and find out the possible protective role of BC on MTX-induced toxicity. Materials & methods: F-BC-MTX-LPHNPs were fabricated using self-assembled nano-precipitation technique. Fructose was conjugated on the surface of the particles. The in vitro cytotoxicity, sub-cellular localization and apoptotic activity of F-BC-MTX-LPHNPs were evaluated against MCF-7 breast cancer cells. The antitumor potential of F-BC-MTX-LPHNPs was further studied. Results & conclusion: Outcomes suggested that F-BC-MTX-LPHNPs induced the highest apoptosis index (0.89) against MCF-7 cells. Following 30 days of treatment, the residual tumor progression was assessed to be approximately 32%, in animals treated with F-BC-MTX-LPHNPs. F-BC-MTX-LPHNPs are competent to selectively convey the chemotherapeutic agent to the breast cancers. Beta carotene ameliorated MTX-induced hepatic and renal toxicity.

Microencapsulation of β-Carotene Based on Casein/Guar Gum Blend Using Zeta Potential-Yield Stress Phenomenon: an Approach to Enhance Photo-stability and Retention of Functionality

β-Carotene, abundant majorly in carrot, pink guava yams, spinach, kale, sweet potato, and palm oil, is an important nutrient for human health due to its scavenging action upon reactive free radicals wherever produced in the body. Inclusion of liposoluble β-carotene in foods and food ingredients is a challenging aspect due to its labile nature and low absorption from natural sources. This fact has led to the application of encapsulation of β-carotene to improve stability and bioavailability. The present work was aimed to fabricate microcapsules (MCs) of β-carotene oily dispersion using the complex coacervation technique with casein (CA) and guar gum (GG) blend. The ratio of CA:GG was found to be 1:0.5 (w/v) when optimized on the basis of zeta potential-yield stress phenomenon. These possessed a higher percentage yield (71.34 ± 0.55%), lower particle size (176.47 ± 4.65 μm), higher encapsulation efficiency (65.95 ± 5.33%), and in general, a uniform surface morphology was observed with particles showing optimized release behavior. Prepared MCs manifested effective and controlled release (up to 98%) following zero-order kinetics which was adequately explained by the Korseymer-Peppas model. The stability of the freeze-dried MCs was established in simulated gastrointestinal fluids (SGF, SIF) for 8 h. Antioxidant activity of the MCs was studied and revealed the retention of the functional architecture of β-carotene in freeze-dried MCs. Minimal photolytic degradation upon encapsulation of β-carotene addressed the challenge regarding photo-stability of β-carotene as confirmed via mass spectroscopy.

Mechanistic Analysis of Human Skin Distribution and Follicular Targeting of Adapalene-Loaded Biodegradable Nanospheres With an Insight Into Hydrogel Matrix Influence, In Vitro Skin Irritation, and In Vivo Tolerability

This work aimed at the development of a biocompatible, non-oily nanomedicine for follicular delivery of adapalene (AD) ameliorating its irritation potential for convenient localized topical treatment of acne vulgaris. AD was efficiently incorporated into poly-ε-caprolactone nanospheres (NS) with an encapsulation efficiency of 84.73% ± 1.52%, a particle size of 107.5 ± 8.19 nm, and zeta potential of -13.1 mV demonstrating a sustained-release behavior. The AD-NS were embedded in either hydroxypropyl methylcellulose (HPMC) or hyaluronate (HA) gel. The ex vivo human skin dermatokinetics of AD from each system was studied. The nanoparticles dispersion showed significantly higher AD retention in the epidermis and dermis than AD suspension. NS-HPMC decreased whereas NS-HA increased AD retained in all the skin layers. The fate of the NS and the role of the hydrogel in modulating skin distribution was evaluated by confocal laser scanning microscopy (CLSM) imaging of fluorescently labeled NS. CLSM illustrated follicular localization of the florescent NS. HPMC gel restricted the presence of NS to the stratum corneum and epidermis. HA gel enhanced the penetration of NS to all the skin layers. In vitro skin irritation using human dermal fibroblasts and in vivo animal tolerability studies were performed. Accordingly, HA gel-dispersed AD-NS presented a nonirritant compromised cosmeceutical formulation suitable for oily acneic skin.