Preparation and Characterization of Minoxidil Loaded Nanostructured Lipid Carriers

Alopecia areata: review of epidemiology, pathophysiology, current treatments and nanoparticulate delivery system

Alopecia areata (AA) is a kind of alopecia that affects hair follicles and nails. It typically comes with round patches and is a type of nonscarring hair loss. Various therapies are accessible for the management and treatment of AA, including topical, systemic and injectable modalities. It is a very complex type of autoimmune disease and is identified as round patches of hair loss and may occur at any age. This review paper highlights the epidemiology, clinical features, pathogenesis and new treatment options for AA, with a specific emphasis on nanoparticulate drug-delivery systems. By exploring these innovative treatment approaches, researchers aim to enhance the effectiveness and targeted delivery of therapeutic agents, ultimately improving outcomes for individuals living with AA.

A Comprehensive Review on Novel Lipid-Based Nano Drug Delivery

Novel drug delivery system opens the doors towards nano/micro formulation strategies to overcome the challenges associated with the poorly soluble and permeable drugs. Lipid based nanoparticles are widely accepted that includes liposomes, niosomes and micelles which are FDA approved. Such lipid based drug delivery allows delivery for natural phytoconstituents, biopharmaceutical classification system (BCS) class II and class IV drugs are effectively delivered to improve its solubility, permeability and bioavailability. The article provides the recent advances and application of lipid based dosage form for improvement of therapeutic efficacy.

Minoxidil delivered via a stem cell membrane delivery controlled release system promotes hair growth in C57BL/6J mice

Objective: Umbilical cord-derived mesenchymal stem cell membrane-loaded minoxidil (MXD) nanoparticles (STCM-MXD-NPs) were prepared to investigate their effects on hair growth in C57BL/6J mice. Methods: STCM-MXD-NPs were obtained by freeze-thawing and differential centrifugation, and their effects on hair growth were evaluated using C57BL/6J mice. The mRNA and protein expression levels of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) were detected by real-time polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. Protein expression levels of marker of proliferation Ki-67 (MKI67) and β-catenin (CTNNB) in skin tissue were detected by immunohistochemistry. Results: STCM-MXD-NPs improved MXD solubility. They released the drug slowly, increasing its transdermal properties, accumulation in the skin, and content in the hair bulb tissues with a better efficacy than that of ordinary MXD. Moreover, STCM-MXD-NPs significantly upregulated the mRNA and protein levels of VEGF and IGF-1 and promoted the protein expression of MKI67 and CTNNB in mouse skin tissues, promoting mouse hair growth. Conclusion: Stem cell membrane-loaded MXD nanoparticles with slow-release properties increased MXD accumulation in the skin by improving its transdermal properties, increasing VEGF, IGF-1, MKI67, and CTNNB expression levels and promoting hair growth in C57BL/6J mice.

Co-delivery of minoxidil and tocopherol acetate ethosomes to reshape the hair Follicular Microenvironment and promote hair regeneration in androgenetic alopecia

The most prevalent kind of hair loss is androgenic alopecia (AGA), which is characterized by hair follicle miniaturization and microenvironment dysfunction. Although topical Minoxidil (MXD) was considered to be a safe and effective treatment for AGA, excess reactive oxygen species (ROS) and lower sulfotransferase activity in the hair follicular microenvironment led to an unsatisfactory treatment of AGA. Here, we developed the ethosome (MTE) load of minoxidil and tocopherol acetate to improve the therapeutic effect of MXD on androgenic alopecia. It could regulate the microenvironment around hair follicles, promote the telogen-to-anagen transition of hair follicles, and boost hair regeneration, thus achieving a synergistic effect of 1 + 1 > 2. The results proved that MTE showed excellent stability, biosafety, and good dermal and follicular permeability in vitro. The hair regeneration ability of AGA model mice showed that the co-delivery ethosome might regulate the microenvironment around the hair follicles and improve hair regeneration in comparison to the commercial minoxidil tincture alone. As a result, the strategy provided a promising new strategy for the treatment of AGA.

Nanotechnology-based techniques for hair follicle regeneration

The hair follicle (HF) is a multicellular complex structure of the skin that contains a reservoir of multipotent stem cells. Traditional hair repair methods such as drug therapies, hair transplantation, and stem cell therapy have limitations. Advances in nanotechnology offer new approaches for HF regeneration, including controlled drug release and HF-specific targeting. Until recently, embryogenesis was thought to be the only mechanism for forming hair follicles. However, in recent years, the phenomenon of wound-induced hair neogenesis (WIHN) or de novo HF regeneration has gained attention as it can occur under certain conditions in wound beds. This review covers HF-specific targeting strategies, with particular emphasis on currently used nanotechnology-based strategies for both hair loss-related diseases and HF regeneration. HF regeneration is discussed in several modalities: modulation of the hair cycle, stimulation of progenitor cells and signaling pathways, tissue engineering, WIHN, and gene therapy. The HF has been identified as an ideal target for nanotechnology-based strategies for hair regeneration. However, some regulatory challenges may delay the development of HF regeneration nanotechnology based-strategies, which will be lastly discussed.

Bioactive Compound-Loaded Nanocarriers for Hair Growth Promotion: Current Status and Future Perspectives

Hair loss (alopecia) has a multitude of causes, and the problem is still poorly defined. For curing alopecia, therapies are available in both natural and synthetic forms; however, natural remedies are gaining popularity due to the multiple effects of complex phytoconstituents on the scalp with fewer side effects. Evidence-based hair growth promotion by some plants has been reported for both traditional and advanced treatment approaches. Nanoarchitectonics may have the ability to evolve in the field of hair- and scalp-altering products and treatments, giving new qualities to hair that can be an effective protective layer or a technique to recover lost hair. This review will provide insights into several plant and herbal formulations that have been reported for the prevention of hair loss and stimulation of new hair growth. This review also focuses on the molecular mechanisms of hair growth/loss, several isolated phytoconstituents with hair growth-promoting properties, patents, in vivo evaluation of hair growth-promoting activity, and recent nanoarchitectonic technologies that have been explored for hair growth.

Design, Development, Evaluation, and In Vivo Performance of Buccal Films Embedded with Paliperidone-Loaded Nanostructured Lipid Carriers

The therapeutic effectiveness of paliperidone in the treatment of schizophrenia has been limited by its poor oral bioavailability; hence, an alternative route could be appropriate. This study investigates the feasibility of developing a buccal film impregnated with paliperidone-loaded nanostructured lipid carriers (NLCs) and assesses the potential to enhance its bioavailability. Box-Behnken-based design optimization of NLCs was performed by examining the particles' physical characteristics. The polymeric film was used to load optimized NLCs, which were then assessed for their pharmaceutical properties, permeability, and pharmacokinetics. The optimization outcomes indicated that selected formulation variables had a considerable (p < 0.05) impact on responses such as particle size, entrapment efficiency, and % drug release. Desired characteristics such as a negative charge, higher entrapment efficiency, and nanoparticles with ideal size distribution were shown by optimized NLC dispersions. The developed film demonstrated excellent physico-mechanical properties, appropriate texture, good drug excipient compatibility (chemically stable formulation), and amorphous drug nature. A sustained Weibull model drug release (p < 0.0005) and superior flux (~5-fold higher, p < 0.005) were seen in NLC-loaded film compared to plain-drug-loaded film. The pharmacokinetics profile in rabbits supports the goal of buccal therapy as evidenced by significantly higher AUC0-12 (p < 0.0001) and greater relative bioavailability (236%) than the control. These results support the conclusion that paliperidone-loaded NLC buccal film has the potential to be an alternate therapy for its effective administration in the treatment of schizophrenia.

Advances and Prospects for Hydrogel-Forming Microneedles in Transdermal Drug Delivery

Transdermal drug delivery (TDD) is one of the key approaches for treating diseases, avoiding first-pass effects, reducing systemic adverse drug reactions and improving patient compliance. Microneedling, iontophoresis, electroporation, laser ablation and ultrasound facilitation are often used to improve the efficiency of TDD. Among them, microneedling is a relatively simple and efficient means of drug delivery. Microneedles usually consist of micron-sized needles (50-900 μm in length) in arrays that can successfully penetrate the stratum corneum and deliver drugs in a minimally invasive manner below the stratum corneum without touching the blood vessels and nerves in the dermis, improving patient compliance. Hydrogel-forming microneedles (HFMs) are safe and non-toxic, with no residual matrix material, high drug loading capacity, and controlled drug release, and they are suitable for long-term, multiple drug delivery. This work reviewed the characteristics of the skin structure and TDD, introduced TDD strategies based on HFMs, and summarized the characteristics of HFM TDD systems and the evaluation methods of HFMs as well as the application of HFM drug delivery systems in disease treatment. The HFM drug delivery system has a wide scope for development, but the translation to clinical application still has more challenges.

Nanoparticles for Topical Application in the Treatment of Skin Dysfunctions-An Overview of Dermo-Cosmetic and Dermatological Products

Nanomaterials (NM) arouse interest in various fields of science and industry due to their composition-tunable properties and the ease of modification. They appear currently as components of many consumer products such as sunscreen, dressings, sports clothes, surface-cleaning agents, computer devices, paints, as well as pharmaceutical and cosmetics formulations. The use of NPs in products for topical applications improves the permeation/penetration of the bioactive compounds into deeper layers of the skin, providing a depot effect with sustained drug release and specific cellular and subcellular targeting. Nanocarriers provide advances in dermatology and systemic treatments. Examples are a non-invasive method of vaccination, advanced diagnostic techniques, and transdermal drug delivery. The mechanism of action of NPs, efficiency of skin penetration, and potential threat to human health are still open and not fully explained. This review gives a brief outline of the latest nanotechnology achievements in products used in topical applications to prevent and treat skin diseases. We highlighted aspects such as the penetration of NPs through the skin (influence of physical-chemical properties of NPs, the experimental models for skin penetration, methods applied to improve the penetration of NPs through the skin, and methods applied to investigate the skin penetration by NPs). The review summarizes various therapies using NPs to diagnose and treat skin diseases (melanoma, acne, alopecia, vitiligo, psoriasis) and anti-aging and UV-protectant nano-cosmetics.

Finasteride-loaded nano-lipidic carriers for follicular drug delivery: preformulation screening and Box-Behnken experimental design for optimization of variables

Finasteride (FIN), a 5-α reductase enzyme inhibitor is mainly used orally for the treatment of androgenic alopecia and benign prostate hyperplasia. The present study was undertaken for systematic optimization and assessment of the designed nanostructured lipid carriers (NLC) to enhance follicular delivery of FIN by topical administration. The NLCs were prepared by microemulsion method, by employing a 3³ Box-Behnken design and subsequently confirmed by ANOVA analysis. Compritol ATO-888 and Fenugreek oil were selected as the solid lipid and liquid lipid respectively for the fabrication of NLCs. The formulations were characterized for particle size, zeta potential, entrapment efficiency, storage stability and in vitro drug release profile. Morphological profile of the NLCs nanocarriers was studied by transmission electron microscopy (TEM). The Fourier Transform Infrared Spectroscopy (FT-IR) spectrum and differential scanning calorimetry (DSC) thermogram demonstrated that FIN entrapment within NLCs was devoid of chemical interaction with the components. The prepared NLCs had satisfactory particle dimensions, zeta potential and entrapment efficiency. The numerical optimization process indicated the optimal NLC composition with 3 mg of SPC, 6 mg lipid and 5 mg of drug. NLCs loaded with FIN had acceptable particle size at 379.8 nm, zeta potential of −37.1 mV and an entrapment efficiency of 84%. Transmission electron microscopy indicated the spherical morphology. In vitro release profile indicated a fast initial release and subsequently a prolonged release of FIN from the carrier for 24 h. The release kinetics data displayed a Higuchi diffusion release model with the best match R² value (0.848). Short-term stability tests conducted over 4 weeks at 6° and 25 °C demonstrated that the formulation could retain their initial properties during the test period.

Hair follicle-targeting drug delivery strategies for the management of hair follicle-associated disorders

The hair follicle is not only a critical penetration route in percutaneous absorption but also has been recognized to be a target for hair follicle-associated disorders, such as androgenetic alopecia (AGA) and acne vulgaris. Hair follicle-targeting drug delivery systems allow for controlled drug release and enhance therapeutic efficacy with minimal side effects, exerting a promising method for the management of hair follicle-associated dysfunctions. Therefore, they have obtained much attention in several fields of research in recent years. This review gives an overview of potential follicle-targeting drug delivery formulations currently applied based on the particularities of the hair follicles, including a comprehensive assessment of their preclinical and clinical performance.

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.

Potential of nanoparticulate based delivery systems for effective management of alopecia

In recent times, more than 50 % of the global population is facing hair-related issues (alopecia) which is seen mostly amongst the people in the age group of 30-40 years. The conventional topical dosage forms available in the market falls short in effectively managing alopecia. Despite various advancements in topical dosage forms, it is still disposed to limited clinical application and provides poor penetration of drug molecules into the skin. The exact etiology of alopecia is still unknown and various researchers link lifestyle, hereditary, and auto immune-based events with its existence. Nanoparticulate-based delivery are hence brought in use to enhance the permeability properties of the drug. In comparison to conventional methods nanotechnology-based drug delivery system tames drug molecules to a specific site with much better efficacy. This review is engrossed in the journey and role of nano technological-based drug delivery in the management of alopecia and its clinical application.

Coenzyme Q10 phospholipidic vesicular formulations for treatment of androgenic alopecia: ex vivo permeation and clinical appraisal

INTRODUCTION

Coenzyme Q10 (CoQ10) is an antioxidant molecule with anti-aging activity on human hair, and because of its pharmaceutical limitations such as large molecular weight, high lipophilicity and poor water solubility, its therapeutic effectiveness has been hampered. Therefore, different vesicular nanocarriers were developed in the current work, for enhancement of the skin penetration of CoQ10 for treatment of androgenic alopecia.

AREAS COVERED

In order to overcome the poor skin penetration of CoQ10, it was formulated in liposomes, transfersomes, ethosomes, cerosomes and transethosomes using the thin-film hydration method. Results revealed that transethosomes were the carrier of choice for CoQ10, in which it displayed a particle size of 146 nm, zeta potential -55 mV and entrapment efficiency of 97.63%. Transethosomes also achieved the highest deposition percentage for CoQ10, exceeding 95% in the different skin layers. Upon clinical examination in patients suffering from androgenic alopecia, CoQ10 transethosomes displayed better clinical response than the administration of CoQ10 solution, which was further confirmed by dermoscopic examination.

EXPERT OPINION

Findings of this study further prove that loading antioxidants such as CoQ10 in nanocarriers maximizes their therapeutic efficiency, and opens many opportunities for their application in treatment of several other topical diseases.

Topical Treatment for Scarring and Non-Scarring Alopecia: An Overview of the Current Evidence

Alopecia is a clinical condition related to hair loss that can significantly affect both male and female adults' quality of life. Despite the high market demand, only few drugs are currently approved for alopecia treatment. Topical formulations still bring drawbacks, such as scalp irritation with frequent use, and low drug absorption to the site of action, which limits the efficacy. The most recent research points out that different formulation technology could circumvent the aforementioned flaws. Such technology includes incorporation of drugs in rigid or deformable nanoparticles, strategies involving physical, energetical and mechanical techniques, such as iontophoresis, sonophoresis, microneedling, and the use of solid effervescent granules to be hydrated at the moment of application in the scalp. In this paper, the progress of current research on topical formulations dedicated to the treatment of alopecia is reviewed and discussed.

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.

Microemulsions as Solubilizers and Penetration Enhancers for Minoxidil Release from Gels

Micro- and nanoemulsions are potential drug solubilizers and penetration enhancers through the high surfactant/co-surfactant content. This study aimed to evaluate the influence of minoxidil (MXD) solubilized in the microemulsions (MEs) on drug release by in vitro/ex vivo diffusion through the semi-permeable membrane Spectra/Por^® (Spectrum Laboratory, Gardena, CA, USA) and porcine ear skin. Moreover, a residual amount of drug in the skin after ex vivo diffusion was evaluated. The reference ME_R, lecithin-containing ME_L, and gelatin-containing ME_G were characterized in terms of their size, polydispersity index, density, viscosity, electrical conductivity and surface tension. Based on the in vitro diffusion, it can be argued that ME_L slowed down the drug release, while ME_R and ME_G have no significant effect compared to the sample, in which propylene glycol (PG) was used as a solubilizer. Determination of the residual drug amount in the skin after 6 h of the ex vivo permeation was demonstrated as the most valuable method to evaluate the effectiveness of the ME’s application. The results indicate that the most optimal MXD permeation enhancers in alginate gel were the natural surfactants containing MEs. MXD solubilization in ME_G and ME_L had caused more than 5% of the drug remaining in the skin, which is almost a 1.5-fold higher amount compared to the reference gel.

Nanoemulsions containing plant oils: How do they influence hair treatment?

OBJECTIVE

Cosmetic and dermatological products, mainly the hair treatments, are projected to have remarkable growing in coming years. Nanotechnology, specifically nanoemulsions, has potential to be used in several hair products, owing to their beneficial properties. Concurrently, plant-derived cosmetics have become more popular over the years to consumers who prefer a safer, natural and sustainable approach. There is a lack of studies combining plant oils and nanotechnology for haircare formulations. In this work, different plant oil-loaded nanoemulsions were prepared to investigate the influence of their particle size, zeta potential and composition on hair treatment efficacy.

METHODS

Coconut, olive and Abyssinian oils, alone or in combination, were loaded into nanoemulsions by high-pressure homogenization method (HPH). The mean particle size, polydispersity index and zeta potential were measured by the dynamic light scattering (DLS) method, and a stability test was performed for five months. A sensorial screening evaluation performed by the analyst and the combing test using Dia-Stron^® instrumentation were applied on hair tresses treated by these nanoemulsions.

RESULTS

The use of different plant oils for nanoemulsion resulted in distinct final particle sizes and zeta potential. However, results suggested no significant difference between them in hair tresses combing efficacy compared by Dia-Stron^® instrument testing. Moreover, the plant-loaded nanoemulsions with increased concentration of cationic surfactant indicated a 50% reduction in combing force using this device when compared to control, in addition to better sensory results by screening test compared to other nanoemulsions and control.

CONCLUSION

The composition of plant oils, particle size or zeta potential of the prepared nanoemulsions does not seem to significantly influence hair performance. Thus, we suggest that finding the right balance between cationic surfactant and plant oils may be the most appropriate path to develop effective nanoemulsions in hair treatment.

Development and Evaluation of Astaxanthin as Nanostructure Lipid Carriers in Topical Delivery

The study is designed to formulate, optimize, and evaluate astaxanthin (ASTA)-loaded nanostructured lipid carrier (NLC) with an aim to improve its stability, water solubility, skin permeability and retention and reduce drug-related side effects. ASTA was extracted from Haematococcus pluvialis. ASTA-NLC was formulated by the technique of melt emulsification-ultrasonic and optimized taking solid:liquid lipid ratio, total lipid:drug ratio, drug concentration, emulsifier types, and amounts as independent variables with particle sizes (PS) and entrapment efficiency (EE) as dependent variables. The optimized formulation (N21) exhibited spherical surfaced stable nanoparticles of 67.4 ± 2.1 nm size and 94.3 ± 0.5% EE. Formulation N21 was then evaluated for its physiological properties, physicochemical properties, drug content, in vitro release and skin penetration, and retention analysis. The ASTA-NLC was found to be nonirritating, homogenous, and with excellent stability and water solubility. In vitro release studies showed the cumulative release rate of NLC was 83.0 ± 3.4% at 48 h. The skin penetration and retention studies indicated that cumulative permeability was 174.10 ± 4.38 μg/cm² and the retention was 8.00 ± 1.62 μg/cm² within 24 h. It can be concluded that NLC serves as a promising carrier for site specific targeting with better stability and skin penetration.

Latanoprost Loaded in Polymeric Nanocapsules for Effective Topical Treatment of Alopecia

Latanoprost has recently been used to treat alopecia as it causes an increase in the capillary density of patients. This work presents for the first time the development of polymeric nanocapsules containing latanoprost for the topical treatment of alopecia. Poly-ε-caprolactone nanocapsules loading latanoprost were developed by nanoprecipitation of the polymer on the surface of drug oily nanodroplets. The method encapsulated 93.9 ± 0.4% of the drug into nanocapsules of 197.8 (± 1.2) nm (PdI = 0.15 ± 0.01). The nanosystem presented a zeta potential equal to - 30.1 ± 1.8 mV and was stable for at least 90 days when stored at 6°C. The colloidal aqueous dispersion was non-irritating, according to the in vitro HET-CAM test. The nanocapsules improved latanoprost accumulation into the hair follicles when topically applied on porcine skin, delivering 30% more drug to these skin structures relative to the control solution (P < 0.05). Also, with a simple manual massage, latanoprost accumulation was increased by twofold (P < 0.05). In conclusion, in addition to being a stable and safe formulation, nanocapsules enhanced latanoprost accumulation into the hair follicles, being a nanosystem with high potential for use as a topical formulation for the treatment of androgenic alopecia.

Bemotrizinol-Loaded Carnauba Wax-Based Nanostructured Lipid Carriers for Sunscreen: Optimization, Characterization, and In vitro Evaluation

Nanostructured lipid carriers (NLC) are aqueous dispersions of nanoparticles formed by solid and liquid lipids. In this study, NLC containing an organic UV filter, bemotrizinol, were developed for sunscreen formulation using carnauba wax and caprylic/capric triglycerides through ultrasonication technique. A Box-Behnken design was used to evaluate the influence of three variables on the particle size with the purpose of choosing the best system for further characterization. The particle size decreased as the surfactant concentration increased, reaching an average size of 122.4 ± 0.3 nm at 30 days of storage. Scanning electron microscopy showed intact and spherical particles. Thermal analysis and Fourier-transform infrared spectroscopy suggest that bemotrizinol was incorporated into the NLC. The X-ray diffraction showed a reduction in the crystallinity of the NLC. In vitro analysis indicated an improvement in the photoprotective activity of bemotrizinol when incorporated into NLC. These findings suggest a promising, stable, and biocompatible system.

Transdermal Drug Delivery for Hair Regrowth

Today, about 50% of men and 15-30% of women suffer from hair loss as well as the associated psychological impact. Drug therapy, especially through topical administration, is the main treatment strategy for stimulating hair regrowth. However, challenges exist due to the skin barrier that hinders drug penetration. To this end, many efforts have been made to enhance drug penetration efficiency. This review focuses on the advancement of the transdermal drug delivery strategies for hair loss therapy reported in the last five years, especially those via nanoformulations for topical administration and microneedles for transdermal delivery. In addition, physical or chemical penetration enhancers are also introduced, which are often applied with the drug delivery systems to achieve a synergy effect.

Enhanced docetaxel delivery using sterically stabilized RIPL peptide-conjugated nanostructured lipid carriers: In vitro and in vivo antitumor efficacy against SKOV3 ovarian cancer cells

Docetaxel (DTX) has poor solubility, low specificity, and severe side effects. For efficient targeting of DTX to hepsin-overexpressing SKOV3 ovarian cancer cells, PEGylated and RIPL peptide (IPLVVPLRRRRRRRRC)-conjugated nanostructured lipid carriers (PEG-RIPL-NLCs) were examined for in vitro and in vivo antitumor efficacy. DTX-loaded plain NLCs (DTX-pNLCs), RIPL-NLCs (DTX-RIPL-NLCs), and PEG-RIPL-NLCs (DTX-PEG-RIPL-NLCs) were prepared using a solvent emulsification-evaporation technique. DTX was successfully loaded with high encapsulation efficiency (>93%), and all NLCs showed homogeneous dispersion with zeta potentials varying from -17 to 15 mV. Drug release was biphasic: initial rapid release, then gradual release. In vitro cytotoxicity was time- and dose-dependent: DTX-RIPL-NLCs and DTX-PEG-RIPL-NLCs exhibited greater cytotoxicity, enhanced cell apoptosis owing to the cell cycle arrest in the G2/M phase, and increased activation of the mitochondria-related intrinsic apoptosis pathway compared to DTX-pNLCs. Pharmacokinetic experiments in male Sprague-Dawley rats revealed that DTX-PEG-RIPL-NLCs increased the mean residence time of DTX but reduced total body clearance and volume of distribution. In a SKOV3-bearing xenograft Balb/c athymic mouse model, DTX-PEG-RIPL-NLCs suppressed tumors, evidenced by tumor volume change and histopathological examination. Thus, we conclude that PEG-RIPL-NLCs have an advantage of high payload of poorly water-soluble drugs and are a good candidate for drug targeting to SKOV3-derived ovarian cancer.

Topical Minoxidil-Loaded Nanotechnology Strategies for Alopecia

Androgenetic alopecia (AGA) is a multifactorial and age-related condition characterized by substantial hair loss affecting both men and women. Conventional treatments include the use of topical minoxidil (MNX) formulations to stimulate hair growth and restore hair condition. However, those treatments are associated with limited performance and a lack of tolerability and compliance due to the emergence of adverse effects. Considering that the development of nanotechnology-based formulations as hair loss therapeutic strategies has been clearly growing, topical MNX delivery by means of these innovative formulations is known to enhance MNX skin permeation and depot formation into hair follicles, allowing for MNX-controlled release, increased MNX skin bioavailability and enhanced therapeutic efficacy with minimal adverse effects. This review highlights the potential of nanotechnology-based MNX delivery formulations for improved hair loss therapeutics, including a thorough assessment of their in vitro and in vivo performances, as well as regulatory and nanosafety considerations.

Nanotechnology advances for hair loss

Alopecia is the partial or total reduction of hair in a specific area of the skin that affects millions of men and women worldwide. Most common approved treatments present inconvenient therapeutic regimes and serious adverse effects. In this scenario, nanoencapsulation has emerged as a relatively simple technology for improving the therapeutic outcome of this pathology, promoting a targeted drug delivery with enhanced local bioavailability, which could reduce the adverse effects. Herein, we present some recent studies involving the nanosystems developed for the pharmacological treatment of alopecia, highlighting how each system represents an improvement in relation to conventional drug products and the future perspectives of these new technologies in reaching the market.

Formulation, Characterization, and Pharmacokinetic Studies of 6-Gingerol-Loaded Nanostructured Lipid Carriers

In this study, an optimized nanostructured lipid carriers (NLCs) were developed and investigated for improving the solubility and oral availability of 6-Gingerol (6G), an active and abundant component of ginger with limited applications due to its poor water solubility plus oral biological availability. The NLCs consisted of a solid lipid (glyceryl monostearate), another liquid lipid (decanoyl/octanoyl-glycerides) and mixed surfactants (Tween 80 and Poloxamer 188), and was prepared by high pressure homogenization method. The optimal 6G-NLC formulation was evaluated through physical properties such as appearance, mean particle size, zeta potential, encapsulation efficiency, and in vitro drug release, alongside techniques viz., transmission electron microscopy (TEM), differential scanning calorimetry (DSC), as well as powder X-ray diffraction (XRD). Pharmacokinetics were also evaluated in rats. The 6G-NLCs prepared with optimal formulation exhibited a homogenous spherical shape with mean particle size and zeta potential of 63.59 ± 5.54 nm and - 12.18 ± 1.06 mV. Encapsulation efficiency and drug loading were 76.71 ± 1.11 and 1.17 ± 0.35%, respectively. In vitro release profile of 6G from NLCs was sustained and fitted with Weibull equation. After oral administration of the 6G-NLCs, drug concentrations in serum, MRT, and AUC_0-t were significantly higher as compared with the free 6G suspension. All these results indicated that the developed NLC formulation could be effective and promising drug carriers to improve the water solubility of 6G while sustaining the drug release as well as prolonging in vivo acting time of the drug coupled with oral bioavailability enhancement.

Enhancement of In Vivo Efficacy and Oral Bioavailability of Aripiprazole with Solid Lipid Nanoparticles

Aripiprazole (ARP), a second-generation or atypical antipsychotic, is poorly soluble and undergoes extensive hepatic metabolism and P-glycoprotein efflux which lead to reduced in vivo efficacy and increased dose-related side effects. To enhance in vivo efficacy and oral bioavailability of aripiprazole, aripiprazole-loaded solid lipid nanoparticles (SLNs) were developed using tristearin as solid lipid. Tween 80 and sodium taurocholate were used as surfactants to prepare SLNs using microemulsification method. SLNs were characterized for particle size, zeta potential, entrapment efficiency, and crystallinity of lipid and drug. In vitro release studies were performed in water containing 0.5% sodium dodecyl sulfate. Pharmacodynamic evaluation was carried out in laca mice using dizocilpine-induced schizophrenic model where behavioral evaluation revealed better in vivo efficacy of SLNs. Pharmacokinetics of aripiprazole-loaded SLNs after oral administration to conscious male Wistar rats was studied. Bioavailability of aripiprazole was increased 1.6-fold after formulation of aripiprazole into SLNs as compared to plain drug suspension. The results indicated that solid lipid nanoparticles can improve the bioavailability of lipophilic drugs like aripiprazole by enhancement of absorption and minimizing first-pass metabolism.

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.