Preparation and characterization of dutasteride-loaded nanostructured lipid carriers coated with stearic acid-chitosan oligomer for topical delivery

Enhanced therapeutic effects of all-trans retinoic acid nanostructured lipid carrier composite gel drug delivery system for alopecia areata

BACKGROUND

Alopecia areata (AA) affects approximately 2% of the global population and causes psychological distress. All-trans retinoic acid (ATRA) has the potential to promote hair regeneration; however, its clinical use is limited by skin irritation and low targeting specificity. To address these limitations, we designed an ATRA-loaded nanostructured lipid carrier gel (ATRA-NLC-Gel) drug delivery system to enhance the therapeutic effects of ATRA in AA.

RESULTS

ATRA-NLC showed a uniform nanoparticle size distribution and excellent biocompatibility. In vitro, they enhanced the uptake ability of dermal papilla cells, increased cell viability, and promoted cell proliferation by facilitating the cell cycle process. Compared to ATRA cream, ATRA-NLC-Gel significantly reduced skin irritation, prolonged residence time on the skin, and achieved a sustained and slow release of ATRA. Treatment with ATRA-NLC-Gel enhanced transdermal penetration and targeted enrichment in the hair follicle region, thereby significantly promoting hair regrowth. ATRA-NLC-Gel improved AA symptoms by upregulating CD200 and Ki-67 expression, activating the Wnt/β-catenin pathway.

CONCLUSIONS

ATRA-NLC-Gel enhanced the transdermal permeability and follicle-targeting efficacy of ATRA, alleviated ATRA-induced skin dryness and irritation, and effectively improved the symptoms of AA in AA model mice. ATRA-NLC-Gel offers a highly promising strategy for transdermal treatment of AA in clinical setting.

Construction of Chitosan Oligosaccharide-Coated Nanostructured Lipid Carriers for the Sustained Release of Strontium Ranelate

BACKGROUND

Strontium ranelate (SR) is an effective bone regeneration drug; however, its low bioavailability and strong hydrophilicity cause a strong cytotoxicity, venous thrombosis, and allergic reactions when administered in its free form. This study aims to enhance the SR bioavailability by utilizing nanostructured lipid carriers (NLC) as a drug delivery system (DDS).

METHODS

To improve the drug delivery efficiency and sustained release of the NLC, their surfaces were coated with chitosan oligosaccharide (COS), a natural polymer. The synthesis of COS-NLC was confirmed by measuring particle size and zeta potential, while surface morphology was evaluated using atomic force microscopy (AFM). SR loading efficiencies and release profiles were analyzed via reversed-phase high-performance liquid chromatography (RP-HPLC), and cytotoxicity was evaluated in mouse fibroblast L929 cells.

RESULTS

Particle characterization indicated that the COS coating slightly increased the particle size (i.e., from 128.99 ± 2.77 to 131.46 ± 2.13 nm) and zeta potential (i.e., from - 13.94 ± 0.49 to - 6.58 ± 0.32 mV) of the NLC. The COS-NLC exhibited a high SR-loading efficiency of ~ 86.31 ± 3.28%. An in vitro release test demonstrated an improved sustained release tendency of SR from the COS-NLC compared to that from the uncoated NLC. In cytotoxicity assays using L929 cells, the COS coating reduced the cytotoxicity of the formulated DDS, and the SR-COS-NLC exhibited a 1.4-fold higher cell regeneration effect than SR alone.

CONCLUSION

These findings suggest that the developed COS-NLC serve as an effective and biocompatible DDS platform for the delivery of poorly bioavailable drugs.

Topical dutasteride for androgenic alopecia: current state and prospects

Androgenic alopecia has a high incidence, affecting 80% of men and 50% of women in their lifetimes. Although not a life-threatening disease, it can be a deep psychological burden to patients and still lacks an effective and safe treatment. Dutasteride is a5-alpha-reductase inhibitor approved to treat benign prostatic hyperplasia that is also commonly prescribed off-label to treat androgenic alopecia. However, oral dutasteride may cause several severe sexual and neurological sideeffects. Therefore, an effective, localized dutasteride treatment that can reduce the effects of systemic uptake is of great interest. Here, we review available therapies to treat androgenic alopecia focusing on topicalformulations developed thus far-including minoxidil, finasteride, and cosmetics-and on dutasteride-loaded nanocarriers targeting hair follicles.

Modulating metal-organic frameworks by surface engineering of stearic acid modification for follicular drug delivery and enhanced hair growth promotion

Cyclodextrin metal-organic frameworks (CD-MOF) as delivery carriers have gained great attention in the biomedical field. However, limited by challenges of moisture-sensitive nature, the design and application of CD-MOF-based hair follicle delivery for androgenic alopecia (AGA) has rarely been explored. We developed the metal-organic frameworks as hair follicle-targeted delivery system (SA-MOF), stearic acid (SA) was used to modify metal-organic frameworks to form a protective hydrophobic layer on the surface and provide the additional hair growth-promoting effect. Cardamonin (CAR), a newly discovered biosafety natural product, was encapsulated in SA-MOF (CAR@SA-MOF) to promote the therapeutic efficacy on AGA. CD-MOF surface-engineered nanoparticles modified by SA avoided the rapid hydration and disintegration of CD-MOF in water, which improved the drug release and follicular deposition of drug. Assisted by the delivery of SA-modified CD-MOF carriers, the drug significantly promoted cell proliferation and migration, achieving the promoting effect on hair follicle differentiation and hair regeneration in testosterone-challenged C57BL/6 mice. Simultaneously, SA modification provided additional promoting effects on human dermal papilla cell proliferation, regulating effect on keratinocyte growth factor, and activating effect of key signaling pathways. The surface engineering design of CD-MOF hair follicle drug delivery based on SA modification exhibits significant potential for the treatment of hair follicle and sebaceous gland-related diseases.

"Enhancing Oral Drug Absorption: Overcoming Physiological and Pharmaceutical Barriers for Improved Bioavailability"

The oral route stands out as the most commonly used method for drug administration, prized for its non-invasive nature, patient compliance, and easy administration. Several elements influence the absorption of oral medications, including their solubility, permeability across mucosal membranes, and stability within the gastrointestinal (GI) environment. Research has delved into comprehending physicochemical, biochemical, metabolic, and biological obstacles that impact the bioavailability of a drug. To improve oral drug absorption, several pharmaceutical technologies and delivery methods have been studied, including cyclodextrins, micelles, nanocarriers, and lipid-based carriers. This review examines both traditional and innovative drug delivery methods, as well as the physiological and pharmacological barriers influencing medication bioavailability when taken orally. Additionally, it describes the challenges and advancements in developing formulations suitable for oral use.

Theoretical design for covering Engeletin with functionalized nanostructure-lipid carriers as neuroprotective agents against Huntington's disease via the nasal-brain route

Objective: To propose a theoretical formulation of engeletin-nanostructured lipid nanocarriers for improved delivery and increased bioavailability in treating Huntington's disease (HD). Methods: We conducted a literature review of the pathophysiology of HD and the limitations of currently available medications. We also reviewed the potential therapeutic benefits of engeletin, a flavanol glycoside, in treating HD through the Keap1/nrf2 pathway. We then proposed a theoretical formulation of engeletin-nanostructured lipid nanocarriers for improved delivery across the blood-brain barrier (BBB) and increased bioavailability. Results: HD is an autosomal dominant neurological illness caused by a repetition of the cytosine-adenine-guanine trinucleotide, producing a mutant protein called Huntingtin, which degenerates the brain's motor and cognitive functions. Excitotoxicity, mitochondrial dysfunction, oxidative stress, elevated concentration of ROS and RNS, neuroinflammation, and protein aggregation significantly impact HD development. Current therapeutic medications can postpone HD symptoms but have long-term adverse effects when used regularly. Herbal medications such as engeletin have drawn attention due to their minimal side effects. Engeletin has been shown to reduce mitochondrial dysfunction and suppress inflammation through the Keap1/NRF2 pathway. However, its limited solubility and permeability hinder it from reaching the target site. A theoretical formulation of engeletin-nanostructured lipid nanocarriers may allow for free transit over the BBB due to offering a similar composition to the natural lipids present in the body a lipid solubility and increase bioavailability, potentially leading to a cure or prevention of HD. Conclusion: The theoretical formulation of engeletin-nanostructured lipid nanocarriers has the potential to improve delivery and increase the bioavailability of engeletin in the treatment of HD, which may lead to a cure or prevention of this fatal illness.

Boosting hair growth through follicular delivery of Melatonin through lecithin-enhanced Pickering emulsion stabilized by chitosan-dextran nanoparticles in testosterone induced androgenic alopecia rat model

The strategy in this work was loading Melatonin (MEL), the powerful antioxidant photosensitive molecule, in novel Pickering emulsions (PEs) stabilized by chitosan-dextran sulphate nanoparticles (CS-DS NPs) and enhanced by lecithin, for treatment of androgenic alopecia (AGA). Biodegradable CS-DS NPs dispersion was prepared by polyelectrolyte complexation and optimized for PEs stabilization. PEs were characterized for droplet size, zeta potential, morphology, photostability and antioxidant activity. Ex-vivo permeation study through rat full thickness skin was conducted with optimized formula. Differential tape stripping trailed by cyanoacrylate skin surface biopsy was executed, for quantifying MEL in skin compartments and hair follicles. In-vivo evaluation of MEL PE hair growth activity was performed on testosterone induced AGA rat model. Visual inspection followed by anagen to telogen phase ratio (A/T) and histopathological examinations were conducted and compared with marketed 5% minoxidil spray "Rogaine ®". Data showed that PE improved MEL antioxidant activity and photostability. Ex-vivo results displayed MEL PE high follicular deposition. In-vivo study demonstrated that MEL PE treated testosterone induced AGA rat group, restored hair loss and produced maximum hair regeneration along with prolonged anagen phase amongst tested groups. The histopathological examination revealed that MEL PE prolonged anagen stage, increased follicular density and A/T ratio by 1.5-fold. The results suggested that lecithin-enhanced PE stabilized by CS-DS NPs was found to be an effective approach to enhance photostability, antioxidant activity and follicular delivery of MEL. Thus, MEL-loaded PE could be a promising competitor to commercially marketed Minoxidil for treatment of AGA.

A Full Factorial Design to Optimize Aminexil Nano Lipid Formulation to Improve Skin Permeation and Efficacy Against Alopecia

Aminexil (AMX) is considered to be one of the most widely used hair growth promoters. Nanostructured lipid carriers (NLC) are employed to increase the permeation of both lipophilic and hydrophilic drugs. Aminexil nanostructured lipid carrier (NLC) designed by pre-emulsion/ultrasonication method was utilized for alopecia treatment. For selecting optimum excipients, a solubility study was executed in liquid lipids, solid lipids, surfactants, and co-surfactants. A 2³ full factorial design was utilized for NLC optimization. Characterization of the developed formulas was performed. The penetration of the optimized formula across cuticle tissues was studied using confocal laser scanning microscopy (CLSM). AMX showed high solubility in glyceryl monostearate (GMS) and stearic acid, 28.87 ± 2.17 and 58.06 ± 2.227 mg/g, respectively. The results of physicochemical characterization showed that formula A7 was the optimized one. It is composed of GMS (solid lipid), oleic acid:garlic oil (1:1 v/v) (liquid lipid), and a surfactant/co-surfactant mixture (Cremophor EL/Transcutol HP). The particle size (PS) was 238.0 ± 2.13 nm, entrapment efficiency (EE) 100.535 ± 6.73%, and zeta potential (ZP) - 29.3 ± 0.93 mv. Ex vivo permeation study demonstrates the potential of AMX-NLC (formula A7) as a delivery system for AMX. The CLSM highly proved AMX-loaded NLC penetration through the skin. The histological study clearly demonstrated that AMX-loaded NLC promoted hair growth more effectively than the market product in chemotherapy-induced alopecia rats. The acquired findings revealed that targeting of AMX-loaded NLC into hair follicles was improved.

Bioengineered polyester nanoparticles for the synergistic treatment of androgenic alopecia via the suppression of 5α-reductase and knockdown of androgen receptor

Androgenic alopecia (AGA) is a common disease that negatively affects patients’ physical and mental health. AGA can be treated with drugs that improve the perifollicular microenvironment, such as 5α-reductase inhibitors (e.g., dutasteride [DUT]), androgen receptor blockers, and minoxidil. However, the efficacy of these treatments is limited. Therefore, this study aimed to show that nanoparticles are effective as stable carriers with high curative benefits and little adverse effects. The in vitro study showed that PLGA-DUT/siAR@DPCM NPs could deliver both DUT and siAR to dermal papilla cells. They could successfully suppress 5α-reductase and knock down androgen receptor, respectively, and thereby promote cell proliferation. In the in vivo study, PLGA-DUT/siAR@DPCM NPs showed a significant therapeutic effect in an AGA mouse model. They successfully penetrated the stratum corneum and showed a clear targeting effect on hair follicles and surrounding tissues. PLGA-DUT/siAR@DPCM NPs could enable the targeted delivery of DUT and siAR through percutaneous penetration, enhancing phagocytosis and decreasing adverse effects. Thus, they have great potential in the clinical treatment of AGA.

Formulation of intranasal surface engineered nanostructured lipid carriers of rotigotine: Full factorial design optimization, in vitro characterization, and pharmacokinetic evaluation

The objective of the present research was to develop, optimize, and evaluate rotigotine (RT)-loaded chitosan (CH) coated nanostructured lipid carriers (RT-CH-NLCs) for nose-to-brain delivery. The NLCs were prepared by homogenization and sonication technique as well as optimized by using three factors at three-level Box-Behnken design. The prepared NLCs were evaluated for particle size, zeta potential, entrapment efficiency, drug release, and ex vivo permeation. The pharmacokinetic study was conducted on albino Wistar rats to evaluate the bioavailability and neuropharmacokinetic parameters after intranasal administration of the optimized formulation (RT-CH-NLCs-OPT). The optimized formulation showed the particle size (170.48 ± 8.37 nm), PDI (0.19 ± 0.03), zeta potential (+ 26.73 mV), and entrapment efficiency (82.37 ± 2.48 %). In vitro drug release study displayed a sustained drug release pattern from RT-CH-NLCs-OPT (86.73±8.58 % in 24 h) in comparison to RT-Dis (98.61±7.24 % in 16 h). The permeability coefficient (PC) was found to be 11.39 ± 1.08×10^-4 cm.h^-1 and 2.34 folds higher than RT-Dis (4.85±1.53×10^-4 cm.h^-1). The relative bioavailability of RT from RT-CH-NLCs-OPT was 3.2-fold greater as compared to RT-Dis. The absolute bioavailability of RT after intranasal administration of RT-CH-NLCs-OPT was 2.1-fold higher than RT-CH-NLCs-OPT administered intravenously. The brain targeting and targeting potential was displayed by DTE (422.03 %) and DTP (76.03 %) after intranasal administration of RT-CH-NLCs-OPT as compared to RT-Dis (DTE 173.91 % and DTP 59.97 %). Furthermore, confocal laser scanning microscopy results confirmed better brain targeting for RT-CH-NLCs-OPT as compared to RT-Dis. From these findings, it could be concluded that RT-CH-NLCs could serve as a promising strategy for targeting RT through the intranasal route.

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.

Nanostructured lipid carriers: a promising drug carrier for targeting brain tumours

Background

In recent years, the field of nanotechnology and nanomedicine has transformed the pharmaceutical industry with the development of novel drug delivery systems that overcome the shortcomings of traditional drug delivery systems. Nanostructured lipid carriers (NLCs), also known as the second-generation lipid nanocarriers, are one such efficient and targeted drug delivery system that has gained immense attention all across due to their myriad advantages and applications. Scientific advancements have revolutionized our health system, but still, brain diseases like brain tumour have remained formidable owing to poor prognosis and the challenging drug delivery to the brain tissue. In this review, we highlighted the application and potential of NLCs in brain-specific delivery of chemotherapeutic agents.

Main body

NLCs are lipid-based formulations with a solid matrix at room temperature and offer advantages like enhanced stability, low toxicity, increased shelf life, improved drug loading capacity, and biocompatibility over other conventional lipid-based nanocarriers such as nanoemulsions and solid lipid nanoparticles. This review meticulously articulates the structure, classification, components, and various methods of preparation exemplified with various research studies along with their advantages and disadvantages. The concept of drug loading and release has been discussed followed by a brief about stability and strategies to improve stability of NLCs. The review also summarizes various in vitro and in vivo research studies on NLCs encapsulated with cytotoxic drugs and their potential application in brain-specific drug delivery.

Conclusion

NLCs are employed as an important carrier for the delivery of food, cosmetics, and medicines and recently have been used in brain targeting, cancer, and gene therapy. However, in this review, the applications and importance of NLCs in targeting brain tumour have been discussed in detail stating examples of various research studies conducted in recent years. In addition, to shed light on the promising role of NLCs, the current clinical status of NLCs has also been summarized.

Graphical Abstract

Nanostructured Drug Delivery Systems for Targeting 5-α-Reductase Inhibitors to the Hair Follicle

Androgenetic alopecia is a multifactorial condition characterized by noticeable hair loss, affecting both men and women and representing a debilitating and chronic disorder that considerably affects the quality of life. Available topical treatments based on minoxidil or finasteride require repeated applications and are associated with a certain number of adverse effects. The challenges associated with current treatments pave the way for the research of new therapeutic strategies, more precise and selective, and capable of providing long-term results. In this context, the present review examines the new proposed formulation strategies to deliver 5-α-reductase inhibitors in order to obtain a targeted drug delivery, for improving drug retention at the site of action in the hair follicle, contemporaneously reducing drug systemic absorption, which is the cause of important adverse effects. In particular, the research will be focused on the several aspects that influence the performance of nanostructured drug delivery systems in creating a depot in the hair follicles, such as particle size, surface charge, excipients, and combined application with external stimuli (infrared radiation, mechanical massage, ultrasounds application).

Engineered Dutasteride-Lipid Based Nanoparticle (DST-LNP) System Using Oleic and Stearic Acid for Topical Delivery

Male pattern baldness (MPB) is a common condition that has a negative impact on the psycho-social health of many men. This study aims to engineer an alcohol-free formulation to cater for individuals who may have had allergic reactions to alcohol-based preparations. A lipid-based nanoparticle system composed of stearic and oleic acid (solid and liquid lipid) was used to deliver dutasteride (DST) for topical application. Two compositions, with oleic acid (Formulation A) and without (Formulation B), were compared to analyse the role of oleic acid as a potential active ingredient in addition to DST. DST-loaded LNP were prepared using the emulsification–ultrasonication method. All of the prepared formulations were spherical in shape in the nanometric size range (150–300 nm), with entrapment efficiencies of >75%. X-ray diffractograms revealed that DST exists in an amorphous form within the NLP matrices. The drug release behaviour from both LNP preparations displayed slow release of DST. Permeation studies through pig ear skin demonstrated that DST-LNP with oleic acid produced significantly lower permeation into the dermis compared to the formulation without oleic acid. These results suggest that the proposed formulation presents several characteristics which are novel, indicating its suitability for the dermal delivery of anti-androgenic molecules.

Improved Bioavailability of Poorly Soluble Drugs through Gastrointestinal Muco-Adhesion of Lipid Nanoparticles

Gastrointestinal absorption remains indispensable in the systemic delivery of most drugs, even though it presents several challenges that, paradoxically, may also provide opportunities that can be exploited to achieve maximal bioavailability. Drug delivery systems made from nanoparticle carriers and especially, lipid carriers, have the potential to traverse gastrointestinal barriers and deploy in the lymphatic pathway, which aptly, is free from first pass via the liver. Several poorly soluble drugs have presented improved systemic bioavailability when couriered in lipid nanoparticle carriers. In this review, we propose an additional frontier to enhancing the bioavailability of poorly soluble drugs when encapsulated in lipid nano-carriers by imparting muco-adhesion to the particles through application of appropriate polymeric coating to the lipid carrier. The combined effect of gastrointestinal muco-adhesion followed by lymphatic absorption is a promising approach to improving systemic bioavailability of poorly soluble drugs following oral administration. Evidence to the potential of this approach is backed-up by recent studies within the review.

Nanostructured lipid carriers (NLCs) as drug delivery platform: Advances in formulation and delivery strategies

NLCs have provoked the incessant impulsion for the development of safe and valuable drug delivery systems owing to their exceptional physicochemical and then biocompatible characteristics. Throughout the earlier period, a lot of studies recounting NLCs based formulations have been noticeably increased. They are binary system which contains both solid and liquid lipids aiming to produce less ordered lipidic core. Their constituents particularly influence the physicochemical properties and effectiveness of the final product. NLCs can be fabricated by different techniques which are classified according to consumed energy. More utilization NLCs is essential due to overcome barriers surrounded by the technological procedure of lipid-based nanocarriers' formulation and increased information of the core mechanisms of their transport via various routes of administration. They can be used in different applications and by different routes such as oral, cutaneous, ocular and pulmonary. This review article seeks to present an overview on the existing situation of the art of NLCs for future clinics through exposition of their applications which shall foster their lucid use. The reported records evidently demonstrate the promise of NLCs for innovate therapeutic applications in the future.

Advances in chitooligosaccharides chemical modifications

Chitooligosaccharides (COS) differ from chitosan by their molar mass: those of COS are defined to be lower than 20 kg mol^-1 . Their functionalization is widely described in the literature and leads to the introduction of new properties that broaden their application fields. Like chitosan, COS modification sites are mainly primary amine and hydroxyl groups. Among their chemical modification, one can find amidation or esterification, epoxy-amine/hydroxyl coupling, Schiff base formation, and Michael addition. When depolymerized through nitrous deamination, COS bear an aldehyde at the chain end that can open the way to other chemical reactions and lead to the synthesis of new interesting amphiphilic structures. This article details the recent developments in COS functionalization, primarily focusing on amine and hydroxyl groups and aldehyde-chain end reactions, as well as paying considerable attention to other types of modification. We also describe and compare the different functionalization protocols found in the literature while highlighting potential mistakes made in the chemical structures accompanied with suggestions. Such chemical modification can lead to new materials that are generally nontoxic, biobased, biodegradable, and usable in various applications.

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.

Solid Lipid Nanoparticles for Topical Drug Delivery: Mechanisms, Dosage Form Perspectives, and Translational Status

Solid lipid nanoparticles (SLNs) have shown potential as a novel lipid-based drug delivery system for the topical applications of innumerable therapeutic compounds. However, the mechanisms governing the absorption and cellular uptake of SLNs through topical route, along with the mechanism of drug release from SLNs are still ambiguous, and require further investigation. In addition, the selection of an appropriate dosage form/formulation base is essential for ease of application of SLNs and to enhance dermal and transdermal delivery. Upscaling and regulatory approvals are other challenges that may impede the clinical translation of SLNs. Therefore, this review focusses on different mechanisms involved in skin penetration and cellular uptake of SLNs. This is followed by a comprehensive discussion on the physicochemical properties of SLNs including various formulation and dosage form factors, which might influence the absorption of SLNs through the skin. Finally, translational status with respect to scale-up and regulatory aspects are also discussed. This review will be useful to researchers with an interest in topical applications of SLNs for the efficient delivery of drugs and cosmetics.

Nanoporous Silica Entrapped Lipid-Drug Complexes for the Solubilization and Absorption Enhancement of Poorly Soluble Drugs

This study aims to examine the contribution of nanoporous silica entrapped lipid-drug complexes (NSCs) in improving the solubility and bioavailability of dutasteride (DUT). An NSC was loaded with DUT (dissolved in lipids) and dispersed at a nanoscale level using an entrapment technique. NSC microemulsion formation was confirmed using a ternary phase diagram, while the presence of DUT and lipid entrapment in NSC was confirmed using scanning electron microscopy. Differential scanning calorimetry and X-ray diffraction revealed the amorphous properties of NSC. The prepared all NSC had excellent flowability and enhanced DUT solubility but showed no significant difference in drug content homogeneity. An increase in the lipid content of NSC led to an increase in the DUT solubility. Further the NSC were formulated as tablets using D-α tocopheryl polyethylene glycol 1000 succinate, glyceryl caprylate/caprate, and Neusilin^®. The NSC tablets showed a high dissolution rate of 99.6% at 30 min. Furthermore, NSC stored for 4 weeks at 60 °C was stable during dissolution testing. Pharmacokinetic studies performed in beagle dogs revealed enhanced DUT bioavailability when administered as NSC tablets. NSC can be used as a platform to develop methods to overcome the technical and commercial limitations of lipid-based preparations of poorly soluble drugs.

Clinicopathological and immunohistochemical evaluation of lonidamine-entrapped lipid-polymer hybrid nanoparticles in treatment of benign prostatic hyperplasia: An experimental rat model

Benign prostatic hyperplasia (BPH) is a progressive proliferative disease, the incidence of which is constantly increasing due to aging of population. In this research, a hexokinase-II enzyme inhibiting agent, lonidamine - the use of which is limited in BPH treatment due to high hepatic toxicity observed after three months of treatment - was selected as an active agent, based on its mechanism of action in treating BPH. The aim of this study was to evaluate in vivo therapeutic efficacy and hepatic toxicity of lipid-polymer hybrid nanoparticles of lonidamine in a rat BPH model created in rat prostates. After local injections of hybrid nanoparticles of lonidamine were administered to the rat prostates, hyperplasic structures of prostates were evaluated in terms of prostatic index values, immunohistochemical evaluations, and histopathological findings. Liver blood enzyme values were also determined to specify hepatic toxicity. Apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) reaction and histopathological methods to determine intravital degenerative destruction in liver. Through this study, lonidamine-loaded hybrid nanoparticles were found to reduce the hepatic toxicity and increase therapeutic efficiency of lonidamine. Therefore, lonidamine-entrapped hybrid nanoparticles may provide a promising, and very safe, drug delivery strategy in the treatment of BPH.

In Vitro Performance of Dutasteride-Nanostructured Lipid Carriers Coated with Lauric Acid-Chitosan Oligomer for Dermal Delivery

Dutasteride, licensed as an oral medicine for the treatment of benign prostatic hypoplasia, has been investigated as a treatment for androgenic alopecia. In this study, the potential for dustasteride to be delivered topically in order to reduce systemic exposure, irritation of the skin, and also cytotoxicity was explored. Chitosan oligomer (CSO) was successfully synthesised with lauric acid as a coating for a dutasteride-loaded nanostructured lipid carriers (DST-NLCs) system. DST-NLCs were prepared using a combination of melt-dispersion and ultrasonication. These negatively charged NLCs (-18.0 mV) had a mean particle size of ~184 nm, which was not significantly increased (p > 0.05) when coated with lauric acid-chitosan oligomer (CSO-LA), whilst the surface charge changed to positive (+24.8 mV). The entrapment efficiency of DST-NLCs was 97%, and coated and uncoated preparations were physically stable for up to 180 days at 4-8 °C. The drug release was slower from DST-NLCs coated with CSO-LA than from uncoated NLCs, with no detectable drug permeation through full-thickness pig ear skin from either preparation. Considering the cytotoxicity, the IC50 values for the DST-NLCs, coated and uncoated with CSO-LA were greater than for dutasteride alone (p < 0.05). DST-NLCs and empty NLCs coated with CSO-LA at 25 µM increased the cell proliferation compared to the control, and no skin irritation was observed when the DST-NLC formulations were tested using EpiDerm™. The cell and skin uptake studies of coated and uncoated NLCs incorporating the fluorescent marker Coumarin-6 showed the time-dependent uptake of Coumarin-6. Overall, the findings suggest that DST-NLCs coated with CSO-LA represent a promising formulation strategy for dutasteride delivery for the treatment of androgenic alopecia, with a reduced cytotoxicity compared to that of the drug alone and lower irritancy than an ethanolic solution of dutasteride.

Novel iron oxide nanocarriers loading finasteride or dutasteride: Enhanced skin penetration for topical treatment of alopecia

In the present study, iron oxide nanoparticles, in the form of maghemite core coated with lauric acid (ION), were synthesized and loaded with finasteride (FIN) or dutasteride (DUT) as a novel drug delivery system for the topical treatment of alopecia. Additionally, developed formulations (FIN-ION and DUT-ION) were completely elaborated with components involved in the follicle metabolism, i.e., lauric acid, which acts as a 5α-reductase inhibitor, and iron which deficiency has been related to hair loss aggravation. Stability assessment conducted over the course of 90 days showed they are highly stable, with pH 7.4, constant EE% (>99%), and practically unchanged particle size and zeta potential. Besides drug distribution, the actual number of iron oxide nanoparticles, through a newly developed method using ferromagnetic resonance, was determined in each skin layer following permeation experiments. Despite the same donor concentration of colloids, nanoparticle distribution in the skin varied according to the loaded molecule. While DUT did not interfere with the nanoparticle natural tendency to accumulate within the hair follicle shafts, FIN presence hampered nanosystem interaction with the skin. Still, both formulations provided a higher skin drug penetration, compared to each respective control solution. Additionally, iron nanocarriers present a desirable visual characteristic, as the dark color aspect might instantly help disguise scarce hair follicle areas. These findings suggest the nanoformulations are highly promising for alopecia therapies.

Nanostructured Lipid Carriers: A Groundbreaking Approach for Transdermal Drug Delivery

Nanostructured lipid carriers (NLCs) are novel pharmaceutical formulations which are composed of physiological and biocompatible lipids, surfactants and co-surfactants. Over time, as a second generation lipid nanocarrier NLC has emerged as an alternative to first generation nanoparticles. This review article highlights the structure, composition, various formulation methodologies, and characterization of NLCs which are prerequisites in formulating a stable drug delivery system. NLCs hold an eminent potential in pharmaceuticals and cosmetics market because of extensive beneficial effects like skin hydration, occlusion, enhanced bioavailability, and skin targeting. This article aims to evoke an interest in the current state of art NLC by discussing their promising assistance in topical drug delivery system. The key attributes of NLC that make them a promising drug delivery system are ease of preparation, biocompatibility, the feasibility of scale up, non-toxicity, improved drug loading, and stability.

Dutasteride nanocapsules for hair follicle targeting: Effect of chitosan-coating and physical stimulus

In general, nanometer-sized drug delivery systems have a natural tendency for accommodation in the follicular cavities, which makes them advantageous in the treatment of conditions affecting these structures. Still, follicular targeting enhancement can improve therapy outcomes. Here, we compare two strategies to further promote dutasteride follicular-targeted delivery: the chemical modulation of nanosystem surface properties by coating with the natural polymer chitosan, and the application of a massage. For this, poly-(ɛ-caprolactone)-lipid-core nanocapsules (NC) containing dutasteride were developed and had their permeation profile compared to chitosan-coated nanocapsules (NC-CS). Nanocapsules showed high drug encapsulation efficiency (>94%), and stability for up to 90 days of storage. As expected, chitosan coating increased the size and zeta potential, from 199.0 ± 0.5 nm (PdI of 0.12) and - 13.6 ± 0.6 mV to 224.9 ± 3.4 nm (PdI 0.23) and + 40.2 ± 0.8 mV, respectively. Both coated and non-coated nanoparticles targeted the hair follicles compared to a drug solution. Enhanced hair follicles targeting was observed after the massage procedure, with 5 and 2-fold increases relative to NC and NC-CS, respectively. In conclusion, this work demonstrates dutasteride nanocapsules can target the follicular casts, and a simple physical stimulation can enhance 5-times the drug amount accumulated.

Construction of an environmentally friendly octenylsuccinic anhydride modified pH-sensitive chitosan nanoparticle drug delivery system to alleviate inflammation and oxidative stress

An environmentally friendly octenylsuccinic anhydride modified pH-sensitive chitosan-octenylsuccinic anhydride (OSA-CS) was synthesized. The critical micelle concentration (CMC) of the modified chitosan was 27 μg/mL, the graft polymers can form solubilized curcumin (CUR) and quercetin (QUE) nanoparticles. The drug-loaded nanoparticles had high encapsulation efficiency and drug loading content, the self-assembly of graft polymers formed spherical uniform nanoparticles with an approximate diameter of 150-180 nm. The nanoparticles were stable under storage conditions and in serum. The results revealed that OSA-CS exhibited excellent biocompatibility, no cytotoxicity. Additionally, the results of pH sensitivity and drug release experiments showed that the nanoparticles were highly sensitive to weakly acidic conditions (pH 6.0) and showed a faster release rate, while they were reasonably stable at physiological conditions (pH 7.4). The drug-loaded nanoparticles exhibited higher cellular uptake in vitro, and exhibited stronger anti-inflammatory and antioxidant efficacy. Therefore, OSA-CS-based nanoparticles are a promising hydrophobic drug delivery system for pH-response targeting therapy.

Physiopathology and current treatments of androgenetic alopecia: Going beyond androgens and anti-androgens

Androgenetic alopecia (AGA) is the most diagnosed hair loss dysfunction. Its physiopathology comprises a genetic predisposition affording an exacerbated response of the hair follicles cells to androgens aggravated by scalp inflammation and extrinsic factors. This paper presents a review of the mechanisms and extrinsic factors involved in the AGA physiopathology as well as its conventional and emerging treatments. The research focused on reports regarding AGA physiopathology and treatments published between January 2001 and July 2019 in medical and related journals. The most used medical treatments for AGA-minoxidil and finasteride-present non satisfactory results in some cases. Currently, the low-level laser therapy is recognized as a safe and effective treatment for AGA. Some minimally invasive techniques-mesotherapy, microneedling, carboxytherapy, and platelet-rich plasma-are also used to stimulate hair growth. Pharmaceutical substances with mechanisms differing from the anti-androgen activity are under current investigation and many of them have botanical origins; however, formulations with higher performance are required, and the hair follicles ability of being a drug and nanoparticle reservoir has been researched. The association of different strategies, that is, substances with synergic mechanisms and the use of advantageous technologies associated with lifestyle changes could improve the treatment outcomes.

Itraconazole lipid nanocapsules gel for dermatological applications: In vitro characteristics and treatment of induced cutaneous candidiasis

There is a growing clinical demand for topical itraconazole (ITC) delivery systems because of the expanding potential of the drug for topical fungal and non-fungal applications. Lipid-based nanocarriers offer great promise in this respect. In the present study, a new topical ITC gel based on lipid nanocapsules (LNC) was developed. ITC-LNC were compared to ITC-loaded nanostructured lipid carriers (ITC-NLC) with more established benefits as topical vectors. Both nanocarriers showed high entrapment efficiency (EE > 98%). Compared to ITC-NLC, the ITC-LNC showed a significantly smaller particle size (∼50 vs 155 nm), narrower size distribution (0.09 vs 0.38), faster initial release rate under sink conditions and greater in vitro antifungal activity against Candida albicans (C. albicans) (inhibition zone 29.4 vs 26.4 mm). ITC-LNC and ITC-NLC-based gels significantly enhanced the dermal retention of ITC in excised human skin relative to a conventional ITC gel. Histopathological assessment of a 14-day treatment of induced cutaneous candidiasis in a rat model indicated efficacy of the gel preparations. Fungal elements developed in the superficial epidermal skin layer were cleared by the end of treatment. Equally important, no histopathological changes in the epidermal and dermal layers of rat skin were observed. Findings of this study verified efficacy of topical ITC in the treatment of superficial fungal infections as well as effectiveness of LNC as biomimetic nanocarrier for dermal drug delivery. Combining ITC and LNC would present a bioactive nanocarrier system with good potentials for fungal infections and other skin applications.

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.