Nanocolloidal Carriers of Isotretinoin: Antimicrobial Activity against Propionibacterium acnes and Dermatokinetic Modeling

Investigating the efficacy of gliclazide encapsulated hydrogel in the preclinical mice model for atopic dermatitis

Atopic dermatitis (AD) is a chronic skin inflammatory ailment commonly observed in young children and adults. Various therapeutic modalities are already explored for mitigation of AD but for prolong application very few modalities are recommended. Considering these challenges, we have successfully developed gliclazide-loaded hydrogels using the physical dispersion method. For preclinical assessment, we developed a DNCB induced an AD-like phenotype in mice, characterized by increased dermatitis index, scratching interval, ear thickness and weight, spleen and lymph node enlargement, mast cell infiltration, and elevated oxidative stress. However, topical application of the GLZ hydrogel significantly improved these DNCB-induced symptoms. Mice treated with the GLZ hydrogel exhibited a marked reduction in inflammatory markers in histological evaluations. Specifically, there was a decrease in epidermal thickness and mast cell infiltration compared to the DNCB + Vehicle group. Additionally, the topical GLZ hydrogel attenuated the AD-like phenotype by reducing oxidative stress markers. Importantly, these therapeutic effects occurred without significantly affecting blood glucose levels, highlighting the safety of the topical GLZ hydrogel. These findings demonstrate the potential of GLZ-loaded hydrogels as an effective and safe topical treatment for alleviating the symptoms of AD by targeting oxidative stress and inflammation.

pH-responsive self-assembled nanoparticles for tumor-targeted drug delivery

Recent advances in the field of drug delivery have opened new avenues for the development of novel nanodrug delivery systems (NDDS) in cancer therapy. Self-assembled nanoparticles (SANPs) based on tumour microenvironment have great advantages in improving antitumor effect, and pH-responsive SANPs prepared by the combination of pH-responsive nanomaterials and self-assembly technology can effectively improve the efficacy and reduce the systemic toxicity of antitumor drugs. In this review, we describe the characteristics of self-assembly and its driving force, the mechanism of pH-responsive NDDS, and the nanomaterials for pH-responsive SANPs type. A series of pH-responsive SANPs for tumour-targeted drug delivery are discussed, with an emphasis on the relation between structural features and theranostic performance.

Co-Delivery of Aceclofenac and Methotrexate Nanoparticles Presents an Effective Treatment for Rheumatoid Arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a common acute inflammatory autoimmune connective tissue arthropathy. The genetic studies, tissue analyses, experimental animal models, and clinical investigations have confirmed that stromal tissue damage and pathology driven by RA mounts the chronic inflammation and dysregulated immune events.

METHODS

We developed methotrexate (MTX)-loaded lipid-polymer hybrid nanoparticles (MTX-LPHNPs) and aceclofenac (ACE)-loaded nanostructured lipid carriers (ACE-NLCs) for the efficient co-delivery of MTX and ACE via intravenous and transdermal routes, respectively. Bio-assays were performed using ex-vivo skin permeation and transport, macrophage model of inflammation (MMI) (LPS-stimulated THP-1 macrophages), Wistar rats with experimental RA (induction of arthritis with Complete Freund's adjuvant; CFA and BCG), and programmed death of RA affected cells. In addition, gene transcription profiling and serum estimation of inflammatory, signaling, and cell death markers were performed on the blood samples collected from patients with RA.

RESULTS

Higher permeation of ACE-NLCs/CE across skin layers confirming the greater "therapeutic index" of ACE. The systemic delivery of MTX-loaded LPHNPs via the parenteral (intravenous) route is shown to modulate the RA-induced inflammation and other immune events. The regulated immunological and signaling pathway(s) influence the immunological axis to program the death of inflamed cells in the MMI and the animals with the experimental RA. Our data suggested the CD40-mediated and Akt1 controlled cell death along with the inhibited autophagy in vitro. Moreover, the ex vivo gene transcription profiling in drug-treated PBMCs and serum analysis of immune/signalling markers confirmed the therapeutic role co-delivery of drug nanoparticles to treat RA. The animals with experimental RA receiving drug treatment were shown to regain the structure of paw bones and joints similar to the control and were comparable with the market formulations.

CONCLUSION

Our findings confirmed the use of co-delivery of drug nanoformulations as the "combination drug regimen" to treat RA.

Cutaneous Pharmacokinetics of Topically Applied Novel Dermatological Formulations

Novel formulations are developed for dermatological applications to address a wide range of patient needs and therapeutic challenges. By pushing the limits of pharmaceutical technology, these formulations strive to provide safer, more effective, and patient-friendly solutions for dermatological concerns, ultimately improving the overall quality of dermatological care. The article explores the different types of novel dermatological formulations, including nanocarriers, transdermal patches, microsponges, and microneedles, and the techniques involved in the cutaneous pharmacokinetics of these innovative formulations. Furthermore, the significance of knowing cutaneous pharmacokinetics and the difficulties faced during pharmacokinetic assessment have been emphasized. The article examines all the methods employed for the pharmacokinetic evaluation of novel dermatological formulations. In addition to a concise overview of earlier techniques, discussions on novel methodologies, including tape stripping, in vitro permeation testing, cutaneous microdialysis, confocal Raman microscopy, and matrix-assisted laser desorption/ionization mass spectrometry have been conducted. Emerging technologies like the use of microfluidic devices for skin absorption studies and computational models for predicting drug pharmacokinetics have also been discussed. This article serves as a valuable resource for researchers, scientists, and pharmaceutical professionals determined to enhance the development and understanding of novel dermatological drug products and the complex dynamics of cutaneous pharmacokinetics.

Design, optimization, and characterization of Althaea officinalis-loaded transliposomes for the treatment of atopic dermatitis: a Box Behnken Design, in vitro, and ex vivo study

A chronic skin disorder called atopic dermatitis (AD) is brought on by the deterioration of the skin's barrier function marked by inflammation, dryness, and bacterial infection along with immunological changes. Althaea officinalis (AO), known for its anti-inflammatory and immunomodulatory properties, has been explored as a potential treatment for AD. This study aimed to develop and evaluate a novel transliposomes (TL) formulation containing AO for AD treatment. Using rotary evaporation, AO-TL formulations were created and optimized employing Box Behnken Design. The optimized AO-TL formulation showed consistent characteristics: vesicle size of 145.8 nm, polydispersity index of 0.201, zeta potential of -28.22 mV, and entrapment efficiency of 86.21%. TEM imaging shows the spherical shapes of the vesicle. These findings demonstrate the formulation's stability and ability to encapsulate AO effectively. In vitro drug release studies revealed that the AO-TL formulation released 81.28% of the drug, outperforming conventional AO dispersion (56.80%). Additionally, when applied to rat skin, the TL gel demonstrated deeper penetration (30 μm) in comparison to the standard solution (5.0 μm) based on confocal laser scanning microscopy (CLSM). Ex vivo and dermatokinetics studies showed improved penetration of drug-loaded transliposomes gel in rat skin than the conventional AO gel. Overall, the optimized AO-TL formulation offers promising characteristics and performance for the topical treatment of AD. Its drug release, antioxidant activity, and deeper penetration suggest enhanced therapeutic effects. Further research and clinical trials are needed to validate its efficacy and safety in AD patients.

β-Caryophyllene-Loaded Microemulsion-Based Topical Hydrogel: A Promising Carrier to Enhance the Analgesic and Anti-Inflammatory Outcomes

Musculoskeletal pain and inflammation can vary from localised pain like pain in the shoulders and neck to widespread pain like fibromyalgia, and as per estimates, around 90% of humans have experienced such pain. Oral non-steroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed for such conditions but are associated with concerns like gastric irritation and bleeding. In the present study, a microemulsion-based gel comprising β-caryophyllene, isopropyl myristate, Tween 80, and normal saline was prepared as a topical option for managing topical pain and inflammation. The globules of the microemulsion were below 100 nm with a zetapotential of around -10 mV. The drug entrapment was >87% with a drug loading of >23%. The permeation studies established better skin permeation (20.11 ± 0.96 μg cm-2 h-1) and retention of the drug (4.96 ± 0.02%) from the developed system vis-à-vis the conventional product (9.73 ± 0.35 μg cm-2 h-1; 1.03 ± 0.01%). The dermatokinetic studies established the better pharmacokinetic profile of the bioactive in the epidermis and dermis layers of the skin. The anti-inflammatory potential in carrageenan-induced rat paw oedema was more pronounced than the conventional product (~91% vis-à-vis ~77%), indicating a better pharmacodynamic outcome from the developed system. The nanotechnology-based natural bioactive product with improved efficacy and drug loading can provide a better alternative for the management of musculoskeletal pain.

QbD-Optimized, Phospholipid-Based Elastic Nanovesicles for the Effective Delivery of 6-Gingerol: A Promising Topical Option for Pain-Related Disorders

In this study, elastic nanovesicles, constructed of phospholipids optimized by Quality by Design (QbD), release 6-gingerol (6-G), a natural chemical that may alleviate osteoporosis and musculoskeletal-related pain. A 6-gingerol-loaded transfersome (6-GTF) formulation was developed using a thin film and sonication approach. 6-GTFs were optimized using BBD. Vesicle size, PDI, zeta potential, TEM, in vitro drug release, and antioxidant activity were evaluated for the 6-GTF formulation. The optimized 6-GTF formulation had a 160.42 nm vesicle size, a 0.259 PDI, and a -32.12 mV zeta potential. TEM showed sphericity. The 6-GTF formulation's in vitro drug release was 69.21%, compared to 47.71% for the pure drug suspension. The Higuchi model best described 6-G release from transfersomes, while the Korsmeyer-Peppas model supported non-Fickian diffusion. 6-GTF had more antioxidant activity than the pure 6-G suspension. The optimized transfersome formulation was converted into a gel to improve skin retention and efficacy. The optimized gel had a spreadability of 13.46 ± 4.42 g·cm/s and an extrudability of 15.19 ± 2.01 g/cm². The suspension gel had a 1.5 μg/cm²/h ex vivo skin penetration flux, while the 6-GTF gel had 2.71 μg/cm²/h. Rhodamine B-loaded TF gel reached deeper skin layers (25 μm) compared to the control solution in the CLSM study. The gel formulation's pH, drug concentration, and texture were assessed. This study developed QbD-optimized 6-gingerol-loaded transfersomes. 6-GTF gel improved skin absorption, drug release, and antioxidant activity. These results show that the 6-GTF gel formulation has the ability to treat pain-related illnesses effectively. Hence, this study offers a possible topical treatment for conditions connected to pain.

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

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

Phospholipid-Based Topical Nano-Hydrogel of Mangiferin: Enhanced Topical Delivery and Improved Dermatokinetics

Mangiferin is a herbal drug that has proven anticancer potential. Owing to its lower aqueous solubility and poor oral bioavailability, the full pharmacological potential of this bioactive drug has not fully been explored. In the present study, phospholipid-based microemulsion systems were developed to bypass oral delivery. The globule size of the developed nanocarriers was less than 150 nm and the drug entrapment was >75% with a drug loading ~25%. The developed system offered a controlled release pattern following the Fickian drug release. This enhanced mangiferin's in vitro anticancer activity by four-fold, the cellular uptake was observed to be improved by three-fold on the MCF-7 cells. Ex vivo dermatokinetic studies showed substantial topical bioavailability with a prolonged residence time. The findings provide a simple technique to administer mangiferin via a topical route promising a safer, topically bioavailable and effective treatment option for breast cancer. Such scalable carriers with immense topical delivery potential may provide a better option for present-day topical products of a conventional nature.

Trilayer dissolving polymeric microneedle array loading Rose Bengal transfersomes as a novel adjuvant in early-stage cutaneous melanoma management

Melanoma remains a global concern, but current therapies present critical limitations pointing out the urgent need for novel strategies. Among these, the cutaneous delivery of drugs selectively damaging cancer cells is highly attractive. Rose Bengal (RB) is a dye exhibiting selective cytotoxicity towards melanoma, but the high water solubility and low permeability hinder its therapeutic potential. We previously developed RB-loaded transfersomes (RBTF) to mediate the RB dermal delivery; however, a platform efficiently delivering RBTF in the deepest strata is essential for a successful therapeutic activity. In this regard, dissolving microneedles release the encapsulated cargo up to the dermis, painlessly piercing the outmost skin layers. Therefore, herein we developed and characterised a trilayer dissolving microneedle array (RBTF-TDMNs) loading RBTF to maximise RBTF intradermal delivery in melanoma management. RBTF-TDMNs were proven strong enough to pierce excised porcine skin and rapidly dissolve and deposit RBTF intradermally while maintaining their physicochemical properties. Also, 3D visualisation of the system itself and while penetrating the skin was performed by multi-photon microscopy. Finally, a dermatokinetic study showed that RBTF-TDMNs offered unique delivery efficiency advantages compared to RBTF dispersion and free drug-loaded TDMNs. The proposed RBTF-TDMNs represent a valuable potential adjuvant tool for the topical management of melanoma.

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.

Revisiting techniques to evaluate drug permeation through skin

INTRODUCTION

Investigating the transportation of a drug molecule through various layers of skin and determining the amount of drug retention in skin layers is of prime importance in transdermal and topical drug delivery. The information regarding drug permeation and retention in skin layers aids in optimizing a formulation and provides insight into the therapeutic efficacy of a formulation.

AREAS COVERED

This perspective covers various methods that have been explored to estimate drug/therapeutics in skin layers using in vitro, ex vivo, and in vivo conditions. In vitro methods such as diffusion techniques, ex vivo methods such as isolated perfused skin models and in vivo techniques including dermato-pharmacokinetics employing tape stripping, and microdialysis are discussed. Application of all techniques at various stages of formulation development where various local and systemic effects need to be considered.

EXPERT OPINION

The void in the existing methodologies necessitates improvement in the field of dermatologic research. Standardization of protocols, experimental setups, regulatory guidelines, and further research provides information to select an alternative for human skin to perform skin permeation experiments to increase the reliability of data generated through the available techniques. There is a need to utilize multiple techniques for appropriate dermato-pharmacokinetics evaluation and formulation's efficacy.

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.

A topical gel of tea tree oil nanoemulsion containing adapalene versus adapalene marketed gel in patients with acne vulgaris: a randomized clinical trial

Adapalene is used for treatment of acne vulgaris, a common dermatological disease. Nano-based carriers have been developed to improve solubility and bioavailability of adapalene and other acne treatment drugs. In our previous report, tea tree oil nanoemulsion containing adapalene gel (TTO NE + ADA Gel) showed appropriate physical and biological properties such as stability, viscosity, pH, size, morphology and biocompatibility in an animal model. The present study was designed to assess efficacy and safety of the TTO NE + ADA Gel in comparison with 0.1% adapalene marketed gel (ADA Marketed Gel). A total of 100 patients were randomized to receive TTO NE + ADA Gel or ADA Marketed Gel, once daily at night, for 12 weeks. Analysis for efficacy was conducted by acne lesion count (total, inflammatory and non-inflammatory) and acne severity index at weeks 4, 8 and 12 using generalized estimating equation along with the safety assessments in each measurement for assessing dryness, erythema, burning sensation and irritation. Significantly better reduction in total, inflammatory, and non-inflammatory acne lesions were reported for TTO NE + ADA Gel as compared to the ADA Marketed Gel overall and on each measurement occasion (p value  < 0.001 for all). Mean acne severity index also reduced with TTO NE + ADA Gel significantly in comparison with ADA Marketed Gel (p value  < 0.001). Dryness was the most common adverse effect reported in both groups and it was higher in TTO NE + ADA Gel group. In conclusion, TTO NE + ADA Gel compared to ADA Marketed Gel appears more effective in the treatment of acne vulgaris, with no important change in adverse effects.

Tailoring of Retinyl Palmitate-Based Ethosomal Hydrogel as a Novel Nanoplatform for Acne Vulgaris Management: Fabrication, Optimization, and Clinical Evaluation Employing a Split-Face Comparative Study

AIM

Retinyl palmitate (RP), the most stable vitamin A derivative, is used to treat photoaging and other skin disorders. The need to minimize the adverse effects of topical drug administration has led to an enhanced interest in loading RP on ethosomes for topical drug delivery. The aim of the current study was to prepare and compare the performance of RP decorated ethosomal hydrogel with tretinoin cream in the treatment of acne vulgaris as an approach to improve drug efficacy and decrease its side effects.

METHODS

RP-loaded ethosomes were prepared using the injection sonication technique. A Box-Behnken design using Design Expert® software was used for the optimization of formulation variables. Particle size, zeta potential (ZP), entrapment efficiency percent (EE%), % drug release, and permeation over 24 h of different formulations were determined. The optimal formulation was incorporated into a hydrogel. Finally, the efficacy and tolerability of the optimized RP ethosomal hydrogel were clinically evaluated for acne treatment using a split-face comparative clinical study.

RESULTS

The optimized ethosomal RP showed particle size of 195.8±5.45 nm, ZP of -62.1±2.85 mV, EE% of 92.63±4.33%, drug release % of 96.63±6.81%, and drug permeation % of 85.98 ±4.79%. Both the optimized RP ethosomal hydrogel and tretinoin effectively reduced all types of acne lesions (inflammatory, non-inflammatory, and total lesions). However, RP resulted in significantly lower non-inflammatory and total acne lesion count than the marketed tretinoin formulation. Besides, RP-loaded ethosomes showed significantly improved tolerability compared to marketed tretinoin with no or minimal skin irritation symptoms.

CONCLUSION

RP ethosomal hydrogel is considerably effective in controlling acne vulgaris with excellent skin tolerability. Therefore, it represents an interesting alternative to conventional marketed tretinoin formulation for topical acne treatment.

Co-delivery of isotretinoin and clindamycin by phospholipid-based mixed micellar system confers synergistic effect for treatment of acne vulgaris

BACKGROUND

The combination therapy of Isotretinoin (ITR) and antibacterial formulations administered through topical route suffer from several limitations including reduced therapeutic efficacy and low patient-compliance.

EXPERIMENT

The present study aimed to develop biocompatible lipid-based mixed micelles of ITR in combination with Clindamycin phosphate (CLIN) employing self-assembly method to improve its skin delivery, photostability, biocompatibility and pharmacodynamic efficacy.

RESULTS

The MTT assay and cellular uptake studies showed non-cytotoxic effect to HaCat cell lines. The zone of inhibition studies conducted in Propionibacterium acnes provides the first literature evidence to support the antimicrobial property of Isotretinoin and Tretinioin. The nano-sized carriers offered (19.3 ± 1.03 nm particle size with -3.12 mV zeta potential) enhanced permeation, skin retention, pre-clinical efficacy and significant skin biocompatibility. The testosterone-induced acne model proved superior pharmacodynamic efficacy of lab developed formulation vis-à-vis marketed products of both the drugs. The results were further confirmed by the histopathological studies of respective skin samples treated with different formulations.

CONCLUSION

The lab developed lipid-based micellar formulation of ITR and CLIN offers a better strategy for the combined delivery of unstable molecules like ITR and CLIN in acne management.

Incorporation of Antibiotics into Solid Lipid Nanoparticles: A Promising Approach to Reduce Antibiotic Resistance Emergence

Antimicrobial resistance is one of the biggest threats to global health as current antibiotics are becoming useless against resistant infectious pathogens. Consequently, new antimicrobial strategies are urgently required. Drug delivery systems represent a potential solution to improve current antibiotic properties and reverse resistance mechanisms. Among different drug delivery systems, solid lipid nanoparticles represent a highly interesting option as they offer many advantages for nontoxic targeted drug delivery. Several publications have demonstrated the capacity of SLNs to significantly improve antibiotic characteristics increasing treatment efficiency. In this review article, antibiotic-loaded solid lipid nanoparticle-related works are analyzed to summarize all information associated with applying these new formulations to tackle the antibiotic resistance problem. The main antimicrobial resistance mechanisms and relevant solid lipid nanoparticle characteristics are presented to later discuss the potential of these nanoparticles to improve current antibiotic treatment characteristics and overcome antimicrobial resistance mechanisms. Moreover, solid lipid nanoparticles also offer new possibilities for other antimicrobial agents that cannot be administrated as free drugs. The advantages and disadvantages of these new formulations are also discussed in this review. Finally, given the progress of the studies carried out to date, future directions are discussed.

Dermatokinetic assessment of luliconazole-loaded nanostructured lipid carriers (NLCs) for topical delivery: QbD-driven design, optimization, and in vitro and ex vivo evaluations

The present study is concerned with the QbD-based design and development of luliconazole-loaded nanostructured lipid carriers (NLCs) hydrogel for enhanced skin retention and permeation. The NLCs formulation was optimized employing a 3-factor, 3-level Box-Behnken design. The effect of formulation variable lipid content, surfactant concentration, and sonication time was studied on particle size and % EE. The optimized formulation exhibited particle size of 86.480 ± 0.799 nm; 0.213 ± 0.004 PDI, ≥ - 10 mV zeta potential and 85.770 ± 0.503% EE. The in vitro release studies revealed sustained release of NLCs up to 42 h. The designed formulation showed desirable occlusivity, spreadability (0.748 ± 0.160), extrudability (3.130 ± 1.570), and the assay was found to be 99.520 ± 0.890%. The dermatokinetics assessment revealed the C_{max Skin} to be ~ 2-fold higher and AUC_0-24 to be ~ 3-fold higher in the epidermis and dermis of NLCs loaded gel in contrast with the marketed cream. The T_max of both the formulations was found to be 6 h in the epidermis and dermis. The obtained results suggested that luliconazole NLCs can serve as a promising formulation to enhance luliconazole's antifungal activity and also in increasing patient compliance by reducing the frequency of application.

Assay and Dermatokinetics of Tetrahydrocurcumin Lipidic Nanostructures Using Reverse Phase-high Performance Liquid Chromatography

BACKGROUND

Envisaging the poor solubility (56 ngml1) and permeability of tetrahydrocurcumin (THCC), it was formulated into lipidic nanostructures to enhance its bioavailability upon topical application to promote the healing process for skin inflammatory disorders. Lack of literature on a suitable method for determining THCC per se and nanoformulations prompted us to develop an RP-HPLC method to detect the drug in its nanostructures and in pig ear skin post dermatokinetics.

OBJECTIVE

The present investigation aimed to develop a simple, precise and RP-HPLC method for the quantitative estimation of THCC in prepared lipidic nanostructures, its ointment, and in skin homogenate obtained post dermatokinetic study.

METHODS

THCC encapsulated nanostructures and ointment were formulated using a modified emulsification method and embedded into an ointment base to enhance its spreadability and improve patient compliance. A fast and sensitive reverse-phase high-performance liquid chromatography method was developed using a Hypersil BDS reverse phase C18 column (4.6 mm × 250 mm, 5 μm) with mobile phase comprising tetrahydrofuran (THF) and 1 mgmL-1 citric acid (4:6), at a flow rate of 1.0 mLmin-1 with a run time of 20 min.

RESULTS

THCC nanostructures were successfully prepared using the spontaneous microemulsification method. THCC was detected at 282 nm and revealed two peaks which were attributed to the keto-enol tautomerism in the molecule with retention times of 6.23 min and 11.06 min, respectively. The assay of THCC in nanostructures and ointment was found to be 98.30 % and 99.98 %, with an entrapment efficiency 77.00±2.74 %. The dermatokinetic studies revealed sufficient release of THCC from its ointment up to 24 hr with a concentration of 1382 μgcm-2, for causing a therapeutic effect.

CONCLUSION

The method was found to be reproducible and robust, as shown by the low coefficient of variation and a constant analyte/IS ratio. It was successfully employed for the estimation of THCC assay in nanostructures and its ointment and dermatokinetic analysis in the skin.

Alkyl polyglucoside-based emulsions as vehicles for topical spironolactone: A textural analysis

Acne vulgaris is a chronic dermatological disease that affects the pilosebaceous unit; androgens play an important role in its pathogenesis. Acne therapy can be either systemic or topical, usual in the treatment of mild and moderate forms of acne. Spironolactone (SP) is an anti-androgen drug with potential to reduce the sebum secretion; in order to avoid systemic side effects, it could be used topically in acne treatment. Nowadays, more and more attention is being paid to the textural profile of dermopharmaceutical emulsions, which is normally influenced by their colloidal structure; texture analysis is performed in order to predict behavior of the emulsion systems in real-time conditions during manufacturing and application; the latter is closely related to ensuring patients' compliance and the positive outcome of the therapy. We formulated emulsions stabilized with different natural alkyl polyglucoside (APG) emulsifiers (Cetearyl glucoside and cetearyl alcohol and Arachidyl glucoside and arachidyl behenyl alcohol) as vehicles for 5% topical SP. Parameters obtained by texture analysis were firmness and cohesiveness. The study showed that SP affected the texture of APG-based emulsion; different APG-based emulsions showed satisfying textural characteristics per se after incorporation of 5% SP, which could imply their satisfying applicative characteristics on the skin with acne. APGs could be used as stabilizers of emulsion vehicles for topical SP. Dermoemulsion with Arachidyl glucoside and arachidyl behenyl alcohol, more lypophillic emulsifier, is a more acceptable carrier for 5% SP due to a better textural profile.

Nanostructured Lipid Carrier-Mediated Transdermal Delivery of Aceclofenac Hydrogel Present an Effective Therapeutic Approach for Inflammatory Diseases

Aceclofenac (ACE), a cyclooxygenase-2 inhibitor, is the derivative of the diclofenac group that has been in use for the symptomatic treatment of systemic inflammatory autoimmune disease, rheumatoid arthritis (RA). Partial solubility, high lipophilic nature, and stability challenge its use in developing topical formulations. Hence, we developed and characterized nanostructured lipid carrier (NLC)-based ACE (ACE-NLC) hydrogel for an efficient transdermal delivery. NLC microemulsion was prepared using different lipids by various methods and was characterized with respect to particle size, zeta potential, surface morphology, and drug encapsulation efficiency. The optimized NLC formulation was incorporated into Carbopol^® 940 gel, and this arrangement was characterized and compared with the existing marketed gel (Mkt-gel) formulation to assess in vitro drug release, rheology, texture profile, in vivo skin retention and permeation, and stability. Furthermore, prepared and characterized ACE-loaded NLC formulation was evaluated for skin integrity and fitted in a dermatokinetic model. The results of this study confirmed the spherical shape; smooth morphology and nanometric size attested by Zetasizer and scanning and transmission electron microcopy; and stability of the ACE-NLC formulation. The ACE-NLC-gel formulation showed good rheological and texture characteristics, and better skin distribution in the epidermis and dermis. Moreover, ACE-NLC permeated deeper in the skin layers and kept the skin integrity intact. Overall, NLC-based gel formulation of ACE might be a promising nanoscale lipid carrier for topical application when compared with the conventional Mkt-gel formulation.

Nanotechnological strategies for systemic microbial infections treatment: A review

Systemic infections is one of the major causes of mortality worldwide, and a shortage of drug approaches applied for the rapid and necessary treatment contribute to increase the levels of death in affected patients. Several drug delivery systems based in nanotechnology such as metallic nanoparticles, liposomes, nanoemulsion, microemulsion, polymeric nanoparticles, solid lipid nanoparticles, dendrimers, hydrogels and liquid crystals can contribute in the biological performance of active substances for the treatment of microbial diseases triggered by fungi, bacteria, virus and parasites. In the presentation of these statements, this review article present and demonstrate the effectiveness of these drug delivery systems for the treatment of systemic diseases caused by several microorganisms, through a review of studies on scientific literature worldwide that contributes to better information for the most diverse professionals from the areas of health sciences. The studies demonstrated that the drug delivery systems described can contribute to the therapeutic scenario of these diseases, being classified as safe, active platforms and with therapeutic versatility.

Isotretinoin and α-tocopherol acetate-loaded solid lipid nanoparticle topical gel for the treatment of acne

AIMS

This study was aimed to develop Isotretinoin (ITN) and α-tocopherol acetate (α-TA) loaded solid lipid nanoparticle topical gel for better skin sensitivity and potentiation of efficacy.

METHODS

ITN and α-TA-loaded solid lipid nanoparticles (AE-SLN) were prepared by microemulsion method with glyceryl mono-stearate as lipid and tween 80: butanol as surfactant_mix and characterised. AE-SLN gel was evaluated for physicochemical characteristics, drug release, skin irritation and anti-acne activity in rats.

RESULTS

AE-SLNs had mean particle size of 193.4 nm (zeta-potential -29 mV) and entrapment efficiency of 84%w/w for ITN and 77.4%w/w for α-TA. AE-SLN gel showed sustained drug release for 24 h with a final cumulative release of 95.8% w/w and 89.1%w/w for ITN and α-TA. AE-SLN gel showed no erythema or edoema in rabbits and potent efficacy in rat model of acne.

CONCLUSION

In conclusion, AE-SLN gel has the potential to use as a non-irritant topical formulation for the treatment of acne.

Nanoemulgel for Improved Topical Delivery of Retinyl Palmitate: Formulation Design and Stability Evaluation

Retinyl palmitate is a vitamin A ester belonging to the family of endogenous natural retinoid and used to treat various skin disorders like acne, skin aging, wrinkles, and dark spots, as well as to protect against psoriasis. Despite the known therapeutic benefits of retinyl palmitate, the conventional topical delivery of retinyl palmitate commonly associated with adverse reactions such as skin irritation, redness, excessive peeling, and dryness. Therefore, the current study aims to encapsulate the retinyl palmitate in nanoemulsion then incorporate it into a hydrogel system to improve the topical delivery and stability. Low-energy emulsification method was used for the nano-encapsulation of retinyl palmitate. The phase behavior study was used for the investigation and the optimization of the formulation. The droplet size of the optimized nanoemulsion was in nano dimension (16.71 nm) with low polydispersity index (PdI) (0.015), negative zeta potential (-20.6 mV). It demonstrated the influence of vortexing on droplet size and PdI during nanoemulsion preparation. The retinyl palmitate loaded nanoemulgel delivery system exhibited significant improvement (p < 0.05) in skin permeability after topical application. Employment of the nano-encapsulation approach afterward dispersion into hydrogel system for the development of a topical delivery system of retinyl palmitate resulted in improvement in its UV and storage stability as well.

Lipid-based nano delivery of antimicrobials to control food-borne bacteria

Direct application of antibacterial agents into foods gives limited advantages because bioactive ingredients may be partially inactivated, neutralized, or easily diffused when contacting with the food matrix. Hence, the aim of this study is to investigate the application of lipid-based nanocarriers as delivery systems for antibacterial ingredients. In this regard, several types of these carriers such as nanoliposomes, nanoemulsions, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs) are explored. This study seeks to cover the important challenges of lipid-based nanocarriers including structures and characteristics, properties, production methods, advantages and drawbacks, and their applications to encapsulate antibacterial compounds effectively, particularly in food systems. However, for more scrutiny inspection of the functionality of lipid-based nanocarriers, we have gathered and discussed the studies related to the antibiotic-loaded lipid-based nanoparticles. Also, the role of such nanocarriers in active packaging systems when combining with edible coatings or films is discussed.

Systematically Optimized Imiquimod-Loaded Novel Hybrid Vesicles by Employing Design of Experiment (DoE) Approach with Improved Biocompatibility, Stability, and Dermatokinetic Profile

The present research work explored the possibility of harnessing the benefits of vesicular carriers for overcoming imiquimod-associated complaints or side effects. Hybrid vesicles were prepared by the most common and easily scalable method, i.e., thin film hydration. The chaffing of myriad of factors, both process and material related, affecting the desirable attributes of conceived vesicles, was performed through Taguchi design. Based upon the analysis of Pareto chart and prior experiences, concentration of phospholipid and poloxamer 407 was selected for optimization by 2 levels, 13 run central composite design (CCD). The optimized hybrid vesicles contained 1% w/v phospholipid and 3% w/v poloxamer 407. The optimized hybrid vesicles were incorporated into the 3% w/v carbopol 940 gel and characterized for morphology, physicochemical properties, and rheological behavior. The release (%) and skin retention (% of total dose) across rat skin from gel at same amount of formulation was more than Imiquad®. The gel delivered the loaded cargo, preferably, in the viable region of skin and formed local depot in confocal microscopic studies. The gel followed one compartment open body dermatokinetic model in rat skin. There was not any harmful effect on the mice skin after repeated applications. The gel was stable at room conditions for 1 year.

Biocompatible Phospholipid-Based Mixed Micelles for Tamoxifen Delivery: Promising Evidences from In - Vitro Anticancer Activity and Dermatokinetic Studies

Tamoxifen (TAM) is frequently prescribed for the management breast cancer, but is associated with the challenges like compromised aqueous solubility and poor bioavailability to the target site. It was envisioned to develop phospholipid-based mixed micelles to explore the promises offered by the biocompatible carriers. Various compositions were prepared, employing soya lecithin, polysorbate 80, sodium chloride/dextrose, and water, by self-assembled technique. The formulations were characterized for micromeritics and evaluated for in vitro drug release, hemolysis study, dermatokinetic studies on rodents, and cytotoxicity on MCF-7 cell lines. Cellular uptake of the system was also studied using confocal laser scanning microscopy. The selected composition was of sub-micron range (28.81 ± 2.1 nm), with spherical morphology. During in-vitro studies, the mixed micelles offered controlled drug release than that of conventional gel. Cytotoxicity was significantly enhanced and IC₅₀ value was reduced that of the naïve drug. The bioavailability in epidermis and dermis skin layers was enhanced approx. fivefold and threefold, respectively. The developed nanosystem not only enhanced the efficacy of the drug but also maintained the integrity of skin, as revealed by histological studies. The developed TAM-nanocarrier possesses potential promises for safe and better delivery of TAM.

Vitamin-Derived Nanolipoidal Carriers for Brain Delivery of Dimethyl Fumarate: A Novel Approach with Preclinical Evidence

Various oral treatment options have been reported for relapsing multiple sclerosis. Recently, dimethyl fumarate (DMF) has been approved for the management of the same. Though effective, DMF is associated with concerns like multiple dosing, patient incompliance, gastrointestinal flushing, lower brain permeation, and economic hurdles. Henceforth, the objective of the present study was to develop vitamin-based solid lipid nanoparticles (SLNs) for effective brain delivery of DMF with a promise of once-a-day dosing. The developed SLNs were characterized for micromeritics, morphology, entrapment efficiency, drug loading and in vitro drug release. Caco-2 and SH-SY5Y cell lines were used to assess the intestinal permeability and neuronal uptake. Pharmacokinetic and biodistribution studies were performed on rats. The developed nanometeric lipidparticles were able to control the drug release and substantially enhance the Caco-2 as well as SH-5YSY cell permeability. The developed systems not only enhanced the oral bioavailability of the drug, but also offered substantially elevated brain drug levels to that of plain drug. The drug was protected from liver and biological residence was increased, indicating promising potential of the carriers in effective brain delivery of DMF. Enhanced bioavailability and elevated bioresidence of DMF by vitamin-based SLNs provided the evidence for once-a-day delivery potential for DMF in the management of neurological disorders.

Self-Assembled ZnO Nanoparticle Capsules for Carrying and Delivering Isotretinoin to Cancer Cells

ZnO@polymer core-shell nanoparticles are assembled into novel capsule shells with diameters of about 100 nm to load isotretinoin (ISO) with a capacity as high as 34.6 wt %. Although ISO, a widely used drug for acne treatment, by itself is not suitable for treating cancer because of its hydrophobicity, our ZnO-ISO composite showed much stronger anticancer activity. The improved cytotoxicity is ascribed to the synergistic effects of the ZnO@polymer and ISO, where the ZnO@polymer helps in the accumulation of ISO in cancer cells on the one hand, and on the other hand, ISO is released completely through ZnO decomposition under acidic conditions of cancer cells. Such a pH-triggered drug-delivery system exhibits a much improved killing of cancer cells in vitro in comparison with the benchmarks, Nintedanib and Crizotinib, two commercial drugs clinically applied against lung cancer.

Surface-tailored nanomixed micelles containing quercetin–salicylic acid physical complex for enhanced cellular and in vivo activities: a quality by design perspective

Aim: The development of surface-tailored quercetin (QCT)–salicylic acid (SA) physical complex for effective treatment of skin carcinoma. Materials & methods: QCT–SA nanomixed micelles were prepared by the self-assembly method employing the Quality by Design (QbD) approach and evaluated for various in vitro, ex vivo and in vivo parameters. Results: The optimized formulation showed enhanced percent permeation (Q24), in other words, 78.12 ± 0.47, improved in vitro cellular uptake and annexin-V–apoptosis assay exhibited 60.86% cell death. The 7,12-dimethylbenz(a)anthracene and histopathology protocol revealed the improved antineoplastic action of QCT. The dermatokinetic profile showed the maximum drug concentration (6 h), in other words, 416.02 ± 26 μg/cm2 in epidermis and 103.65 ± 12 μg/cm2 in dermis. Conclusion: The overall performance ratified the safety and efficacy of optimized nanomixed micelless of QCT with SA in a synergistic manner.

Enhanced Brain Delivery of Dimethyl Fumarate Employing Tocopherol-Acetate-Based Nanolipidic Carriers: Evidence from Pharmacokinetic, Biodistribution, and Cellular Uptake Studies

Dimethyl fumarate (DMF) is an approved drug for the management of relapsing multiple sclerosis. Despite efficacy, DMF is also reported to be a challenging drug owing to concerns like gastrointestinal tract flushing, multiple dosing, lower brain permeability, less patient compliance, and economic hurdles. The present study aims to develop DMF-tocopherol acetate nanolipidic carrier (NLCs) to enhance brain permeability and improve the gastric tolerance. The developed DMF-tocopherol acetate NLCs offered an average size of 69.70 nm, PDI of 0.317, and a zeta potential of -9.71 mV. Higher drug entrapment (90.12%) and drug loading (20.13%) assured controlled drug release behavior both in gastric and intestinal pH. Cellular uptake studies on Caco-2 and SH-SY5Y monolayers confirmed better intestinal absorption and neuronal uptake of the developed system, which was further corroborated by the pharmacokinetic and biodistribution studies. The oral bioavailability was enhanced by 4.09 times and brain availability was substantially improved vis-à-vis plain drug. The findings are promising and offer preclinical evidence for better brain availability of DMF, which can be exploited in the better management of diseases like multiple sclerosis.

Delivery of Thermoresponsive-Tailored Mixed Micellar Nanogel of Lidocaine and Prilocaine with Improved Dermatokinetic Profile and Therapeutic Efficacy in Topical Anaesthesia

The topical delivery of local anaesthetics has always been a difficult task due to the limited percutaneous absorption of local anaesthetic drugs across the various barriers of the skin. In this pursuit, a thermoresponsive mixed micellar nanogel (MMNG) system of lidocaine and prilocaine has been attempted in the current piece of work. The system relies on the ability to alter its phase state (sol-to-gel) for feasibility of the topical application in response to change in temperature. The composition of MMNG entails majorly of Pluronic® F127 and Tween 80 in a fixed combination so as to provide the desired thermoreversibility for the skin application. The gels were optimized with respect to phase transition temperature (T _sol/gel), turbidity and viscosity. The optimized systems were then characterized for particle size, spreadability, syringeability, bioadhesive strength, ex vivo skin permeation, retention and dermatokinetic studies. The skin compatibility revealed that no histological changes were observed for optimized formulation, while the conventional system showed changes in the skin-tissues. Further, the enhanced intensity of anaesthetic effect was noted in an in vivo rabbit model and tail flick model in mice. The overall results suggest that the prepared MMNG system possesses the potential in providing an efficacious, safe and acceptable alternative therapeutic system for topical anaesthesia.