Effect of oleic acid modified polymeric bilayered nanoparticles on percutaneous delivery of spantide II and ketoprofen

Freeze-Dried Camelina Lipid Droplets Loaded with Human Basic Fibroblast Growth Factor-2 Formulation for Transdermal Delivery: Breaking through the Cuticle Barrier to Accelerate Deep Second-Degree Burn Healing

Transdermal administration of chemo therapeutics into burn healing may be an effective treatment to reduce toxic side effects and improve patient compliance for burns. As a transdermal delivery system, Camelina lipid droplets (CLDs) have received great attention due to their biocompatibility, high drug payload, and rapid absorption. However, the absorbed-related mechanisms of Camelina lipid droplets have not yet been reported. Thus, this paper not only demonstrated that CLD can accelerate skin burn healing through promoting hFGF2 absorption, but also elucidated the mechanism between the skin tissue and keratinocytes using Franz, HE staining, DSC, FTIR spectroscopy, and atomic force microscopy with the presence of CLD-hFGF2 freeze-dried powder. We found that the cumulative release rate of CLD-hFGF2 freeze-dried powder was significantly higher than that of free hFGF2 freeze-dried powder into the skin. At the same time, CLD can change the structure and content of lipids and keratin to increase the permeability of hFGF2 freeze-dried powder in skin tissue. Unlike the free state of hFGF2, the biophysical properties of single cells, including height and adhesion force, were changed under CLD-hFGF2 freeze-dried powder treatment. Meanwhile, CLD-hFGF2 freeze-dried powder was more easily taken up through keratinocytes without damaging cell integrity, which provided a new viewpoint for understanding the absorption mechanism with the CLD system for cellular physiology characteristics. Overall, our findings demonstrated that CLD could break through the stratum corneum (SC) barrier and elucidated the transport mechanism of lipid droplets in skin tissue, which provides a crucial guideline in drug delivery applications for future engineering.

Ketoprofen-FA Co-crystal: In Vitro and In Vivo Investigation for the Solubility Enhancement of Drug by Design of Expert

The present piece of research work is framed for improving the solubility of ketoprofen by forming co-crystal using fumaric acid as a coformer. Co-crystal of ketoprofen and fumaric acid was prepared by simple solvent-assisted grinding method, containing drug and coformer as independent variables and solubility and % drug release were assumed to be dependent variables. Differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, nuclear magnetic resonance and scanning electron microscopy techniques were used to characterize the preparation of optimized batch of co-crystal and further, evaluated for in vitro and in vivo anti-inflammatory and analgesic activities. Based on results of solubility and dissolution rate studies the formulation showed magnified improvement in both the properties on co-crystallization. The values of Gibbs free energy are negative at all levels of carrier demonstrating spontaneity of the drug solubilization process. The IC₅₀ value of optimized batch of co-crystal formulation and the pure drug was observed as 327.33 μg/ml and 556.11 μg/ml, respectively, demonstrating that co-crystal formulation possesses more percentage protection against protein denaturation than the drug ketoprofen. In vivo (anti-inflammatory and analgesic) activities revealed that optimized batch of co-crystal formulation delivered a rapid pharmacological response in Wistar rats and albino mice when compared with standard drug.

Potential of nanoparticulate based delivery systems for effective management of alopecia

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

Recent Progress in Transdermal Nanocarriers and Their Surface Modifications

Transdermal drug delivery system (TDDS) is an attractive method for drug delivery with convenient application, less first-pass effect, and fewer systemic side effects. Among all generations of TDDS, transdermal nanocarriers show the greatest clinical potential because of their non-invasive properties and high drug delivery efficiency. However, it is still difficult to design optimal transdermal nanocarriers to overcome the skin barrier, control drug release, and achieve targeting. Hence, surface modification becomes a promising strategy to optimize and functionalize the transdermal nanocarriers with enhanced penetration efficiency, controlled drug release profile, and targeting drug delivery. Therefore, this review summarizes the developed transdermal nanocarriers with their transdermal mechanism, and focuses on the surface modification strategies via their different functions.

Camelina lipid droplets as skin delivery system promotes wound repair by enhancing the absorption of hFGF2

Human basic fibroblast growth factor (hFGF2) is widely recognized for accelerating skin wound healing in both animal models and randomized clinical trials. However, the low skin permeation and bioavailability of hFGF2 remain the most limiting factors in the pharmacological application. For the first time, Camelina Lipid Droplets (CLD) delivery system was displayed important virtue, by promoting the skin absorption of hFGF2, which is a key factor that accelerates the skin wound repair, and provide a new alternative for skin therapy. In this study, we used the CLD as a safer material to prepare the nanoparticles, which were characterized by size and morphology. Our data revealed that particle sizes of Camelina Lipid Droplets linked to hFGF2 (CLD-hFGF2) were around 133.5 nm; it also displayed that the complex of CLD-hFGF2 penetrates the skin barrier in deeper than an individual hFGF2. This suggests that once the hFGF2 is fixed onto the surface of CLD, it can cross the stratum corneum and play a therapeutic role into the dermis. Furthermore, we demonstrated that CLD-hFGF2 enhances fibroblast migration, and significantly improves skin regeneration for accelerating wound healing without any significant toxicity. This paper highlights the importance of CLD as an emerging delivery system; it is also providing a new and applicable therapeutic research direction through enhancing the skin permeation of hFGF2 to accelerate wound healing.

Impressic Acid Ameliorates Atopic Dermatitis-Like Skin Lesions by Inhibiting ERK1/2-Mediated Phosphorylation of NF-κB and STAT1

Impressic acid (IPA), a lupane-type triterpenoid from Acanthopanax koreanum, has many pharmacological activities, including the attenuation of vascular endothelium dysfunction, cartilage destruction, and inflammatory diseases, but its influence on atopic dermatitis (AD)-like skin lesions is unknown. Therefore, we investigated the suppressive effect of IPA on 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin symptoms in mice and the underlying mechanisms in cells. IPA attenuated the DNCB-induced increase in the serum concentrations of IgE and thymic stromal lymphopoietin (TSLP), and in the mRNA levels of thymus and activation regulated chemokine (TARC), macrophage derived chemokine (MDC), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) in mice. Histopathological analysis showed that IPA reduced the epidermal/dermal thickness and inflammatory and mast cell infiltration of ear tissue. In addition, IPA attenuated the phosphorylation of NF-κB and IκBα, and the degradation of IκBα in ear lesions. Furthermore, IPA treatment suppressed TNF-α/IFN-γ-induced TARC expression by inhibiting the NF-κB activation in cells. Phosphorylation of extracellular signal-regulated protein kinase (ERK1/2) and the signal transducer and activator of transcription 1 (STAT1), the upstream signaling proteins, was reduced by IPA treatment in HaCaT cells. In conclusion, IPA ameliorated AD-like skin symptoms by regulating cytokine and chemokine production and so has therapeutic potential for AD-like skin lesions.

Drug nanodelivery systems based on natural polysaccharides against different diseases

Drug nanodelivery systems (DNDSs) are fascinated cargos to achieve outstanding therapeutic results of various drugs or natural bioactive compounds owing to their unique structures. The efficiency of several pharmaceutical drugs or natural bioactive ingredients is restricted because of their week bioavailability, poor bioaccessibility and pharmacokinetics after orally pathways. In order to handle such constraints, usage of native/natural polysaccharides (NPLS) in fabrication of DNDSs has gained more popularity in the arena of nanotechnology for controlled drug delivery to enhance safety, biocompatibility, better retention time, bioavailability, lower toxicity and enhanced permeability. The main commonly used NPLS in nanoencapsulation systems include chitosan, pectin, alginates, cellulose, starches, and gums recognized as potential materials for fabrication of cargos. Herein, this review is centered on different polysaccharide-based nanocarriers including nanoemulsions, nanohydrogels, nanoliposomes, nanoparticles and nanofibers, which have already served as encouraging candidates for entrapment of therapeutic drugs as well as for their sustained controlled release. Furthermore, the current article explicitly offers comprehensive details regarding application of NPLS-based nanocarriers encapsulating several drugs intended for the handling of numerous disorders, including diabetes, cancer, HIV, malaria, cardiovascular and respiratory as well as skin diseases.

Tazarotene-loaded PLGA nanoparticles potentiate deep tissue pressure injury healing via VEGF-Notch signaling

BACKGROUND AND PURPOSE

New capillaries are essential for deep tissue pressure injury wound healing. Tazarotene is a recently discovered small molecule drug and functions to promote neovascularization and tissue repair. At present, the application of tazarotene in the repair of pressure injuries has not previously been investigated. This study used poly (lactic-co-glycolic acid) (PLGA) as nanoparticle carriers loaded with tazarotene (Ta/PLGA NPs) for drug delivery and to overcome shortcomings associated with the low water solubility, short half-life, easy photolysis and low bioavailability of tazarotene itself.

METHODS

The physicochemical properties, drug release and bioactivity of Ta/PLGA NPs were examined in vitro by transmission electron microscope, spectrophotometry and cell assays. Mouse models of deep tissue pressure injuries (DTPI) were established and the therapeutic effects and mechanisms of Ta/PLGA NPs in local wound repair were studied.

RESULTS

The results showed that Ta/PLGA NPs were of uniform size and distribution and were non-toxic both in vitro and in vivo. In vivo experiments suggested that Ta/PLGA NPs significantly promoted DTPI wound repair through activation of the VEGF/VEGFR-Notch1/DLL4 signaling pathway.

CONCLUSION

This study highlights the potential clinical significance of implementation of tazarotene small molecule drugs in combination with effective biomaterial carriers for the treatment of chronic refractory wounds, such as DTPI.

Herbal ethosomal gel containing luliconazole for productive relevance in the field of biomedicine

This study includes development, characterization, and optimization of herbal ethosomal formulation. The aim of the present study is to develop drug loaded ethosomes capped with Azadirachta indica (neem) which, was further incorporated in Carbopol 934 K thereby, resulting in the formation of ethosomal gel. The formulation is aimed to express effective treatment against fungal infection. The build was formulated using drug (Luliconazole), soyalecithin, ethanolic neem extract and propylene glycol. In total nine ethosomal, formulations of distinct concentrations of ingredients were processed, to determine out the optimized formulation among the all. Further the prepared drug loaded ethosomes were subjected to various evaluation parameters like particle size, zeta potential, polydispersity index (PDI) and % entrapment efficiency. For the evaluation of its surface morphology, transmission electron microscopy was executed whereas, atomic force microscopy was carried out which contributes in detail and depth information of surface morphology. For the analysis of thermal behavior Thermal gravimetric analysis graph was obtained for luliconazole, soyalecithin, neem extract, physical mixture and optimized formulation (LF5). Attenuated total internal reflection Fourier transforms infra-red spectroscopy was performed for luliconazole, soyalecithin, neem extract, physical mixture, and optimized formulation (LF5) to examine the interaction between the drug and the excipients. Viscosity, pH, spreadability and extrudability of the ethosomal gel were calculated to determine the suitability of the formulation for topical application. In vitro drug permeation study and antifungal activity was executed out with the aid of Wistar albino rat skin model and tube dilution assay respectively. The complete study wrap up, that this herbal ethosomal approach provides advanced sustained and targeted delivery of luliconazole. On analyzing the results, ethosomal formulation LF5 was found to be optimized one, due to its optimum concentration of soyalecithin (300 mg) and ethanol (35%). Hence it has maximum entrapment efficiency of 86.56 ± 0.74%. Optimum vesicle size, zeta potential, and PDI were found to be 155.30 ± 1.2 nm, - 42.20 ± 0.3 mV, and 0.186 ± 0.07 respectively. In vitro drug permeation study expresses release of 83.45 ± 2.51 in 24 h whereas; the in vivo activity proved that LF5 is more active and effective against Candida parapsilosis in comparison to Aspergillus niger. In the end, it was estimated that ethosomal suspension and lyophilized ethosomal suspension was utmost stable at 4 °C/60 ± 5 RH. The complete study clearly indicates that the buildup of ethosomal formulation with luliconazole and neem extract show synergistic effect thereby, expressing excellent result against the treatment of fungal infection.

Antibacterial Activity of Fusidic Acid and Sodium Fusidate Nanoparticles Incorporated in Pine Oil Nanoemulgel

Purpose

Fusidic acid (FA) and sodium fusidate (SF) have problems in their skin penetration and stability resulting in a reduction in their potency; therefore, the objective of this study was to develop FA and SF nanoemulgels to improve the antibacterial activity of the drugs.

Methods

FA and SF nanoemulgel formulations were prepared by the incorporation of FA and SF nanoemulsions with Carbopol hydrogel. First, the drugs were screened for their solubility in different oils and surfactants to choose the suitable oil and surfactants for the drugs, and then the drug nanoemulsion formulations were prepared by a self-nanoemulsifying technique using Tween 80, Span 20 and pine oil. The drug nanoemulgels were evaluated for their particle size, polydispersity index (PDI), rheological behaviour, drug release and anti-microbial activity.

Results

Based on the solubility test, pine oil was the best solubilising oil for both drugs, Tween 80 and Span 20 showed the highest solubilising ability for both the drugs among the surfactants; therefore, they were chosen as surfactant and co-surfactant, respectively. The optimum self-nanoemulsifying formulations showed a particle size for fusidic acid and Sodium fusidate of 140.58 nm and 151.86 nm respectively, and both showed a low PDI below 0.3. After incorporating both drug SNEDDS formulations with Carbopol at different concentrations, the results of the drugs particle size and PDI showed no significant difference. The zeta potential results for both drugs nanoemulgels showed a negative potential with more than 30 mV. All nanoemulgel formulations showed pseudo-plastic behaviour with the highest release pattern at 0.4% Carbopol. The antibacterial activity of both drug nanoemulgel formulations showed superiority over the market product.

Conclusion

Nanoemulgel is a promising delivery system for FA and SF that helps in improving the stability and antibacterial activities of the drugs.

Formulation of topical ibuprofen solid lipid nanoparticle (SLN) gel using hot melt extrusion technique (HME) and determining its anti-inflammatory strength

Solid lipid nanoparticles (SLN) have been formulated using various batch processes, e.g., solvent diffusion evaporation, emulsification solvent evaporation followed by size reduction using high-pressure homogenization (HPH) or ultrasonication. However, for the manufacturing of formulations, continuous processes are always preferred over batch processes since they are more efficient and offer better quality of the end product. Hence, we developed topical SLN of ibuprofen (IBU) using hot melt extrusion (HME), prepared a gel formulation, and performed its in vitro and in vivo evaluation. Effect of different variables of HME equipment and materials used in SLN was optimized using design of experiment (DoE) approach. Stable 0.48% IBU SLN with particle size 60.2 ± 4.81 nm and entrapment efficiency 90.41 ± 3.46% were developed which further gelled using 1% carbopol 981A. Drug release study, skin deposition study, and in vivo anti-inflammatory activity studies showed 84.37 ± 4.65% drug release, 12.05 ± 0.81% drug deposition, and 40.17 ± 2.41% edema inhibition respectively in case of IBU SLN gel (IBU-SLN-G) which was significantly higher (p < 0.05) than control IBU gel (C-IBU-G) with 50.11 ± 0.57% drug release, 4.11 ± 1.10% deposition, and 20.08 ± 3.23% edema inhibition respectively. In conclusion, HME offers a single step process for manufacturing for SLN which avoids high stress particle size reduction techniques used for SLN preparation.

Combination of UVB Absorbing Titanium Dioxide and Quercetin Nanogel for Skin Cancer Chemoprevention

Sunscreens are widely prescribed and used to prevent skin cancer; however, they have been reported to contain various chemicals which mimic hormones and disrupt hormonal functioning in humans. The aim of this study was to develop topical nanogel for skin cancer prevention using an antioxidant compound quercetin (Qu) and inorganic titanium dioxide (TiO₂). Two formulations of Qu nanocrystals were optimized with low and high concentration of drug using the Box-Behnken design with the quadratic response surface model and further homogenized with TiO₂. Qu nanocrystal (0.08% and 0.12%) formulations showed a particle size of 249.65 ± 2.84 nm and 352.48 ± 3.56 nm with zeta potential of - 14.7 ± 0.41 mV and - 19.6 ± 0.37 mV and drug content of 89.27 ± 1.39% and 90.38 ± 1.81% respectively. Scanning electron microscopy (SEM) images showed rod-shaped nanocrystals with a particle size below 400 nm. Qu (0.08%), Qu (0.12%), Qu (0.12%) + TiO₂ (5%), and Qu (0.12%) + TiO₂ (15%) nanogels showed over 70% drug release with significantly (p < 0.001) enhanced skin deposition of Qu as compare with Qu suspension within 24 h. The average numbers of tumor, tumor volume, and percentage of animals with tumors at onset in the Qu (0.12%) + TiO₂ (15%) nanogel-pretreated group was found to be significantly (p < 0.05) less as compared with the UV only exposed group. Further, Qu (0.12%) + TiO₂ (15%) nanogel significantly (p < 0.001) downregulated COX-2, EP3, EP4, PCNA, and cyclin D1 expressions in contrast to Qu and TiO₂ only pretreated groups. Therefore, novel combination of Qu (0.12%) + TiO₂ (15%) with enhanced skin deposition can be used as a chemopreventive strategy in UVB-induced skin photocarcinogenesis.

Flurbiprofen loaded ethosomes - transdermal delivery of anti-inflammatory effect in rat model

Background

Ethosomes have been widely used in Transdermal Drug Delivery System (TDDS) as they increase the permeation of drug across the skin.

Methods

Flurbiprofen loaded vesicular ethosomes were formulated, optimized and characterized for particle size, entrapment efficiency, poly dispersive index (PDI), microscopy using Atomic force microscopy (AFM), Scanning electron microscope (SEM) and Transmission electron microscopy (TEM) and Interaction of drug and excipients were studied using Fourier transform infra-red (FTIR) spectroscopy, Differential scanning colorimetry (DSC), Thermo gravimetric analysis (TGA). Further, ethosomal formulations of flurbiprofen were evaluated for stability study of three months and in vitro drug permeation study was carried out using albino rat skin. In addition, skin irritation test was evaluated by Draize test and in vivo study of prepared formulation was examined through paw edema assay by inducing carrageenan and cold plate method.

Results

Amongst all formulations, EF5 formulation exhibited ideal surface morphology, with maximum entrapment efficiency (95%) with optimal excipient concentration i.e. 200 mg phospholipid and 35% ethanol. The ideal vesicle size was achieved as 162.2 ± 2 nm, with zeta potential − 48.14 ± 1.4 mV with the PDI of 0.341. In-vitro permeation study shows a release of 82.56 ± 2.11 g/cm² in 24 h and transdermal flux was found as 226.1 μg/cm²/h. Cold plate test indicates that the formulation EF5 showed a marked analgesic activity and Carrageenan induced paw edema test indicates that the formulation EF5 inhibits the increase in paw edema. Ethosomal suspension at 4 °C showed maximum stability.

Conclusions

The overall study concluded that this ethosomal approach offers a new delivery system for sustained and targeted delivery for flurbiprofen.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1064-x) contains supplementary material, which is available to authorized users.

Flurbiprofen-loaded ethanolic liposome particles for biomedical applications

Present study deals with the preparation, characterization and in-vivo evaluation of flurbiprofen loaded ethanolic liposome which provides predetermined and controlled release of drug through a transdermal drug delivery system. Ethanolic liposomes were prepared by using flurbiprofen, phospholipon 90-G, and ethanol in varied concentration ratio. The prepared ethanolic liposomes were optimized and characterized for particle size, zeta potential, polydispersive index and % entrapment efficiency. FTIR study was performed to analyze the interaction between drug and excipient. To study the thermal behavior of the formulation DSC and TGA were carried out. The surface morphology of ethanolic liposome was performed with the help of SEM, TEM, and AFM. In-vitro drug permeation study of the optimized formulation was carried out using the albino rat skin model and peripheral nociceptive activity was evaluated by writhing assay. In addition, formulations were also inspected for stability study for three months at a different temperature. The optimized formulation EF5 exhibited a particle size of 167.2 ± 3.7 nm with a zeta potential of -51.6 ± 0.2 mV and PDI of 0.209. The optimized formulation showed an ideal surface morphology with a maximum % entrapment efficiency i.e. 93.51 ± 2.1. In-vitro permeation study shows a release of 70.23% in 24 h and transdermal flux was found as 238.2 μg/cm²/h. Writhing assay demonstrate that the optimized formulation decreases the number of writhes and thus shows the peripheral analgesic activity. In stability study, optimized formulation showed maximum stability at 4 °C. These results suggest that transdermal system mediated application of flurbiprofen loaded ethanolic liposome can be considered as an effective way to afford consistent and predictable release of flurbiprofen which could provide beneficial effects in the management of various inflammatory diseases.

Therapeutic effects of bee venom and its major component, melittin, on atopic dermatitis in vivo and in vitro

BACKGROUND AND PURPOSE

Atopic dermatitis (AD) is a multifactorial skin condition with complex interactions of innate and adaptive immune responses. There are several existing therapies for AD, including topical glucocorticosteroids, emollients, phototherapies, calcineurin inhibitors and immunosuppressants, such as cyclosporine A. Although these therapies reduce inflammation, they also cause serious side effects. Therefore, it is necessary to develop new therapeutic approaches for AD treatment without side effects. There are several studies on natural materials or toxins, such as herbs, ginseng extract and snake venom, for AD treatment. However, treatment of AD with bee venom and its major component, melittin has rarely been studied.

EXPERIMENTAL APPROACH

Effects of bee venom and melittin were studied in a model of AD in vivo induced by 1-chloro-2,4-dinitrobenzene (DNCB) in female Balb/c mice and in cultures of human keratinocytes, stimulated by TNF-α/IFN-γ. The potential pharmacological effects of bee venom and melittin on these in vivo and in vitro AD-like skin disease models were studied.

KEY RESULTS

Bee venom and melittin exhibited potent anti-atopic activities, shown by decreased AD-like skin lesions, induced by DNCB in mice. In vitro studies using TNF-α/IFN-γ-stimulated human keratinocytes showed that bee venom and melittin inhibited the increased expression of chemokines, such as CCL17 and CCL22, and pro-inflammatory cytokines, including IL-1β, IL-6 and IFN-γ, through the blockade of the NF-κB and STAT signalling pathways.

CONCLUSIONS AND IMPLICATIONS

Our results suggest that bee venom and melittin would be suitable for epicutaneous application, as topical administration is often appropriate for the treatment of AD.

Biodegradable Ingredient-Based Emulgel Loaded with Ketoprofen Nanoparticles

Biodegradable materials are extensively employed to design nanocarriers that mimic extracellular environment in arthritis. The aim of this study was to formulate and characterize biocompatible, biodegradable ketoprofen-loaded chitosan-chondroitin sulfate (CHS-CS) nanoparticles with natural ingredients for transdermal applications. Polymers used in the design of nanocarriers are biodegradable and produce synergistic anti-inflammatory effect for the treatment of arthritis. For transdermal application, argan oil-based emulgel is utilized to impart viscosity to the formulation. Furthermore, naturally occurring argan oil synergizes anti-inflammatory effect of formulation and promotes skin penetration. CHS and CS form nanoparticles by polyelectrolyte complex formation or complex coacervation at pH 5.0. These particles were loaded into argan oil-based emulgel. Employing this method, nanoparticles were formulated with particle size in the range of 300-500 nm. These nanocarriers entrapped ketoprofen and showed more than 76% encapsulation efficiency and 77% release of the ketoprofen at pH 7.4 within 72 h. Drug releases from CHS-CS nanoparticles by mechanism of simple diffusion. Nanoparticle-loaded argan oil emulgel significantly enhanced skin penetration of ketoprofen as compared to marketed gel (p < 0.05). Nanocarriers prepared successfully delivered drug through transdermal route using natural ingredients. Graphical abstract ᅟ.

Novel mono, di and tri-fatty acid esters bearing secondary amino acid ester head groups as transdermal permeation enhancers

Mono-oleate derivative (MOAPE) enhancing in vitro transdermal permeation of tenofovir.

Potential enhancement and targeting strategies of polymeric and lipid-based nanocarriers in dermal drug delivery

Nanocarriers used for alternative drug-delivery strategies have gained interest due to improved penetration and delivery of drugs into specific regions of the skin in recent years. Dermal drug delivery via polymeric-based nanocarriers (polymeric nanoparticles, micelles, dendrimers) and lipid-based nanocarriers (solid–lipid nanoparticles and nanostructured lipid carriers, vesicular nanocarriers including liposomes, niosomes, transfersomes and ethosomes) has been widely investigated. Although penetration of nanocarriers through the intact skin could be restricted, these carriers are particularly considered as feasible for the treatment of dermatological diseases in which the skin barrier is disrupted and also for follicular delivery of drugs for management of skin disorders such as acne. This review mainly highlights the recent approaches on potential penetration enhancement and targeting mechanisms of these nanocarriers.

Functionalised nanostructures for transdermal delivery of drug cargos

Nanotechnology has burgeoned over last decade exploring varieties of novel applications in all areas of science and technology. Utilisation of bio-friendly polymers for engineering nanostructures (NS) improves safety and efficacy in drug delivery. Biopolymers not merely employed for fabricating drug carriers but also leveraged for surface functionalisation of other NS to impart bio-mimicking properties. Biopolymer functionalised NS garnered researcher's attention because of their potential to enhance skin permeability of drug cargo. Biopolymers, i.e. cell-penetrating peptides (CPP), chitosan and hyaluronic acid not only enhance skin permeability but also add multiple functions due to their intrinsic biomimetic properties. This multifunctional drug delivery system is a promising tool to achieve skin delivery of large number of therapeutic agents. In this review, functionalisation of NS with biopolymers particularly polysaccharides and polypeptides is discussed in detail. In particular, applications of these functionalised NS for TDDS is elaborated. Moreover, this review provides framework for elaborating importance of functionalisation of NS to enhance skin permeability and depicts advantages of biopolymers to construct more biocompatible carriers for drug cargos.

Lipid-polymer hybrid nanoparticles: Development & statistical optimization of norfloxacin for topical drug delivery system

Poly lactic acid is a biodegradable, biocompatible, and non-toxic polymer, widely used in many pharmaceutical preparations such as controlled release formulations, parenteral preparations, surgical treatment applications, and tissue engineering. In this study, we prepared lipid-polymer hybrid nanoparticles for topical and site targeting delivery of Norfloxacin by emulsification solvent evaporation method (ESE). The design of experiment (DOE) was done by using software to optimize the result, and then a surface plot was generated to compare with the practical results. The surface morphology, particle size, zeta potential and composition of the lipid-polymer hybrid nanoparticles were characterized by SEM, TEM, AFM, and FTIR. The thermal behavior of the lipid-polymer hybrid nanoparticles was characterized by DSC and TGA. The prepared lipid-polymer hybrid nanoparticles of Norfloxacin exhibited an average particle size from 178.6 ± 3.7 nm to 220.8 ± 2.3 nm, and showed very narrow distribution with polydispersity index ranging from 0.206 ± 0.36 to 0.383 ± 0.66. The surface charge on the lipid-polymer hybrid nanoparticles were confirmed by zeta potential, showed the value from +23.4 ± 1.5 mV to +41.5 ± 3.4 mV. An Antimicrobial study was done against Staphylococcus aureus and Pseudomonas aeruginosa, and the lipid-polymer hybrid nanoparticles showed potential activity against these two. Lipid-polymer hybrid nanoparticles of Norfloxacin showed the %cumulative drug release of 89.72% in 24 h. A stability study of the optimized formulation showed the suitable condition for the storage of lipid-polymer hybrid nanoparticles was at 4 ± 2 °C/60 ± 5% RH. These results illustrated high potential of lipid-polymer hybrid nanoparticles Norfloxacin for usage as a topical antibiotic drug carriers.

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Efficient topical drug delivery systems of norfloxacin have been synthesized.

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Norfloxacin loaded to the core of lipid- polymer hybrid nanoparticles were prepared.

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The formulations were optimized by factorial design and characterization techniques.

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A unique formulation of norfloxacin that offer prolonged and control delivery.

Capsaicin-loaded nanolipoidal carriers for topical application: design, characterization, and in vitro/in vivo evaluation

Capsaicin has been used in clinical applications for the treatment of pain disorders and inflammatory diseases. Given the strong pungency and high oil/water partition coefficient of capsaicin, capsaicin-loaded nanolipoidal carriers (NLCs) were designed to increase permeation and achieve the analgesic, anti-inflammatory effect with lower skin irritation. Capsaicin-loaded NLCs were prepared and later optimized by the Box–Behnken design. The physicochemical characterizations, morphology, and encapsulation of the capsaicin-loaded NLCs were subsequently confirmed. Capsaicin-loaded NLCs and capsaicin-loaded NLCs gel exhibited sustained release and no cytotoxicity properties. Also, they could significantly enhance the penetration amount, permeation flux, and skin retention amounts of capsaicin due to the application of NLCs. To study the topical permeation mechanism of capsaicin, 3,3′-dioctadecyloxacarbocyanine perchlorate (Dio) was used as a fluorescent dye. Dio-loaded NLCs and Dio-loaded NLCs gel could effectively deliver Dio up to a skin depth of 260 and 210 μm, respectively, primarily through the appendage route on the basis of version skin sections compared with Dio solution, which only delivered Dio up to 150 μm. In vivo therapeutic experiments demonstrated that capsaicin-loaded NLCs and capsaicin-loaded NLCs gel could improve the pain threshold in a dose-dependent manner and inhibit inflammation, primarily by reducing the prostaglandin E2 levels in the tissue compared with capsaicin cream and capsaicin solution. Meanwhile, skin irritation was reduced, indicating that application of NLCs could decrease the irritation caused by capsaicin. Overall, NLCs may be a potential carrier for topical delivery of capsaicin for useful pain and inflammation therapy.

Biocompatible Colloidal Suspensions Based on Magnetic Iron Oxide Nanoparticles: Synthesis, Characterization and Toxicological Profile

The use of magnetic iron oxide nanoparticles in biomedicine has evolved intensely in the recent years due to the multiple applications of these nanomaterials, mainly in domains like cancer. The aim of the present study was: (i) to develop biocompatible colloidal suspensions based on magnetic iron oxide nanoparticles as future theranostic tools for skin pathology and (ii) to test their effects in vitro on human keratinocytes (HaCat cells) and in vivo by employing an animal model of acute dermal toxicity. Biocompatible colloidal suspensions were obtained by coating the magnetic iron oxide nanoparticles resulted during the solution combustion synthesis with a double layer of oleic acid, as innovative procedure in increasing bioavailability. The colloidal suspensions were characterized in terms of dynamic light scattering (DLS) and transmission electron microscopy (TEM). The in vitro effects of these suspensions were tested by means of Alamar blue assay and the noxious effects at skin level were measured using non-invasive methods. The in vitro results indicated a lack of toxicity on normal human cells induced by the iron oxide nanoparticles colloidal suspensions after an exposure of 24 h to different concentrations (5, 10, and 25 μg·mL⁻¹). The dermal acute toxicity test showed that the topical applications of the colloidal suspensions on female and male SKH-1 hairless mice were not associated with significant changes in the quality of barrier skin function.

Design of an Inflammation-Sensitive Polyelectrolyte-Based Topical Drug Delivery System for Arthritis

The most successful treatment strategy for arthritis is intra-articular injections that are costly and have reduced patient compliance. The purpose of the current study was to develop an inflammation-sensitive system for topical drug administration. Multi-macromolecular alginate-hyaluronic acid-chitosan (A-H-C) polyelectrolyte complex nanoparticles, loaded with indomethacin were developed employing pre-gel and post-gel techniques in the presence of dodecyl-L-pyroglutamate (DLP). In addition to in vitro studies, in silico simulations were performed to affirm and associate the molecular interactions inherent to the formulation of core all-natural multi-component biopolymeric architectures composed of an anionic (alginate), a cationic (chitosan), and an amphi-ionic polyelectrolytic (hyaluronic acid) macromolecule. The results demonstrated that DLP significantly influenced the size of the synthesized nanoparticles. Drug-content analysis revealed higher encapsulation efficiency (77.3%) in the presence of DLP, irrespective of the techniques used. Moreover, in vitro drug release studies showed that indomethacin release from the nanosystem was significantly improved (98%) in Fenton's reagent. Drug permeation across a cellulose membrane using a Franz diffusion cell system showed an initial surge flux (0.125 mg/cm(-2)/h), followed by sustained release of indomethacin for the post-gel nanoparticles revealing its effective skin permeation efficiency. In conclusion, the study presents novel nanoparticles which could effectively encapsulate and deliver hydrophobic drugs to the target site, particularly for arthritis.

Ultra-flexible nanocarriers for enhanced topical delivery of a highly lipophilic antioxidative molecule for skin cancer chemoprevention

PURPOSE

In this study, we developed cationic ultra-flexible nanocarriers (UltraFLEX-Nano) to surmount the skin barrier structure and to potentiate the topical delivery of a highly lipophilic antioxidative diindolylmethane derivative (DIM-D) for the inhibition of UV-induced DNA damage and skin carcinogenesis.

METHODS

UltraFLEX-Nano was prepared with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-dioleoyl-3-trimethylammonium-propane, cholesterol and tween-80 by ethanolic injection method; was characterized by Differential Scanning Calorimetric (DSC), Fourier Transform Infrared (FT-IR) and Atomic Force Microscopic (phase-imaging) analyses and permeation studies were performed in dermatomed human skin. The efficacy of DIM-D-UltraFLEX-Nano for skin cancer chemoprevention was evaluated in UVB-induced skin cancer model in vivo.

RESULTS

DIM-D-UltraFLEX-Nano formed a stable mono-dispersion (110.50±0.71nm) with >90% encapsulation of DIM-D that was supported by HPLC, DSC, FT-IR and AFM phase imaging. The blank formulation was non-toxic to human embryonic kidney cells. UltraFLEX-Nano was vastly deformable and highly permeable across the stratum corneum; there was significant (p<0.01) skin deposition of DIM-D for UltraFLEX-Nano that was superior to PEG solution (13.83-fold). DIM-D-UltraFLEX-Nano pretreatment delayed the onset of UVB-induced tumorigenesis (2 weeks) and reduced (p<0.05) the number of tumors observed in SKH-1 mice (3.33-fold), which was comparable to pretreatment with sunscreen (SPF30). Also, DIM-D-UltraFLEX-Nano caused decrease (p<0.05) in UV-induced DNA damage (8-hydroxydeoxyguanosine), skin inflammation (PCNA), epidermal hyperplasia (c-myc, CyclinD1), immunosuppression (IL10), cell survival (AKT), metastasis (Vimentin, MMP-9, TIMP1) but increase in apoptosis (p53 and p21).

CONCLUSION

UltraFLEX-Nano was efficient in enhancing the topical delivery of DIM-D. DIM-D-UltraFLEX-Nano was efficacious in delaying skin tumor incidence and multiplicity in SKH mice comparable to sunscreen (SPF30).

Novel Gefitinib Formulation with Improved Oral Bioavailability in Treatment of A431 Skin Carcinoma

PURPOSE

Oral administration of anticancer agents presents a series of advantages for patients. However, most of the anticancer drugs have poor water solubility leading to low bioavailability.

METHODS

Controlled released spray dried matrix system of Gefitinib with hydroxypropyl β-cyclodextrin, chitosan, hydroxy propyl methyl cellulose, vitamin E TPGS, succinic acid were used for the design of formulations to improve the oral absorption of Gefitinib. Spray drying with a customized spray gun which allows simultaneous/pulsatile flow of two different liquid systems through single nozzle was used to prepare Gefitinib spray dried formulations (Gef-SD). Formulation was characterized by in vitro drug release and Caco-2 permeability studies. Pharmacokinetic studies were performed in Sprague Dawley rats. Efficacy of Gef-SD was carried out in A431 xenografts models in nude mice.

RESULTS

In Gef-SD group 9.14-fold increase in the AUC was observed compared to free Gef. Improved pharmacokinetic profile of Gef-SD translated into increase (1.75 fold compared to Gef free drug) in anticancer effects. Animal survival was significantly increased in Gef formulation treated groups, with superior reduction in the tumor size (1.48-fold) and volumes (1.75-fold) and also increase in the anticancer effects (TUNEL positive apoptotic cells) was observed in Gef-SD treated groups. Further, western blot, immunohistochemical and proteomics analysis demonstrated the increased pharmacodynamic effects of Gef-SD formulations in A431 xenograft tumor models.

CONCLUSION

Our studies suggested that Gefitinib can be successfully incorporated into control release microparticles based oral formulation with enhanced pharmacokinetic and pharmacodynamic activity. This study demonstrates the novel application of Gef in A431 tumor models.

Design of topical nanostructured lipid carrier of silymarin and its effect on 7,12-dimethylbenz[a]anthracene (DMBA) induced cellular differentiation in mouse skin

Effect of silymarin NLC on DMBA induced cell changes in mouse skin.

Study of magnetic silk fibroin nanoparticles for massage-like transdermal drug delivery

A synergistic approach by the combination of magnetic nanoparticles with an alternating magnetic field for transdermal drug delivery was investigated. Methotrexate-loaded silk fibroin magnetic nanoparticles were prepared using suspension-enhanced dispersion by supercritical CO₂. The physiochemical properties of the magnetic nanoparticles were characterized. In vitro studies on drug permeation across skin were performed under different magnetic fields in comparison with passive diffusion. The permeation flux enhancement factor was found to increase under a stationary magnetic field, while an alternating magnetic field enhanced drug permeation more effectively; the combination of stationary and alternating magnetic fields, which has a massage-like effect on the skin, achieved the best result. The mechanistic studies using attenuated total reflection Fourier-transform infrared spectroscopy demonstrate that an alternating magnetic field can change the ordered structure of the stratum corneum lipid bilayers from the gel to the lipid-crystalline state, which can increase the fluidity of the stratum corneum lipids, thus enhancing skin penetration. Compared with the other groups, the fluorescence signal with a bigger area detected in deeper regions of the skin also reveals that the simulated massage could enhance the drug permeation across the skin by increasing the follicular transport. The combination of magnetic nanoparticles with stationary/alternating magnetic fields has potential for effective massage-like transdermal drug delivery.

Doxorubicin liposomes as an investigative model to study the skin permeation of nanocarriers

The objectives of this study were to develop an innovative investigative model using doxorubicin as a fluorophore to evaluate the skin permeation of nanocarriers and the impact of size and surface characteristics on their permeability. Different doxorubicin-loaded liposomes with mean particle size <130 nm and different surface chemistry were prepared by ammonium acetate gradient method using DPPC, DOPE, Cholesterol, DSPE-PEG 2000 and 1,1-Di-((Z)-octadec-9-en-1-yl) pyrrolidin-1-ium chloride (CY5)/DOTAP/1,2-dioleoyl-sn-glycero-3-phosphate (DOPA) as the charge modifier. There was minimal release of doxorubicin from the liposomes up to 8h; indicating that fluorescence observed within the skin layers was due to the intact liposomes. Liposomes with particle sizes >600 nm were restricted within the stratum corneum. DOTAP (p<0.01) and CY5 (p<0.05) liposomes demonstrated significant permeation into the skin than DOPA and PEG liposomes. Tape stripping significantly (p<0.01) enhanced the skin permeation of doxorubicin liposomes but TAT-decorated doxorubicin liposomes permeated better (p<0.005). Blockage of the hair follicles resulted in significant reduction in the extent and intensity of fluorescence observed within the skin layers. Overall, doxorubicin liposomes proved to be an ideal fluorophore-based model. The hair follicles were the major route utilized by the liposomes to permeate skin. Surface charge and particle size played vital roles in the extent of permeation.

Nanocarriers in therapy of infectious and inflammatory diseases

Nanotechnology is a growing science that has applications in various areas of medicine. The composition of nanocarriers for drug delivery is critical to guarantee high therapeutic performance when targeting specific host sites. Applications of nanotechnology are prevalent in the diagnosis and treatment of infectious and inflammatory diseases. This review summarizes recent advancements in the application of nanotechnology to the therapy of infectious and inflammatory diseases. The major focus is on the design and fabrication of various nanomaterials, characteristics and physicochemical properties of drug-loaded nanocarriers, and the use of these nanoscale drug delivery systems in treating infectious and inflammatory diseases, such as AIDS, hepatitis, tuberculosis, melanoma, and representative inflammatory diseases. Clinical trials and future perspective of the use of nanocarriers are also discussed in detail. We hope that such a review will be valuable to researchers who are exploring nanoscale drug delivery systems for the treatment of specific infectious and inflammatory diseases.

Nanoengineered drug delivery systems for enhancing antibiotic therapy

Formulation scientists are recognizing nanoengineered drug delivery systems as an effective strategy to overcome limitations associated with antibiotic drug therapy. Antibiotics encapsulated into nanodelivery systems will contribute to improved management of patients with various infectious diseases and to overcoming the serious global burden of antibiotic resistance. An extensive review of several antibiotic-loaded nanocarriers that have been formulated to target drugs to infectious sites, achieve controlled drug release profiles, and address formulation challenges, such as low-drug entrapment efficiencies, poor solubility and stability is presented in this paper. The physicochemical properties and the in vitro/in vivo performances of various antibiotic-loaded delivery systems, such as polymeric nanoparticles, micelles, dendrimers, liposomes, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles, nanohybirds, nanofibers/scaffolds, nanosheets, nanoplexes, and nanotubes/horn/rods and nanoemulsions, are highlighted and evaluated. Future studies that will be essential to optimize formulation and commercialization of these antibiotic-loaded nanosystems are also identified. The review presented emphasizes the significant formulation progress achieved and potential that novel nanoengineered antibiotic drug delivery systems have for enhancing the treatment of patients with a range of infections.

Nanomedicine strategies for targeting skin inflammation

Topical treatment of skin diseases is an attractive strategy as it receives high acceptance from patients, resulting in higher compliance and therapeutic outcomes. Recently, the use of variable nanocarriers for dermal application has been widely explored, as they offer several advantages compared with conventional topical preparations, including higher skin penetration, controlled and targeted drug delivery and the achievement of higher therapeutic effects. This article will focus on skin inflammation or dermatitis as it is one of the most common skin problems, describing the different types and causes of dermatitis, as well as the typical treatment regimens. The potential use of nanocarriers for targeting skin inflammation and the achievement of higher therapeutic effects using nanotechnology will be explored.

Challenges associated with Penetration of Nanoparticles across Cell and Tissue Barriers: A Review of Current Status and Future Prospects

Nanoparticles (NPs) have emerged as an effective modality for the treatment of various diseases including cancer, cardiovascular and inflammatory diseases. Various forms of NPs including liposomes, polymer particles, micelles, dendrimers, quantum dots, gold NPs and carbon nanotubes have been synthesized and tested for therapeutic applications. One of the greatest challenges that limit the success of NPs is their ability to reach the therapeutic site at necessary doses while minimizing accumulation at undesired sites. The biodistribution of NPs is determined by body's biological barriers that manifest in several distinct ways. For intravascular delivery of NPs, the barrier manifests in the form of: (i) immune clearance in the liver and spleen, (ii) permeation across the endothelium into target tissues, (iii) penetration through the tissue interstitium, (iv) endocytosis in target cells, (v) diffusion through cytoplasm and (vi) eventually entry into the nucleus, if required. Certain applications of NPs also rely on delivery through alternate routes including skin and mucosal membranes of the nose, lungs, intestine and vagina. In these cases, the diffusive resistance of these tissues poses a significant barrier to delivery. This review focuses on the current understanding of penetration of NPs through biological barriers. Emphasis is placed on transport barriers and not immunological barriers. The review also discusses design strategies for overcoming the barrier properties.

Effect of combination of hydrophilic and lipophilic permeation enhancers on the skin permeation of kahalalide F

OBJECTIVES

The purpose of this study was to investigate the influence of combination of various lipophilic and hydrophilic chemical enhancers on skin delivery of kahalalide F (KF).

METHODS

KF formulations comprising a combination of lipophilic and hydrophilic chemical enhancers with varied per cent were prepared and evaluated for skin permeation studies. In vitro skin permeation of KF formulations was performed using Franz diffusion cell. Stability studies of KF formulations were performed according to the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use guideline, and the therapeutic efficacy of KF formulation was evaluated using allergic contact dermatitis animal model.

KEY FINDINGS

The efficacy of KF formulations to improve skin delivery of KF was sequenced in the order of: formulation #4 > formulation #2 > formulation #1 > formulation #3, where formulation #4 contains labrasol (40% w/v), ethyl oleate (5% w/v) and span 80 (5% w/v) along with transcutol (40% w/v) and ethanol (10% w/v). Further, all the formulations were stable for 1 month when stored at 30°C/65% relative humidity.

CONCLUSIONS

The results of present study suggest that therapeutically effective concentrations of KF can be delivered in the skin using combination of lipophilic and hydrophilic chemical enhancers.

Design, synthesis of novel lipids as chemical permeation enhancers and development of nanoparticle system for transdermal drug delivery

In the present study, we designed and developed novel lipids that include (Z)-1-(Octadec-9-en-1-yl)-pyrrolidine (Cy5T), 1, 1-Di-((Z)-octadec-9-en-1-yl)pyrrolidin-1-ium iodide (Cy5), (Z)-1-(Octadec-9-en-1-yl)-piperidine (Cy6T), and 1, 1-Di-((Z)-octadec-9-en-1-yl) piperidin-1-ium iodide (Cy6) to enhance the transdermal permeation of some selected drugs. Firstly, we evaluated the transdermal permeation efficacies of these lipids as chemical permeation enhancers in vehicle formulations for melatonin, ß-estradiol, caffeine, α-MSH, and spantide using franz diffusion cells. Among them Cy5 lipid was determined to be the most efficient by increasing the transdermal permeation of melatonin, ß-estradiol, caffeine, α-MSH, and spantide by 1.5 to 3.26-fold more at the epidermal layer and 1.3 to 2.5-fold more at the dermal layer, in comparison to either NMP or OA. Hence we developed a nanoparticle system (cy5 lipid ethanol drug nanoparticles) to evaluate any further improvement in the drug penetration. Cy5 lipid formed uniformly sized nanoparticles ranging from 150–200 nm depending on the type of drug. Further, Cy5 based nanoparticle system significantly (p<0.05) increased the permeation of all the drugs in comparison to the lipid solution and standard permeation enhancers. There were about 1.54 to 22-fold more of drug retained in the dermis for the Cy5 based nanoparticles compared to OA/NMP standard enhancers and 3.87 to 66.67-fold more than lipid solution. In addition, epifluorescent microscopic analysis in rhodamine-PE permeation studies confirmed the superior permeation enhancement of LEDs (detection of fluorescence up to skin depth of 340 μm) more than lipid solution, which revealed fluorescence up to skin depth of only 260 μm. In summary the present findings demonstrate that i) cationic lipid with 5 membered amine heterocyclic ring has higher permeating efficacy than the 6 membered amine hertocyclic ring. ii) The nanoparticle system prepared with Cy5 showed significant (p<0.05) increase in the permeation of the drugs than the control penetration enhancers, oleic acid and NMP.

Improved percutaneous delivery of ketoprofen using combined application of nanocarriers and silicon microneedles

Objectives

The aim of our study was to evaluate the effect of designing ketoprofen-loaded nanosized spheres and combining them with solid silicon microneedles for enhanced and sustained percutaneous drug delivery.

Methods

Ketoprofen-loaded nanoparticles (KET-NP) were designed by modified solvent displacement method, using poly (D, L-lactic acid) (PDLLA). All prepared nanoparticles were characterised with regard to their particle size distribution, morphology, surface properties, thermal behaviour, drug content, drug release and stability. In-vitro skin permeation studies were conducted on Franz-type diffusion cells using porcine skin treated with ImmuPatch silicon microneedles (Tyndall Nation Institute, Cork, Ireland).

Key findings

The study showed that uniform nanospheres were prepared with high encapsulation efficiency and retained stable for 2 months. After an initial burst release, the PDLLA nanoparticles were capable of sustaining and controlling ketoprofen release that followed Korsmeyer–Peppas kinetics. An enhanced flux of ketoprofen was observed in the skin treated with silicon microneedles over a prolonged period of time.

Conclusions

Following application of silicon microneedle arrays, KET-NP were able to enhance ketoprofen flux and supply the porcine skin with drug over a prolonged (24 h) period of time. Our findings indicate that the delivery strategy described here could be used for the further development of effective and painless administration systems for sustained percutaneous delivery of ketoprofen.

(31)P solid-state NMR based monitoring of permeation of cell penetrating peptides into skin

The main objective of the current study was to investigate penetration of cell penetrating peptides (CPPs: TAT, R8, R11, and YKA) through skin intercellular lipids using (31)P magic angle spinning (MAS) solid-state NMR. In vitro skin permeation studies were performed on rat skin, and sections (0-60, 61-120, and 121-180μm) were collected and analyzed for (31)P NMR signal. The concentration-dependent shift of 0, 25, 50, 100, and 200mg/ml of TAT on skin layers, diffusion of TAT, R8, R11, and YKA in the skin and time dependent permeation of R11 was measured on various skin sections using (31)P solid-state NMR. Further, CPPs and CPP-tagged fluorescent dye encapsulate liposomes (FLip) in skin layers were tagged using confocal microscopy. The change in (31)P NMR chemical shift was found to depend monotonically on the amount of CPP applied on skin, with saturation behavior above 100mg/ml CPP concentration. R11 and TAT caused more shift in solid-state NMR peaks compared to other peptides. Furthermore, NMR spectra showed R11 penetration up to 180μm within 30min. The results of the solid-state NMR study were in agreement with confocal microscopy studies. Thus, (31)P solid-state NMR can be used to track CPP penetration into different skin layers.