Formulation and in vitro evaluation of polymeric enteric nanoparticles as dermal carriers with pH-dependent targeting potential

Formulation of Budesonide-Loaded Polymeric Nanoparticles into Hydrogels for Local Therapy of Atopic Dermatitis

Budesonide is a mineral corticoid applied in the local therapy of pediatric atopic dermatitis. Unfortunately, its dermal administration is hindered by the concomitant adverse effects and its physicochemical properties. The characteristic pH change in the atopic lesions can be utilized for the preparation of a pH-sensitive nanocarrier. In this view, the formulation of Eudragit L 100 nanoparticles as a budesonide delivery platform could provide more efficient release to the desired site, improve its penetration, and subsequently lower the undesired effects. In this study, budesonide-loaded Eudragit L100 nanoparticles were prepared via the nanoprecipitation method (mean diameter 57 nm, -31.2 mV, and approx. 90% encapsulation efficiency). Their safety was proven by cytotoxicity assays on the HaCaT keratinocyte cell line. Further, the drug-loaded nanoparticles were incorporated into two types of hydrogels based on methylcellulose or Pluronic F127. The formulated hydrogels were characterized with respect to their pH, occlusion, rheology, penetration, spreadability, and drug release. In conclusion, the developed hydrogels containing budesonide-loaded nanoparticles showed promising potential for the pediatric treatment of atopic dermatitis.

The Application of Nanogels as Efficient Drug Delivery Platforms for Dermal/Transdermal Delivery

The delivery of active molecules via the skin seems to be an efficient technology, given the various disadvantages of oral drug administration. Skin, which is the largest human organ of the body, has the important role of acting as a barrier for pathogens and other molecules including drugs; in fact, it serves as a primary defense system blocking any particle from entering the body. Therefore, to overcome the skin barriers and poor skin permeability, researchers implement novel carriers which can effectively carry out transdermal delivery of the molecules. Another significant issue which medical society tries to solve is the effective dermal delivery of molecules especially for topical wound delivery. The application of nanogels is only one of the available approaches offering promising results for both dermal and transdermal administration routes. Nanogels are polymer-based networks in nanoscale dimensions which have been explored as potent carriers of poorly soluble drugs, genes and vaccines. The nanogels present unique physicochemical properties, i.e., high surface area, biocompatibility, etc., and, importantly, can improve solubility. In this review, authors aimed to summarize the available applications of nanogels as possible vehicles for dermal and transdermal delivery of active pharmaceutical ingredients and discuss their future in the pharmaceutical manufacturing field.

Design and optimization of a novel herbosomal-loaded PEG-poloxamer topical formulation for the treatment of cold injuries: a quality-by-design approach

The spectrum of cold injuries ranges from frostnip, chilblains to severe frostbite. Cold injuries occur upon prolonged exposure to freezing temperature and are pathologically a combination of ice crystal formation in the tissue resulting in inflammation, thrombosis and ischemia in the extremities, often necessitating limb amputation in extreme cases due to tissue necrosis. Severe forms of frostbite are a cause of major concern to patients as well as the treating physician. Due to the lack of effective treatment modalities and paucity of research on prophylaxis and therapeutics of cold injuries, we developed a novel herbosomal-loaded PEG-poloxamer topical formulation (n-HPTF) employing quality-by-design (QBD) approach. Natural compounds exhibiting potent therapeutic potential for the management of cold injuries were incorporated in novel lipid vesicles (herbosomes) loaded in PEG-poloxamer polymers. The herbosomal formulation effectively creates an occlusion barrier that promotes epithelial regeneration, desmosome scale-up and angiogenesis and thus promotes rapid healing, indicating controlled release of herbosomes. Optimized novel herbosomes showed entrapment efficiency > 90% and < 300 nm mean particle size and in vitro drug permeation of about 2 µg/cm² followed Higuchi's release kinetics. Skin irritancy study on female Sprague-Dawley rats showed no edema or erythema. In vivo bio-efficacy study revealed significant efficacy (p < 0.05) when compared to the standard treatment groups. Graphical abstract presenting the designing and optimization of novel herbosomal-loaded PEG-poloxamer topical formulation (n-HPTF) and predictive model for the in vivo study of the developed n-HPTF on cold injury rat skin model.

Preparation, Characterization and In vitro Biological activity of 5-Fluorouracil Loaded onto poly (D, L-lactic-co-glycolic acid) Nanoparticles

Nanoscale devices offer a lot of potential in drug delivery because of their small size. The goal of this work was to increase the oral bioavailability of the anti-cancer hydrophilic drug as 5-fluorouracil (5-FU) by incorporating it into poly (D, L-lactide-co-glycolide) nanoparticles (PLGNPs) using the double emulsion process, 5-FU- PLGNPs nanoparticles were created. Various factors, such as drug, polymer, and stabilizer concentrations, were investigated for assembly in order to arrive at the most effective formulation of 5-FU-PLGNPs. PLGNPs had a drug encapsulation efficiency of 9.75 to 24.8%. The prepared nanoparticles had a spherical shape and an average size of 212.3–285 nm, as shown by TEM. The dispersion of the drug into the prepared PLGNPs was confirmed by XRPD and FTIR. The optimized nanoparticles (F225) had high encapsulation efficiency 24.8 ± 0.21%, low particles size 212.3 ± 48.2 nm with an appropriate PDI value of 0.448, and ZP of − 48.3 ± 2.7 mV. The molecular dispersion of the medication within the system was validated by thermal behavior studies (DSC). In vitro drug release from the best-selected formulations revealed a sustained release of nanoparticles, with slower release reported when lower PVA concentrations were utilized. Three 5-FU-PLGNPs formulations were tested for anticancer efficacy against cell cultures of HCT-116 (human colorectal carcinoma), MCF-7 (human breast carcinoma), and HepG2 (human hepatocellular carcinoma). The created formulations were examined for in vitro cytotoxic activity, revealing that they appeared to be promising effective anticancer formulations when compared to the positive controlled (doxorubicin).

Design and Evaluation of pH-Sensitive Nanoformulation of Bergenin Isolated from Bergenia ciliata

The aim of the current study is extraction and isolation of bergenin from Bergenia ciliata and fabrication of pH-sensitive Eudragit^® L100 (EL100) polymeric nanoparticles (NP) to tackle limitations of solubility. Bergenin-loaded EL100 nanoparticles (BN-NP) were fabricated via nanoprecipitation and an experimental design was conducted for optimization. A reverse phase-high performance liquid chromatography (RP-HPLC) method was developed for the quantitation of bergenin. The optimized nanoformulation was characterized by its particle size, morphology, loading capacity, entrapment efficiency, drug-excipient interaction and crystallinity. An in vitro assay was executed to gauge the release potential of pH-sensitive nanoformulation. The mean particle size, zeta potential and polydispersity index (PDI) of the optimized nanoparticles were observed to be 86.17 ± 2.1 nm, -32.33 ± 5.53 mV and 0.30 ± 0.03, respectively. The morphological analysis confirmed the spherical nature of the nanoparticles. Drug loading capacity and entrapment efficiency were calculated to be 16 ± 0.34% and 84 ± 1.3%, respectively. Fourier transform infrared spectroscopy (FTIR) studies unfolded that no interaction was present between the drug and the excipients in the nanoformulation. Crystallography studies revealed that the crystalline nature of bergenin was changed to amorphous and the nanoformulation was stable for up to 3 months at 40 °C. The present study confirms that bergenin isolation can be scaled up from abundantly growing B. ciliata. Moreover, it could also be delivered by entrapment in stimuli-responsive polymer, preventing the loss of drug in healthy tissues.

Keratinocyte membrane-mediated nanodelivery system with dissolving microneedles for targeted therapy of skin diseases

There is a lack of actively targeting drug delivery carriers for the topical treatment of epidermal diseases, which results in drug waste and an increased incidence of toxic side effects in the clinic. We recently discovered that epidermal cells (HaCaT cells) have homologous targeting functions and developed HaCaT cell membrane-coated pH-sensitive micelles for therapeutic active targeting of skin disease. We encapsulated shikonin in these biomimetic nanocarriers and found that the nanocarriers accumulated mainly in the active epidermis when delivered with karaya gum-fabricated water-soluble microneedles. The nanocarriers were internalized by the target cells, resulting in swelling of histidine fragments with protonation and subsequent triggering of drug release, which increased the therapeutic efficacy of shikonin against imiquimod-induced psoriatic epidermal hyperplasia. This emerging biomimetic delivery strategy is a new approach for improving the treatment of skin diseases and is also very promising for use in the field of cosmetics. Additionally, we found abnormally high protein expression of Na⁺/K⁺-ATPase in diseased skin; thus, this protein may be a biomarker of psoriasis.

Polymer-Based Smart Drug Delivery Systems for Skin Application and Demonstration of Stimuli-Responsiveness

Progress in recent years in the field of stimuli-responsive polymers, whose properties change depending on the intensity of a signal, permitted an increase in smart drug delivery systems (SDDS). SDDS have attracted the attention of the scientific community because they can help meet two current challenges of the pharmaceutical industry: targeted drug delivery and personalized medicine. Controlled release of the active ingredient can be achieved through various stimuli, among which are temperature, pH, redox potential or even enzymes. SDDS, hitherto explored mainly in oncology, are now developed in the fields of dermatology and cosmetics. They are mostly hydrogels or nanosystems, and the most-used stimuli are pH and temperature. This review offers an overview of polymer-based SDDS developed to trigger the release of active ingredients intended to treat skin conditions or pathologies. The methods used to attest to stimuli-responsiveness in vitro, ex vivo and in vivo are discussed.

Chitosan and glyceryl monooleate nanostructures containing gallic acid isolated from amla fruit: targeted delivery system

Gallic acid, active constituent of amla fruit its natural abundance with beneficial multi actions in body make them attractive for clinical applications. In present study, we focused on extracting, separating and characterizing gallic acid from amla and further formulated into chitosan nanoparticles, so bring it to increase its aqueous solubility and thereby bioactivity. Gallic acid nanoparticles were prepared by using poloxamer 407, chitosan and Glyceryl Monooleate (GMO) using probe sonicator and high pressure homogenization method. Prepared nanoparticles were characterized by particle size, zeta potential, DSC, XRD, SEM, entrapment efficiency, loading content, in-vitro release and stability study. They showed approximately 76.80% encapsulation of gallic acid with average size of 180.8 ± 0.21 nm, and zeta potential +24.2 mV. The cumulative in vitro drug release upto 24 hrs 77.16% was achieved suggesting that from all our findings, it can be concluded that work will facilitate extraction, design and fabrication of nanoparticles for protection and sustained release of gallic acid particularly to colonic region.

The role of internal and external stimuli in the rational design of skin-specific drug delivery systems

The concept of skin-specific drug delivery with a spatio-temporal control has just recently received concerns in dermatology. Inspired by the progress in smart materials and their perspective application in medicine science, development of stimuli responsive drug delivery systems with skin-specificity has become possible, which has led to a new era in the localized treatment of skin diseases. This review highlights both the internal and external stimuli that have been employed in this field, with a focus on their implication on the rational design of pharmaceutical formulations, especially those nanoscale drug carriers that are able to provide release of payloads with a precise spatio-temporal control in response to specific stimuli. Also, the strategy of dual stimuli responsive drug delivery systems will be discussed for further improvement of the efficacy of skin drug delivery. The prominent examples of the established approaches are described as comprehensive and current as possible. The review is expected to provide some inspiration for utilizing different stimuli for realizing the site-specific and on-demand drug delivery to the skin.

PEG Graft Polymer Carriers of Antioxidants: In Vitro Evaluation for Transdermal Delivery

The in vitro biochemical evaluation of the applicability of polymers carrying active substances (micelles and conjugates) was carried out. Previously designed amphiphilic graft copolymers with retinol or 4-n-butylresorcinol functionalized polymethacrylate backbone and poly(ethylene glycol) (PEG) side chains that included Janus-type heterografted copolymers containing both PEG and poly(ε-caprolactone) (PCL) side chains were applied as micellar carriers. The polymer self-assemblies were convenient to encapsulate arbutin (ARB) as the selected active substances. Moreover, the conjugates of PEG graft copolymers with ferulic acid (FA) or lipoic acid (LA) were also investigated. The permeability of released active substances through a membrane mimicking skin was evaluated by conducting transdermal tests in Franz diffusion cells. The biological response to new carriers with active substances was tested across cell lines, including normal human dermal fibroblasts (NHDF), human epidermal keratinocyte (HaCaT), as well as cancer melanoma (Me45) and metastatic human melanoma (451-Lu), for comparison. These polymer systems were safe and non-cytotoxic at the tested concentrations for healthy skin cell lines according to the MTT test. Cytometric evaluation of cell cycles as well as cell death defined by Annexin-V apoptosis assays and senescence tests showed no significant changes under action of the delivery systems, as compared to the control cells. In vitro tests confirmed the biochemical potential of these antioxidant carriers as beneficial components in cosmetic products, especially applied in the form of masks and eye pads.

Determination of the pH Gradient in Hair Follicles of Human Volunteers Using pH-Sensitive Melamine Formaldehyde-Pyranine Nile Blue Microparticles

Nanoparticles can be applied to the hair follicles, which can serve as reservoirs for triggered drug release. A valid measurement method for the determination of the pH within the hair follicle in vivo has not been shown yet. Here, melamine formaldehyde particles up to 9 µm in size were applied on 40 freshly plucked scalp hairs of eight individuals to determine the pH along the hair shaft down to the root area of the hair. For fluorescent pH indicators, pyranine and Nile blue were incorporated into the particles. Measurements were conducted using confocal laser scanning microscopy. A pH decay gradient could be found from the hair sheath towards the external hair shaft (p = 0.012) with pH values at the hair sheath of 6.63 ± 0.09, at the hair sheath end at 6.33 ± 0.11, and at the external hair shaft at 6.17 ± 0.09 (mean ± SE). The pH difference between the hair sheath end and the external hair shaft was found to be significant (p = 0.036). The results might be comparable with the pH within the hair follicle in vivo indicating a pH increase towards the hair root.

Formulation development of linagliptin solid lipid nanoparticles for oral bioavailability enhancement: role of P-gp inhibition

Linagliptin (LGP), a novel anti-diabetic drug, is a DPP-4 inhibitor used in the treatment of type II diabetes. One of the major disadvantages of LGP is its low oral bioavailability (29.5%) due to first-pass metabolism and P-gp efflux. In an attempt to increase the oral bioavailability, LGP solid lipid nanoparticles (LGP-SLNs) were developed with poloxamer 188 and Tween 80 as P-gp inhibitors. LGP-SLNs were formulated using palmitic acid, poloxamer 188 and Tween 80 as lipid, surfactant and co-surfactant, respectively, by hot homogenization ultrasonication method and optimized using 3² full factorial designs. Particle size, entrapment efficiency (%EE) and drug release at 24 h were evaluated as responses. An optimized batch of LGP-SLNs (L12) was evaluated for intestinal transport of LGP by conducting in situ single-pass intestinal perfusion (SPIP), everted gut sac and Caco-2 permeability study. The pharmacokinetic and pharmacodynamic evaluation of L12 was carried out in albino Wistar rats. The mean particle size, polydispersity index, zeta potential and %EE of L12 were found to be 225.96 ± 2.8 nm, 0.180 ± 0.034, - 5.4 ± 1.07 mV and 73.8 ± 1.73%, respectively. %CDR of 80.96 ± 3.13% was observed in 24 h. The permeability values of LGP-SLNs in the absorptive direction were 1.82-, 1.76- and 1.74-folds higher than LGP-solution (LGP-SOL) in SPIP, everted gut sac and Caco-2 permeability studies, respectively. LGP-SLNs exhibited relative bioavailability of 300% and better reduction in glucose levels in comparison with LGP-SOL in rats. The enhanced oral bioavailability exhibited by LGP-SLNs bioavailability may be due to P-gp efflux inhibition and lymphatic targeting. Improved bioabsorption can cause reduction in dose, dose-related side effects and frequency of administration. Thus, LGP-SLNs can be considered promising carriers for oral delivery but clinical studies are required to confirm the proof of concept.Graphical abstract.

Tazarotene-loaded in situ gels for potential management of psoriasis: biocompatibility, anti-inflammatory and analgesic effect

Psoriasis is a chronic autoinflammatory disorder characterized by patches of abnormal skin. For psoriasis management, the application of topical retinoids as Tazarotene is recommended. However, Tazarotene could induce skin irritation limiting its use. Herein, it is evaluated the possible usage of in situ gels for tazarotene skin delivery. The topical in situ gels were developed using thermosensitive poloxamers via cold method. They were examined for their appearance, sol-gel temperature, clarity, pH, viscosity, in vitro release, and stability. Their biocompatibility was evaluated by investigating their cytotoxicity and irritation inducing capacity. The possible anti-inflammatory and analgesic activities were determined by measuring the nitric oxide and prostaglandin E₂ levels production in LPS-stimulated RAW264.7 murine macrophage cells. It was revealed that the in situ gels had no cytotoxic effect (∼95-100% cell viability) and nor irritation potential (∼97% cell viability), according to the in vitro EpiDerm™ reconstituted skin irritation test. Additionally, the 10% tazarotene-in situ gels showed possible analgesic activity since the production of prostaglandin E₂ (PGE₂) was decreased. In further, both concentrations of 5% and 10% tazarotene-in situ gels inhibited significantly the nitrite oxide production at 16% and 19%, respectively. Finally, the prepared in situ gels can act as a potential non-irritant alternative option for tazarotene topical skin delivery.

Formulation, characterization and in vitro release study of 5-fluorouracil loaded chitosan nanoparticles

The main objective of this study was to evaluate the most suitable conditions to prepare 5-fluorouracil (5-FU) loaded chitosan nanoparticles (CSNPs). 5-FU loaded CSNPs were prepared employing the ionic gelation technique using three different molecular weights of CS with the polyanion sodium tripolyphosphate (STPP) as cross-linking agent. The preparation was based on the ionic interaction of positively charged CS and negatively charged STPP. The entrapment efficiency (EE%) of CSNPs was in the range of 3.86-21.82% EE% exhibited a clear increase with increasing CS concentration. The averge particles size was in the nanosize range and monodisperse in nature whereas transmission electron microscope micrographs showed that the prepared nanoparticles have a spherical shape. Fourier transform infrared (FTIR), X- ray differaction (XRD) and differential scanning calorimetry (DSC) confirmed successful incorporation of 5-FU in prepared CSNPs. In vitro release of 5-FU from selected formulations exhibited sustained release from the nanoparticles where slower release was observed when higher molecular weight CS was used. The study of drug release kinetics revealed that the release of 5-FU from CSNPs followed a diffusion controlled pattern.

Design strategies for programmable oligonucleotide nanotherapeutics

A systematic review on how to design different programmable nanotherapeutics using oligonucleotides as building blocks or as surface and matrix modifiers for controlled and targeted delivery of various therapeutic agents in presented.

Engineering the niche for hair regeneration - A critical review

Recent progress in hair follicle regeneration and alopecia treatment necessitates revisiting the concepts and approaches. In this sense, there is a need for shedding light on the clinical and surgical therapies benefitting from nanobiomedicine. From this perspective, this review attempts to recognize requirements upon which new hair therapies are grounded; to underline shortcomings and opportunities associated with recent advanced strategies for hair regeneration; and most critically to look over hair regeneration from nanomaterials and pluripotent stem cell standpoint. It is noteworthy that nanotechnology is able to illuminate a novel path for reprogramming cells and controlled differentiation to achieve the desired performance. Undoubtedly, this strategy needs further advancement and a lot of critical questions have yet to be answered. Herein, we introduce the salient features, the hurdles that must be overcome, the hopes, and practical constraints to engineer stem cell niches for hair follicle regeneration.

pH-sensitive nanoparticles for improved oral delivery of dapsone: risk assessment, design, optimization and characterization

Aim: To optimize the production of pH-sensitive dapsone (DAP) nanoparticles based on Eugradit L100 (NPs-EL100-DAP) for oral delivery. Materials & methods: NPs-EL100-DAP were optimized using a Plackett–Burman design and a Box-Behnken design. The physicochemical properties of the obtained nanoparticles were monitored by microscopy, dynamic light scattering, Fourier transform infrared spectroscopy, differential scanning calorimetry, in vitro release assays, and examined for cytotoxicity and permeation across intestinal barrier. Results: The in vitro release assay of NPs-EL100-DAP confirmed the nanoparticles’ pH sensitivity and the ability to deliver DAP at intestinal environment. NPs-EL100-DAP demonstrated enhanced intestinal interactions in comparison to free DAP, across Caco-2 monolayers. Conclusion: These studies demonstrate the potential of NPs-EL100-DAP as a therapeutic platform for oral treatment of leprosy.

Formulation and ex vivo evaluation of polymeric nanoparticles for controlled delivery of corticosteroids to the skin and the corneal epithelium

Controlled delivery of corticosteroids using nanoparticles to the skin and corneal epithelium may reduce their side effects and maximize treatment effectiveness. Dexamethasone-loaded ethyl cellulose, Eudragit® RS and ethyl cellulose/Eudragit® RS nanoparticles were prepared by the solvent evaporation method. Dexamethasone release from the polymeric nanoparticles was investigated in vitro using Franz diffusion cells. Drug penetration was also assessed ex vivo using excised human skin. Nanoparticle toxicity was determined by MTT and H2DCFDA assays. Eudragit® RS nanoparticles were smaller and positively charged but had a lower dexamethasone loading capacity (0.3-0.7%) than ethyl cellulose nanoparticles (1.4-2.2%). By blending the two polymers (1:1), small (105nm), positively charged (+37mV) nanoparticles with sufficient dexamethasone loading (1.3%) were obtained. Dexamethasone release and penetration significantly decreased with decreasing drug to polymer ratio and increased when Eudragit® RS was blended with ethyl cellulose. Ex vivo, drug release and penetration from the nanoparticles was slower than a conventional cream. The nanoparticles bear no toxicity potentials except ethyl cellulose nanoparticles had ROS generation potential at high concentration. In conclusion, the nanoparticles showed great potential to control the release and penetration of corticosteroids on the skin and mucus membrane and maximize treatment effectiveness.

Formulation and comparative in vitro evaluation of various dexamethasone-loaded pH-sensitive polymeric nanoparticles intended for dermal applications

pH-sensitive nanoparticles have a great potential for dermal and transfollicular drug delivery. In this study, pH-sensitive, dexamethasone-loaded Eudragit^® L 100, Eudragit^® L 100-55, Eudragit^® S 100, HPMCP-50, HPMCP-55 and cellulose acetate phthalate nanoparticles were prepared by nanoprecipitation and characterized. The pH-dependent swelling, erosion, dissolution and drug release kinetics were investigated in vitro using dynamic light scattering and Franz diffusion cells, respectively. Their toxicity potential was assessed by the ROS and MTT assays. 100-700nm nanoparticles with high drug loading and entrapment efficiency were obtained. The nanoparticles bear no toxicity potential. Cellulose phthalates nanoparticles were more sensitive to pH than acrylates nanoparticles. They dissolved in 10mM pH 7.5 buffer and released>80% of the drug within 7h. The acrylate nanoparticles dissolved in 40mM pH 7.5 buffer and released 65-70% of the drug within 7h. The nanoparticles remained intact in 10 and 40mM pH 6.0 buffers (HPMCP nanoparticles dissolved in 40mM pH 6.0 buffer) and released slowly. The nanoparticles properties could be modulated by blending the different polymers. In conclusion, various pH-sensitive nanoparticles that could release differently on the skin surface and dissolve and release in the hair follicles were obtained.

Comparison of different in vitro release methods used to investigate nanocarriers intended for dermal application

In vitro drug release measurement is one of the most important methods used to assess the quality of a nanocarrier and estimate it́s in vivo performance. Different in vitro drug release methods have been used to investigate the drug release from nanocarriers, however, little information is available with regard to a comparison of these methods (e.g. discriminative power, reproducibility). Thus, drug release from four nanocarriers (nanocrystals, lipid nanoparticles, Eudragit^® RS and ethyl cellulose nanoparticles) was investigated under sink and non-sink conditions with three drug release methods: an in situ method using Sirius^® inForm and two in vitro methods using dialysis bags and Franz diffusion cells. Dexamethasone was used as the model drug. The in situ measurement was a simple and fast method but not adequately discriminating because of a too rapid drug dissolution/release. Franz diffusion cells and dialysis bags were in most cases discriminative for the different nanocarriers with the drug dissolution/release being in the order of nanocrystals>Eudragit^® RS nanoparticles>lipid nanoparticles>ethyl cellulose nanoparticles. Drug release experiments with Franz diffusion cells had the highest reproducibility. The Franz diffusion cells could also be easily used with semisolid dosage forms.