Effect of penetration enhancers and amorphization on transdermal permeation flux of raloxifene-encapsulated solid lipid nanoparticles: an ex vivo study on human skin

Science of, and insights into, thermodynamic principles for dermal formulations

Studies have demonstrated the significant role of the thermodynamic activity of drugs in skin drug delivery. This thermodynamic activity works as a driving force for increasing/improving the absorption of drugs by the skin. It can be changed according to the physicochemical parameters (e.g., solubility, partition coefficient, and water activity) of the drug in the vehicle. Thermodynamic principles have been used for the development of novel topical and transdermal delivery systems, demonstrating the importance of thermodynamic activity in enhancing drug permeation through the skin. In this review, we provide insights into thermodynamic principles and their roles in optimizing topical and transdermal drug delivery systems.

Nanotherapeutics in autophagy: a paradigm shift in cancer treatment

Autophagy is a catabolic process in which an organism responds to its nutrient or metabolic emergencies. It involves the degradation of cytoplasmic proteins and organelles by forming double-membrane vesicles called "autophagosomes." They sequester cargoes, leading them to degradation in the lysosomes. Although autophagy acts as a protective mechanism for maintaining homeostasis through cellular recycling, it is ostensibly a cause of certain cancers, but a cure for others. In other words, insufficient autophagy, due to genetic or cellular dysfunctions, can lead to tumorigenesis. However, many autophagy modulators are developed for cancer therapy. Diverse nanoparticles have been documented to induce autophagy. Also, the highly stable nanoparticles show blockage to autophagic flux. In this review, we revealed a general mechanism by which autophagy can be induced or blocked via nanoparticles as well as several studies recently performed to prove the stated fact. In addition, we have also elucidated the paradoxical roles of autophagy in cancer and how their differential role at different stages of various cancers can affect its treatment outcomes. And finally, we summarize the breakthroughs in cancer disease treatments by using metallic, polymeric, and liposomal nanoparticles as potent autophagy modulators.

Lipid-Based Nanoparticles as a Pivotal Delivery Approach in Triple Negative Breast Cancer (TNBC) Therapy

Triple-negative breast cancer is considered the most aggressive type of breast cancer among women and the lack of expressed receptors has made treatment options substantially limited. Recently, various types of nanoparticles have emerged as a therapeutic option against TNBC, to elevate the therapeutic efficacy of the existing chemotherapeutics. Among the various nanoparticles, lipid-based nanoparticles (LNPs) viz. liposomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipid nanocarriers, and lipid–polymer hybrid nanoparticles are developed for cancer treatment which is well confirmed and documented. LNPs include various therapeutic advantages as compared to conventional therapy and other nanoparticles, including increased loading capacity, enhanced temporal and thermal stability, decreased therapeutic dose and associated toxicity, and limited drug resistance. In addition to these, LNPs overcome physiological barriers which provide increased accumulation of therapeutics at the target site. Extensive efforts by the scientific community could make some of the liposomal formulations the clinical reality; however, the relatively high cost, problems in scaling up the formulations, and delivery in a more targetable fashion are some of the major issues that need to be addressed. In the present review, we have compiled the state of the art about different types of LNPs with the latest advances reported for the treatment of TNBC in recent years, along with their clinical status and toxicity in detail.

Combination Therapy Comprising Paclitaxel and 5-Fluorouracil by Using Folic Acid Functionalized Bovine Milk Exosomes Improves the Therapeutic Efficacy against Breast Cancer

Paclitaxel (PAC) has been approved by FDA for clinical use (Taxol^®), yet dose-dependent severe toxicity due to the adjuvant Cremophor EL^® in combination with ethanol is a major drawback. The drawbacks of the current therapy can be overcome by (i) finding a suitable vehicle that cannot only bypass the above adjuvant but also be used to deliver drugs orally and (ii) combining the PAC with some other chemotherapeutics to have the enhanced therapeutic efficacy. In the current work, we have used folic acid (FA) functionalized bovine milk-derived exosomes for oral delivery of PAC in combination with 5-fluorouracil (5-FU). Exosomes before and after the drug loading were found to have a particle size in the range of 80–100 nm, polydispersity index (PDI ~0.20), zeta potential (~−25 mV), entrapment efficiency (~82%), practical drug loading (~28%) and sustained drug release for 48 h. Significant decreases in IC₅₀ were observed in the case of exosomes loaded drugs which further improved following the FA functionalization. FA functionalized coumarin-6-loaded exosomes showed remarkably higher cellular uptake in comparison with free coumarin-6. Moreover, FA-functionalized drug-loaded exosomes showed a higher apoptotic index with better control over cell migration. Collectively, data suggested the enhanced efficacy of the combination following its loading to the folic acid functionalized exosomes against breast cancer.

Luliconazole Nail Lacquer for the Treatment of Onychomycosis: Formulation, Characterization and In Vitro and Ex Vivo Evaluation

Onychomycosis is the most common fungal infection of the nail affecting the skin under the fingertips and the toes. Currently, available therapy for onychomycosis includes oral and topical therapies, either alone or in combination. Oral antifungal medication has been associated with poor drug bioavailability and potential gastrointestinal and systemic side effects. The objective of this study was to prepare and evaluate the luliconazole nail lacquer (LCZ-NL) for the effective treatment of onychomycosis. In the current work, LCZ-NL was formulated in combination with penetration enhancers to overcome poor penetration. A 3² full factorial formulation design of experiment (DOE) was applied for optimization of batches with consideration of dependent (drying time, viscosity, and rate of drug diffusion) and independent (solvent ratio and film former ratio) variables. The optimized formulation was selected based on drying time, viscosity, and rate of drug diffusion. The optimized formulation was further evaluated for % non-volatile content assay, smoothness of flow, water resistance, drug content, scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), in vitro drug release, ex vivo transungual permeation, antifungal efficacy, and stability study. The optimized LCZ-NL contained 70:30 solvent ratio and 1:1 film former ratio and was found to have ~ 1.79-fold higher rate of drug diffusion in comparison with LULY™. DSC and XRD studies confirmed that luliconazole retains its crystalline property in the prepared formulation. Antifungal study against Trichophyton spp. showed that LCZ-NL has comparatively higher growth inhibition than LULY™. Hence, developed LCZ-NL can be a promising topical drug delivery system for treating onychomycosis.

Emergence of Nanotechnology as a Powerful Cavalry against Triple-Negative Breast Cancer (TNBC)

Triple-negative breast cancer (TNBC) is considered one of the un-manageable types of breast cancer, involving devoid of estrogen, progesterone, and human epidermal growth factor receptor 2 (HER 2) receptors. Due to their ability of recurrence and metastasis, the management of TNBC remains a mainstay challenge, despite the advancements in cancer therapies. Conventional chemotherapy remains the only treatment regimen against TNBC and suffers several limitations such as low bioavailability, systemic toxicity, less targetability, and multi-drug resistance. Although various targeted therapies have been introduced to manage the hardship of TNBC, they still experience certain limitations associated with the survival benefits. The current research thus aimed at developing and improving the strategies for effective therapy against TNBC. Such strategies involved the emergence of nanoparticles. Nanoparticles are designated as nanocavalries, loaded with various agents (drugs, genes, etc.) to battle the progression and metastasis of TNBC along with overcoming the limitations experienced by conventional chemotherapy and targeted therapy. This article documents the treatment regimens of TNBC along with their efficacy towards different subtypes of TNBC, and the various nanotechnologies employed to increase the therapeutic outcome of FDA-approved drug regimens.

Using Chitosan-Coated Polymeric Nanoparticles-Thermosensitive Hydrogels in association with Limonene as Skin Drug Delivery Strategy

Topical delivery of local anesthetics (LAs) is commonly used to decrease painful sensations, block pain throughout procedures, and alleviate pain after surgery. Dermal and/or transdermal delivery of LAs has other advantages, such as sustained drug delivery and decreased systemic adverse effects. This study reports the development of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles coated with chitosan for the sustained release and topicality of benzocaine (BZC) and topical delivery. BZC PLGA nanoparticles or nonencapsulated drugs were further incorporated into Poloxamer hydrogels (Pluronic™ F-127). The nanoparticles showed a mean diameter of 380 ± 4 nm, positive zeta potential after coating with chitosan (23.3 ± 1.7 mV), and high encapsulation efficiency (96.7 ± 0.02%). Cellular viability greater than 70% for both fibroblasts and keratinocytes was observed after treatment with nanoparticles, which is in accordance with the preconized guidelines for biomedical devices and delivery systems. Both the nanoparticles and hydrogels were able to modulate BZC delivery and increase drug permeation when compared to the nonencapsulated drug. Furthermore, the incorporation of limonene into hydrogels containing BZC-loaded nanoparticles increased the BZC permeation rates. Non-Newtonian and pseudoplastic behaviors were observed for all hydrogel nanoformulations with or without nanoparticles. These results demonstrate that the hydrogel-nanoparticle hybrids could be a promising delivery system for prolonged local anesthetic therapy.

Combination of lipid nanoparticles and iontophoresis for enhanced lopinavir skin permeation: Impact of electric current on lipid dynamics

Nanostructured lipid carriers (NLC)-loaded with lopinavir (LPV) were developed for its iontophoretic transdermal delivery. Electronic paramagnetic resonance (EPR) spectroscopy of fatty acid spin labels and differential scanning calorimetry (DSC) were applied to investigate the lipid dynamic behavior of NLC before and after the electrical current. In vitro release and permeation studies, with and without anodic and cathodic iontophoresis were also performed. NLC-LPV had nanometric size (179.0 ± 2.5 nm), high drug load (∼x223C 4.14%) and entrapment efficiency (EE) (∼x223C 80%). NLC-LPV was chemically and physically stable after applying an electric current. The electrical current reduced EE after 3 h (67.21 ± 2.64%), resulting in faster LPV in vitro release. EPR demonstrated that iontophoresis decreased NLC lipid dynamics, which is a long-lasting effect. DSC studies demonstrated that electrical current could trigger the polymorphic transition of NLC and drug solubilization in the lipid matrix. NLC-LPV, combined with iontophoresis, allowed drug quantification in the receptor medium, unlike unloaded drugs. Cathodic iontophoresis enabled the quantification of about 7.9 µg/cm² of LPV in the receptor medium. Passive NLC-LPV studies had to be done for an additional 42 h to achieve similar concentrations. Besides, anodic iontophoresis increased by 1.8-fold the amount of LPV in the receptor medium, demonstrating a promising antiviral therapy strategy.

In Vitro Skin Permeation of Idebenone from Lipid Nanoparticles Containing Chemical Penetration Enhancers

Lipid nanoparticles (LNPs) have been proposed as carriers for drug skin delivery and targeting. As LNPs effectiveness could be increased by the addition of chemical penetration enhancers (PE), in this work, the feasibility of incorporating PE into LNPs to improve idebenone (IDE) targeting to the skin was investigated. LNPs loading IDE 0.7% w/w were prepared using hydrophilic (propylene glycol, PG, 10% w/w or N-methylpyrrolidone, NMP, 10% w/w) and/or lipophilic PE (oleic acid, OA, 1% w/w; isopropyl myristate, IPM, 3.5% w/w; a mixture of 0.5% w/w OA and 2.5% w/w IPM). All LNPs showed small sizes (<60 nm), low polydispersity index and good stability. According to the obtained results, IDE release from LNPs was not the rate-limiting step in IDE skin penetration. No IDE permeation was observed through excised pigskin from all LNPs, while the greatest increase of IDE penetration into the different skin layers was obtained using the mixture OA/IPM. The antioxidant activity of IDE-loaded LNPs, determined by the oxygen radical absorbance capacity assay, was greater than that of free IDE. These results suggest that the use of suitable PE as LNPs components could be regarded as a promising strategy to improve drug targeting to the skin.

Triphenylphosphonium functionalized Ficus religiosa L. extract loaded nanoparticles improve the mitochondrial function in oxidative stress induced diabetes

The present study was aimed to enhance the mitochondrial function in oxidative stress-induced diabetes. To achieve this, Ficus religiosa L. extract loaded solid lipid nanoparticles (ETNPs) were prepared and functionalized by using triphenylphosphonium. Developed nanoparticles demonstrated desired quality attributes with sustained release for up to 24 h and excellent storage stability for up to 180 days at 40 ± 2°C and 75 ± 5% relative humidity. In vitro cytotoxicity assessment showed no toxicity of ETNPs. Interestingly, oral administration of ETNPs to diabetic rats demonstrated improved mitochondrial function by normalizing the mitochondrial morphology, intracellular calcium ion concentration, complexes I, II, IV, and V activity, mitochondrial membrane potential, and antioxidant levels. Further, reduction in apoptotic markers viz. cytochrome-C, caspase-3, and caspase-9 was observed following the ETNP treatment. Moreover, significant reduction in blood glucose and glycosylated hemoglobin while significant improvement in plasma insulin was observed as compared to the diabetic group following the treatment with developed formulation. Furthermore, histopathology studies confirmed the safety of the developed formulation and thus, data in hand collectively suggest that proposed strategy can be effectively used to improve the mitochondrial function in oxidative stress-induced diabetes along with better control over blood glucose and glycosylated hemoglobin.

Preparation of Solid Lipid Nanoparticles and Nanostructured Lipid Carriers for Drug Delivery and the Effects of Preparation Parameters of Solvent Injection Method

Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) have emerged as potential drug delivery systems for various applications that are produced from physiological, biodegradable, and biocompatible lipids. The methods used to produce SLNs and NLCs have been well investigated and reviewed, but solvent injection method provides an alternative means of preparing these drug carriers. The advantages of solvent injection method include a fast production process, easiness of handling, and applicability in many laboratories without requirement of complicated instruments. The effects of formulations and process parameters of this method on the characteristics of the produced SLNs and NLCs have been investigated in several studies. This review describes the methods currently used to prepare SLNs and NLCs with focus on solvent injection method. We summarize recent development in SLNs and NLCs production using this technique. In addition, the effects of solvent injection process parameters on SLNs and NLCs characteristics are discussed.

Self-assembled lecithin-chitosan nanoparticles improve the oral bioavailability and alter the pharmacokinetics of raloxifene

In this study, we report the development and evaluation of soy lecithin-chitosan hybrid nanoparticles to improve the oral bioavailability of raloxifene hydrochloride. The nanoparticles were formed by interaction of negatively charged soy lecithin with positively charged chitosan. The ratio of soy lecithin to chitosan was critical for the charge, and hence the size of the nanoparticles. The optimal soy lecithin to chitosan ratio was 20:1 to obtain nanoparticles with particle size of 208 ± 3 nm, a ζ-potential of 36 ± 2 mV and an entrapment efficiency of 73 ± 3%. The nanoparticles were also characterized by differential scanning calorimetry and FT-IR spectrophotometer. In-vitro drug release was assessed using dialysis bag method in pH 7.4 buffer. The drug loaded nanoparticles did not cause significant reduction in the cell viability at low doses. Pharmacokinetic studies in female Wistar rats showed significant improvement (~4.2 folds) in the oral bioavailability of the drug when loaded into nanoparticles. Further, the modified everted gut sac study showed that these nanoparticles are taken up by active endocytic processes in the intestine. The ex-vivo mucoadhesion studies proved that the nanoparticles get bound to the mucus layer of the intestine, which in turn correlates with reduced excretion of the drug in faeces. In conclusion, the proposed nanoparticles appear promising for effective oral delivery of poorly bioavailable drugs like raloxifene hydrochloride.

Parenteral Sustained Release Lipid Phase-Transition System of Ziprasidone: Fabrication and Evaluation for Schizophrenia Therapy

Introduction

Ziprasidone (ZP) is a novel atypical antipsychotic agent effective in the treatment of positive and negative symptoms of schizophrenia with low chances for extrapyramidal side effects (EPs) and cognitive deficits. ZP possesses poor oral bioavailability (~50%), short biological half-life (~2.5 h) and due to extensive first-pass metabolism, a repeated dose is administered which makes the therapy non-adherent, leading to patient non-compliance. Therefore, this is a first report of developing parenteral ZP loaded sustained release phospholipid based phase-transition system (ZP-LPS).

Methods

The ZP-LPS system was formulated by mixing of biocompatible materials including phospholipid E 80, medium chain triglyceride (MCT) and ethanol. Optimization was done by aqueous titration method using pseudo-ternary phase diagram and dynamic rheological measurements. In vivo depot formation was confirmed by gamma scintigraphy after subcutaneous injection. Biodegradation and biocompatibility studies were performed for its safety evaluation. Finally, the efficacy of the formulation was assessed by Morris water maze (MWM) test and dizocilpine (MK-801) was used to induce schizophrenia in Sprague-Dawley rats.

Results

Optimized ZP-LPS showed rapid gelation (2 min), highest change in viscosity (~48000 mPa.s) and sustained release of ZP over a period of 1 month. Gamma scintigraphy depicted that the low-viscosity ZP-LPS system undergo rapid in situ gelation. Biodegradation and biocompatibility studies revealed gradual degradation in size of depot over a period of 28 days without any inflammation at the injection site. In MWM test, escape latency, time spent and total distance in target quadrant were significantly improved (p < 0.001) in the ZP-LPS group in comparison to the MK-801 group when evaluated at day 0, day 7 and day 28. However, significant improvement (p < 0.001) was observed only at day 0 in ZP suspension group.

Conclusion

The overall result indicates that the novel ZP-LPS system is safe, biodegradable, and effective for the management of schizophrenia.

Dextran methacrylate hydrogel microneedles loaded with doxorubicin and trametinib for continuous transdermal administration of melanoma

Microneedles (MNs) technology has many advantages and is an ideal local transdermal drug delivery method. Here we synthesized photocrosslinkable dextran methacrylate (DexMA), and its degree of substitution is 5 % higher than the previous method. We used DexMA hydrogel for the first time to develop a new type of MNs for continuous transdermal administration. The prepared hydrogel MNs can successfully penetrate the epidermal layer and achieve sustained drug release. Doxorubicin (DOX) and trametinib (Tra) are anticancer drugs approved by FDA. Besides, Tra can also reverse P-gp-mediated multidrug resistance (MDR) to effectively block the efflux of DOX by P-gp. We used MNs to simultaneously load Tra and DOX, and achieved synergy in a B16 cell xenograft nude mouse model. The DexMA hydrogel MNs developed in this study can be used to enhance the transdermal delivery of small molecule drugs and reduce systemic toxicity and side effects.

Preparation and Characterisation of Polyphenol-HP-β-Cyclodextrin Inclusion Complex that Protects Lamb Tripe Protein against Oxidation

Grape seed extract (GSE) displays strong antioxidant activity, but its instability creates barriers to its applications. Herein, three HP-β-CD/GSE inclusion complexes with host-guest ratios of 1:0.5, 1:1, and 1:2 were successfully prepared by co-precipitation method to improve stability. Successful embedding of GSE in the HP-β-CD cavity was confirmed by fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analyses. The Autodock Tools 1.5.6 was used to simulate the three-dimensional supramolecular structure of the inclusion complex of 2-hydroxypropyl-β-cyclodextrin and grape seed extract (HP-β-CD/GSE) by molecular docking. The MALDI-TOF-MS technology and chemical database Pubchem, and structural database PDB were combined to reconstitute the three-dimensional structure of target protein. The binding mode of the HP-β-CD/GSE inclusion complex to target protein was studied at the molecular level, and the antioxidant ability of the resulting HP-β-CD/GSE inclusion complexes was investigated by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The effects of HP-β-CD/GSE on myofibrillar protein from lamb tripe were also investigated under oxidative conditions. The positions and interactions of the binding sites of HP-β-CD/GSE inclusion complexes and target protein receptors were simulated by molecular docking. The results showed that HP-β-CD/GSE inclusion complexes were successfully prepared, optimally at a molar ratio of 1:2. At low (5 μmol/g) to medium (105 μmol/g) concentrations, HP-β-CD/GSE inclusion complexes decreased the carbonyl content, hydrophobicity, and protein aggregation of myofibrillar protein from lamb tripe, and increased the sulphydryl content. Furthermore, high concentration (155 μmol/g) of HP-β-CD/GSE inclusion complexes promoted protein oxidation.

Antibiofilm Potential of Silver Sulfadiazine-Loaded Nanoparticle Formulations: A Study on the Effect of DNase-I on Microbial Biofilm and Wound Healing Activity

Biofilm resistance is one of the severe complications associated with chronic wound infections, which impose extreme microbial tolerance against antibiotic therapy. Interestingly, deoxyribonuclease-I (DNase-I) has been empirically proved to be efficacious in improving the antibiotic susceptibility against biofilm-associated infections. DNase-I hydrolyzes the extracellular DNA, a key component of the biofilm responsible for the cell adhesion and strength. Moreover, silver sulfadiazine, a frontline therapy in burn wound infections, exhibits delayed wound healing due to fibroblast toxicity. In this study, a chitosan gel loaded with solid lipid nanoparticles of silver sulfadiazine (SSD-SLNs) and supplemented with DNase-I has been developed to reduce the fibroblast cytotoxicity and overcome the biofilm-imposed resistance. The extensive optimization using the Box-Behnken design (BBD) resulted in the formation of SSD-SLNs with a smooth surface as confirmed by scanning electron microscopy and controlled release (83%) for up to 24 h. The compatibility between the SSD and other formulation excipients was confirmed by Fourier transform infrared, differential scanning calorimetry, and powder X-ray diffraction studies. Developed SSD-SLNs in combination with DNase-I inhibited around 96.8% of biofilm of Pseudomonas aeruginosa as compared to SSD with DNase-I (82.9%). In line with our hypothesis, SSD-SLNs were found to be less toxic (cell viability 90.3 ± 3.8% at 100 μg/mL) in comparison with SSD (Cell viability 76.9 ± 4.2%) against human dermal fibroblast cell line. Eventually, the results of the in vivo wound healing study showed complete wound healing after 21 days' treatment with SSD-SLNs along with DNase-I, whereas marketed formulations SSD and SSD-LSNs showed incomplete healing after 21 days. Data in hand suggest that the combination of SSD-SLNs with DNase-I is an effective treatment strategy against the biofilm-associated wound infections and accelerates wound healing.