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The role of mycobacterial efflux pumps in drug-resistant tuberculosis has been widely reported. Recently, a new compound, named SS13, has been synthesized, and its activity as a potential efflux inhibitor has been demonstrated. In this work, the chemical-physical properties of the SS13 were investigated; furthermore, a formulative study aimed to develop a formulation suitable for oral administration was performed. SS13 shows nonintrinsic antitubercular activity, but it increases the antitubercular activity of all the tested drugs on several strains. SS13 is insoluble in different simulated gastrointestinal media; thus, its oral absorption could be limited. Solid lipid nanoparticles (SLNs) were, therefore, developed by using two different lipids, Witepsol and/or Gelucire. Nanoparticles, having a particle size (range of 200-450 nm with regards to the formulation composition) suitable for intestinal absorption, are able to load SS13 and to improve its permeation through the intestinal mucosa compared to the pure compound. The cytotoxicity is influenced by the concentration of nanoparticles administered. These promising results support the potential application of these nanocarriers for increasing the oral permeation of SS13 in multidrug-resistant tuberculosis management.

Genistein has been reported to have antioxidant and neuroprotective activity. Despite encouraging in vitro and in vivo results, several disadvantages such as poor water solubility, rapid metabolism, and low oral bioavailability limit the clinical application of genistein. The aim of this study was to design and characterize genistein-loaded chitosan nanoparticles for intranasal drug delivery, prepared by the ionic gelation technique by using sodium hexametaphosphate. Nanoparticles were characterized in vitro and their cytotoxicity was tested on PC12 cells. Genistein-loaded nanoparticles were prepared, and sodium hexametaphosphate was used as a valid alternative to well-known cross-linkers. Nanoparticle characteristics as well as their physical stability were affected by formulation composition and manufacturing. Small (mean diameters of 200⁻300 nm) and homogeneous nanoparticles were obtained and were able to improve genistein penetration through the nasal mucosa as compared to pure genistein. Nanoparticle dispersions showed a pH consistent with the nasal fluid and preserved PC12 cell vitality.

Potential positive effects of flavonol quercetin on humans were suggested by many studies. However, it is not clear if these effects are mediated by quercetin or its metabolites. The in vivo confirmation of quercetin effects is largely hindered by its low water solubility and thus impossibility to test directly its impact. Therefore, a solid dispersion of quercetin with polyvinylpyrrolidone (PVP) was developed to prepare an injectable formulation of water-soluble quercetin. The optimized formulation provided a 20,000-fold increase in quercetin solubility. This formulation was tested on conventional and spontaneously hypertensive rats; it lowered their blood pressure in both short- and long-term basis. Pharmacokinetic data are also provided. This study reports for the first time an injectable water-soluble formulation of quercetin suitable for confirmation of its vascular effect in vivo., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The aim of this study was the development of novel fluorescent microspheres as embolic agent for transarterial embolization (TAE) of advanced stages of hepatocellular carcinoma (HCC). TAE is a minimally invasive procedure that induces tumour regression blocking the blood flow by injection of microparticles. The microspheres currently used in clinical application cannot be visualized in vivo. Surgeon could exploit the intraoperative detection of embolic agents during resection of the malignant mass. Biocompatible indocyanine green (ICG)-loaded microspheres (CAB-CS-ICG) were prepared using a multi-step method. Chitosan (CS)-ICG particles were prepared via spray-dryer and then loaded into cellulose acetate butyrate (CAB) microspheres, fabricated by emulsion solvent extraction method. Technological parameters such as yield, size, encapsulation efficiency and morphology were studied. CAB-CS-ICG microspheres showed spherical shape and smooth surface, as well as good injectability through a 21 G×1½ needle. ICG release from CAB-CS-ICG was very low due to the strong interaction between CS and ICG. This result was also confirmed by in vitro fluorescence imaging studies, conducted using Photodynamic Eye (PDE) for the detection of particles incubated in human plasma. CAB-CS-ICG were capable to maintain the fluorescence selectivity for 4weeks. Our data suggested the potential usefulness of CAB-CS-ICG in TAE application as embolic agents and following imaging of tumour during surgical procedure., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: In situ forming biodegradable poly(ε-caprolactone) (PCL) microspheres (PCL-ISM) system was developed as a novel embolic agent for transarterial embolization (TAE) therapy of hepatocellular carcinoma (HCC). Ibuprofen sodium (Ibu-Na) was loaded on this platform to evaluate its potential for the treatment of post embolization syndrome., Methods: The influence of formulation parameters on the size/shape, encapsulation efficiency and drug release was investigated using mixture experimental design. Regression models were derived and used to optimize the formulation for particle size, encapsulation efficiency and drug release profile for TAE therapy. An ex vivo model using isolated rat livers was established to assess the in situ formation of microspheres., Results: All PCL-ISM components affected the studied properties and fitting indices of the regression models were high (Radj 2  = 0.810 for size, 0.964 encapsulation efficiency, and 0.993 or 0.971 for drug release at 30 min or 48 h). The optimized composition was: PCL = 4%, NMP = 43.1%, oil = 48.9%, surfactant = 2% and drug = 2%. Ex vivo studies revealed that PCL-ISM was able to form microspheres in the hepatic arterial bed., Conclusions: PCL-ISM system provides a novel tool for the treatment of HCC and post-embolization syndrome. It is capable of forming microspheres with desirable size and Ibu-Na release profile after injection into blood vessels.

Indocyanine green (ICG) is a cyanine compound that displays fluorescent properties in the near infrared region. This dye is employed for numerous indications but nowadays its major application field regards tumour diagnosis and treatments. Optical imaging by near infrared fluorescence provides news opportunities for oncologic surgery. The imaging of ICG can be useful for intraoperative identification of several solid tumours and metastases, and sentinel lymph node detection. In addition, ICG can be used as an agent for the destruction of malignant tissue, by virtue of the production of reactive oxygen species and/or induction of a hyperthermia effect under irradiation. Nevertheless, ICG shows several drawbacks, which limit its clinical application. Several formulative strategies have been studied to overcome these problems. The rationale of the development of ICG containing drug delivery systems is to enhance the in vivo stability and biodistribution profile of this dye, allowing tumour accumulation and resulting in better efficacy. In this review, ICG containing nano-sized carriers are classified based on their chemical composition and structure. In addition to nanosystems, different formulations including hydrogel, microsystems and others loaded with ICG will be illustrated. In particular, this report describes the preparation, in vitro characterization and in vivo application of ICG platforms for cancer imaging and treatment. The promising results of all systems confirm their clinical utility but further studies are required prior to evaluating the formulations in human trials., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Recently, the potential application of deferoxamine (DFO) in several iron dysregulation diseases has been highlighted. However, DFO presents significant limitations in clinical use due to its poor absorption in the gut and very short plasma half-life. To overcome these problems, the feasibility of chitosan/alginate hydrogels as prolonged delivery systems of DFO was investigated. Hydrogel alone or co-formulated with poly(D,L-lactide-co-glycolide) microspheres were prepared and studied in vitro. The influence of the preparation methods on the performance of composite hydrogels on controlled DFO release was explored. Spray-dried microspheres based on poly(D,L-lactide-co-glycolide) were able to encapsulate DFO, a highly water soluble drug. Nevertheless, only the composite hydrogels managed to provide sustained drug release. The inclusion of microspheres into pre-formed chitosan/alginate hydrogel provided the most efficient delivery system; the drug released from microspheres is strongly entrapped in the hydrogel network and slowly released by diffusion., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Ciprofloxacin is a drug active against a broad spectrum of aerobic Gram-positive and Gram-negative bacteria, for the therapy of ocular infections. It requires frequent administrations owing to rapid ocular clearance and it is a good candidate for ocular controlled release formulations. The preparation of such drug release systems is still a challenge. Ionic interactions between ciprofloxacin and the polyelectrolytes chondroitin sulfate or lambda carrageenan result in coprecipitates that can act as microparticulate controlled release systems from which the drug is released after being displaced by the medium's ions. In some formulations, Carbopol was added to improve the mucoadhesive properties. The aim of this research was the study of the influence of the technological parameters of the preparation method of coprecipitates on their particle size, with the goal of achieving particles engineered with a size suitable for the ocular administration. Technological parameters taken into account were: concentration of drug and polymer solutions utilized for the preparation of interaction products, possible use of surfactants (kind and concentration), temperature of the solutions and stirring during the process of preparation of the coprecipitates. Preliminary stability study tests were carried out to further characterize the leader formulation. Particle size in suspensions for ocular drug delivery is a critical parameter influencing the quality of the formulation. The results obtained from this study show that chondroitin sulfate coprecipitates present the best characteristics in terms of particle size suitable for ocular administration. A further improvement of the particle size characteristics has been obtained with the addition of surfactants.

Objectives: Thermosensitive chitosan/glycerophosphate (C/GP) solutions exhibiting sol-gel transition around body temperature were prepared to develop a class of injectable hydrogel platforms for the imaging and loco-regional treatment of hepatocellular carcinoma (HCC). Indocyanine green (ICG) was loaded in the thermosensitive solutions in order to assess their potential for the detection of tumor nodules by fluorescence., Methods: The gel formation of these formulations as well as their gelling time, injectability, compactness and resistance of gel structure, gelling temperature, storage conditions, biodegradability, and in vitro dye release behavior were investigated. Ex vivo studies were carried out for preliminary evaluation using an isolated bovine liver., Results: Gel strengths and gelation rates increased with the cross-link density between C and GP. These behaviors are more evident for C/GP solutions, which displayed a gel-like precipitation at 4°C. Furthermore, formulations with the lowest cross-link density between C and GP exhibited the best injectability due to a lower resistance to flow. The loading of the dye did not influence the gelation rate. ICG was not released from the hydrogels because of a strong electrostatic interaction between C and ICG. Ex vivo preliminary studies revealed that these injectable formulations remain in correspondence of the injected site., Conclusions: The developed ICG-loaded hydrogels have the potential for intraoperative fluorescence imaging and local therapy of HCC as embolic agents. They form in situ compact gels and have a good potential for filling vessels and/or body cavities.