Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro-as well as nanoparticles. The prepared particles have been exploited as a potential carrier for different therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and nonparenteral administration. Therapeutic agent-loaded chitosan micro- or nanoparticles were found to be more stable, permeable, and bioactive. In this review, we are highlighting the different methods of preparation and characterization of chitosan micro- and nanoparticles, while reviewing the pharmaceutical applications of these particles in drug delivery. Moreover, the roles of chitosan derivatives and chitosan metal nanoparticles in drug delivery have been illustrated.

Spurred by recent progress in medicinal chemistry, numerous lead compounds have sprung up in the past few years, although the majority are hindered by hydrophobicity, which greatly challenges druggability. In an effort to assess the potential of platinum (Pt) candidates, the nanosizing approach to alter the pharmacology of hydrophobic Pt(IV) prodrugs in discovery and development settings is described. The construction of a self-assembled nanoparticle (NP) platform, composed of amphiphilic lipid-polyethylene glycol (PEG) for effective delivery of Pt(IV) prodrugs capable of resisting thiol-mediated detoxification through a glutathione (GSH)-exhausting effect, offers a *

Background and objective Miconazole is a broad-spectrum antifungal drug that has poor aqueous solubility (<1 µg/mL); as a result, a reduction in its therapeutic efficacy has been reported. The aim of this study was to formulate and evaluate miconazole-loaded solid lipid nanoparticles (MN-SLNs) for oral administration to find an innovative way to alleviate the disadvantages associated with commercially available capsules. Methods MN-SLNs were prepared by hot homogenization/ultrasonication. The solubility of miconazole in different solid lipids was measured. The effect of process variables, such as surfactant types, homogenization and ultrasonication times, and the charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release, antifungal activity against Candida albicans , and in vivo pharmacokinetics were studied in rabbits. Results The MN-SLN, consisting of 1.5% miconazole, 2% Precirol ATO5, 2.5% Cremophor RH40, 0.5% Lecinol, and 0.1% Dicetylphosphate, had an average diameter of 23 nm with a 90.2% entrapment efficiency. Furthermore, the formulation of MN-SLNs enhanced the antifungal activity compared with miconazole capsules. An in vivo pharmacokinetic study revealed that the bioavailability was enhanced by >2.5-fold. Conclusion MN-SLN was more efficient in the treatment of candidiasis with enhanced oral bioavailability and could be a promising carrier for the oral delivery of miconazole.

Oral ketoconazole therapy is commonly associated with serious hepatotoxicity. Improving ocular drug delivery could be sufficient to treat eye fungal infections. The purpose of this study was to develop optimized ketoconazole poly(lactide-co-glycolide) nanoparticles (NPs) with subsequent loading into in situ gel (ISG) formulation for ophthalmic drug delivery. Three formulation factors were optimized for their effect on particle size (Y1) and entrapment efficiency (Y2) utilizing central composite experimental design. Interaction among components was studied using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. Ketoconazole crystalline state was studied using X-ray powder diffraction. Six different polymeric ISG formulations were prepared and loaded with either optimized NPs or a pure drug. The prepared ISG formulations were characterized for in vitro gelation, drug release and antifungal activity. The permeation through human epithelial cell line was also investigated. The results revealed that all the studied formulation parameters significantly affected Y1 and Y2 of the developed NPs. DSC and FTIR studies illustrated compatibility among NP components, while there was a change from the crystalline state to the amorphous state of the NPs. The in vitro release from the ISG formulations loaded with drug NPs showed sustained and enhanced drug release compared to pure drug formulations. In addition, ISG loaded with NPs showed enhanced anti-fungal activity compared to pure drug formulations. Alginate–chitosan ISG formulation loaded with optimized ketoconazole NPs illustrated higher drug permeation through epithelial cell lines and is considered as an effective ophthalmic drug delivery in the treatment of fungal eye infections.

Polymeric systems have been extensively studied as polyelectrolyte complexes to enhance the cellular delivery and transfection efficiency of genetic materials, such as plasmid DNA (pDNA). Here, self-assembled nanoparticles were formulated by complexation of hyaluronic acid (HA)-conjugated poly­(ethylene glycol) (HA–PEG) and poly­(ethylenimine) (HA–PEI), respectively, with pDNA creating relatively small, stable, and multifunctional nanoparticle complex formulations with high transfection efficiency. This formulation strategy offers high gene expression efficiency and negligible cytotoxicity in HeLa and A549 human lung cancer cell lines. To develop the ideal formulation, in vitro transfection efficiency was studied for three different nanoparticle formulations (HA–PEI/HA–PEG, HA–PEI, and HA–PEG) with different concentrations. The combination of the three polymers (HA, PEG, and PEI) was significant for the formulation to achieve the maximum gene expression results. The nanoparticles were found to be stable for up to a week at 4 °C conditions. Overall, these HA-based nanoparticles showed promising aspects that can be utilized in the designing of gene delivery vectors for cancer therapy.

BackgroundVinpocetine (VNP), a semisynthetic natural product, is used as a vasodilator for cerebrovascular and age-related memory disorders. VNP suffers from low oral bioavailability owing to its low water solubility and extensive first-pass metabolism. This work aimed at utilizing D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and alpha lipoic acid (ALA) to develop efficient micellar system for transdermal delivery of VNP.Materials and methodsVNP-TPGS-ALA micelles were prepared, characterized for particle size using particle size analyzer, and investigated for structure using transmission electron microscope. Optimization of VNP-TPGS-ALA micelles-loaded transdermal films was performed using Box–Behnken experimental design. The investigated factors were percentage of ALA in TPGS (X1), citral concentration (X2), and propylene glycol concentration (X3). Elongation percent (Y1), initial permeation after 2 hours (Y2), and cumulative permeation after 24 hours (Y3) were studied as responses.ResultsStatistical analysis revealed optimum levels of 16.62%, 3%, and 2.18% for X1, X2, and X3, respectively. Fluorescent laser microscopic visualization of skin penetration of the optimized transdermal film revealed marked widespread fluorescence intensity in skin tissue after 0.5, 2, and 4 hours compared with raw VNP transdermal film formulation, which indicated enhancement of VNP skin penetration.ConclusionThe obtained results highlighted the potentiality of VNP nanostructure-based films for controlling the transdermal permeation of the drug and improving its effectiveness.

As a hallmark of solid tumors, hypoxia promotes tumor growth, metastasis, and therapeutic resistance by regulating the expression of hypoxia-related genes. Hypoxia also represents a tumor-specific stimulus that has been exploited for the development of bioreductive prodrugs and advanced drug delivery systems. Cell division cycle 20 (CDC20) functions as an oncogene in tumorigenesis, and we demonstrated the significant upregulation of CDC20 mRNA in the tumor vs paratumor tissues of breast cancer patients and its positive correlation with tumor hypoxia. Herein, a hypoxia-responsive nanoparticle (HRNP) was developed by self-assembly of the 2-nitroimidazole-modified polypeptide and cationic lipid-like compound for delivery of siRNA to specifically target CDC20, a hypoxia-related protumorigenic gene, in breast cancer therapy. The delivery of siCDC20 by HRNPs sufficiently silenced the expression of CDC20 and exhibited potent antitumor efficacy. We expect that this strategy of targeting hypoxia-correlated protumorigenic genes by hypoxia-responsive RNAi nanoparticles may provide a promising approach in cancer therapy.

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