Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar,Mohali, Punjab-160 062, India, Institute of Biochemistry, Faculty of Medicine, Polytechnic University, Via Ranieri 67, IT-60100 Ancona, Italy,Green Biotechnology Research Group, The Special Division for Human Life Technology, National Institute of Advanced Industrial Science andTechnology, 1-8-31 Midorigaoka, Ikeda, Osaka-563-8577, Japan, and Department of Medicinal Chemistry & Natural Products,The Hebrew University of Jerusalem, School of Pharmacy-Faculty of Medicine, Jerusalem 91120, IsraelReceived March 2, 2004

Chitosan chemistry and pharmaceutical perspectives.

Nanotechnology is the understanding and control of matter generally in the 1-100 nm dimension range. The application of nanotechnology to medicine, known as nanomedicine, concerns the use of precisely engineered materials at this length scale to develop novel therapeutic and diagnostic modalities. Nanomaterials have unique physicochemical properties, such as ultra small size, large surface area to mass ratio, and high reactivity, which are different from bulk materials of the same composition. These properties can be used to overcome some of the limitations found in traditional therapeutic and diagnostic agents.

Nanoparticles in Medicine: Therapeutic Applications and Developments

Micelles, self-assembling nanosized colloidal particles with a hydrophobic core and hydrophilic shell are currently successfully used as pharmaceutical carriers for water-insoluble drugs and demonstrate a series of attractive properties as drug carriers. Among the micelle-forming compounds, amphiphilic copolymers, i.e., polymers consisting of hydrophobic block and hydrophilic block, are gaining an increasing attention. Polymeric micelles possess high stability both in vitro and in vivo and good biocompatibility, and can solubilize a broad variety of poorly soluble pharmaceuticals many of these drug-loaded micelles are currently at different stages of preclinical and clinical trials. Among polymeric micelles, a special group is formed by lipid-core micelles, i.e., micelles formed by conjugates of soluble copolymers with lipids (such as polyethylene glycol-phosphatidyl ethanolamine conjugate, PEG-PE). Polymeric micelles, including lipid-core micelles, carrying various reporter (contrast) groups may become the imaging agents of choice in different imaging modalities. All these micelles can also be used as targeted drug delivery systems. The targeting can be achieved via the enhanced permeability and retention (EPR) effect (into the areas with the compromised vasculature), by making micelles of stimuli-responsive amphiphilic block-copolymers, or by attaching specific targeting ligand molecules to the micelle surface. Immunomicelles prepared by coupling monoclonal antibody molecules to p-nitrophenylcarbonyl groups on the water-exposed termini of the micelle corona-forming blocks demonstrate high binding specificity and targetability. This review will discuss some recent trends in using micelles as pharmaceutical carriers.

Micellar nanocarriers: pharmaceutical perspectives.

Importance of the field: Metal oxide nanoparticles, including zinc oxide, are versatile platforms for biomedical applications and therapeutic intervention. There is an urgent need to develop new classes of anticancer agents, and recent studies demonstrate that ZnO nanomaterials hold considerable promise.Areas covered in this review: This review analyzes the biomedical applications of metal oxide and ZnO nanomaterials under development at the experimental, preclinical and clinical levels. A discussion regarding the advantages, approaches and limitations surrounding the use of metal oxide nanoparticles for cancer applications and drug delivery is presented. The scope of this article is focused on ZnO, and other metal oxide nanomaterial systems, and their proposed mechanisms of cytotoxic action, as well as current approaches to improve their targeting and cytotoxicity against cancer cells.What the reader will gain: This review aims to give an overview of ZnO nanomaterials in biomedical applications.Take home...

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Zinc oxide nanoparticles for selective destruction of tumor cells and potential for drug delivery applications.

Purpose. Although oral delivery has become a widely accepted route of administration of therapeutic drugs, the gastrointestinal tract presents several formidable barriers to drug delivery. Colonic drug delivery has gained increased importance not just for the delivery of the drugs for the treatment of local diseases associated with the colon but also for its potential for the delivery of proteins and therapeutic peptides. To achieve successful colonic delivery, a drug needs to be protected from absorption and /or the environment of the upper gastrointestinal tract (GIT) and then be abruptly released into the proximal colon, which is considered the optimum site for colon-tar- geted delivery of drugs. Colon targeting is naturally of value for the topical treatment of diseases of colon such as Chron's diseases, ulcerative colitis, colorectal cancer and amebiasis. Peptides, proteins, oligonucleotides and vac- cines pose potential candidature for colon targeted drug delivery. Methods. The various strategies for targeting orally administered drugs to the colon include covalent linkage of a drug with a carrier, coating with pH-sensitive polymers, formulation of timed released systems, exploita- tion of carriers that are degraded specifically by colonic bacteria, bioadhesive systems and osmotic controlled drug delivery systems. Various prodrugs (sulfasalazine, ipsala- zine, balsalazine and olsalazine) have been developed that are aimed to deliver 5-amino salicylic acid (5-ASA) for localized chemotherapy of inflammatory bowl disease (IBD). Microbially degradable polymers especially azo crosslinked polymers have been investigated for use in tar- geting of drugs to colon. Certain plant polysaccharides such as amylose, inulin, pectin and guar gum remains unaf- fected in the presence of gastrointestinal enzymes and pave the way for the formulation of colon targeted drug delivery systems. The concept of using pH as a rigger to release a drug in the colon is based on the pH conditions that vary continuously down the gastrointestinal tract. Times dependent drug delivery systems have been devel- oped that are based on the principle to prevent release of drug until 3-4 h after leaving the stomach. Redox sensitive polymers and bioadhesive systems have also been exploited to deliver the drugs into the colon. Results. The approach that is based on the formation of prodrug involves covalent linkage between drug and carrier. The type of linkage that is formed between drug and carrier would decide the triggering mechanism for the release of drug in colon. The presence of azo reductase enzymes play pivotal role in the release of drug from azo bond prodrugs while glycosidase activity of the colonic microflora is responsible for liberation of drugs from glycosidic pro- drugs. Release of drugs from azo polymer coated dosage forms is supposed to take place after reduction and thus cleavage of the azo bonds by the azoreductase enzymes present in the colonic microflora. Natural polysaccharides have been used as tools to deliver the drugs specifically to the colon. These polysaccharides remain intact in the phys- iological environment of stomach and small intestine but once the dosage form enters into colon, it is acted upon by polysaccharidases, which degrades the polysaccharide and releases the drug into the vicinity of bioenvironment of colon. However, they should be protected while gaining entry into stomach and small intestine due to enormous swelling and hydrophilic properties of polysaccharides. This has been achieved either by chemical crosslinking or by addition of a protective coat. Formulation coated with enteric polymers releases drug when pH move towards alkaline range while as the multicoated formulation passes the stomach, the drug is released after a lag time of 3-5 h that is equivalent to small intestinal transit time. Drug coated with a bioadhesive polymer that selectively provides adhesion to the colonic mucosa may release drug in the colon. Conclusions. Improved drug delivery systems are required for drugs currently in use to treat localized dis- eases of the colon. The advantages of targeting drugs spe- cifically to the diseased colon are reduced incidence of systemic side effects, lower dose of drug, supply of the drug to the biophase only when it is required and mainte- nance of the drug in its intact form as close as possible to the target site.

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Pharmaceutical approaches to colon targeted drug delivery systems.

This paper describes a new nuclear imaging agent, 2-(4-isothiocyanatobenzyl)−1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid of human albumin (HAC), potentially suitable for application in the Radio-guided Occult Lesion Localization (ROLL) of non-palpable mammalian cancerous lesions, as a tool to overtake the short radio-signal half-life of the technetium-99m based radiopharmaceutical currently used. This conjugate is a microsized powder aggregate, water-insoluble between pH 3 and 8.5, obtained by conjugating the protein with the macrocyclic chelating agent DOTA through a one-pot reaction in aqueous medium. The product has been fully characterized and is stable to the thermal conditions adopted for labeling; after radiolabeling with longer half-life radionuclides such as 177Lu or 111In, it has shown radiochemical purity (RCP) >90% and resulted stable when stored in saline or plasma for 6 days at 37 °C. A μPET/CT study, performed in vivo on adult female rats, showed that the radioactivity of HAC labeled with 64Cu remained located in the mammary glands for at least 40 h, without diffusion or drainage in healthy tissues or in the lymphatic circulation. This new imaging agent might make the ROLL procedure more accessible, safe and flexible, promoting a significant time and cost reduction of this intervention. Moreover, HAC might also be used in other radio-guided surgical procedures in oncology.

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A new microdispersed albumin derivative potentially useful for radio-guided surgery of occult breast cancer lesions.

Usually, the administration of drugs by feeding tube in dysphagic patients involves handling of marketing licenses outside their term, due to the lack of suitable formulations. This circumstance has put health professionals in the dilemma of choosing the formulation whose manipulation possibly does not alter the effectiveness of the drug. In this regard, a practical guide providing indications on the prescription, handling, and administration of drugs through enteral feeding tube could be of paramount utility. For this purpose, we have considered the 1047 solid oral pharmaceutical forms included in the formulary of San Paolo Hospital (Savona, Italy). From our analysis, it emerges that 95% of medicinal products are worryingly used off-label and 40% have to be managed by the hospital pharmacists without having suitable indications by either the manufacturers or by literature studies. To fill this gap, we have compiled a detailed table containing missing indications derived from pharmacist expertise and evidence-based practices, with the aim that the sharing of our procedures will contribute to make uniform pharmacological therapies from one hospital to another. This study will allow doctors to have easy access to information on drugs that can be prescribed and nurses to become familiar only with the pharmaceutical forms that can be administered.

https://www.mdpi.com/2075-4426/12/8/1307/pdf?version=1660308902

The Role of the Pharmacist in Selecting the Best Choice of Medication Formulation in Dysphagic Patients

Objects touched by patients and healthcare workers in hospitals may harbor pathogens, including multi-drug resistant (MDR) staphylococci, enterococci (VRE), Escherichia coli, Acinetobacter, and Pseudomonas species. Medical devices contaminated by these pathogens may also act as a source of severe and difficult-to-treat human infections, thus becoming a critical public health concern requiring urgent resolutions. To this end, we recently reported the bactericidal effects of a cationic copolymer (CP1). Here, aiming at developing a bactericidal formulation possibly to be used either for surfaces disinfection or to treat skin infections, CP1 was formulated as a hydrogel (CP1_1.1-Hgel). Importantly, even if not cross-linked, CP1 formed the gel upon simple dispersion in water, without requiring gelling agents or other additives which could be skin-incompatible or interfere with CP1 bactericidal effects in possible future topical applications. CP1_1.1-Hgel was characterized by attenuated-total-reflectance Fourier transform infrared (ATR-FTIR) and UV-Vis spectroscopy, as well as optic and scanning electron microscopy (OM and SEM) to investigate its chemical structure and morphology. Its stability was assessed by monitoring its inversion properties over time at room temperature, while its mechanical characteristics were assessed by rheological experiments. Dose-dependent cytotoxicity studies performed on human fibroblasts for 24 h with gel samples obtained by diluting CP_1.1-Hgel at properly selected concentrations established that the 3D network formation did not significantly affect the cytotoxic profile of CP1. Also, microbiologic investigations carried out on two-fold serial dilutions of CP1-gel confirmed the minimum inhibitory concentrations (MICs) previously reported for the not formulated CP1.Selectivity indices values up to 12 were estimated by the values of LD50 and MICs determined here on gel samples.

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A Self-Forming Hydrogel from a Bactericidal Copolymer: Synthesis, Characterization, Biological Evaluations and Perspective Applications

A method for the preparation of a three-dimensional hydrogel scaffold for cell culturing, which comprises the steps of: a) preparing at least one first uniform solid mixture comprising at least one gas-forming agent, at least one water-soluble salt and at least one non-water-soluble, water-swellable cross-linked poly(acrylic) polymer; b) preparing compressed or compact units starting from the first solid mixture; c) subjecting the compressed or compact units thus obtained to heating at a temperature in the range of 20°C-160°C, for a time of 1-120 minutes; d) leaching the thermally treated units thus obtained in an aqueous medium; e) conditioning the leached units thus obtained in water or in an aqueous solution; f) subjecting the conditioned units thus obtained to sterilization; the three-dimensional hydrogel scaffold for cell culturing obtainable with the above method comprises a non-water soluble, water-swellable cross-linked poly(acrylic) polymer, such as Carbomer or Polycarbophil, has a porosity higher than 80% and a pore size comprised between 0.1 nm and 600 μm.

Guendalina Zuccari

Papers

A new microdispersed albumin derivative potentially useful for radio-guided surgery of occult breast cancer lesions.

The Role of the Pharmacist in Selecting the Best Choice of Medication Formulation in Dysphagic Patients

A Self-Forming Hydrogel from a Bactericidal Copolymer: Synthesis, Characterization, Biological Evaluations and Perspective Applications

A three-dimensional hydrogel scaffold for cell culturing and a method for the production thereof

Metodo di produzione di matrici compatte gastroritentive per il rilascio controllato di sostanze attive e matrici compatte così ottenute