Search results for "polymers"
showing 10 items of 3567 documents
Tailoring the physicochemical properties of core-crosslinked polymeric micelles for pharmaceutical applications.
2016
To optimally exploit the potential of (tumor-) targeted nanomedicines, platform technologies are needed in which physicochemical and pharmaceutical properties can be tailored according to specific medical needs and applications. We here systematically customized the properties of core-crosslinked polymeric micelles (CCPM). The micelles were based on mPEG-b-pHPMAmLacn (i.e. methoxy poly(ethylene glycol)-b-poly[N-(2-hydroxypropyl) methacrylamide-lactate]), similar to the block copolymer composition employed in CriPec® docetaxel, which is currently in phase I clinical trials. The CCPM platform was tailored with regard to size (30 to 100 nm), nanocarrier degradation (1 month to 1 year) and drug…
In-situ forming gel-like depot of a polyaspartamide-polylactide copolymer for once a week administration of Sulpiride
2015
Abstract Objectives An in-situ forming gel-like depot, prepared by using an appropriate polyaspartamide-polylactide graft copolymer, has been employed to release in a sustained way sulpiride. Methods α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide-g-polylactic acid (PHEA-g-PLA) has been used as a polymer component. Its physicochemical properties make possible to dissolve it in N-methyl-2-pyrrolidone, with the obtainment of a solution able to form a gel-like depot once injected into a physiological medium. Cell compatibility of PHEA-g-PLA depot has been investigated, using murine dermal fibroblasts as cell model. 3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazo…
Aloin delivery on buccal mucosa: ex vivo studies and design of a new locoregional dosing system
2014
Context: Chemoprevention of potential malignant disorders or cancerous lesions that affect oral mucosae requires extended duration of treatment. Locoregional delivery of natural products could represent a promising strategy for this purpose. Objective: To investigate the aptitude of aloin to permeate through, or accumulate in, the buccal mucosa and to develop a new prolonged oro-mucosal drug delivery system. Materials and Methods: Permeation/accumulation of aloin from Curacao Aloe (containing 50% barbaloin) was evaluated ex vivo, using porcine buccal mucosa as the most useful model to simulate human epithelium. Oro-mucosal matrix tablets were prepared by dispersing aloin (10% w/w) in Eudrag…
PLGA nanoparticles are effective to control the colonic release and absorption on ibuprofen.
2018
The oral controlled release (CR) formulations have become more important in recent years. Among them, the polymeric nanoparticles have been thoroughly studied during the last decades, consequently they are extensively employed for a broad range of applications and drugs. The objective of this research was to develop polymeric nanoparticles (NPs) of ibuprofen with poly(lactic-co-glycolic) acid (PLGA) as polymer, and to test their applicability for oral CR formulations development. Different proportions of drug/polymer were employed to develop the ibuprofen NPs and their in vitro release profiles were analysed. The in situ segmental permeability of ibuprofen was tested in Wistar rat and demon…
From In Silico to Experimental Validation: Tailoring Peptide Substrates for a Serine Protease.
2020
Smart nanocarriers for the transport of drugs to tumor cells are nowadays of great interest for treating cancer. The use of enzymatic stimuli to cleave peptide-based drug nanocapsules for the selective release of nanocapsule cargo in close proximity to tumor cells opens new possibilities in cancer research. In the present work, we demonstrate a methodology for finding and optimizing cleavable substrate sequences by the type II transmembrane serine protease hepsin, which is highly overexpressed in prostate cancer. The design and screening of combinatorial libraries in silico against the binding cavity of hepsin allow the identification of a panel of promising substrates with high-calculated …
In VitroRelease of Local Anaesthetic and Anti-Inflammatory Drugs from Crosslinked Collagen Based Device
2012
The drug delivery systems that are the object of this article take the form of a hydrophilic matrix (collagen or crosslinked collagen) containing a drug. These devices can be used as The model active agents, were chosen from the range of local anaesthetics (lidocaine hydrochloride), anti-inflammatory (diclofenac sodium salt) and antioxydant (caffeic acid). Whatever the drug affinity for water, in the first time of the experiments, the release appears to be systematically delayed when the matrix is crosslinked. For lidocaine hydrochloride based systems, as the amount of drug increases in the matrix, the high gap concentration between the matrix and the buffer solution promote the diffusion a…
Functionalized Poly(N-isopropylacrylamide)-Based Microgels in Tumor Targeting and Drug Delivery
2021
Over the past several decades, the development of engineered small particles as targeted and drug delivery systems (TDDS) has received great attention thanks to the possibility to overcome the limitations of classical cancer chemotherapy, including targeting incapability, nonspecific action and, consequently, systemic toxicity. Thus, this research aims at using a novel design of Poly(N-isopropylacrylamide) p(NIPAM)-based microgels to specifically target cancer cells and avoid the healthy ones, which is expected to decrease or eliminate the side effects of chemotherapeutic drugs. Smart NIPAM-based microgels were functionalized with acrylic acid and coupled to folic acid (FA), targeting the f…
Amphiphilic Copolymers Shuttle Drugs Across the Blood-Brain Barrier.
2015
Medical treatment of diseases of the central nervous system requires transport of drugs across the blood-brain barrier (BBB). Here, it is extended previously in vitro experiments with a model compound to show that the non-water-soluble and brain-impermeable drug domperidone (DOM) itself can be enriched in the brain by use of an amphiphilic copolymer as a carrier. This carrier consists of poly(N-(2-hydroxypropyl)-methacrylamide), statistically copolymerized with 10 mol% hydrophobic lauryl methacrylate, into whose micellar aggregates DOM is noncovalently absorbed. As tested in a BBB model efficient transport of DOM across, the BBB is achievable over a wide range of formulations, containing 0.…
Microfibrillar polymeric ocular inserts for triamcinolone acetonide delivery.
2019
Abstract Despite eye drops generally represent the most convenient, simple and patient-friendly formulations to treat ocular diseases, they suffer from poor retention on the ocular surface and low drug bioavailability leading to the necessity of prolonged and continuous treatment over time. Therefore, ocular insert could represent an innovative way to benefit from ocular topical administration while minimizing all the relevant limitation related to this route of administration. Polymeric non-erodible mucoadhesive ocular inserts should be comfortable and should rapidly adhere on the ocular surface, remain in situ for prolonged period, assure a reproducible and controlled drug release as well…
In vitro study of N-succinyl chitosan for targeted delivery of 5-aminosalicylic acid to colon
2011
In vitro study on N-succinyl chitosan and chitosan (control) matrices for selective colon delivery of 5-aminosalicylic acid is described. Matrices containing β-cyclodextrin were also prepared. As shown by DSC analyses, the drug was successfully loaded into the matrices reaching up to 95% entrapment efficiency. Swelling and drug release were studied at pH 1.2, pH 7.4, and in a pH gradient medium to simulate the gastro-intestinal transit. Main result of this study was a higher capability of N-succinyl chitosan alone to better control drug release in the simulated gastro-intestinal transit: N-succinyl chitosan gave the lowest release in acid medium (≅15%) and the highest in alkaline environmen…