Search results for "Delivery systems"

Theme issue 5th World Conference on Drug Absorption, Transport and Delivery.

2014

Core-Shell Arginine-Containing Chitosan Microparticles for Enhanced Transcorneal Permeation of Drugs

2019

Chitosan oligosaccharide (C) was functionalized with L-arginine (A) and short hydrocarbon chains (C-8) to design an amphiphilic copolymer, henceforth CAC(8), leading to microparticles (MPs) consisting of an arginine-decorated hydrophilic shell and inner hydrophobic domains allowing the encapsulation of high amount hydrophobic drugs such as sorafenib tosylate (>10% w/w). L-arginine side chains were selected in order to impart the final MPs enhanced transcorneal penetration properties, thus overcoming the typical biological barriers which hamper the absorption of drugs upon topical ocular administration. The mucoadhesive properties and drug release profile of the CAC(8) MPs (CAC(8)-MPs) were …

5-Fluorouracil Buccal Tablets for Locoregional Chemotherapy of Oral Squamous Cell Carcinoma: Formulation, Drug Release and Histological Effects on Re…

2010

5-Fluorouracil (5-FU) is currently used for treatment of oral squamous cell carcinoma (OSCC). 5-FU is given by i.v. although the systemic administration is associated with severe toxic effects and no topical formulations of 5-FU for buccal drug delivery have been reported. In this study we would report the development of buccal tablets suitable for direct application of low-doses of 5-FU on cancer lesions. The topical administration could be effective on tumor area while systemic undesired side effects are avoided. Preliminarily, the limited tendency of 5-FU to cross the buccal tissue was established using reconstituted human oral epithelium (RHOE, in vitro) and porcine buccal mucosa (ex vi…

Medium-Term Culture of Primary Oral Squamous Cell Carcinoma in a Three- Dimensional Model: Effects on Cell Survival Following Topical 5-Fluororacile …

2012

Since the activity of several conventional anticancer drugs is restricted by resistance mechanisms and dose-limiting side-effects, the design of formulations for local application on malignant lesions seems to be an efficient and promising drug delivery approach. In this study, the effect of locally applied 5-FU on cell death was evaluated both in a SCC4/HEK001 model and in a newly proposed 3D outgrowth model of oral squamous cell carcinoma (OSCC). Initially, the optimal drug dose was established by delivery of solutions containing different amounts of 5-FU. The solution containing 1% (w/v) of 5-FU resulted effective in inducing cell death with complete eradication of cell colonies. Buccal …

Cationic Supramolecular Vesicular Aggregates for Pulmonary Tissue Selective Delivery in Anticancer Therapy

2016

The biopharmaceutical properties of supramolecular vesicular aggregates (SVAs) were characterized with regard to their physicochemical features and compared with cationic liposomes (CLs). Neutral and cationic SVAs were synthesized using two different copolymers of poly(aspartyl hydrazide) by thin-layer evaporation and extrusion techniques. Both copolymers were self-assembled in pre-formulated liposomes and formed neutral and cationic SVAs. Gemcitabine hydrochloride (GEM) was used as an anticancer drug and loaded by a pH gradient remote loading procedure, which significantly increased drug loading inside the SVAs. The resulting average size of the SVAs was 100 nm. The anticancer activity of …

Efficacy of budesonide-loaded mesoporous silica microparticles capped with a bulky azo derivative in rats with TNBS-induced colitis.

2019

Abstract A colon targeted drug delivery system for inflammatory bowel diseases (IBD), consisting in budesonide loaded mesoporous silica microparticles functionalized with a selective azo-molecular gate (M-Bud), has been evaluated for in vivo efficacy. Experimental colitis in male Wistar rats was induced by rectal instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS). M-Bud was orally administered to the rats as a suspension in water. Colon/body weight ratio, clinical activity score, and histological evaluation were used as inflammatory indices to measure the performance of the microparticles. The formulation was compared with a suspension prepared from the commercial drug Entocord®. Sta…

Montmorillonite nanodevices for the colon metronidazole delivery.

2013

The adsorption profiles of the antibiotic metronidazole (MNE) into the K10-montmorillonite (MMT-K10) clay and the subsequent release have been investigated as a function of pH and MNE/MMT-K10 ratio, in order to evaluate the potential of the MNE/MMT-K10 hybrids as controlled drug delivery system. The adsorption mechanism has been first elucidated by performing complementary equilibrium and kinetic studies and through the X-ray diffractometry (XRD) characterization of the obtained composite materials. The gathered results allowed us to propose a mechanism consisting of a multi-step pathway involving the neutral and the cationic form of the drug, which interact with different sites of the clay…

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…

Potential transbuccal delivery of l-DOPA methylester prodrug: stability in the environment of the oral cavity and ability to cross the mucosal tissue

2016

Levodopa (l-DOPA) is the most effective pharmacologic agent in Parkinson's disease and remains the "gold standard". Nevertheless, in long-term treatments, dyskinesias and motor complications can emerge. In this work, the combined use of l-DOPA methylester hydrochloride prodrug (LDME) with transbuccal drug delivery was supposed as a good alternative method to optimize the bioavailability of l-DOPA, to maintain constant plasma levels and to decrease the drug unwanted effects. The effects of environmental pH on buccal delivery of LDME were evaluated ex vivo. The increase of pH value from 5.8 to 6.2 implies an improvement of drug permeation. Since the pH increase causes the raising of hydrolyti…