Evaluation of crosslinked chitosan hydrogels as carriers for prolonged delivery of some novel nitric oxide donor compounds based on theophylline and paracetamol

Abstract

The hydrogels of crosslinked chitosan with different glutaraldehyde amounts have been "in vitro" tested as carriers for prolonged release of some drugs for inflammatory and bronchopulomonary diseases. These hydrogels have been loaded with two novel nitric oxide donors, derivatives of 7-[2-nitroxyacethyloxy-3-(4-acethyl-amino-phenoxy)-propyl]-8-R-1,3-dimethyl-xanthine compounds (R=H, NO 2 for 65 and respectively 77 compounds) designed as multitarget drugs and parent compounds as paracetamol, theophylline, two xanthine derivatives 7-[2-hydroxy-3-(4-acethyl-amino-phenoxy)-propyl]-8-R-1,3-dimethyl-xanthine derivatives with (R=H, NO 2 for D 1 and respectively D 2 ) and their release was evaluated in an acidic solution (pH=2.2) simulating the gastric fluid. Results have been correlated with the swelling behaviour which was also followed in acidic media with pH=2.2. The relationships between the release profiles and kinetics and matrix characteristics and/or drug properties have been established.

Preparation and Characterization of Alginate and Chitosan Ipc Based Gel Formulation for Mucosal Application

“…Previously, it was determined that the higher the amount of chitosan, the higher strength of the gel. [21][22][23][24] By increasing the amount of chitosan, particularly in the case of IPC with SA/CS 50/50 (v/v %), the expected flow behavior should be a combined shear thinning with a dilatant specific trend-line; instead, no clear dependence was obtained because of the formed compact structure, the free move of macromolecules being limited. The matrix containing 40% chitosan (SA/CS 60/40 (v/v %)) was considered suitable, as the desired pseudoplastic flow behaviour was obtained (Fig.…”

“…This showed that an increased amount of chitosan led to a denser network, hindering the swelling of the IPC matrix. [21][22][23][24] As shown in Figure 6, NYS seemed to play a plastifying role, as the swelling ability of the loaded matrices is different.…”

Formulation and Evaluation of Chitosan-Polypyrrole Nanocomposites for Controlled Release of Anticancer Drug Doxorubicin

“…The regression coefficient (r 2 Due to the swelling ability of the polymer, there is an opening of the pore channels in between the polymer matrix which helps with the diffusion of the drug through the polymer matrix chains, thus, releasing the drug from the films. Table 4 depicts the values of various release kinetics parameters for the films [10,[19][20][21][22].…”

Application of montmorillonite in bentonite as a pharmaceutical excipient in drug delivery systems

“…In many cases, increasing the montmorillonite content decreases the drug release rate. In addition, incorporating montmorillonite decreases swellability of formulation (Cojocariu et al 2012a;Abdeen and Salahuddin 2013). An ofloxacin-loaded chitosan hydrogel shows fast drug release under a low pH condition, but montmorillonite decreased the release rate (Hua et al 2010b).…”