New formulations based on salicyl-imine-chitosan hydrogels for prolonged drug release

A theoretical mathematical model for assessing diclofenac release from chitosan-based formulations

“…The drug delivery systems were prepared by in situ hydrogelation of chitosan with salicylaldehyde in the presence of DCF, according to a procedure developed in our group (Craciun et al., 2019 ; Ailincai et al., 2018 ; Iftime et al., 2020 ). Using two different molar ratio of the amine/aldehyde functional units, ( 1.5:1 and 2:1 ), and keeping constant the amount of drug (1.5 mg), two formulations coded D1.5 and D2 were prepared.…”

“…At fixed intervals, 2 mL aliquots were withdrawn and replaced with 2 mL fresh buffer. The supernatant samples were collected and the DCF amount was determined by quantitative absorption spectroscopy, recording the characteristic absorption band at 275 nm, and fitting its absorbance on a predetermined calibration curve (Iftime et al., 2020 ; Dragan & Cocarta, 2016 ). The cumulative release of the DCF was estimated from the Lambert-Beer law.…”

“…Taking account of this state of the art, our group developed a new strategy for chitosan hydrogelation with natural monoaldehydes, which are of natural origin and have no toxicity (Marin et al., 2015 ; Ailincai et al., 2016 ; Iftime et al, 2017 ; Marin et al., 2017 ; Olaru et al., 2018 ; Bejan et al., 2018 ; Iftime & Marin, 2018 ; Xiong et al., 2019 ). The hydrogels prepared by this route proved excellent ability to accommodate biologic agents, such as drugs or fertilizers (Craciun et al., 2019 ; Iftime et al., 2019 ; Ailincai et al., 2018 ; Iftime et al., 2020 ). Among these new hydrogels, that using salicylaldehyde as crosslinker lead to chitosan hydrogels which demonstrated appropriate properties for the design of drug delivery systems, such as biocompatibility, biodegradability, swelling ability, thixotropy and self-healing (Iftime et al, 2017 ).…”

“…Among these new hydrogels, that using salicylaldehyde as crosslinker lead to chitosan hydrogels which demonstrated appropriate properties for the design of drug delivery systems, such as biocompatibility, biodegradability, swelling ability, thixotropy and self-healing (Iftime et al, 2017 ). They proved capacity to encapsulate a model drug, diclofenac sodium salt (DCF), and further to slowly release it along 10 days, based on the strong physical forces developed between matrix and drug (Iftime et al., 2020 ). These excellent findings, encouraged us to further investigate these formulations in order to better understand the release mechanism, to create a proper structure-drug release correlation, and further to improve the design to reach the thorny goal of a real world application.…”

The Tuning of Chitosan�s Hydrophilicity by Changing the PEG Content Grafted on the Chitosan Backbone

“…In the recent years, the researchers' attention has been directed towards the exploitation of polysaccharides, due to their extraordinary properties which recommend them for a large variety of applications [1,2]. Among them, chitosan occupies a special place, being widely used in the design and development of materials and biomaterials with advanced functions and applications [3,4], being involved in each application field, from agriculture [5,6], waste water treatment [7,8], diapers industry [9] to drug delivery [10][11][12][13], gene therapy [14] or bioengineering [15,16].…”