In Vitro Release from Reverse Poloxamine/α-Cyclodextrin Matrices: Modelling and Comparison of Dissolution Profiles

Abstract

Gels obtained by complexation of octablock star polyethylene oxide/polypropylene oxide copolymers (Tetronic 90R4) with α‐cyclodextrin (α‐CD) were evaluated as matrices for drug release. Both molecules are biocompatible so they can be potentially applied to drug delivery systems. Two different types of matrices of Tetronic 90R4 and α‐CD were evaluated: gels and tablets. These gels are capable to gelifying in situ and show sustained erosion kinetics in aqueous media. Tablets were prepared by freeze‐drying and comprising the gels. Using these two different matrices, the release of two model molecules, L‐tryptophan (Trp), and a protein, bovine serum albumin (BSA), was evaluated. The release profiles of these molecules from gels and tablets prove that they are suitable for sustained delivery. Mathematical models were applied to the release curves from tablets to elucidate the drug delivery mechanism. Good correlations were found for the fittings of the release curves to different equations. The results point that the release of Trp from different tablets is always governed by Fickian diffusion, whereas the release of BSA is governed by a combination of diffusion and tablet erosion. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:197–206, 2014

Cotton‐hydrogel composite for improved wound healing: Antimicrobial activity and anti‐inflammatory evaluation—Part 2

“…The predominance of Fickian diffusion as drug delivery mechanism on cyclodextrin-based hydrogels was also described in several works. 33,43,44 The same behavior was, also, observed on composites obtained by the conjugation of hydrogel networks and textile substrates. For instance, Cirillo and coworkers 45 developed a cotton-gauze-hydrogel composite electroresponsive drug delivery system to be used as wound dressing.…”

“…The diffusional constants obtained were superior for the composites, comparative with the control substrates, regardless the cyclodextrins used. The predominance of Fickian diffusion as drug delivery mechanism on cyclodextrin‐based hydrogels was also described in several works …”

Smart Hydrogel for the pH‐Selective Drug Delivery of Antimicrobial Compounds

“…The drug release mechanics of the composites was control by Fickian, since the diffusion k D values were always superior to k R . The predominance of Fickian diffusion as drug delivery mechanism on cyclodextrins based hydrogels was also described in several works …”

Preparation and Characterization of Silk Beads for Protein Delivery System

“…Bovine serum albumin (BSA) extracted from cows is a soluble protein of the circulatory system and helps binding and transport of nutrients to cells . BSA has been previously studied as a model protein drug (Karrañeta et al, 2013) Silk is a natural, fibrous protein spun by silkworms, and has been used traditionally in textile fibers and as surgical sutures for human subjects (Wang et al, 2010;Kweon et al, 2012). It is composed of two kinds of proteins, a core protein (fibroin) and a gum-like protein (sericin).…”