Dexamethasone sodium phosphate-loaded Chitosan based delivery systems for buccal application

Abstract

Chitosan (CH) was used as a biocompatible and bioadhesive polymer material to prepare solid dispersions as well as hydrogels loaded with dexamethasone sodium phosphate (DSP), a steroidal anti-inflammatory agent clinically used for treatment of different mouth diseases. Binary solid dispersions at various drug-to-polymer weight ratios were prepared by freeze-drying; their direct compression gave tablets which were characterized for the swelling behaviour and drug release in vitro. Similarly, DSP-loaded hydrogels composed of CH and glycerine were prepared and characterized. CH and DSP showed a good physical compatibility. A slow and prolonged release of the drug was observed in vitro from both kinds of systems. The swelling properties of the polymer seemed to be the main parameter affecting the drug release profile from both tablets and hydrogels at the pH value of mouth. In vivo buccal application of both the systems allowed to obtain a prolonged release of DSP, as compared with a glycerine solution of the drug. From the in vitro swelling studies and in vivo test, the 2:1 CH-DSP solid dispersion in particular can be designated for further investigation.

Introduction

“…The same authors showed the enhancing effect of a CHT hydrogel on the transit of a peptide drug, the growth factor TGF-β [124], and again CHT was used for applications against a periodontal pathogen [48]. The anti-inflammatory activity of dexamethasone by buccal application of a CHT hydrogel was reported by Pignatello et al [100], while the anesthetic activity of a mucoadhesive hydrogel based on CHT glutamate and lidocaine HCl was assessed in vivo [101]. Also insulin was proposed for buccal administration, and a pronounced hypoglycaemic effect by means of an insulin-loaded mucoadhesive CHT-EDTA hydrogel system was evidenced [21].…”

Design of colon-targeted drug delivery of dexamethasone: Formulation and in vitro characterization of solid dispersions

“…DEX exhibited poor aqueous solubility of 89 μg/mL, limiting its oral bioavailability [ 67 ]. It has been shown that the solubility of DEX enhanced upon dispersion in several carriers such as polyethylene glycol 6000 [ 68 ], propylene glycol [ 69 ], and chitosan [ 70 ]. In this study, the solubility of DEX significantly improved upon its dispersion in the polymeric carriers at 37 ± 1 and 25 ± 1 °C in PBS (pH = 7.4), compared to that of pure DEX ( Table 2 ).…”

Suppression of Fibrotic Reactions of Chitosan-Alginate Microcapsules Containing Porcine Islets by Dexamethasone Surface Coating

“…The encapsulated islets were washed with 1×HBSS and 1 mg/mL Dexa contained pH 4.5 1% filtrated chitosan solution (w/v in deionized distilled water) for 10 minutes with stirring for Dexa-chitosan coating. Chitosan, high affinity positive charged residue [24], was used as an intermediary to link alginate and Dexa because both alginate and Dexa have negative charges.…”