Evaluation of dibutyrylchitin as new excipient for sustained drug release.

Dibutyrylchitin (DBC), a lipophilic chitin diester, has been synthesized from chitin and butyric anhydride with methanesulfonic acid as catalyst. Exhaustive esterification of free alcoholic groups of chitin was assessed by FT-IR and (1)H-NMR spectroscopy. High degree of alkyl substitution allowed DBC to acquire an almost completely lipophilic character.

Surface characterisation of bioadhesive PLGA/chitosan microparticles produced by supercritical fluid technology.

Purpose: Novel biodegradable and mucoadhesive PLGA/chitosan microparticles with the potential for use as a controlled release gastroretentive system were manufactured using supercritical CO(2) (scCO(2)) by the Particle Gas Saturated System (PGSS) technique (also called CriticalMix(TM)).

Methods: Microparticles were produced from PLGA with the addition of mPEG and chitosan in the absence of organic solvents, surfactants and crosslinkers using the PGSS technique. Microparticle formulations were morphologically characterized by scanning electron microscope; particle size distribution was measured using laser diffraction.

A study of free radical release from beta-cyclodextrin-anticancer pro-drugs adducts in water.

A novel approach in cancer chemotherapy concerns the attempt to employ radical affording substances (RAS) as pro-drugs able to produce irreversible damages on the tumor cell, so stimulating cellular apoptosis. However, radical species can react quickly towards the chemical environment into which they have been generated before reaching their proper sites of action, i.e.