2016 journal article

Formulation and characterization of a plasma sterilized, pharmaceutical grade chitosan powder

CARBOHYDRATE POLYMERS, 146, 420–426.

By: A. Crofton*, S. Hudson n, K. Howard*, T. Pender*, A. Abdelgawad n, D. Wolski n, W. Kirsch*

co-author countries: United States of America 🇺🇸
author keywords: Chitosan; Cryomilling; Jet milling; Ball milling; Cryo-ball milling; Cryo jet milling; Plasma sterilization
MeSH headings : Chemistry, Pharmaceutical; Chitosan / chemistry; Excipients / chemistry; Molecular Weight; Particle Size; Powders; Viscosity; Wettability
Source: Web Of Science
Added: August 6, 2018

Chitosan has great potential as a pharmaceutical excipient. In this study, chitosan flake was micronized using cryo-ball and cryo-jet milling and subsequently sterilized with nitrogen plasma. Micronized chitosan was characterized by laser diffraction, scanning electron microscopy (SEM), conductometric titration, viscometry, loss on drying, FTIR, and limulus amebocyte lysate (LAL) assays. Cryo-jet milling produced mean particle size of 16.05μm, 44% smaller than cryo-ball milling. Cryomilled chitosan demonstrated increased hygroscopicity, but reduced molecular weight and degree of deacetylation (DD). SEM imaging showed highly irregular shapes. FTIR showed changes consistent with reduced DD and an unexplained shift at 1100cm(-1). Plasma treated chitosan was sterile with <2.5EU/g after low-pressure plasma and <1.3EU/g after atmospheric pressure plasma treatment. Plasma treatment decreased the reduced viscosity of chitosan flake and powder, with a greater effect on powder. In conclusion, pharmaceutical grade, sterile chitosan powder was produced with cryo-jet milling and plasma sterilization.