This article, published in Drug Delivery Technology Magazine in October 2010, highlights how high tech spray drying techniques and a novel biopolymer of non-animal origin can be combined for the production of pharmaceutically relevant bioadhesive microparticles with controlled particle size lower than 5 micrometers and a cationic surface change, ideally suited for mucosal controlled drug delivery and vaccination.
Spray drying is the preferred technique to prepare microparticles for pharmaceutical applications because it is a scalable, rapid, controlled, clean and economic process. BUCHI Labortechnik AG has recently developed the Nano Spray Dryer B-90 which enables the production of submicron particles. The spray dryer was designed to emulate drying during the early stages of product development of small sample amounts at high yields. BUCHI’s Mini Spray Dryer B-290 was also used in these experiments.
The B-90 Spray Dryer is suitable for a variety of applications, including spray drying solutions, nanoemulsions, nanosuspensions, structural transformations and micro or nanoencapsulations. By means of a piezoelectric driven spray head, millions of precisely sized tiny droplets are generated every second. The dried particles are separated by an electrostatic collector with excellent particle recovery rates even for nanoparticles of milligram sample amounts.
Chitosan is increasingly used as a safe excipient in advanced pharmaceutical formulations with unique functionalities such as enhanced mucoadhesion, enhanced drug bioavailability, enhanced biological barrier permeability and bioresorbability. Chitosan is a bioresorbable biopolymer made of D-glucosamine and N-acetyl-D-glucosamine.