Production of pH-responsive microparticles by spray drying: investigation of experimental parameter effects on morphological and release properties

Rizi, K., Green, B., Donaldson, M. and Williams, A. ORCID: https://orcid.org/0000-0003-3654-7916 (2011) Production of pH-responsive microparticles by spray drying: investigation of experimental parameter effects on morphological and release properties. Journal of Pharmaceutical Sciences, 100 (2). pp. 566-579. ISSN 1520-6017 doi: 10.1002/jps.22291

Abstract/Summary

During spray drying, emphasis is placed on process optimisation to generate favourable particle morphological and flow properties. The effect of the initial feed solution composition on the drug release from the prepared microparticles is rarely considered. We investigated the effects of solvent composition, feed solution concentration and drug-loading on sodium salicylate, hydrocortisone and triamcinolone release from spray dried Eudragit L100 microparticles. Eudragit L100 is a pH-responsive polymer whose dissolution threshold is pH 6 so dissolution testing of the prepared microparticles at pH 5 and 1.2 illustrated non-polymer controlled burst release. Increasing the water content of the initial ethanolic feed solution significantly reduced hydrocortisone burst release at pH 5, as did reducing the feed solution concentration. These findings caution that changes in feed solution concentration or solvent composition not only affect particles’ morphological characteristics but can also negatively alter their drug release properties. This work also illustrate that drug-free microparticles can have different morphological properties to drug-loaded microparticles. Therefore, process optimisation needs to be carried out using drug-loaded systems. Depending on the physicochemical properties of the encapsulated API, drug-loading can affect the polymer solubility in the initial feed solution with consequent impact on microparticles morphological and release properties.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/21363
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Pharmaceutics Research Group
Uncontrolled Keywords	spray drying; Eudragit L100; microparticles; burst release; encapsulation; polymeric drug delivery systems; controlled release
Publisher	Wiley
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