Mechanistic insights into dissolution enhancement of co-spray dried meloxicam with chitosan and solubilization agent

Abstract

Abstract This study presents a co-spray drying formulation approach to enhance the dissolution rate of meloxicam (MX), a poorly soluble model drug, by combining it with chitosan (CHIT) and sodium lauryl sulfate (SLS). Ternary formulations were prepared using both mini- and medium-scale spray dryers and compared with physical mixtures and RAW MX. In vitro dissolution testing revealed a significant increase in the release rate, with up to 80% of MX dissolved within 5 min. A comprehensive set of solid-state analytical techniques (XRPD, FTIR, and confocal Raman microscopy) revealed subtle changes in MX crystallinity and hydrogen-bonding interactions with both excipients. These findings support three key mechanisms contributing to enhanced dissolution: (i) reduced agglomeration of MX via adsorption onto the CHIT surface, (ii) improved wettability of products due to the presence of SLS, and (iii) increased matrix hydrophilicity facilitating drug–medium contact. The successful scale-up using a medium-scale spray dryer demonstrated the feasibility of this strategy for industrial application. The results highlight co-spray drying with functional excipients as a robust and scalable method for improving the biopharmaceutical performance of poorly soluble drugs. The simple co-spraying of the CHIT dispersion with the drug solution, without the need to dissolve the chitosan, is additional advantage.