Thermal analysis studies on the compatibility of furosemide with solid state and liquid crystalline excipients

Abstract

In the context of the present study, the thermal behavior of furosemide and the solid state excipients, sodium alginate, poly(ethylene oxide), poly(vinylpyrrolidone), lactose mono-hydrate and magnesium stearate, using Differential Scanning Calorimetry (DSC), was probed. It was found that the thermal behavior of these solid-state pharmaceutical excipients and furosemide correlates nicely with the literature relevant data. Regarding the furosemide-excipients mixtures, the DSC scans appear as a compilation of the thermal curves of each excipient. This suggests that the formulations containing these mixtures, may retain their stability over time. This information, which arises from the cooperativity of materials, their thermal stability and behavioris very helpful for the research and development of safe and effective pharmaceutical formulations. DSC experiments were also carried out with chimeric bilayers (called “liposomes”), composed of hydrogenated soy phosphatidylcholine (HSPC) and poly(n-butylacrylate)-b-poly(acrylic acid) block copolymer with 70 % content of poly(acrylic acid (PnBA-b-PAA 30/70) with the addition of furosemide at the molar ratio of 9:0.1:1.0 in the system HSPC:PnBA-b-PAA 30/70:furosemide. Chimeric liposomal systems were characterized as “fluid-like” by their DSC curves, which may be potentially translated as an easy way for release of furosemide from the advanced delivery system.

Keywords

• differential scanning calorimetry
• cooperativity
• stability
• chimeric liposomal systems
• magnesium stearate
• lactose