Solid-state characterization of two polymorphic forms of R-albuterol sulfate.

R-albuterol (levalbuterol) is a drug used for asthma therapy and some formulations of it are in solid dosage forms. The aim of this work was to describe and characterize two polymorphic modifications of R-albuterol sulfate by means of typical structure-sensitive analytical techniques such as X-ray powder diffraction, FT-IR spectroscopy, visual and microscopic inspection, and DSC. Substantial differences were observed between the solid-state properties of the crystals, confirming the existence of at least two polymorphic forms for R-albuterol sulfate: Form I and Form II.