Microspherical Particles of Solid Dispersion of Polyvinylpyrrolidone K29-32 for Inhalation Administration

Figure 10

IR spectra of PVP K29-32, PHE, and microspherical particles formed using spray drying with three different spray caps (4.0, 5.5, and 7.0 μm hole size) in the wavenumber range 600–4000 cm⁻¹ (a) and 1600–1700 cm⁻¹ (b).

(a)

(b)