Preparation and evaluation of aviptadil acetate loaded plga microparticles: A preliminary study to treat pulmonary hypertension

The purpose was to develop suitable poly lactic-co-glycolic acids (PLGA) polymeric microparticles containing avaptadil, an investigational drug for the treatment of pulmonary arterial hypertension, for sustained release. In the current study, aviptadil PLGA loaded microparticles were prepared by double emulsion and solvent evaporation method. The developed microparticles were evaluated for particle size, polydispersity index, drug entrapment, drug loading, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), Powder X-ray diffraction pattern (XRD), Scanning electron microscopic (SEM) and release profiles in simulated lung fluid. Among the six formulations (F1 to F6), formulation prepare with 75:25 (F5) showed an average particle size (2.91µm), high entrapment of drug (66.37%) and drug loading (3.33%). SEM images and surface morphology confirmed that microparticles were spherical and had smooth surfaces. In vitro release studies showed sustained release pattern; the optimized formulation (F5) approximately released 57% of the drug over 7 days. The release profile of the aviptadil in simulated lung fluid showed a sustained release pattern that may allow spreading of the drug inside the lung tissues to cover most of the area.