Pulmonary arterial hypertension (PAH) is a progressive, fatal syndrome characterised by increased vascular resistance that leads to right-ventricular hypertrophy and heart failure, eventually leading to death. The chapters of this book describe the molecular mechanisms and cellular events regulating vascular remodelling in PAH; the various animal models and drugs currently being used in various laboratories to study mechanisms leading to pulmonary arterial hypertension; and nifedipine, its pharmacology and its role in the management of pulmonary hypertension and some of the drawbacks concerning its use. The authors also discuss drug delivery systems that can lead to different crystallisation forms of the immobilised drug which can lead to better solubility and bioavailability.