Preparation and characterization of papaverine-loaded poly[(r)-3-hydroxybutyrate] membranes to be used in the prevention of vasospasm.

The objective of this study is the preparation and characterization of poly[(R)-3-hydroxybutyrate] (PHB) membrane loaded with a vasodialative agent (i.e., papaverine hydrochloride) as a blood vessel coverage strip to be used in the prevention of undesired vascular vasospasm. Papaverine-loaded PHB membranes were especially designed to act locally and provide an efficient, long term, and sustained prevention of vasospasm at the site of the newly created vascular anastomosis without any systemic vasodilation effect of the papaverine, which may be life-threatening for the patient. The membranes were prepared by gelation of PHB followed by solvent casting. PHB membranes were characterized in terms of morphology, chemical structure, swelling behavior, in vitro drug release, degradation, and blood compatibility studies as in vitro coagulation tests. Activated partial thromboplastin time, prothrombin time, and fibrinogen concentration were measured by blood coagulation assays. Investigated and evaluated parameters for in vitro drug release, degradation, and in vitro coagulation studies were the concentration of PHB and drug content. Similar effective parameters were used for swelling behavior studies (i.e., concentration of PHB and drug content). Drug release, swelling behavior, degradation, and in vitro coagulation of the membranes were found to be influenced by these parameters. Obtained results showed that papaverine-loaded PHB membranes provide an efficient and advantegous means for the prevention of vasospasm during vascular anastomosis as a local application.