Functional Properties of Polyurethane Ureteral Stents with PLGA and Papaverine Hydrochloride Coating

Despite the obvious benefits of using ureteral stents to drain the ureters, there is also a risk of complications from 80–90%. The presence of a foreign body in the human body causes disturbances in its proper functioning. It can lead to biofilm formation on the stent surface, which may favor the development of urinary tract infections or the formation of encrustation, as well as stent fragmentation, complicating its subsequent removal. In this work, the effect of the polymeric coating containing the active substance-papaverine hydrochloride on the functional properties of ureteral stents significant for clinical practice were assessed. Methods: The most commonly clinically used polyurethane ureteral Double-J stent was selected for the study. Using the dip-coating method, the surface of the stent was coated with a poly(D,L-lactide-glycolide) (PLGA) coating containing the papaverine hydrochloride (PAP). In particular, strength properties, retention strength of the stent ends, dynamic frictional force, and the fluoroscopic visibility of the stent during X-ray imaging were determined. Results: The analysis of the test results indicates the usefulness of a biodegradable polymer coating containing the active substance for the modification of the surface of polyurethane ureteral stents. The stents coated with PLGA+PAP coating compared to polyurethane stents are characterized by more favorable strength properties, the smaller value of the dynamic frictional force, without reducing the fluoroscopic visibility.

Development of a Comprehensive HPLC Method for Determination of Product-related Impurities and Assay of Active Ingredients in Papaverine Hydrochloride Products

Papaverine hydrochloride products are used as anticonvulsants in routine medical practice. Most of the approved product specification files include thin-layer chromatography for assessment of product-related impurities and UV spectrophotometry for determination of active pharmaceutical ingredients. An HPLC assay is not used for determination of papaverine hydrochloride in drug dosage forms.The aim of the study was to develop an HPLC test method for determination of product-related impurities and for quantification of papaverine hydrochloride in solutions for injection, tablets, and rectal suppositories.Materials and methods: samples of the following Russian-made papaverine products were used in the study: Papaverine, solution for injection, 20 mg/mL; Papaverine, rectal suppositories, 20 mg; Papaverine, tablets, 40 mg. The Agilent 1260 Infinity II DAD System was used for the HPLC assay, and the Agilent 8453Е UV-Vis System was used for recording UV spectra. The determination of product-related impurities and the assay of active ingredients were performed simultaneously by HPLC using a reversed-phase column Kromasil 100-5-C18, 250×4.6 mm, 5 μm, the gradient elution mode, and detection at 238 nm. Papaverine Hydrochloride USP RS, 99% purity, and Noscapine EP CRS were used as reference standards.Results: the study demonstrated that determination of product-related impurities and assay of active ingredients in papaverine products can be performed simultaneously using HPLC.Conclusions: the authors proposed an HPLC test method for determination of active ingredients in papaverine products, which is aligned with the “consistent standardisation” principle and can be recommended for inclusion into draft monographs for papaverine products.

Comprehensive Treatment of Single Finger Frostbite: A Case Study

Third- and fourth-degree frostbites usually result in loss of skin and tissue requiring amputation, and scarring. The 3- to 6-week waiting period is often necessary to determine the severity of the lesion. This period is also a critical time for the rescue of frostbitten tissue. This patient was a 30-year-old man who developed frostbite of his right index finger. He presented to our hospital 4 hours after injury with loss of sensation on the whole index finger and early signs of necrosis. The patient received a series of comprehensive treatments, including fasciotomy, injection of papaverine hydrochloride, baking lamp irradiation, and negative pressure treatment. At the time of discharge, he had re-epithelialization of the index finger by 21 days after injury. The conclusion of this paper is that the comprehensive treatments combined with negative pressure wound treatment has certain clinical application value for the rescue of deep frostbite tissues.

The Impact of Intra-Arterial Papaverine-Hydrochloride on Cerebral Metabolism and Oxygenation for Treatment of Delayed-Onset Post-Subarachnoid Hemorrhage Vasospasm

BACKGROUND Delayed posthemorrhagic vasospasm remains among the major complications after aneurysmal subarachnoid hemorrhage (SAH) and can result in devastating ischemic strokes. As rescue therapy, neurointerventional procedures are used for selective vasodilatation. OBJECTIVE To investigate the effects of intra-arterial papaverine-hydrochloride on cerebral metabolism and oxygenation. METHODS A total of 10 consecutive patients, suffering from severe aneurysmal SAH were prospectively included. Patients were under continuous multimodality neuromonitoring and required intra-arterial papaverine-hydrochloride for vasospasm unresponsive to hypertensive therapy. Cerebral metabolism (microdialysis), brain tissue oxygen tension (ptiO2), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) were analyzed for a period of 12 h following intervention. RESULTS A median dose of 125 mg papaverine-hydrochloride was administered ipsilateral to the multimodality probe. Angiographic improvement of cerebral vasospasm was observed in 80% of patients. During intervention, a significant elevation of ICP (13.7 ± 5.2 mmHg) and the lactate-pyruvate ratio (LPR) (54.2 ± 15.5) was observed, whereas a decrease in cerebral glucose (0.9 ± 0.5 mmol/L) occurred. Within an hour, an increase of cerebral lactate (5.0 ± 2.0 mmol/L) and glycerol (104.4 ± 89.8 μmol/L) as well as a decrease of glucose (0.9 ± 0.4 mmol/L) were measured. In 2 to 5 h after treatment, the LPR significantly decreased (pretreatment: 39.3 ± 15.3, to lowest 30.5 ± 6.7). Cerebral pyruvate levels increased in 1 to 10 h (pretreatment: 100.1 ± 33.1 μmol/L, to highest 141.4 ± 33.7 μmol/L) after intervention. No significant changes in ptiO2 or CPP occurred. CONCLUSION The initial detrimental effects of the endovascular procedure itself were outweighed by an improved cerebral metabolism within 10 h thereafter. As the effect was very limited, repeated interventions or continuous application should be considered.