Szerkezetváltozások hatása kondenzált fázisok szabadtérfogatára: pozitronannihilációs vizsgálatok = Effects of structural changes on the free volume of condensed phases: a positron annihilation study

Munkánk során olyan területre igyekeztünk kiterjeszteni a pozitronannihilációs kutatásokat, ahol eddig nem használták azokat szerkezetvizsgálatra. Habár az élettartam spektroszkópia mostanra a polimerek szerkezetvizsgálatának bevett módszerévé vált, nagyon kevesen alkalmazták rajtunk kívül adalékolt, ipari, gyógyszerészeti polimerek vizsgálatára. A pályázat keretében polimerkeverékeket, kopolimereket, gyógyszeralapanyagokat vizsgáltunk. Pozitronannihilációs spektroszkópiák, ab initio számítások és hagyományos polimervizsgáló módszerek segítségével több különböző rendszerben derítettük fel a polimerek szerkezete és gyógyszrészeti használhatóságuk közötti összefüggéseket. Vizsgáltuk a szabadtérfogat változását a polimer öregedésének függvényében, a polimer és a lágyítószer kölcsönhatását, a polimerkeverék és a hatóanyag kapcsolatát, illetve összetett polimerrendszer vízfelvételét különböző rendszerekben. Munkánkat folyamatosan publikáltuk. 14 folyóiratcikk, egy könyvfejezet és két konferenciakiadványban megjelent cikk jelzi munkánk eredményét. | During the last few years, we have introduced positron annihilation to fields where it hasn't been used for structural studies. Although positrons are used regularly for the study of polymers, there are very few detailed studies are known in the field of complex, industrially or pharmaceutically important polymer systems. In this project, we have studied polymer mixtures, copolymers and pharmaceutic materials. We have combined positron annihilation with ab initio calculations and conventional structural characterization methods to study complex polymeric systems. We have studied the connections between the free volume and the physical ageing, the effects of plasticizers, the interactions between the polymer and the drug, and the swelling of polymers during physical ageing. We have published the results in international journals. 14 articles in peer reviewed journals, a chapter in a book and 2 articles in conference proceedings mark our work

Recent Development of Electrospinning for Drug Delivery

Several promising techniques have been developed to overcome the poor solubility and/or membrane permeability properties of new drug candidates, including different fiber formation methods. Electrospinning is one of the most commonly used spinning techniques for fiber formation, induced by the high voltage applied to the drug-loaded solution. With modifying the characteristics of the solution and the spinning parameters, the functionality-related properties of the formulated fibers can be finely tuned. The fiber properties (i.e., high specific surface area, porosity, and the possibility of controlling the crystalline–amorphous phase transitions of the loaded drugs) enable the improved rate and extent of solubility, causing a rapid onset of absorption. However, the enhanced molecular mobility of the amorphous drugs embedded into the fibers is also responsible for their physical–chemical instability. This Special Issue will address new developments in the area of electrospun nanofibers for drug delivery and wound healing applications, covering recent advantages and future directions in electrospun fiber formulations and scalability. Moreover, it serves to highlight and capture the contemporary progress in electrospinning techniques, with particular attention to the industrial feasibility of developing pharmaceutical dosage forms. All aspects of small molecule or biologics-loaded fibrous dosage forms, focusing on the processability, structures and functions, and stability issues, are included

Qualitative and quantitative research of medication review and drug-related problems in Hungarian community pharmacies: a pilot study

Abstract Background Pharmaceutical care is the pharmacist’s contribution to the care of individuals to optimize medicines use and improve health outcomes. The primary tool of pharmaceutical care is medication review. Defining and classifying Drug-Related Problems (DRPs) is an essential pillar of the medication review. Our objectives were to perform a pilot of medication review in Hungarian community pharmacies, a DRP classification was applied for the first time. Also, our goal was the qualitative and quantitative description of the discovered DRPs, and of the interventions for their solution in order to prove the safety relevance of the service and to map out the competence limits of GPs and community pharmacists to drug therapy. Methods The project took place in Hungarian community pharmacies. The study was performed with patients taking vitamin K antagonist (VKA) and/or ACE inhibitor and NSAID simultaneously (ACEI-NSAID). 61 pharmacists and 606 patients participated in the project. Pharmacists reviewed the medication for 3 months and the classification of DRPs was performed (category of DRP1 – DRP6). Patient data were statistically analyzed. Results Patients consumed on average 7.9 ± 3.1 medications and other products. 571 DRPs were detected in 540 patients, averaging 1.06 DRPs per patient (SD = 1.07). The highest frequency category was DRP5 (non-quantitative safety problem; 51.0%). The most common root cause was an interaction (42.0%) and non-adherence (19.4%.). The most commonly used intervention was education (25.4%) and medication replacement by the pharmacist (20.1%). The changing of the frequency and dosage in any direction were negligible. Conclusions Patients are struggling with many DRPs that can be assessed and categorized by this system and which remain unrecognizable without pharmacists. Further projects need to be developed to assist in the development of physician-pharmacist cooperation and the widespread dissemination of pharmaceutical care

Preformulation Studies of Furosemide-Loaded Electrospun Nanofibrous Systems for Buccal Administration

Furosemide loaded electrospun fibers were prepared for buccal administration, with the aim of improving the oral bioavailability of the poorly soluble and permeable crystalline drug, which can be achieved by the increased solubility and by the circumvention of the intensive first pass metabolism. The water soluble hydroxypropyl cellulose (HPC) was chosen as a mucoadhesive polymer. In order to improve the electrospinnability of HPC, poly (vinylpyrrolidone) (PVP) was used. During the experiments, the total polymer concentration was kept constant at 15% (w/w), and only the ratio of the two polymers (HPC-PVP = 5:5, 6:4, 7:3, 8:2, 9:1) was changed. A combination of rheological measurements with scanning electron microscopic morphological images of electrospun samples was applied for the determination of the optimum composition of the gels for fiber formation. The crystalline–amorphous transition of furosemide was tracked by Fourier transform infrared spectroscopy. A correlation was found between the rheological properties of the polymer solutions and their electrospinnability, and the consequent morphology of the resultant samples. With decreasing HPC ratio of the system, a transition from the spray-dried droplets to the randomly oriented fibrous structures was observed. The results enable the determination of the polymer ratio for the formation of applicable quality of electrospun fibers

A környezeti paraméterek szerepe szilárd gyógyszerformák előállításában és stabilitásában = Role of circumstances in the preparation and stability of solid dosage forms

A nedveségtartalom igen fontos preformulációs paraméter, melynek a szilárd gyógyszerformák előállítása során valamennyi technológiai lépésben szerepe van. E mellett a készítmény stabilitását is befolyásolja, ami az egyes összetételek esetében változó lehet. A korábban megkezdett vizsgálatok (termet, felület, szemcseméret-megoszlás) folytatásaként tanulmányoztuk a gördülékenység változását a nedvességtartalom függvényében.. A munkaterv fontos részét képezi továbbá a polimerek, polimer filmek fizikai-kémiai tulajdonságainak és szerkezetének a tanulmányozása is. Vizsgáltuk a filmekben levő adalékanyagok (lágyítók) hatását a filmek tulajdonságaira, és a környezeti paraméterek befolyását a filmek öregedésére. Termoanalitikai és pozitronium életidő-vizsgálatok eredményei alapján összefüggést találtunk a lágyító-tartalom (polietilén-glikol) és a filmek szabad-térfogata között. Megállapítottuk, hogyan változik a filmek nedvességtartalma a környezeti paraméterek hatására, és ez milyen befolyással van a filmek mechanikai szilárdságára, deformációs folyamatára. Eredményeinket több nemzetközi fórumon bemutattuk, és több közleményt is összeállítottunk, melyek közül kettőt már közlésre elfogadtak. Vizsgáltuk több hatóanyag feldolgozhetóságát mikroszférák formájában. Vizsgáltuk a termékek morfológiáját,termikus viselkedését és tulajdonságait. Eredményeinket részben bemutattuk. Két cikket már közlésre elfogadtak és további közlemények összeállítását tervezzük. | The moisture content ? which has been influenced by the enviroment of preparation and the relative air humidity ? is very important preformulation parameter. It influences the stability (physical, chemical and microbiological), flowability tabletability and the physical parameters of dosage forms. The establishment and continuous control of the optimal moisture content are very important. The other important part of this project is the study of the physico-chemical characteristics of polymer films. The influence of the plasticizers and the influence of the environmental parameters were tested on the behaviour and ageing of polymer films. Based on the results of the thermoanalytical and pozitronium life-time study a relationship was found between the content of plasticizer and the free volume of films. The moisture content and the deformation process of the films was tested stored at different air humidity and temperature. Some microspheres were prepared and the habit and termic behaviour of these products were investigated. Our results were presented at different conference, two paper are already accepted for publish and some new papers are in preparatio

Formulation of Chlorine-Dioxide-Releasing Nanofibers for Disinfection in Humid and CO2-Rich Environment

Background: Preventing infectious diseases has become particularly relevant in the past few years. Therefore, antiseptics that are harmless and insusceptible to microbial resistance mechanisms are desired in medicine and public health. In our recent work, a poly(ethylene oxide)-based nanofibrous mat loaded with sodium chlorite was formulated. Methods: We tested the chlorine dioxide production and bacterial inactivation of the fibers in a medium, modeling the parameters of human exhaled air (ca. 5% (v/v) CO(2), T = 37 °C, RH > 95%). The morphology and microstructure of the fibers were investigated via scanning electron microscopy and infrared spectroscopy. Results: Smooth-surfaced, nanoscale fibers were produced. The ClO(2)-producing ability of the fibers decreased from 65.8 ppm/mg to 4.8 ppm/mg with the increase of the sample weight from 1 to 30 mg. The effect of CO(2) concentration and exposure time was also evaluated. The antibacterial activity of the fibers was tested in a 24 h experiment. The sodium-chlorite-loaded fibers showed substantial antibacterial activity. Conclusions: Chlorine dioxide was liberated into the gas phase in the presence of CO(2) and water vapor, eliminating the bacteria. Sodium-chlorite-loaded nanofibers can be sources of prolonged chlorine dioxide production and subsequent pathogen inactivation in a CO(2)-rich and humid environment. Based on the results, further evaluation of the possible application of the formulation in face-mask filters as medical devices is encouraged