Bicelles: New Lipid Nanosystems for Dermatological Applications.

Bicelles have emerged as promising membrane models, and due to their attractive combination of lipid composition and physicochemical characteristics, they have become new nanostructures for biomedical research. Depending on the composition, temperature and other experimental factors, these nanosystems exhibit high structural and morphological versatility. Additionally, bicelles are able to modulate the biophysical parameters and barrier function of skin. Given these properties, these nanostructures appear to be smart nanosystems with great potential in biomedicine and dermopharmacy.

Invivo absorption behaviour of theophylline from starch-methyl methacrylate matrix tablets in beagle dogs.

This study evaluates in vivo the drug absorption profiles from potato starch-methyl methacrylate matrices(*) using theophylline as a model drug. Healthy beagle dogs under fasting conditions were used for in vivo studies and plasma samples were analyzed by a fluorescence polarization immunoassay analysis (FPIA method). Non-compartmental and compartmental (population approach) analysis was performed to determine the pharmacokinetic parameters. The principle of superposition was applied to predict multiple dose plasma concentrations from experimental single dose data. An in vitro-in vivo correlation (IVIVC) was also assessed. The sustained absorption kinetics of theophylline from these formulations was demonstrated by comparison with two commercially available oral sustained-release theophylline products (Theo-Dur(®) and Theolair(®)). A one-compartment model with first order kinetics without lag-time best describes the absorption/disposition of theophylline from the formulations. Results revealed a theophylline absorption rate in the order FD-HSMMA≥Theo-Dur(®)≥OD-CSMMA>Theolair(®)≥FD-CSMMA. On the basis of simulated plasma theophylline levels, a twice daily dosage (every 12h) with the FD-CSMMA tablets should be recommended. A Level C IVIVC was found between the in vitrot50% and the in vivo AUC/D, although further optimization of the in vitro dissolution test would be needed to adequately correlate with in vivo data.

Novel microparticulate systems for the vaginal delivery of nystatin: development and characterization.

To develop more effective antifungal microparticulate therapeutic systems for the treatment of Candida vaginitis, microparticles containing nystatin were elaborated by emulsification/internal gelation method. Three types of microparticles were successfully prepared, alginate microparticles, chitosan and poloxamer 407 coated alginate microparticles. DSC and FT-IR studies were performed to test the efficacy of the method. After physicochemical characterization, mean particle sizes ranged from 36.088 µm to 56.146 µm. The encapsulation efficiency was found to be similar for alginate and chitosan coated microparticles and lower for poloxamer 407 coated. Optimal mucoadhesive properties in all kind of microparticles where exhibited. Release studies showed the best kinetic parameters for poloxamer 407 coated microparticles. After ex vivo permeation studies through porcine vaginal mucosa, and determination of the amount of nystatin retained as well as microbiologic studies performed, it could be inferred that the developed microparticulate systems offered an antifungal effect against Candida albicans without toxic systemic absorption.

Evaluation of novel nystatin nanoemulsion for skin candidosis infections.

One of the most common fungal skin infections is candidosis. Topical application of drugs at the pathological sites offers potential advantage of direct drug delivery to the site of action. The main aim of this work was to evaluate an optimal nystatin nanoemulsion for topical application avoiding undesirable side effects as systemic absorption and toxicity. Surface morphology and droplet size distribution of nystatin nanoemulsion was determined by transmission electronic microscopy and dynamic light scattering. Vertical diffusion Franz-type cells and high-performance liquid chromatography were used to perform the in vitro release and ex vivo human skin permeation studies. Transdermal permeation parameters were estimated from the permeation values using different theoretical approaches. Microbiological studies were performed to evaluate the antifungal effect. Nanoemulsion exhibited a spherical shape with smooth surface and mean droplet size between 70 and 80 nm. The pharmacokinetic release showed the nanoemulsion is faster than commercial ointment Mycostatin(®) improving the potential therapeutic index. Permeation studies demonstrated nystatin was not absorbed into systemic circulation and the retained amount in the skin was sufficient to ensure an antifungal effect. This antifungal effect was higher for nystatin loaded nanoemulsion than nystatin itself. A therapeutic improvement of the nystatin nanoemulsion treatment compared with the classical ones was achieved.

Autoaprendizaje de recursos informaticos en Biofarmacia y Farmacocinetica / Self-learning of Biopharmacy and Pharmacokinetic computer software

Uno de los pilares de la Biofarmacia y Farmacocinética es el tratamiento de datos, para lo que resulta imprescindible el conocimiento de programas informáticos estadísticos y de regresión no lineal. Estos son ampliamente usados en nuestra Unidad y forman parte de las destrezas prácticas que el alumno debe adquirir. Debido a las dificultades presentadas por los alumnos en la comprensión de ambas disciplinas, nos hemos planteado realizar una guía de apoyo virtual, sobre el uso del programa de regresión no lineal WinNonLin®. Dicho material estará a disposición del alumno a través de la plataforma virtual moodle para que pueda ser consultado antes de realizar las prácticas de la asignatura. Para valorar la utilidad de este material de apoyo como herramienta TIC, se han realizado una encuesta a profesores y alumnos vinculados a la Unidad, que son los usuarios principales de estas herramientas informáticas. Los resultados de las encuestas reflejaron su agrado y facilidad de compresión, de tal forma que para el próximo curso 2011-2012 se colgará en moodle para todos los alumnos de grado(AU)

One of the most important tasks in the biopharmaceutical and pharmacokinetics area is data management, being the statistical and non linear regression software widely used. Those IT skills should be acquired by students in practical lessons, but due to the comprehension difficulties showed, the Biopharmaceutical and Pharmacokinetics Unit of University of Barcelona elaborated a virtual guidance about the use of WinNonLin®, non-linear regression software. This guidance will be used to solve student’s queries by the virtual campus Moodle, before the attending sessions. The main software users, professors and internal students, were polled about the usefulness of this guide. The survey conclusions emphasized its easy understanding and its utility, therefore all students, who were inscribed in Biopharmaceutics and Pharmacokinetic subject, will have access to this guidance next term(AU)

Virtualización de las practicas de biofarmacia: ensayos de disolución de diferentes formas de dosificación / Biopharmacy practices virtualization: dissolution test of several dosage forms

En años anteriores, la Unidad de Biofarmacia y Farmacocinética de la Universidad de Barcelona, haestado inmersa en la virtualización de las prácticas de la asignatura de cara a que en un futuro próximopuedan realizarse con mayor autonomía. En un trabajo previo se llevó a cabo la virtualización de laparte referente a las prácticas de farmacocinética. Prosiguiendo con esta labor, ahora se presenta lavirtualización de las prácticas de biofarmacia. Debido a limitaciones temporales y económicas, elestudiante de grado, realiza la práctica del ensayo de disolución de comprimidos de formasimplificada. Para que el alumno pueda ver como se realizan los ensayos de disolución de formafarmacéuticas sólidas según las directrices internacionales que realizará en su vida laboral, hemosconfeccionado una serie de videos explicativos de dicha tarea, y se ha ampliado con materialaudiovisual sobre ensayos de disolución de formas sólidas y de parches transdérmicos, los cuales no serealizan de forma rutinaria durante las prácticas de la licenciatura. Dicho material audiovisual estará adisposición de los alumnos en la plataforma virtual moodle para que pueda ser consultado cuando seanecesario(AU)

Previously, the Biopharmaceutical and Pharmacokinetic Unit of the University of Barcelona had beenimmersed in the practices’ virtualization of the grade subject, looking for an improvement of student’sautonomy in a foreseeable future. The virtualization of the pharmacokinetic practices was madepreviously, and now we are presenting the virtualization of the biopharmaceutical section. Due to theeconomic and time limitations, students only carried out the tablet dissolution assay in a simplifiedway. The aim of this guide is to show how to perform a different dissolution test by visualizing avideo, which teaches the students, how to proceed according to the international guidelines. Studentswill be able to study it in the virtual platform moodle, whenever it may be necessary(AU)