Advanced Inorganic Nanosystems for Skin Drug Delivery.

On/into/through the skin drug delivery represents an attractive alternative for the oral route, providing local and/or systemic drug delivery. Due to its complex and well-organised structure, most of the drugs show difficulties to penetrate the human skin. Therefore, enormous efforts have been invested to develop intelligent drug delivery systems overcoming the skin barrier with particular emphasis on increasing therapeutic activity and minimizing undesirable side-effects. Most of these strategies require the use of singular materials with new properties. In particular, and on the basis of their inherent properties, including biocompatibility, biodegradability and relative low-cost, inorganic nanoparticles are ideal candidates for the development of skin drug delivery systems. This review provides an updated and comprehensive overview of the state of the art in the trends towards skin drug delivery with a particular focus in the attractive alternative offered by inorganic-based nanosystems.

Assessment of halloysite nanotubes as vehicles of isoniazid.

Equilibrium and thermodynamic aspects of the adsorption of isoniazid (INH) onto halloysite nanotubes (HLNTs) and characteristics of the resultant drug/nanocarrier systems are investigated. Equilibrium studies were performed in aqueous medium at different times, temperatures and drug concentrations. The overall adsorption process was explained as the result of two simple processes: adsorption on the activated sites of HLNTs and precipitation of INH on HLNTs surface. Formation of the INH-loaded HLNTs was spontaneous, endothermic and endoentropic, increasing the thermodynamic stability of the system (ΔH=70.40kJ/mol; ΔS=0.2519kJ/molK). Solid state characterization corroborated the effective interaction between the components that was also described by modeling at molecular level by quantum mechanics calculations along with empirical interatomic potentials. Transmission electron microphotographs confirmed the double allocation and homogeneous distribution of INH in the nanohybrids. FTIR spectra revealed the interaction via hydrogen bonds between the inner hydroxyl groups of HLNTs and N in INH molecules. Loading of INH in the nanohybrids was approximately 20% w/w. Effective loading of INH and activation energies of the interactions enable to propose the designed nanohybrids in the development of modified drug delivery systems.

Carvacrol/clay hybrids loaded into in situ gelling films.

The aim of the present work was the development of polymer films loaded with a carvacrol (CVR)/clay hybrid (HYBD) for the delivery of CRV in infected skin ulcer treatment. Different clays were considered: montmorrilonite, halloysite and palygorskite (PHC). CRV incorporation in PHC reduced its volatility. HYBD showed 20% w/w CRV loading capacity and was able to preserve CRV antioxidant properties. HYBD was characterized by improved antimicrobial properties against S. aureus and E. coli and cytocompatibility towards human fibroblasts with respect to pure CRV. Films were prepared by casting an aqueous dispersion containing poly(vinylalcohol) (PVA), poly(vinylpyrrolidone) (PVP), chitosan glutamate (CS), sericin and HYBD. Optimization of film composition was supported by a Design of Experiments (DoE) approach. In a screening phase, a full factorial design (FFD) was used and the following factors were investigated at two levels: PVA (12-14%w/w), PVP (2-4%w/w) and CS (0.134-0.5%w/w) concentrations. For the optimization phase, FFD was expanded to a "central composite design". The response variables considered were: elongation, tensile strength and buffer absorption of films, durability of the gels formed after film hydration. Upon hydration, the optimized film formed a viscoelastic gel able to protect the lesion area and to modulate CRV release.

Release kinetics of 5-aminosalicylic acid from halloysite.

This paper investigates desorption of 5-aminosalicilyc acid (5-ASA) adsorbed onto halloysite (HL). Desorption isotherms were fitted according to kinetic laws obtained considering release of 5-ASA from HL as the phase of desorption of the previously adsorbed drug molecules both inside the nanotubes of HL as onto the surface of clay particles and/or in the inter-particle spaces of their aggregates. Desorption isotherms has been also fitted with other equations frequently used in drug release kinetics studies. The best fitting corresponded to the kinetic model proposed; in agreement with the results of adsorption.

Coordinación de asignaturas en el plan de estudios como actividad formativa del equipo docente multidisciplinar para la Licenciatura de Farmacia / Coordination of subjects in the program as a formative activity of the multidisciplinary educational team for the degree in Pharmacy

La Universidad de Granada, dentro del Plan Estratégico y el Contrato Programa 2007-2011 de lasUniversidades Públicas de Andalucía puso en marcha la convocatoria de apoyo a la formación delprofesorado principiante y mejora de la docencia por el Vicerrectorado para la Garantía de la Calidad(http://calidad.ugr.es/pages/secretariados/form_apoyo_calidad/apoyo_formacion_principiante/convocatoria). En el proyecto participan 15 profesores, 5 profesores experimentados y 10 profesores novelesde seis departamentos diferentes.. Entre los objetivos se incluye la optimización de la actividaddocente de profesorado principiante. En este sentido se estudió la situación en el nuevo plan de estudiode Grado en Farmacia de las asignaturas que dichos profesores impartimos, así como la relación entreellas y la posible existencia de solapamientos de contenidos docentes. Las fichas docentes muestranciertos solapamientos de competencias y carencias en algunos casos. Esto supuso una revisiónexhaustiva para llevar a cabo una correcta coordinación entre los profesores que le permita alalumnado un aprendizaje organizado y coherente(AU)

The University of Granada, inside the Strategic Plan and the Contract Program 2007-2011 of thePublic Universities of Andalusia started a public call to improve the formation of young lecturers andthe teaching activity(http://calidad.ugr.es/pages/secretariados/form_apoyo_calidad/apoyo_formacion_principiante/convocatoria). In the project there take part 15 lecturers, 5 experienced and 10 young lecturers from sixdifferent departments. Within the objectives it is included the optimisation of the teaching activity ofyoung lecturers. In this sense, it was studied the situation of the subjects that the above mentionedlecturers give within the new degree in Pharmacy, as well as the relation between they and the possibleexistence of any overlapping in the contents. The teaching contents showed the existence of certainoverlapping within competences and deficiencies in some cases. This supposed an exhaustive reviewto carry out the correct coordination between the different lecturers so that it will allow the organizedand coherent learning of the students(AU)

Polyelectrolyte-drug complexes of lambda carrageenan and basic drugs: relevance of particle size and moisture content on compaction and drug release behavior.

The interaction between polyelectrolytes (PE) and oppositely charged drugs (D) results in complexes (PE-D) that can be exploited in controlled release drug delivery systems. The aim of this work is to better understand the relevance of some preparative parameters such as moisture content and particle size on the performance of two PE-D complexes to be used in oral controlled release tablets. PE-D complexes containing diltiazem HCL (DTZ) or metoprolol tartrate (MTP) and lambda carrageenan were obtained at two particle size levels (<45 microm and 75-105 microm), maintained at different values of relative humidity (RH) (11, 52, 75, and 93%), and compressed. The tablets were characterized for porosity, hardness, moisture content, and contact angle. Drug release profiles were fitted to the Weibull equation, and a factorial design was used to understand the relevance of particle size and RH% on release rate as a function of medium pH. The results indicated that the hydrophobic character of the complex between PE and D depended on the drug and in the present case was more pronounced for DTZ than for MTP. This in turn affected the possible release mechanism and therefore the importance of particle size and RH%.