Influence of Chemical Enhancers and Iontophoresis on the In Vitro Transdermal Permeation of Propranolol: Evaluation by Dermatopharmacokinetics

[EN] The aims of this study were to assess, in vitro, the possibility of administering propranolol transdermally and to evaluate the usefulness of the dermatopharmacokinetic (DPK) method in assessing the transport of drugs through stratum corneum, using propranolol as a model compound. Four chemical enhancers (decenoic and oleic acid, laurocapram, and R-(+)-limonene) and iontophoresis at two current densities, 0.25 and 0.5 mA/cm(2) were tested. R-(+)-limonene, and iontophoresis at 0.5 mA/cm(2) were proven to be the most efficient in increasing propranolol transdermal flux, both doubled the original propranolol transdermal flux. Iontophoresis was demonstrated to be superior than the chemical enhancer because it allowed faster delivery of the drug. The DPK method was sufficiently sensitive to detect subtle vehicle-induced effects on the skin permeation of propranolol. The shorter duration of these experiments and their ability to provide mechanistic information about partition between vehicle and skin and diffusivity through skin place them as practical and potentially insightful approach to quantify and, ultimately, optimize topical bioavailability.This research was funded by Ministerio de Ciencia e Innovación (AP2007-03456) and the Universidad CEU Cardenal Herrera.Calatayud-Pascual, M.; Sebastian-Morelló, M.; Balaguer-Fernandez, C.; Delgado-Charro, M.; Lopez-Castellano, A.; Merino Sanjuán, V. (2018). Influence of Chemical Enhancers and Iontophoresis on the In Vitro Transdermal Permeation of Propranolol: Evaluation by Dermatopharmacokinetics. Pharmaceutics. 10(4):1-15. https://doi.org/10.3390/pharmaceutics10040265S11510

Transdermal therapeutic systems for memantine delivery. Comparison of passive and iontophoretic transport

[EN] Memantine is a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist used in the treatment of moderate to severe dementia including the symptoms of Alzheimer's disease (AD). It is administered orally but compliance, swallowing problems and the routine use of multiple medications in elderly AD patients means that an alternative route of administration would be of interest. The aim of the present. study was to develop memantine hydrochloride occlusive transdermal therapeutic systems (TI'S) for passive and iontophoretic delivery across the skin. Polyvinyl pyrrolidone (PVP) and a mixture with polyvinyl alcohol (PVA) were employed as polymeric matrices. The study involved the TTS characterization in addition to quantification of the memantine transport across porcine skin in vitro. The evaluation of the ITS physical properties suggested that systems were made more mechanically resistant by including PVA (6%) or high concentrations of PVP (24%). Moreover, a linear correlation was observed between the concentration of PVP and the bioadhesion of the systems. Drug delivery expefiments showed that the highest transdermal flux provided by a passive TTS (PVP 24% w/w limonene) was 8.89 +/- 0.81 mu g cm(-2) h(-1) whereas the highest iontophoretic transport was 46.4 +/- 3.6 mu g cm(-2) h(-1). These innovative TTS would enable two dosage regimens that could lead to therapeutic plasma concentrations.The authors wish to thank the "Generalitat Valenciana" (AP-114/09; AP-155/10; AP-175/11) and the "Universidad CEU Cardenal Herrera" for their financial support. The authors also thank Pharsight corp. for the academic license of WinNonlin 5.0.1.Del Rio-Sancho, S.; Serna-Jiménez, C.; Sebastián-Morelló, M.; Calatayud-Pascual, M.; Balaguer-Fernández, C.; Femenia-Font, A.; Kalia, Y.... (2017). Transdermal therapeutic systems for memantine delivery. Comparison of passive and iontophoretic transport. International Journal of Pharmaceutics. 517(1-2):104-111. https://doi.org/10.1016/j.ijpharm.2016.11.038S1041115171-

Consenso Delphi de las recomendaciones para el tratamiento de los pacientes con atrofia muscular espinal en España (consenso RET-AME)

Introducción La atrofia muscular espinal (AME) es una enfermedad neurodegenerativa, causada por una mutación bialélica del gen 5q SMN1, que afecta predominantemente a las neuronas motoras del asta anterior medular causando una progresiva debilidad y atrofia muscular. La aparición de tratamientos modificadores del curso de la enfermedad está cambiando considerablemente la historia natural de la AME, pero existe todavía incertidumbre sobre qué pacientes se pueden beneficiar de estos tratamientos y cómo se debería medir ese beneficio. Metodología Un grupo de expertos especialistas en neurología, neuropediatría y rehabilitación, y de la asociación de pacientes con AME de España, analizaron, siguiendo la metodología Delphi, 5 apartados relacionados con el uso de los nuevos tratamientos: aspectos generales; objetivos del tratamiento; herramientas de medición de resultados; requisitos de los centros tratantes; y regulación de su uso. Se definió como consenso cuando una respuesta recibió al menos el 80% de los votos. Resultados Los protocolos de tratamiento son útiles para regular el uso de medicamentos de alto impacto y deben constituir una guía para aquel, pero se deben actualizar regularmente para recoger la evidencia más reciente disponible y su implementación se debe valorar de forma individualizada. La edad, la funcionalidad basal y, en el caso de los niños, el tipo de AME y el número de copias de SMN2 son características que se deben tener en cuenta a la hora de establecer los objetivos terapéuticos, las herramientas de medición y el uso de dichos tratamientos. El aspecto más determinante del coste-efectividad de estos tratamientos en la edad pediátrica es su inicio precoz, por lo que se recomienda la instauración de un cribado neonatal. Conclusiones Las recomendaciones del consenso RET-AME proporcionan un marco de referencia para el uso adecuado de tratamientos modificadores de la enfermedad en pacientes con AME