Microneedle/nanoencapsulation-mediated transdermal delivery: mechanistic insights.

A systematic study was undertaken to gain more insight into the mechanism of transdermal delivery of nanoencapsulated model dyes across microneedle (MN)-treated skin, a complex process not yet explored. Rhodamine B (Rh B) and fluorescein isothiocyanate (FITC) as model hydrophilic and hydrophobic small/medium-size molecules, respectively, were encapsulated in poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) and delivered through full thickness porcine skin pretreated with MN array. Permeation through MN-treated skin was affected by physicochemical characteristics of NPs and the encapsulated dyes.

Effect of microneedle treatment on the skin permeation of a nanoencapsulated dye.

Objectives: The aim of the study was to investigate the effect of microneedle (MN) pretreatment on the transdermal delivery of a model drug (Rhodamine B, Rh B) encapsulated in polylactic-co-glycolic acid (PLGA) nanoparticles (NPs) focusing on the MN characteristics and application variables.

Methods: Gantrez MNs were fabricated using laser-engineered silicone micro-mould templates. PLGA NPs were prepared using a modified emulsion-diffusion-evaporation method and characterised in vitro.

Flux of ionic dyes across microneedle-treated skin: effect of molecular characteristics.

Drug flux across microneedle (MN)-treated skin is influenced by the characteristics of the MN array, formed microconduits and physicochemical properties of the drug molecules in addition to the overall diffusional resistance of microconduits and viable tissue. Relative implication of these factors has not been fully explored. In the present study, the in vitro permeation of a series of six structurally related ionic xanthene dyes with different molecular weights (MW) and chemical substituents, across polymer MN-pretreated porcine skin was investigated in relation of their molecular characteristics.

Laser-engineered dissolving microneedles for active transdermal delivery of nadroparin calcium.

There is an urgent need to replace the injection currently used for low molecular weight heparin (LMWH) multidose therapy with a non- or minimally invasive delivery approach. In this study, laser-engineered dissolving microneedle (DMN) arrays fabricated from aqueous blends of 15% w/w poly(methylvinylether-co-maleic anhydride) were used for the first time in active transdermal delivery of the LMWH nadroparin calcium (NC). Importantly, an array loading of 630IU of NC was achieved without compromising the array mechanical strength or drug bioactivity.

Lyophilized inserts for nasal administration harboring bacteriophage selective for Staphylococcus aureus: in vitro evaluation.

Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) poses an infection risk and eradication during hospitalization is recommended. Bacteriophage therapy may be effective in this scenario but suitable nasal formulations have yet to be developed. Here we show that lyophilization of bacteriophages in 1ml of a viscous solution of 1-2% (w/v) hydroxypropyl methylcellulose (HPMC) with/without the addition of 1% (w/v) mannitol, contained in Eppendorf tubes, yields nasal inserts composed of a highly porous leaflet-like matrix.