Influence of the Vehicle on the Penetration of Particles into Hair Follicles

Abstract

Recently, it has been demonstrated that particulate substances penetrate preferentially into the hair follicles and that the penetration depth depends on the particle size. In the present study, the influence of the vehicle of the particulate substances on the penetration depth was investigated. Four different formulations (ethanolic suspension, aqueous suspension, ethanolic gel and aqueous gel) containing peptide-loaded particles of 1 μm in diameter were prepared and applied on porcine ear skin. After penetration, punch biopsies were taken and the penetration depths of the particles were investigated by laser scanning microscopy. The deepest penetration was achieved with the gel formulations demonstrating an influence of the vehicle on the penetration depth of particulate substances.

Ratchet effect for nanoparticle transport in hair follicles

“…Since the hair structure resembles a sawtooth-like profile with a rather well defined corrugation amplitude, a ratchet mechanism indeed might explain the enhanced particle transport induced by hair motion. Other material properties and the solvent properties were shown to only have a minor influence on the transport efficiency of nanoparticles [11]. The so-called ratchet effect has been amply described in literature and refers to directed particle motion generated by a non-equilibrium perturbation of a periodic system.…”

Microneedle-Facilitated Intradermal Proretinal Nanoparticle Delivery

“…Nanoparticles have been applied in various topical formulations in dermatology. The penetration of different particles is different and also affected by the formulation [49,50]. Up to this point, nanoparticles rarely get into the dermal layer of the skin [51].…”

Subunit Vaccine Delivery

“…The last pathway is the appendageal pathway which utilizes the sweat glands and hair follicles (Bolzinger et al 2012 ). This route is of interest for nanoparticle delivery into the skin as the appendages can also act as a depot for particles from which drug can be slowly released Morgen et al 2011 ;Patzelt et al 2011 ). Despite drug delivery via hair follicles being an effective delivery route, it cannot be a major route due to the fact that the number of pores in skin is only 0.1 % of the entire surface (Otberg et al 2004 ).…”