Drug Targeting Through Pilosebaceous Route

Abstract

Local skin targeting is of interest for the pharmaceutical and the cosmetic industry. A topically applied substance has basically three possibilities to penetrate into the skin: transcellular, intercellular, and follicular. The transfollicular path has been largely ignored because hair follicles constitute only 0.1% of the total skin. The hair follicle is a skin appendage with a complex structure containing many cell types that produce highly specialised proteins. The hair follicle is in a continuous cycle: anagen is the hair growth phase, catagen the involution phase and telogen is the resting phase. Nonetheless, the hair follicle has great potential for skin treatment, owing to its deep extension into the dermis and thus provides much deeper penetration and absorption of compounds beneath the skin than seen with the transdermal route. In the case of skin diseases and of cosmetic products, delivery to sweat glands or to the pilosebaceous unit is essential for the effectiveness of the drug. Increased accumulation in the pilosebaceous unit could treat alopecia, acne and skin cancer more efficiently and improve the effect of cosmetic substances and nutrients. Therefore, we review herein various drug delivery systems, including liposomes, niosomes, microspheres, nanoparticles, nanoemulsions, lipid nanocarriers, gene therapy and discuss the results of recent researches. We also review the drugs which have been investigated for pilosebaceous delivery.

Follicular delivery of spironolactone via nanostructured lipid carriers for management of alopecia

“…45 Generally, drug penetration into the skin can occur through the corneocytes (transcellular route), between the corneocytes (intercellular route), and via the appendages. 46 Figure 7 demonstrates the distribution of the studied RH-NLCs across the skin. Figure 7A presents a normal xy image of rat skin, which is depicted in Figure 7B in the form of a 1,024×1,024 three-dimensional plot.…”

“…It is worth mentioning that within the stratum corneum, the follicular ducts represent intrusions containing lipophilic content due to sebum secretion from the sebaceous gland. 46 In this domain, the lipophilic nature of the proposed NLCs is likely to contribute to follicular penetration. Fluorescence deposition was also present at the outermost layer of the hair structure, probably due to the interaction between the NLCs and hair cuticle.…”

Lipid nanoparticles for topical and transdermal application for alopecia treatment: development, physicochemical characterization, and in vitro release and penetration studies

“…[6][7][8] LNs exhibit many advantageous features for dermal application of cosmetic and pharmaceutical products, such as: controlled drug release and drug targeting; improved drug physical stability; feasibility to incorporate lipophilic and hydrophilic drugs; avoidance of organic solvents; and no problems with respect to large-scale production and sterilization. 9,10 Furthermore, LNs have occlusive properties that can increase the water content of the skin and that favor drug penetration into the skin, 7,8 and readily interact with skin lipids. 11 LNs also protect the loaded compounds against chemical degradation.…”

Nanocarrier Systems for Transdermal Drug Delivery

“…Improvement in physical permeationenhancement technologies has led to renewed interest in transdermal drug delivery. Some of these novel advanced transdermal permeation enhancement technologies include: iontophoresis, electroporation, ultrasound, microneedles to open up the skin and more recently the use of transdermal nanocarriers [3,[7][8][9][10].A number of excellent reviews that have been published contain detailed discussions concerning many aspects of transdermal nanocarriers [11][12][13][14][15][16][17]. The present chapter shows an updated overview of the use of submicron particles and other nanostructures in the pharmaceutical field, specifically in the area of topical and transdermal drugs.…”

“…A number of excellent reviews that have been published contain detailed discussions concerning many aspects of transdermal nanocarriers [11][12][13][14][15][16][17]. The present chapter shows an updated overview of the use of submicron particles and other nanostructures in the pharmaceutical field, specifically in the area of topical and transdermal drugs.…”