Drug Permeation Through Hair Follicles: Importance and Potential

January 2017 in “ Springer eBooks ”

Hiroaki Todo, Mohd Fadli

hair follicles hydrophilic drugs macromolecules skin permeation acne androgenetic alopecia systemic drug delivery drug lipophilicity formulation in vitro studies in vivo conditions particle size penetration depth drug pharmacokinetics pharmaceutical formulation safety evaluation

Studysummary This chapter reviews the hair follicle's role in drug and chemical penetration through the skin but does not present new experimental findings.

Our plain-language summary. Not medical advice or a treatment recommendation. Consult a qualified healthcare professional before changing treatment. Full disclaimer

The 2017 document discussed the importance of hair follicles as a pathway for the permeation of hydrophilic drugs and macromolecules through the skin, emphasizing their potential in targeting conditions like acne and androgenetic alopecia and for systemic drug delivery. It reviewed various studies on drug permeation, noting that hair follicle contribution to skin permeation varies with drug lipophilicity and formulation. The document also pointed out that in vitro studies may underestimate drug recovery from hair follicles compared to in vivo conditions and that particle size influences penetration depth. The conclusion stressed the need for advanced analytical methods and high-resolution measurement techniques to improve understanding of drug pharmacokinetics in hair follicles for better pharmaceutical formulation and safety evaluation.

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Research cited in this study

18 / 18 results

research Contribution of the Hair Follicular Pathway to Total Skin Permeation of Topically Applied and Exposed Chemicals

39 citations , November 2016 in “Pharmaceutics”

This study found that the contribution of the hair follicle pathway to skin permeation of chemicals can be predicted using lipophilicity, with hydrophilic chemicals showing greater permeation reduction from hair follicle plugging than lipophilic ones.

research Topical Formulations Containing Finasteride: In Vitro Permeation/Penetration Study and In Vivo Pharmacokinetics in Hairless Rat

23 citations , June 2014 in “Journal of Pharmaceutical Sciences”

This study found that the HPCH-based formulation P-08–016 may facilitate finasteride deposition in the dermis, potentially offering an alternative to systemic therapy by minimizing systemic absorption.

Topical Formulations Containing Finasteride: Determination of Finasteride Penetration into Hair Follicles Using the Differential Stripping Technique

research Topical Formulations Containing Finasteride: Determination of Finasteride Penetration into Hair Follicles Using the Differential Stripping Technique

14 citations , June 2014 in “Journal of Pharmaceutical Sciences”

This study validated the differential stripping technique on hairless rat skin and found that the P-08–016 formulation delivered more finasteride to the epidermis and appendages compared to P-10–008.

research Quantification of Nanoparticle Uptake Into Hair Follicles in Pig Ear and Human Forearm

110 citations , January 2014 in “Journal of Controlled Release”

Phospholipid-coated nanoparticles penetrate hair follicles better than others, especially in pig ears.

Hair Follicles Contribute Significantly to Penetration Through Human Skin Only Shortly After Application as a Solvent Deposited Solid in Humans

research Hair Follicles Contribute Significantly to Penetration Through Human Skin Only Shortly After Application as a Solvent Deposited Solid in Humans

94 citations , May 2011 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology”

This study found that hair follicles contribute significantly to caffeine absorption shortly after topical application, with a faster absorption rate compared to the stratum corneum.

research Selective Follicular Targeting by Modification of the Particle Sizes

263 citations , February 2011 in “Journal of Controlled Release”

This study found that medium-sized particles (643 and 646 nm) penetrated deeper into porcine hair follicles in vitro than smaller or larger particles, suggesting size-selective targeting within follicular sites.

research Targeting to the Hair Follicles: Current Status and Potential

142 citations , January 2010 in “Journal of dermatological science”

This review covers follicle-targeting drug delivery systems, exploring their potential for improving localized and systemic therapies, and highlights the need for further research into follicle penetration mechanisms.

research Relative Uptake of Minoxidil Into Appendages and Stratum Corneum and Permeation Through Human Skin In Vitro

55 citations , June 2009 in “Journal of Pharmaceutical Sciences”

This study found that ethanol-containing formulations significantly increased minoxidil retention in the stratum corneum and appendages initially, while a propylene glycol-rich formulation enhanced deeper skin penetration over time.

research Permeation of Topically Applied Caffeine Through Human Skin – A Comparison of In Vivo and In Vitro Data

82 citations , May 2009 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology”

The study reported that combining the Follicular Closing Technique with the Franz diffusion cell is a valuable method for investigating follicular caffeine penetration in vitro, though kinetics differ from in vivo results.

research Follicular Transport Route: Research Progress and Future Perspectives

211 citations , February 2009 in “European journal of pharmaceutics and biopharmaceutics”

This review summarizes recent advancements in follicular targeting for drug delivery via hair follicles and calls for pilot studies in humans to explore potential clinical applications.

research The Role of Hair Follicles in the Percutaneous Absorption of Caffeine

182 citations , December 2007 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology”

This study demonstrated that hair follicles significantly expedite the absorption of caffeine through the skin compared to interfollicular pathways.

research 40nm, But Not 750 or 1,500nm, Nanoparticles Enter Epidermal CD1a+ Cells After Transcutaneous Application on Human Skin

323 citations , April 2006 in “The journal of investigative dermatology/Journal of investigative dermatology”

This study found that 40 nm nanoparticles can effectively penetrate into hair follicles and epidermal Langerhans cells in human skin samples, potentially enabling efficient transcutaneous vaccine delivery.

research Transfollicular Drug Delivery: Is It a Reality?

141 citations , November 2005 in “International journal of pharmaceutics”

This review examines the role of hair follicles and sebaceous glands in percutaneous drug delivery but does not report new clinical results; it calls for further exploration of follicle-targeting therapies.

research Penetration Profile of Microspheres in Follicular Targeting of Terminal Hair Follicles

316 citations , June 2004 in “The journal of investigative dermatology/Journal of investigative dermatology”

This study found that using a standardized protocol with microspheres of approximately 1.5 micrometers enhances penetration into hair follicles, particularly when skin is treated with cyanoacrylate skin surface stripping.

research Variations of Hair Follicle Size and Distribution in Different Body Sites

405 citations , January 2004 in “Journal of Investigative Dermatology”

This study found that hair follicle characteristics vary significantly across different body sites, with the forehead and calf showing the highest potential follicular reservoirs, challenging previous assumptions about skin appendage distribution.

research Gene Delivery to the Hair Follicle

34 citations , September 2003 in “Journal of Investigative Dermatology Symposium Proceedings”

This review discusses advancements in gene delivery to hair follicles and suggests potential gene therapy applications for treating hair loss, but it reports no new experimental results.

Transfollicular Drug Delivery: Penetration of Drugs Through Human Scalp Skin and Comparison of Penetration Between Scalp and Abdominal Skins In Vitro

research Transfollicular Drug Delivery: Penetration of Drugs Through Human Scalp Skin and Comparison of Penetration Between Scalp and Abdominal Skins In Vitro

82 citations , January 2002 in “Journal of drug targeting”

This study found that drug delivery through human scalp skin may be more effective for lipophilic and hydrophilic drugs compared to abdominal skin, highlighting the potential of intrafollicular delivery methods.

research Description of the Intrafollicular Delivery of Large Molecular Weight Molecules to Follicles of Human Scalp Skin In Vitro

47 citations , September 1997 in “Journal of Pharmaceutical Sciences”

This study found that cationic lipid-based formulations enhanced the delivery of large molecules into hair follicles in human scalp skin, with potential to reach pharmacologically active concentrations in the hair bulb.