TLDR Nanocrystals improve skin penetration and stability of caffeine, suggesting a new method for delivering similar substances through the skin.
The 2014 document details a study on improving dermal delivery of medium soluble actives, using caffeine as a model compound, by formulating nanocrystals. The study found that nanocrystals can maintain a constant concentration gradient for better skin penetration and can accumulate in hair follicles. The production strategy involved low energy milling with stabilizers like Carbopol® 981 to prevent crystal growth. Nanocrystals around 660 nm were optimal for hair follicle accumulation, while those around 250 nm dissolved faster. The study concluded that nanocrystals increased the solubility of caffeine by 35% to 70%, depending on the particle size, and the most stable formulation remained stable for 60 days, indicating its suitability for in vivo testing. The method could potentially be applied to other medium soluble actives for dermal delivery.
122 citations,
March 2013 in “Expert opinion on drug delivery” Optimizing drug delivery to hair follicles is crucial for effective treatment.
263 citations,
February 2011 in “Journal of Controlled Release” Medium-sized particles penetrate hair follicles better than smaller or larger ones, which could improve delivery of skin treatments.
82 citations,
May 2009 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology” Caffeine penetrates human skin in lab tests similarly to real-life conditions, but actual skin use is still essential for accurate results.
211 citations,
February 2009 in “European journal of pharmaceutics and biopharmaceutics” Hair follicles help absorb and store topical compounds, aiding targeted drug delivery.
182 citations,
December 2007 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology” Hair follicles significantly increase the speed and amount of caffeine absorbed through the skin.
316 citations,
June 2004 in “The journal of investigative dermatology/Journal of investigative dermatology” Microspheres about 1.5 micrometers in size can best penetrate hair follicles, potentially reaching important stem cells.
42 citations,
July 2014 in “European journal of pharmaceutics and biopharmaceutics” Caffeine nanocrystals for skin products stay stable with the right stabilizer, but grow in size at higher temperatures.
10 citations,
July 2021 in “European journal of pharmaceutics and biopharmaceutics” Nanoparticles sized between 470 and 750 nm are best for delivering substances like caffeine into hair follicles for absorption.
2 citations,
January 2014 Improved methods create smaller, more effective gelatin nanoparticles for skin delivery, and new caffeine nanocrystals enhance absorption and effectiveness.
Plant-based compounds can improve wound dressings and skin medication delivery.
130 citations,
August 2020 in “Drug Design Development and Therapy” Nanoparticles can improve skin drug delivery but have challenges like toxicity and stability that need more research.
