Related Experiment Video
Updated: Jan 21, 2026

Development, Characterization, and Evaluation of CAGE-based Ionic Liquid Systems for Transdermal Delivery
Published on: September 26, 2025
New insight into transdermal drug delivery with supersaturated formulation based on co-amorphous system
Yuya Hirakawa1, Hiroshi Ueda2, Tetsuya Miyano2
1Physicochemical and Preformulation, Applied Chemistry and Analysis, Research Laboratory for Development, Shionogi & Co., Ltd., 3-1-1, Futaba-cho, Toyonaka-shi, Osaka 561-0825, Japan; Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, Motooka 744, Nishi-ku, Fukuoka 819-0395, Japan.
Abstract:
The objective of this study was to prepare a supersaturated formulation based on formation of a co-amorphous system of a drug and a coformer in order to enhance skin permeation. Atenolol (ATE) and urea (URE) were used as the model drug and the coformer, respectively. Thermal analysis of physical mixtures of ATE and URE showed decreases in the melting points and the formation of a co-amorphous system which was in a supercooled liquid state because of a low glass transition temperature. Supersaturated solutions of ATE and URE at different molar ratios in polyethylene glycol 400 (PEG400) were prepared. The precipitations were observed under storage at 25 °C for all formulations except for ATE-URE at 1:8 molar ratio which remained in the supersaturated state for 2 months. 1H NMR analysis confirmed the interactions between ATE and URE in PEG400. The ATE-URE supersaturated formulation showed higher permeability for mice skin than that of ATE saturated formulation, which was superior to the expected permeability from the degree of supersaturation. We concluded that co-amorphous based supersaturated formulation offers much promise for transdermal drug delivery.
Related Concept Videos
Insulin Formulations: Types and Delivery
Short-acting insulins are divided into...
Drug Delivery: Overview
Enteral delivery involves administering drugs directly through swallowing, sublingual placement, or buccal application. Orally administered drugs predominantly navigate the...
Drug Delivery: Enteral Route
Drug Delivery: Parenteral Route
There are three primary parenteral routes: intravenous (IV), intramuscular (IM), and subcutaneous (SC). The IV route introduces the drug directly into the bloodstream, ensuring immediate action. The IM route...
Drug Delivery: Miscellaneous Routes
Oral inhalation and nasal sprays swiftly transfer drugs across the respiratory epithelium's mucosal layer. Inhaled glucocorticoids and bronchodilators directly target lung conditions such as asthma, while fluticasone nasal spray mitigates allergic rhinitis.
Transdermal patches transport drugs...
Factors Affecting Dissolution: Polymorphism, Amorphism and Pseudopolymorphism
Some polymorphic crystals possess lower aqueous solubility than their amorphous counterparts, leading to incomplete absorption. For instance, the oral suspension of Chloramphenicol, which...

