Development of a simple and practical method for estimating the liquid absorption of pharmaceutical porous materials using a capillary rise technique

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Vol. 29; no. 12; pp. 3210 - 3219
• Main Authors: Oba, Takuma, Tahara, Kohei, Kato, Yasutomi, Sonoda, Ryoichi, Kawashima, Yoshiaki, Takeuchi, Hirofumi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2018
• Subjects: Capillary rise; Liquid absorption; Permeation rate; Porous materials; Liquid absorption; Permeation rate; Capillary rise; Porous materials
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2018.08.027

[Display omitted] •Permeation rate showed the affinity of porous carriers with various solvents.•Permeation rate was strongly affected by the viscosity of the solvent.•Liquid absorption experiment could predict the available intra-particle pore volume.•Efficiently drug loaded particles could be prepared based on the results. Porous materials are attractive substances for designing pharmaceutical particulates. However, understanding the behavior of liquid absorption into the intra-pores and interstices of porous carrier particles is important to effectively manufacture active pharmaceutical ingredients (APIs) using these carriers. In this study, we established a simple and practical method for evaluating the liquid absorption behavior of porous carriers using force tensiometry and a capillary rise technique. Different-sized tablets of porous materials were prepared and evaluated by this method using various solvents to estimate liquid absorption into the intra-particle pores and interstices of the particles. The amount of liquid trapped in the interstices of the particles decreased with decreasing tablet volume, after which the amount of liquid in the intra-particle pores could be estimated. Finally, API-loaded particles were prepared by absorbing the API solution into porous carriers based on the intra-capacity revealed above. No free API was found on the surface of the prepared particles, as it was well absorbed into the intra-particle pores. Collectively, this tensiometer method using different-sized tablets of porous materials appears to be a promising technique for evaluating the liquid absorption characteristics of porous pharmaceutical materials.