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  • Drug loading and release properties of ion-exchange resin complexes as a drug delivery matrix.

Drug loading and release properties of ion-exchange resin complexes as a drug delivery matrix.

International journal of pharmaceutics (2008-06-21)
Seong Hoon Jeong, Kinam Park
ABSTRACT

Complexes of ion-exchange resins and dextromethorphan (DM), a model drug, were prepared using different methods including a batch and a column method with different functional groups, ion-exchange capacity, degree of crosslinking, and resin particle size. Drug loading efficiency, release profiles, and scanning electron micrographs were also investigated. Most of the functional groups of resins were loaded with DM after the completion of a double batch method and it was recommended for drug loading into the ion-exchange resin. Using a column method, drug loading could be monitored by simply measuring changes in the pH of the reaction medium since as complex formation reached completion, the pH returned to the initial pH of the eluent due to the limited amount of functional groups available for the exchange. DM could be loaded up to the ratio of 3 (drug): 1 (resin), depending on the physicochemical properties of the resin. As the crosslinking ratio and particle size increased, the drug loading and release rate decreased due to the reduced effective diffusion coefficient and surface area. Assuming that the resin particles are uniform spheres of radius r, release mechanism was evaluated using plots of a Bt-t relationship, where B (=pi(2)D(i)/r(2)) and t are the rate constant and time, respectively. D(i) represents the effective diffusion coefficient of DM inside the resin. The Bt-t plots displayed a straight line indicating that the diffusion of DM in the resin matrix is the rate-controlling step.

MATERIALS
Product Number
Brand
Product Description

Supelco
AmberChrom 50WX4 hydrogen form, hydrogen form, 50-100 mesh
Supelco
AmberChrom 50WX4 hydrogen form, hydrogen form, 100-200 mesh
Supelco
AmberChrom 50WX4 hydrogen form, 200-400 mesh, Cation Exchange Resin
Supelco
AmberChrom 50WX2 200-400 Mesh (H+) Cation Exchange Resin
Supelco
AmberChrom 50WX2 50-100 Mesh (H+) Cation Exchange Resin, hydrogen form, 50-100 mesh
Supelco
AmberChrom 50WX2 100-200 Mesh (H+) Cation Exchange Resin