Use of ion-exchange resins to prepare 100 μm-sized microcapsules with prolonged drug-release by the Wurster process

• Published in: International journal of pharmaceutics Vol. 216; no. 1; pp. 67 - 76
• Main Authors: Ichikawa, Hideki, Fujioka, Kazuhiro, Adeyeye, Moji Christianah, Fukumori, Yoshinobu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 23.03.2001; Elsevier
• Subjects: Biological and medical sciences; Coating; Diclofenac sodium; General pharmacology; Ion-exchange resin; Medical sciences; Microcapsule; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Prolonged release; Wurster process; Diclofenac sodium; Wurster process; Coating; Prolonged release; Microcapsule; Ion-exchange resin; Encapsulation; Particle size; Pharmaceutical technology; Controlled release form; Control release polymer; Cellulose(ethyl); Drug carrier; Methyl methacrylate copolymer; In vitro; Diclofenac; Arylacetic acid derivatives; Dosage form; Ion exchange resin; Release
• ISSN: 0378-5173; 1873-3476
• DOI: 10.1016/S0378-5173(01)00573-7

Ion-exchange resin (IER)–drug complexes were used as core materials to explore their capability to prepare a 100 μm-sized, highly drug-incorporated microcapsule with a prolonged drug release by the Wurster process. Diclofenac sodium was loaded into Dowex 1-X2 fractionated into 200–400 mesh and subsequently microencapsulated with two types of aqueous colloidal polymer dispersion, Aquacoat® or Eudragit® RS30D. The mass median diameter and drug content of the microcapsules thus obtained were 98 μm and 46% with Aquacoat®, and 95 μm and 50% with Eudragit® RS30D, respectively. Each microcapsule was obtained at a product yield of 94%. The rate of drug release from the microcapsules was highly dependent on the encapsulating materials. For the microcapsules coated with Aquacoat®, diclofenac sodium was found to be rapidly released over 4 h, even at a 25 wt% coating level because of cracks on the microcapsule surfaces resulting from the swelling stress of the drug-loaded IER cores. In contrast, significantly prolonged drug-release was achieved in the microcapsules prepared with Eudragit® RS30D: even such a very low coating level as 3 wt% provided an exceptionally prolonged drug-release over 24 h. The results indicated that the use of IER along with a flexible coating material would be a feasible way to prepare a prolonged release type of microcapsules with a diameter of 100 μm and a drug content of more than 50% by the Wurster process.