Development of oral drug delivery system using floating microspheres

• Published in: Journal of microencapsulation Vol. 16; no. 6; pp. 715 - 729
• Main Authors: LEE, J.-H, PARKS, T. G, CHOI, H.-K
• Format: Journal Article
• Language: English
• Published: Colchester Informa UK Ltd 01.11.1999; Taylor & Francis; Informa
• Subjects: 2-Propanol - chemistry; Acrylic Resins - administration & dosage; Administration, Oral; Biological and medical sciences; Drug Delivery Systems; Ethanol - chemistry; General pharmacology; Medical sciences; Methylene Chloride - chemistry; Microscopy, Electron, Scanning; Microsphere;Floating;Acyrlic Polymer;Release;Oral Delivery; Microspheres; Particle Size; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Polymethacrylic Acids - administration & dosage; Solubility; Solvents; Temperature; Time Factors; Encapsulation; Particle size; Microsphere; Pharmaceutical technology; Controlled release form; Control release polymer; Buoyancy; Oral administration; Polymer; Drug carrier; Dosage form; Release; Physicochemical properties
• ISSN: 0265-2048; 1464-5246
• DOI: 10.1080/026520499288663

Floating acrylic resin microspheres with an internal hollow structure were prepared by a solvent diffusion and evaporation method. The yield of microspheres depended on the diffusion rate of ethanol and/or isopropanol in the organic phase. They were successfully produced when amixture of ethanol and isopropanol was used instead of ethanol alone. The mixing ratioof components in the organic phase affected the size and the yield of microspheres and the best results were obtained at the volume ratio of ethanol:isopropanol:dichloromethane (8:2:5). Direct introduction of the organic phase into the aqueous phase through aglass tube alsosignificantly improved the yield by avoiding the contact of organic phase with the surface of water. The optimum rotation speed and temperature were 250rpm and 25 C, respectively. Several different drugs with various physico-chemical properties were used as model drugs for encapsulation and release tests. When a drug had low solubility in dichloromethaneandhighsolubilityin both water and amixture of ethanol/isopropanol, the loading efficiency was the lowest. The release profiles were significantly different depending on the solubility of a drug in the release medium and the physico-chemical properties of an encapsulated drug.