Diffusion loading and drug delivery characteristics of alginate gel microparticles produced by a novel impinging aerosols method.
Microencapsulation of a hydrophilic active (gentamicin sulphate (GS)) and a hydrophobic non-steroidal anti-inflammatory drug (ibuprofen) in alginate gel microparticles was accomplished by molecular diffusion of the drug species into microparticles produced by impinging aerosols of alginate solution and CaCl(2) cross-linking solution. A mean particle size in the range of 30-50 µm was measured using laser light scattering and high drug loadings of around 35 and 29% weight/dry microparticle weight were obtained for GS and ibuprofen respectively. GS release was similar in simulated intestinal fluid (phosphate buffer saline (PBS), pH 7.4, 37°C) and simulated gastric fluid (SGF) (HCl, pH 1.2, 37°C) but was accelerated in PBS following incubation of microparticles in HCl. Ibuprofen release was restricted in SGF but occurred freely on transfer of microparticles into PBS with almost 100% efficiency. GS released in PBS over 7 h, following incubation of microparticles in HCl for 2 h was found to retain at least 80% activity against Staphylococcus epidermidis while Ibuprofen retained around 50% activity against Candida albicans. The impinging aerosols technique shows potential for producing alginate gel microparticles of utility for protection and controlled delivery of a range of therapeutic molecules.
The University of Queensland, Pharmacy Australia Centre of Excellence, Brisbane, QLD, Australia.
Dewi M
DM
Hariyadi
Sharon Chien-Yu
SC
Lin
Yiwei
Y
Wang
Thor
T
Bostrom
Mark S
MS
Turner
Bhesh
B
Bhandari
Allan G A
AG
Coombes
D000464:Alginates / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology; D002122:Calcium Chloride / Q000737:chemistry; D002176:Candida albicans / Q000187:drug effects; D002214:Capsules; D003432:Cross-Linking Reagents / Q000737:chemistry; D004058:Diffusion; D016503:Drug Delivery Systems; D005750:Gastric Juice / Q000378:metabolism; D005782:Gels; D005839:Gentamicins / Q000008:administration & dosage* / Q000494:pharmacology; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007052:Ibuprofen / Q000008:administration & dosage* / Q000494:pharmacology; D007419:Intestinal Secretions / Q000378:metabolism; D013212:Staphylococcus epidermidis / Q000187:drug effects; D013997:Time Factors
D000464:Alginates; D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D002214:Capsules; D003432:Cross-Linking Reagents; D005782:Gels; D005839:Gentamicins; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D002122:Calcium Chloride; D007052:Ibuprofen