Development and evaluation of extended release Ambroxol HCl and Guaifenesin suspension

The main objective of the present work was to develop extended release suspension of Ambroxol HCl and Guaifenesin. An oral extended release suspension was prepared using ion-exchange resin technology. A strong cation exchange resin Dowex50 was utilized for the sorption of the drug and the drug resinates was evaluated for various physical and chemical parameters. The drug-resinate complex was microencapsulated with a polymer Ethylcellulose to further retard the release characteristics. Ethylcellulose coated ion exchange resinates of Ambroxol HCl and Guaifenesin were prepared using Dowex50 by Spay Draying technology. Among the various formulation of microcapsule (drug resinate-Ethylcellulose ratio) prepared. An ideal formulation (drug resinate 1:1) and 10% Ethylcellulose coating was selected for the formulation of an extended release suspension. Prepared drug-resinate complex was then microencapsulated and the microencapsulated drug resin complex were suspended in a palatable aqueous suspension base and evaluated for extended release characteristic. Three formulation of suspension were prepared having varying concentration of coating polymer ethylcellulose to study the drug release profile from the suspension. This suspension was evaluated for physical stability, redispersibility and in vitro drug release pattern. The result showed that the suspension prepared with ethylcellulose with 10% concentration shows uniform extend drug release, and is suitable for preparation of good extended release suspension.