Controlled Release Coating of Aqueous Ethyl Cellulose Dispersion Combined with Different Grades of Hydroxypropyl Methylcellulose

摘要

Three grades of hydroxypropyl methylcellulose (HPMC E5, E15 and E50), Methocel?, had been added to the aqueous ethyl cellulose dispersion, Surelease?, to modify the release profile of the coated multiparticulate dosage form. The influence of coating levels, molecular weight of HPMC and curing effect were investigated. The dissolution rate decreased with the increase of coating level. The higher ratio of HPMC/EC led to fast dissolution for all three grades of HPMC. The dissolution profile demonstrated that at the same coating level and with the same HPMC/EC ratio, pellets coated with HPMC-E15 showed the lowest release rate and pellets with HPMC E5 exhibited the slowest release profile, which did not correlate with the molecular weight/viscosity rank of E5, E15 and E50. The curing study exhibited that there is varying pattern for the release change after curing. The pellets coated with 7.5% HPMC-E15 had a faster dissolution after curing; however, the pellets with 10% HPMC E15 had a slightly slower release after curing.