Physical and technological parameters influencing floating properties of matrix tablets based on cellulose ethers

For drug substances suitable for oral administration and sustained-release applications, a controlled and delayed gastric emptying of the dosage form would be advantageous In the formulation of the floating polymer matrix tab lets, different decisive physical and technological parameters were studied . Tablets containing hydroxypropyl cellulose HXF, hydroxyethyl cellulose HH X, hydroxypropylmethyl cellulose K100M, hydroxypropylmethyl cellulose K4M o r hydroxypropylmethyl cellulose E4M were compressed and their hardness, por osity: floating and swelling properties were investigated. Swelling ability was confirmed as essential for floating. The water intake followed the Fic kian diffusion mechanism, except for hydroxypropyl cellulose HXF tablets, w here diffusion was of a "non-Fickian" type. The outer hydrated tablet layer s express viscoelastic gel structure. The results reveal that the increased matrix volume, entrapped air and dry core are also responsible for floatin g. Good technological and floating properties of hydroxypropylmethyl cellul ose polymers are able to compensate the deficient floating properties of th e drug substance, which makes them interesting for novel dosage form design .