Functionality testing of gellan gum, a polymeric excipient material for ophthalmic dosage forms

Low acetyl gellan gum, originally a food ingredient, has been used to devise novel ophthalmic formulations, significantly improving drug ocular bioavailability. This increase in drug bioavailability results from the unique gelling property of gellan gum in the presence of tear fluid cations. The aim of this study was to develop a functionality test ensuring the consistency of the dosage form's gelling property and a reproducible pharmacological effect. The rupture strength of the gel was shown to be a reliable indicator of the ocular drug bioavailability in the albino rabbit. The test parameters susceptible to influence the test results were identified. evaluated and optimized. The influence of the raw material characteristics and of the processing parameters on the final product gel strength were determined and optimized, and finished product specifications established. (C) 1997 Elsevier Science B.V.