The role of hyaluronan as a drug carrier to enhance the bioavailability of extended release ophthalmic formulations. Hyaluronan-timolol ionic complexes as a model case

BATTISTINI, F.D.; TÁRTARA, L.I.; BOIERO, C.; GUZMÁN, M.L.; LUCIANI-GIACCOBBE, L.C.; PALMA, S.D.; ALLEMANDI, D.A.; MANZO, R.H.; OLIVERA, M.E.

EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES

ELSEVIER SCIENCE BV

Año: 2017 vol. 105 p. 188 - 188

0928-0987

he aim of this work was to obtain information concerning the properties of ophthalmic formulations based on hyaluronic-drug ionic complexes, to identify the factors that determine the onset, intensity and duration of the pharmacotherapeutic effect. Dispersions of a complex of 0.5% w/v of sodium hyaluronate (HyNa) loaded with 0.5% w/v of timolol maleate (TM) were obtained and presented a counterionic condensation higher than 75%. For comparison a similar complex obtained with hyaluronic acid (HyH) was also prepared. Although the viscosity of HyNa-TM was significantly higher than that of HyH-TM, in vitro release of TM from both complexes showed a similar extended drug release profile (20?31% over 5 h) controlled by diffusion and ionic exchange. Ocular pharmacokinetic study performed in normotensive rabbits showed that HyNa-TM complex exhibited attractive bioavailability properties in the aqueous humor (AUC and Cmax significantly higher and later Tmax) compared to commercial TM eye-drops