Formulation development, optimization and evaluation of once a day occuserts of brimonidine tartrate.

Brimonidine Tartrate is a highly selective α2-adrenoceptor agonist which reduces intra-ocular pressure (IOP) by reducing aqueous humour production and increasing aqueous humour outflow via the uveoscleral pathway. The objective of the present work was to develop ocular inserts of Brimonidine Tartrate and evaluate their potential for sustained ocular delivery. Matrix-type ocular inserts were prepared by solvent casting technique-employing mercury as substrate and characterized in vitro by drug release studies using a flow-through apparatus that simulated the eye conditions. Nine formulations were developed, which differed in the ratio and weight of polymers carbopol 934P and HPMC-K15M. All formulations carried PEG-400 (30 % w/w) plasticizers. The optimized formulation was subjected to interaction studies, all physico-chemical study, sterility test, in vivo studies, and stability studies to assess the effectiveness of the formulation. Cumulative drug released from the formulation ranged from 90-98% within 24 hours. On the basis of in vitro drug release studies, the formulation with Carbopol-934: HPMC K15M (80:20) was found to be better than the other formulations and it was selected as an optimized formulation. On the basis of interaction studies, all physico-chemical study, sterility test, in vivo studies, and stability studies, it can be concluded that this ocular insert formulation provided the desired drug release in vitro for one day and remained stable and intact at ambient conditions.