Comparative evaluation of Butea frondosa and flurbiprofen for ocular anti-inflammatory activity in rabbits

The roots and leaves of the plant Butea frondosa were evaluated for ocular anti-inflammatory activity on the subacute model of ocular inflammation in rabbits. The arkas (liquid preparations obtained by distillation of certain liquids or drugs soaked in water, using the Arka-Yantra or any other convenient modern distillation apparatus) were prepared using the roots and leaves of the plant. The arkas were formulated as gels using Pluronic F-127 (PF-127) 30% w/w as the polymer. The anti-inflammatory activity of the preparations were assessed by determining their effects on elevated intraocular pressure consequent to breakdown of blood/aqueous humour barrier. A commercial eyedrop of flurbiprofen 0.03% w/w was used to compare the ocular anti-inflammatory activity of the arkas of the plant. A marketed root arka was included in the study for comparison. The anti-inflammatory activity of the arkas formulated as gels were compared with flurbiprofen gel prepared using the same polymer. The changes in intraocular pressure were monitored at various time intervals after a single dose administration of the aqueous as well as gel formulations. In multiple dose studies the aqueous preparations were administered three times a day, while the gels were administered once a day up to day 30 and the intraocular pressure was monitored on different days post-administration. The findings reveal statistically significant differences (P < 0.05) between the arkas of the plant and the commercial eyedrop of flurbiprofen. The arkas of the plant proved to be better than the eyedrop of flurbiprofen, while with respect to gels, the intraocular pressure monitored at various time intervals revealed no statistically significant difference (P > 0.05) between the gel formulations. However, the changes in intraocular pressure monitored on different days post-administration until day 30, demonstrated that the gel produced from B. frondosa leaves arka was superior to all the other gels with respect to the extent of reduction of elevated intraocular pressure elicited experimentally.