controlled release.

Colon specific tablets of Oxaliplatin combined with anti-inflammatory agents, Diclofenac sodium were prepared using guar gum as matrix carriers in varying concentrations from 40% to 65%. The drug combination in the tablet was estimate simultaneously using newly developed and validated UV derivative spectroscopy method. In vitro drug release profile was studied in changing media method, first in 0.1N HCl for two hours followed by 3 hours in phosphate buffer media, pH 7.4 (PB7.4) and in simulated colon fluid (phosphate buffer pH 6.8 added with rat ceacal content) (SCF) for 19 hours. The drug release profiles from PB7.4 and simulated colon fluid were found to be dependent on the gaur gum concentration. Matrix tablets of oxaliplatin and diclofenac sodium combination with 60% w/w Gaur gum showed a total release of ~66% of Oxaliplatin and ~53% of Diclofenac sodium after 24 hrs. The colon tissue homogenate studies conducted after oral administration of the optimized matrix tablet in New Zealand Rabbits showed 156 µg oxaliplatin and 96 µg Diclofenac sodium recovery in 24 hours.  X-ray Images of matrix tablets containing barium sulphate in Rabbit showed tablets to be intact in small intestine (6 hours after administration) but were diffused and spread out in large intestine and colon confirming enzyme mediated erosion of the tablet in these regions.