The Water Absorption Behavior of the Karaya Gum Ointment

The water absorption behavior of karaya gum ointment, which improves perianal dermatitis following definitive operation for diseases, such as Hirschsprung was investigated to elucidate the mechanisms of its action. Forty percent karaya gum ointment (10g) swelled and absorbed 7. 5 and 16g of saline solution under the experimental condition of after 6 and 24hr, respectively. The water absorption was not saturable during the experimental periods. The linear square root of time plots suggested that the water absorption properties of karaya gum ointment are controlled by the diffusion model of water into ointment, and the observed absorption rate constant of 40% ointment was 0.426g/10gitnin1/2. Distilled water as a tested fluid was absorbed more rapidly than saline solution.The effect of concentration on the absorption behavior for the karaya gum and CMC-Na ointment showed that CMC-Na ointment is more absorbent in intermediate concentrations. The water absorption pattern of ointments containing other high molecular compounds was also studied. The order of water absorbency was CMC-Na, sodium alginate, karaya gum, tragacanth gum and acacia at concentration of 40%. Karaya gum ointment exhibited water absorbency comparable to those of the marketed skin barriers containing karaya gum. These results suggest that the water absorption effect of karaya gum ointment is associated with one of the mechanisms by which it improves perianal dermatitis.