Physical characteristics of the prepared patches are shown in Table III. In general, the physical characteristics including the flexibility of the chitosan patch are dependent on molecular weight and quantity of chitosan in the patch formulation. Using high molecular weight (100 000– 1 000 000 Da) and high content (5% w/w) generally results in the tight packing of the polymer macromolecules, consequently decreasing the polymer’s free volume. In this case, they hardly move and hence there is a decrease in the flexibility of the polymer molecules [16]. In this study, however, it is interesting to note that the polymer solution of squid was highly viscous than the others. In addition, the patch obtained from squid was very flexible whereas that obtained from shrimp shell or crab shell was hard and brittle.