2.4. Stability in normal saline solution
The samples stability in normal saline solution was determined by measurement of loss of weight of the dried samples (initial weight M1) in normal saline solution at 37 ◦C about 24 h Then, each sample was dried to constant weight (M2) at 40◦C. The weight loss ratio = (M1 − M2)/M1 × 100%. All experiments were done in quintuplicate.