Research of material for making hard capsule shell has developed so fast. Commercial capsule shell with gelatin mostly are made from pig skin and makes Muslim people cannot consume drug with capsule preparation. Therefore, more capsule shell material development is needed, raw material which can be substitute gelatin is carrageenan. However, by using carrageenan is still less effective as a drug delivery agent because is easy to crack. With these problems, to improve performance a capsule shell as a drug delivery agent, Spirulina platensis is needed. To optimize both of material between carrageenan and Spirulina platensis, cross linker is used. The purpose of this study was to use CaCl2 as cross linker to combine the bond between two functional groups and decrease solubility both of material in the water so prolongs the dissolution of the drugs to release into the intestine. The formulation of the solution that used in this research is variation of CaCl2 (0.75%; 1%; 3%; 5%, 7%) (w/v). The characterization was performed by using water content, pH, water resistance, durability in acid solution test and this parameter follow Department of Health Republic of Indonesia. The best concentration of CaCl2 which used in this research is 7% (w/v), with characterization that obtained as follows: water content is 13.52%, resistance in water in 38'09”, resistance in acid environment in 44'54”, and pH is 6.4. This capsule is able to survive in acid condition at pH 1.2 for 75 minutes, with release the drug as much as 61.30%, and then at pH 4.5 release the drug of 54.90%, and pH 6.8 release the drug of 89.58%. The CaCl2 concentration affected to porosity of capsule shell and drug release from inside capsule shell, besides that CaCl2 also effect the absorption ability of capsule shell. By paying attention to these parameters, it is expected that the capsule formed will have strong structural and not easy to dissolution in the water and acid environment, so that the drug will be released according to the destination organ.