Objective: The study aimed to compare the calcium content of the shells of oyster (Crassostrea echinata), green shell (Perna viridis), Capiz shell (Placuna placenta), and Nylon shell (Callista erycina) from Panay Island, Philippines.
Methodology: Calcium content of the four shells was determined using potassium permanganate titration and atomic absorption spectroscopy (AAS).
Results: There was no significant difference (p = >5) on the calcium content of the oyster shell, the green shell, the Capiz shell, and the Nylon shell. Also, there was no significant difference (p = >5) between the two methods used in determining their calcium content.
Conclusion: Among the four shells, the Nylon shell showed the highest calcium content in both potassium permanganate titration and AAS. Also, the extraction of calcium content does not vary as to what method was used. This study can be utilized as a reference in formulating calcium-related drug products.
Keywords: Calcium content, shells, oyster, green shell, Capiz shell, Nylon shell.