Three-dimensional pharmacophore hypothesis was built on the basis of a set of known cyclooxygenase inhibitors using PHASE program to understand the essential structural features for cyclooxygenase inhibitors. Four point pharmacophore with one hydrogen bond acceptor (A), one hydrophobic group (H) and two aromatic rings (R) as pharmacophoric features were developed. Amongst them the pharmacophore hypothesis AHRR14 yielded a statistically significant 3D-QSAR model with 0.716 as R2 value and was considered to be the best pharmacophore hypothesis. The developed pharmacophore model
was validated by predicting the activity of test set molecules. The squared predictive correlation coefficient of 0.977 was observed between experimental and predicted activity values of test set molecules.