<span style="mso-bidi-language:HI">QSAR studies of 2,3-diarylpyrazolo[1<b><i><span style="mso-bidi-font-family:Arial;mso-bidi-language:HI">,</span></i></b><span style="mso-bidi-font-family:Arial;mso-bidi-language:HI">5-<i>b</i>]<b><i>-</i></b><span style="mso-bidi-language:HI">pyridazine analogs as cyclooxygenase-2 inhibitors </span></span></span>

2763-2769Cyclooxygenase-2 inhibitors arc of current interest, because these alleviate inflammation, fever, pain, rheumatic and osteoarthritis without side effects, produced by classical NSAlDs. QSAR analysis helps in exploring molecular insight, which are responsible for drug-receptor interactions. QSAR studies have been performed on a series of some 2,3-diaryl-pyrazolo[1,5-b)pyridazine analogs as COX-2 inhibitors using substituent constant in lead structure for 2D and physicochemical properties of molecules for 3D-QSAR analysis respectively. The correlations have been established using regression analysis techniques. 2D-QSAR analysis study has revealed that the substitution of hydrophobic group in the 2,3-diaryl-pyrazolo[1<span style="mso-bidi-font-family:Arial; mso-bidi-language:HI">,<span style="mso-bidi-font-family:Arial; mso-bidi-language:HI">5-b)pyridazines at R2 position is favourable while substitution of bulkier group at R2 position is unfavourable for COX-2 inhibitory activity. In 3D-model, Morl4u and Mor29v are 3D-MoRSE code have been calculated by summing atom weights which have been viewed by a different angular scattering function contributed positively to COX-2 inhibitory activity. G (O..O) is a conformational dependent descriptor based on the geometry of the molecule contributed negatively to COX-2 inhibitory activity.