Validated methods for the determination of some analgesics and antiinflammatory drugs monitoring the effect of irradiation on the stability of the selected drugs

Inflammation is a part of the complex biological response of vascular tissues to irritants, cell damage, physical injury or harmful stimuli. The immune system is usually involved with inflammatory disorders such as allergic reactions and auto immune diseases as rheumatoid arthritis. In response to cell damage associated with inflammation, arachidonic acid (AA) is mobilized or released from membrane phospholipids by phospholipase A2 (PLA2). Following mobilization, AA is oxidatively metabolized mainly by the cyclooxygenase (COX) and lipoxygenase (LOX) enzymes producing eicosanoids (prostaglandins, thromboxanes, prostacyclin; collectively termed prostanoids and leukotrienes (Figure 1). The classical signs of inflammation are initiated by the release of prostaglandins (PGs), cytokines such as interleukins- 1 and -2 and leukotrienes as they have a powerful effect on blood vessels and nerve endings. PGs cause vasodilation and increase vascular permeability, so plasma and leukocytes diffuse from the blood into the injured tissues leading to pain, swelling, and redness. Moreover, leukotrienes have a chemotactic effect on eosinophils, neutrophils, and macrophages, cause alterations in vascular permeability and promote bronchoconstriction. Loss of functions of the inflamed organ may happen in chronic inflammation as the destruction of bone and cartilage leading to severe disability in case of rheumatoid arthritis