لخّصلي

Pain is a common global health problem. Pain management has presented major challenges for physicians including patient satisfaction, reduction of clinical complications, and costs (1). Pain can be classified as acute and chronic. Acute pain usually progresses suddenly, does not last longer than six months, and goes away when there is no longer an underlying cause for the pain. Its main causes are surgery, burns, broken bones, and childbirth. Chronic pain is ongoing, usually lasts longer than six months, and does not goes away even after an underlying cause for the pain is healed. Its main causes are headache, cancer, ar- thritis, nerve pain, and back pain (2). Physicians describe pain medications according to pain severity and origin. Traditionally, opioid analgesics regardless of their side effects are prescribed for the management of pain, such as postoperative pain, that cannot be managed well enough with non-opioid pain medica- tions. Currently, there is a global trend to reduce the use of opioids and develop alternative multimodal analgesia (opioid and non-opioid analgesic) approaches that maximize the analgesic ef- fect, decrease doses, and thus minimize the side effects (3–5).
SeglentisVR is the first in class multimodal analgesia tablets development by ESTEVE Pharmaceuticals (Barcelona, Spain) that contain 56 mg celecoxib and 44 mg tramadol per tablet. It was recently approved by the United States Food and Drug Administration in October 2021 for the management of acute pain in adults, that cannot be managed well enough with non- opioid pain medications (6).
Celebrex (CLX), Figure 1(a), is a nonsteroidal anti- inflammatory drug (NSAID) that selectively inhibits the COX-2 enzyme which is responsible for pain and inflammation. It is in- dicated for the management of acute pain as well as chronic pain conditions such as rheumatoid arthritis and osteoarthritis. Tramadol (TMD), Figure 1(b), is an opioid analgesic that is a partial agonist for the mu-opioid receptor and inhibits serotonin and norepinephrine reuptake. It is indicated in adults for the manage- ment of pain severe enough to require an opioid analgesic (7).
Different analytical techniques have been described for the quantification of CLX alone in its pharmaceutical formulations and plasma including HPLC, spectrofluorometric, and spectro- photometric methods (8–15). Similarly, different analytical tech- niques have been reported for the quantification of TMD alone in its pharmaceutical formulations and plasma including HPLC, electrochemical, spectrofluorometric and spectrophotometric methods (16–25).
It is noteworthy that, to date, no analytical procedure has been published for the concurrent determination of CLX and TMD. Therefore, our intention was to develop the first spectro- photometric methods for concurrent quantification of CLX and TMD in tablet dosage form. The UV absorption spectra of CLX and TMD showed strong overlap. Mathematical simultaneous equa- tions and ratio difference methods were developed to resolve the spectral overlap and quantify the drugs in combination.