Diclofenac

Overview

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) widely used in therapy for pain and inflammation. Its pharmacological activity is primarily associated with inhibition of cyclooxygenase enzymes, especially Prostaglandin-endoperoxide synthase 2 (COX-2), leading to reduced prostaglandin synthesis and downstream anti-inflammatory, analgesic, and antipyretic effects. In biomedical research, diclofenac is frequently used as a reference compound for comparing analgesic potency, COX-2 inhibition, and related pharmacological responses.

Beyond its therapeutic use, diclofenac is also an important environmental micropollutant because it is commonly detected in wastewater and surface waters. This dual role has made it a recurring subject in studies of drug efficacy, toxicology, environmental fate, and wastewater treatment. Recent research has examined diclofenac alongside compounds such as ibuprofen, indomethacin, mefenamic acid, naproxen, and (RS)-ketoprofen, both as a comparator drug in pharmacological assays and as a contaminant targeted for removal in engineered treatment systems.

Focus of Latest Publications

Recent publications on diclofenac have focused on its use as an analgesic and anti-inflammatory comparator, as well as on new delivery and monitoring approaches. In cancer pain management, one report noted that the efficacy of switching patients from prior nonsteroidal anti-inflammatory drugs to transdermal diclofenac has not been fully evaluated, highlighting interest in its role for mild cancer pain and as an adjunct to opioids in more severe pain. Another study developed a thermoresponsive, mucoadhesive in-situ nasal gel incorporating diclofenac sodium for intranasal delivery, aiming to improve bioavailability by bypassing first-pass metabolism, increasing mucosal retention, and minimizing irritation.

Several studies examined diclofenac in formulation and drug-delivery contexts. A cationic bionanocomplex based on aryl-modified chitosan derivatives was evaluated for controlled release of diclofenac sodium alongside other drugs; diclofenac showed the fastest release from the system, and kinetic modeling suggested non-Fickian diffusion. In a separate comparison of anti-inflammatory agents, diclofenac sodium served as a reference COX inhibitor in the in vitro and in silico assessment of multi-functionalized pyrimidines, where the new compounds outperformed diclofenac in COX-2 selectivity and in some cases in 5-LOX, IL-6, and reactive oxygen species-related assays. Diclofenac sodium was also used as a benchmark in a phytochemical study of Diospyros sylvatica leaves, where the plant fraction showed analgesic activity but remained less potent than diclofenac sodium in the acetic acid-induced writhing model.

Beyond therapeutic development, diclofenac has appeared in safety and environmental studies. In calves with bovine respiratory disease complex, diclofenac sodium administered with tilmicosin was associated with elevated cardiac biomarkers, suggesting early subclinical myocardial injury and additive hepatocellular and myocardial stress, while creatinine and hematological parameters were unchanged. In an urban river monitoring study, diclofenac was detected as a localized spike along the Ciliwung River, consistent with point-source inputs from healthcare or residential discharge. Diclofenac was also among the compounds that produced comparable responses in a graphene-based electrochemical platform for detecting oxidizable contaminants in water, supporting its relevance in broader pharmaceutical pollution screening.