Challenges and Opportunities for Celecoxib Repurposing.

Drug repositioning, also known as drug repurposing, reprofiling, or rediscovery, is considered to be one of the most promising strategies to accelerate the development of new original drug products. Multiple examples of successful rediscovery or therapeutic switching of old molecules that did not show clinical benefits or safety in initial trials encourage the following of the discovery of new therapeutic pathways for them. This review summarizes the efforts that have been made, mostly over the last decade, to identify new therapeutic targets for celecoxib. To achieve this goal, records gathered in MEDLINE PubMed and Scopus databases along with the registry of clinical trials by the US National Library of Medicine at the U.S. National Institutes of Health were explored. Since celecoxib is a non-steroidal anti-inflammatory drug that represents the class of selective COX-2 inhibitors (coxibs), its clinical potential in metronomic cancer therapy, the treatment of mental disorders, or infectious diseases has been discussed. In the end, the perspective of a formulator, facing various challenges related to unfavorable physicochemical properties of celecoxib upon the development of new oral dosage forms, long-acting injectables, and topical formulations, including the latest trends in the pharmaceutical technology, such as the application of mesoporous carriers, biodegradable microparticles, lipid-based nanosystems, or spanlastics, was presented.

Pharmacokinetics of robenacoxib following single intravenous, subcutaneous and oral administrations in Baladi goats (Capra hircus).

The purpose of this study was to assess the pharmacokinetics of robenacoxib (RX), a COX-2 selective non-steroidal anti-inflammatory drug, in goats after single intravenous (IV), subcutaneous (SC) and oral (PO) administrations. 5-month-old healthy female goats (n = 8) were used. The animals were subjected to a three-phase, two-dose (2 mg/kg IV, 4 mg/kg SC, PO) unblinded, parallel study design, with a four-month washout period between the IV and SC treatment, and a one-week period between the SC and PO treatment. Blood was drawn from the jugular vein in heparinized vacutainer tubes at 0, 0.085 (for IV only), 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10 and 24 h. Plasma RX concentrations were measured using HPLC coupled to a UV multiple wavelength detector, and the data were pharmacokinetically analysed using ThothPro™ 4.3 software in a non-compartmental approach. Following IV administration, terminal elimination half-life, volume of distribution and total clearance were 0.32 h, 0.24 L/kg and 0.52 L/h/kg, respectively. For SC and PO, the mean peak plasma concentrations were 2.34 and 3.34 µg/mL at 1.50 and 0.50 h, respectively. The t1/2λz was significantly different between the IV and the extravascular (EV) administrations (0.32 h IV vs 1.37 h SC and 1.63 h PO), suggesting the occurrence of a flip-flop phenomenon. The significant difference in Vd values between IV (0.24 L/kg) and EV (0.95 L/kg SC and 1.71 L/kg; corrected for F %) routes might have also triggered the t1/2λz difference. The absolute average SC and PO bioavailability were high (98% and 91%, respectively). In conclusion, the IV administration of RX might not be suitable for goats, due to its short t1/2λz. The EV routes, however, appear to be convenient for the drug's occasional use.

Selective inhibitors of cyclooxygenase 2 - their past, present and future.

Pain is a serious subjective experience, which, although it has a protective nature, it physically and mentally exhausts the patient. The pharmacological field of development and research in the treatment and relief of pain has been dynamic and interesting ever since the isolation of salicylic acid. After discovering the molecular nature of cyclooxygenase and its inhibition, research focused on selective COX-2 inhibitors, but they were a big disappointment. Today, the possibility of contributing to safe and effective analgesic-antiphlogistic treatment for the patient with a combination of drugs is emerging again.

New horizons in the roles and associations of COX-2 and novel natural inhibitors in cardiovascular diseases.

Age-related cardiovascular disease is the leading cause of death in elderly populations. Coxibs, including celecoxib, valdecoxib, etoricoxib, parecoxib, lumiracoxib, and rofecoxib, are selective cyclooxygenase-2 (COX-2) inhibitors used to treat osteoarthritis and rheumatoid arthritis. However, many coxibs have been discontinued due to adverse cardiovascular events. COX-2 contains cyclooxygenase (COX) and peroxidase (POX) sites. COX-2 inhibitors block COX activity without affecting POX activity. Recently, quercetin-like flavonoid compounds with OH groups in their B-rings have been found to serve as activators of COX-2 by binding the POX site. Galangin-like flavonol compounds serve as inhibitors of COX-2. Interestingly, nabumetone, flurbiprofen axetil, piketoprofen-amide, and nepafenac are ester prodrugs that inhibit COX-2. The combination of galangin-like flavonol compounds with these prodrug metabolites may lead to the development of novel COX-2 inhibitors. This review focuses on the most compelling evidence regarding the role and mechanism of COX-2 in cardiovascular diseases and demonstrates that quercetin-like compounds exert potential cardioprotective effects by serving as cofactors of COX-2.

COXIBs and 2,5-dimethylcelecoxib counteract the hyperactivated Wnt/ß-catenin pathway and COX-2/PGE2/EP4 signaling in glioblastoma cells.

BACKGROUND: Glioblastoma (GBM) is the deadliest and the most common primary brain tumor in adults. The invasiveness and proliferation of GBM cells can be decreased through the inhibition of Wnt/ß-catenin pathway. In this regard, celecoxib is a promising agent, but other COXIBs and 2,5-dimethylcelecoxib (2,5-DMC) await elucidation. Thus, the aim of this study was to analyze the impact of celecoxib, 2,5-DMC, etori-, rofe-, and valdecoxib on GBM cell viability and the activity of Wnt/ß-catenin pathway. In addition, the combination of the compounds with temozolomide (TMZ) was also evaluated. Cell cycle distribution and apoptosis, MGMT methylation level, COX-2 and PGE2 EP4 protein levels were also determined in order to better understand the molecular mechanisms exerted by these compounds and to find out which of them can serve best in GBM therapy. METHODS: Celecoxib, 2,5-DMC, etori-, rofe- and valdecoxib were evaluated using three commercially available and two patient-derived GBM cell lines. Cell viability was analyzed using MTT assay, whereas alterations in MGMT methylation level were determined using MS-HRM method. The impact of COXIBs, in the presence and absence of TMZ, on Wnt pathway was measured on the basis of the expression of ß-catenin target genes. Cell cycle distribution and apoptosis analysis were performed using flow cytometry. COX-2 and PGE2 EP4 receptor expression were evaluated using Western blot analysis. RESULTS: Wnt/ß-catenin pathway was attenuated by COXIBs and 2,5-DMC irrespective of the COX-2 expression profile of the treated cells, their MGMT methylation status, or radio/chemoresistance. Celecoxib and 2,5-DMC were the most cytotoxic. Cell cycle distribution was altered, and apoptosis was induced after the treatment with celecoxib, 2,5-DMC, etori- and valdecoxib in T98G cell line. COXIBs and 2,5-DMC did not influence MGMT methylation status, but inhibited COX-2/PGE2/EP4 pathway. CONCLUSIONS: Not only celecoxib, but also 2,5-DMC, etori-, rofe- and valdecoxib should be further investigated as potential good anti-GBM therapeutics.

Pharmacokinetics of the novel COX-2 selective inhibitor vitacoxib in cats: The effects of feeding and dose.

The purpose of this study was to determine the pharmacokinetics and dose-scaling model of vitacoxib in either fed or fasted cats following either oral or intravenous administration. The concentration of the drug was quantified by UPLC-MS/MS on plasma samples. Relevant parameters were described using noncompartmental analysis (WinNonlin 6.4 software). Vitacoxib is relatively slowly absorbed and eliminated after oral administration (2 mg/kg body weight), with a Tmax of approximately 4.7 hr. The feeding state of the cat was a statistically significant covariate for both area under the concentration versus time curve (AUC) and mean absorption time (MATfed ). The absolute bioavailability (F) of vitacoxib (2 mg/kg body weight) after oral administration (fed) was 72.5%, which is higher than that in fasted cats (F = 50.6%). Following intravenous administration (2 mg/kg body weight), Vd (ml/kg) was 1,264.34 ± 343.63 ml/kg and Cl (ml kg-1  hr-1 ) was 95.22 ± 23.53 ml kg-1  hr-1 . Plasma concentrations scaled linearly with dose, with Cmax (ng/ml) of 352.30 ± 63.42, 750.26 ± 435.54, and 936.97 ± 231.27 ng/ml after doses of 1, 2, and 4 mg/kg body weight, respectively. No significant undesirable behavioral effects were noted throughout the duration of the study.

Exposure to cox-2 inhibitors (coxibs) during the first trimester and pregnancy outcome: a prospective observational cohort study.

PURPOSE: Cox-2-inhibitors (coxibs) are not recommended in pregnancy but early exposure may occur, for instance in unplanned pregnancies. Experience in pregnancy is limited leading to concerns in patients and their health care providers. Therefore, further data on coxibs and their effects on embryogenesis are needed. METHODS: This observational cohort study evaluates pregnancies ascertained in Germany during the study period from January 2000 to January 2016. A cohort of 174 women exposed to coxibs in the first trimester was compared to a randomly selected cohort of 521 women without exposure to coxibs, other nonsteroidal anti-inflammatory drugs or known teratogens. RESULTS: The overall rate of major birth defects was not significantly increased in the study cohort (2.9 vs. 2.7%, OR 1.08, 95% CI 0.34-3.42; OR adjusted 0.96, 95% CI 0.28-3.26). The cumulative incidence of spontaneous abortions was nonsignificantly lower in the exposed cohort (14.3 vs. 20.0%; HR, 0.90, 95% CI 0.51-1.58; HR adjusted, 0.87; 95% CI, 0.49-1.56). Elective terminations of pregnancies (ETOP), mainly for 'social' reasons, were more frequent in the coxib cohort (17.5 vs. 7.0%, HR, 2.31; 95% CI, 1.26-4.24; HR adjusted 2.12, 95% CI 1.13-3.97). CONCLUSIONS: Our study results support the assumption that coxibs are not major teratogens. Considering the still limited evidence basis on coxib exposure during pregnancy, well-established alternatives should be preferred.

NSAIDs utilization for musculoskeletal indications in elderly patients with cerebro/cardiovascular disease.

OBJECTIVES: To describe NSAID utilization for musculoskeletal conditions in a large cohort of Italian elderly with cerebro/cardiovascular disease, a population in which NSAIDs should be generally avoided due to the prothrombotic potential. METHODS: Administrative data from five Italian geographic areas were analyzed. Patients aged ≥ 65 with a cerebro/cardiovascular event recorded between 2008 and 2011 (cohort entry) were selected. Prescription NSAIDs reimbursed for musculoskeletal conditions and dispensed during 1 year follow-up were retrieved to describe (i) prevalence of use, (ii) average amount of defined daily doses of NSAIDs claimed by users per day of follow-up, and (iii) distribution of the received daily dose (RDD) among patients with ≥ 2 dispensings. Among new users, i.e., patients without NSAID dispensings during 2 years before cohort entry, the first dispensed NSAID molecule was observed. RESULTS: Overall, 511,989 patients were selected. Across the five geographic areas, prevalence of use ranged from 48 to 21% and average consumption ranged between 30 and 67 DDD/1000 users/day. Around 10% of patients in the overall cohort had a RDD > 1. Nimesulide (9.6%) and diclofenac (7.5%) had the highest prevalence of use. The most consumed NSAIDs were nimesulide and coxibs with 10.6 and 7.5 DDD/1000 users/day, respectively. Among new users recruited in 2011, 30% had diclofenac or a coxibs as the first prescription. CONCLUSIONS: NSAID use was common in the study cohort, particularly in central-southern areas. In contrast with current recommendations, coxibs and diclofenac were among the most prescribed active principles, even in new users. Interventions to promote appropriateness of use are warranted.

Safety assessment of vitacoxib: 180-day chronic oral toxicity studies.

Vitacoxib, a selective COX-2 inhibitor, is approved for the relief of pain and inflammation associated with orthopedic surgery and osteoarthritis in dogs. In the current study, a chronic toxicity research was performed to evaluate the safety of vitacoxib in male and female rats for long-term. Vitacoxib was dosed orally to groups of rats for 180 days at 1.2, 6, 30 mg/kg bw/day by gavage. The chronic study oral administration of vitacoxib did not show observational or toxicological effects on the body or organ weights, food consumption, hematology and biochemistry at dose 6 mg/kg bw. However, vitacoxib (30 mg/kg) showed minor alterations to histopathology of liver, kidney and stomach related to treatment. These results provide further indication that vitacoxib is safe and well-tolerated in rats after 180 days of daily oral administration at 6 mg/kg bw and the NOAEL for both sexes was 6 mg/kg bw for 180 consecutive days.

[Acute pain therapy in orthopedics/trauma surgery]. / Akutschmerztherapie in Orthopädie/Unfallchirurgie.

The management of acute pain is of utmost importance in the treatment regimen of orthopedic and trauma patients. Pain perception is different for each patient and has to be individually addressed. Especially in a postoperative setting often with a very dynamic course of pain, it is optimal that the pain management is adapted to the individual course of pain. In this situation it makes sense to apply patient-controlled systems. By combining different analgesic substance classes and non-pharmaceutical therapy in the sense of a multimodal concept, the mechanisms of action complement each other and side effects can be reduced. Patient satisfaction is higher when they are actively involved in the (medicinal) pain therapy and in the decision making. This is particularly important for patient-controlled analgesia (PCA). In addition to invasive catheter administration procedures, there are also modern approaches for oral individual self-administered opioid treatment.

In Vivo Evaluation of Anti-inflammatory Activity of 2-[3-Acetyl- 5-(4-chloro-phenyl)-2-methyl-pyrrol-1-yl]-4-methylsulfanylbutyric Acid.

BACKGROUND: Persisting inflammatory stimuli cause chronic inflammation recognized as the major factor contributing to the development of a number of diseases. One group of drugs used in the treatment of chronic inflammation is the group of non-steroidal anti-inflammatory drugs and, more specifically, the selective COX-2 inhibitors (coxibs). However, most of the coxibs were withdrawn from the market in view of their safety profile. In the present study, 2-[3-Acetyl-5-(4-chlorophenyl)- 2-methyl-pyrrol-1-yl]-4-methylsulfanyl-butyric acid (compound 3e), an Npyrrolylcarboxylic acid derivative structurally related to celecoxib, is evaluated for anti-inflammatory activity after single and multiple (14 days) administration using an animal inflammation model. AIM: To evaluate the anti-inflammatory properties of 2-[3-Acetyl-5-(4-chlorophenyl)-2-methyl-pyrrol-1-yl]-4-methylsulfanyl-butyric acid (compound 3e) after single and multiple (14 days) administration using an animal inflammation model. MATERIALS AND METHODS: Forty Wistar rats were allocated into 5 groups (n=8) treated with saline (controls), diclofenac (25 mg/kg b.w.), compound 3e (10, 20 and 40 mg/kg b.w.) intraperitoneally. The volume of the right hind paw of the animals of all groups is measured prior to treatment and two, three and four hours after administration of carrageenan using a plethysmometer (Ugo Basile, Italy). The percentage of paw edema is calculated using the Trinus formula. RESULTS: In a single administration, compound 3e in doses of 10 and 20 mg/kg b.w. did not inhibit paw edema, while a dose of 40 mg/kg b.w. significantly inhibited carrageenan-induced paw edema at 2 hours in comparison with the control group. After continuous administration, compound 3e in doses of 10, 20 and 40 mg/kg b.w. significantly reduced paw edema at 2, 3, and 4 hours compared to animals treated with saline. CONCLUSIONS: Compound 3e shows anti-inflammatory properties similar to those of diclofenac after continuous administration.

Risk of incident active tuberculosis disease in patients treated with non-steroidal anti-inflammatory drugs: a population-based study.

BACKGROUND: Mycobacterium tuberculosis (TB) is one of the world's most devastating public health threats. Our goal is to evaluate whether the use of non-steroidal anti-inflammatory drugs (NSAIDs) affect the risk of new incident active TB disease. METHODS: We conducted a nested case-control analysis by using a 1 million longitudinally followed cohort, from Taiwan's national health insurance research database. Effects of NSAIDs on active TB were estimated by conditional logistic regression and adjusted using a TB-specific disease risk score (DRS). NSAIDs exposures were defined as having a prescription record of NSAIDs ≧ 7 days that ended between 31 and 90 days prior to the index date. RESULTS: A total of 123,419 users of traditional NSAIDs, 16,392 users of cyclooxygenase-2 selective inhibitor (Coxibs), and 4706 incident cases of active TB were identified. Compared with nonusers, use of traditional NSAIDs was associated with an increased risk of TB in the unadjusted analysis ([RR], 1.39; 95% [CI], 1.24 - 1.57 and DRS adjusted analysis ([ARR], 1.30; 95% [CI], 1.15- 1.47). However, use of Coxibs was not associated with a significant increase in the risk of TB after DRS adjustment ([ARR], 1.23; 95% [CI], 0.89 - 1.70). CONCLUSIONS: In this large population-based study, we found that subjects using traditional NSAIDs were associated with increased risk for active TB. We did not find evidence for a causative mechanism between traditional NSAIDs and TB, and more research is required to verify whether the association between traditional NSAIDs and TB is causal, or simply reflects an increased use of anti-inflammatory drugs in the early phases of TB onset.

Safety assessment of vitacoxib: Acute and 90-day sub-chronic oral toxicity studies.

Vitacoxib, is a newly developed coxibs NSAID (selective inhibitors of cyclooxygenase-2). To date, no experimental data have been published concerning its safety for use as an additive in the human diet. In the present study, we assessed the acute and sub-chronic toxicity of vitacoxib administered by gavage. The acute toxicity tests in Sprague Dawley (SD) rats and ICR mice demonstrated that vitacoxib at a dose of 5000 mg/kg BW failed to alter any of the parameters studied. In the 90-day sub-chronic toxicity test, vitacoxib was administered to SD rats at the doses of 0 (control), 5, 10, 20, 30, and 60 mg/kg BW. The results demonstrated that there were no significant differences for most indexes of sub-chronic toxicity throughout the experiment at the dose of 5-20 mg/kg BW, indicating no apparent dose-dependent. However, there were significant histopathology changes in the liver and kidney, and alterations in some biochemical parameters in the 60 mg/kg BW group. Based on these findings, the gavage LD50 was determined to be > 5000 mg/kg in SD rats and ICR mice, and the 90-day gavage no-observed-adverse-effect level (NOAEL) of vitacoxib was considered to be 20 mg/kg BW under the present study conditions.

Status of etoricoxib in the treatment of rheumatic diseases. Expert panel opinion.

Pain is one of the most disabling symptoms of rheumatoid diseases. Patients with pain secondary to osteoarthritis (OA), rheumatoid arthritis (RA), ankylosing spondylitis (AS) or gout require effective analgesic treatment, and the physician's task is to select a drug that is best suited for an individual patient. The choice of pharmacotherapy should be based both on drug potency and clinical efficacy, and its safety profile, particularly in the elderly population, as the number of comorbidities (and hence the risk of treatment complications and drug interactions) rises with age. In cases involving a high risk of gastrointestinal complications or concerns about hepatotoxicity, with a low cardiovascular risk, the first-line nonsteroidal anti-inflammatory drugs to consider should be coxibs including etoricoxib.

Mucosal exfoliation as a selective reaction to etoricoxib.

WHAT IS KNOWN AND OBJECTIVE: Etoricoxib is a non-steroidal anti-inflammatory drug (NSAID) that inhibits the inducible cyclooxygenase (COX-2) with a good safety profile. We describe the first case of two mucosal adverse events to etoricoxib in the same patient. CASE DESCRIPTION: Our patient developed stomatitis with mucosal exfoliation after etoricoxib assumption. Some months later, after a new etoricoxib intake, she presented with vaginal burning, tongue angioedema and erosions, oral exfoliation and wheals on the hands. A provocation test with diclofenac was negative. WHAT IS NEW AND CONCLUSION: The peculiarities of our case are the rare clinical manifestation and the selective hypersensitivity to COX-2 inhibitor with tolerance to a non-selective NSAID.

A potential role of PUFAs and COXIBs in cancer chemoprevention.

Polyunsaturated fatty acids (PUFAs), particularly the ω-3 PUFAs and COXIBs have been associated with decreased inflammation and the prevention of tumorigenesis. ω-3 PUFAs have shown to display multiple antitumour actions, while ω-6 PUFAs and its derived eicosanoids promote the effects in cancer cell growth, angiogenesis, and invasion. ω-3 PUFAs may act by suppressing the metabolism of arachidonic acid to form proinflammatory mediators or as a precursors of novel lipid mediators with pro-resolving activity, while COXIBs are able to modulate inflammatory response by inhibiting cyclooxygenase 2 (COX-2), an inducible prostaglandin synthase overexpressed in several human cancers. As recently has been postulated, the anti-inflammation and pro-resolution processes are not equivalent. A family of lipid mediators from ω-3 PUFAs can act as agonist promoting resolution, while antinflammatory agents such as COXIBs may act as antagonists limiting the inflammatory response. The present paper reviews the current knowledge about the role of PUFAs and its derivatives (metabolites), as well as the COXIBs activity in cancer process as a sinergic therapeutic alternative for cancer treatment.

Enhancing the pharmacodynamic profile of a class of selective COX-2 inhibiting nitric oxide donors.

We report herein the development, synthesis, physicochemical and pharmacological characterization of a novel class of pharmacodynamic hybrids that selectively inhibit cyclooxygenase-2 (COX-2) isoform and present suitable nitric oxide releasing properties. The replacement of the ester moiety with the amide group gave access to in vivo more stable and active derivatives that highlighted outstanding pharmacological properties. In particular, the glycine derivative proved to be extremely active in suppressing hyperalgesia and edema.

The novel anti-inflammatory agent VA694, endowed with both NO-releasing and COX2-selective inhibiting properties, exhibits NO-mediated positive effects on blood pressure, coronary flow and endothelium in an experimental model of hypertension and endothelial dysfunction.

Selective cyclooxygenase 2 (COX2) inhibitors (COXIBs) are effective anti-inflammatory and analgesic drugs with improved gastrointestinal (GI) safety compared to nonselective nonsteroidal anti-inflammatory drugs known as traditional (tNSAIDs). However, their use is associated with a cardiovascular (CV) hazard (i.e. increased incidence of thrombotic events and hypertension) due to the inhibition of COX2-dependent vascular prostacyclin. Aiming to design COX2-selective inhibitors with improved CV safety, new NO-releasing COXIBs (NO-COXIBs) have been developed. In these hybrid drugs, the NO-mediated CV effects are expected to compensate for the COXIB-mediated inhibition of prostacyclin. This study evaluates the potential CV beneficial effects of VA694, a promising NO-COXIB, the anti-inflammatory effects of which have been previously characterized in several in vitro and in vivo experimental models. When incubated in hepatic homogenate, VA694 acted as a slow NO-donor. Moreover, it caused NO-mediated relaxant effects in the vascular smooth muscle. The chronic oral administration of VA694 to young spontaneously hypertensive rats (SHRs) significantly slowed down the age-related development of hypertension and was associated with increased plasma levels of nitrates, stable end-metabolites of NO. Furthermore, a significant improvement of coronary flow and a significant reduction of endothelial dysfunction were observed in SHRs submitted to chronic administration of VA694. In conclusion, VA694 is a promising COX2-inhibiting hybrid drug, showing NO releasing properties which may mitigate the CV deleterious effects associated with the COX2-inhibition.

Recommendations for the Use of Nonsteroidal Anti-inflammatory Drugs and Cardiovascular Disease Risk: Decades Later, Any New Lessons Learned?

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most prescribed pharmacologic therapies worldwide due to their therapeutic analgesic efficacy and relative tolerability. In the past several decades, various cardiovascular (CV) adverse events have emerged regarding both traditional NSAIDs (tNSAIDs) and cyclo-oxygenase 2 (COX-2) selective (coxibs). This review will provide an updated report on the CV risk profile of NSAIDs, focusing on several of the larger clinical trials, meta-analyses, and registry studies. We aim to provide rheumatologists with a framework for NSAID use in the context of rheumatologic chronic pain management. Recent findings: In patients with and without CV diseases, the use of NSAIDs, both tNSAIDs and coxibs, is associated with an increased risk of adverse CV events, myocardial infarction, heart failure, and cerebrovascular events. These CV risks have increased within weeks of coxib use and higher doses of tNSAIDs. The risk of adverse CV events is heterogenous across NSAIDs; naproxen and low-dose ibuprofen appear to have lower increased CV risk among NSAIDs. A variation in CV risk is associated with multiple factors, including NSAID class, COX-2 selectivity, treatment dose and duration, and baseline patient risk. Summary: Many important questions remain regarding the safety of NSAIDs and whether the culmination of research performed could inform us whether specific patient subtypes or NSAID class may have a more favorable profile. tNSAIDs such as naproxen and low-dose ibuprofen may have a lower CV risk profile, while coxibs have a more favorable GI risk profile. In general, any NSAID can be optimized if used at the lowest effective dose for the shortest amount of time, especially among individuals with increased CV risk.

Comprehensive Assessment of the Stability of Selected Coxibs in Variable Environmental Conditions along with the Assessment of Their Potential Hepatotoxicity.

Determining the influence of environmental factors on the stability of drugs is very helpful when choosing excipients, storage conditions or packaging materials. In addition, information about possible toxic degradation products enables detecting and avoiding the harmful side effects of the drug. We used the thin-layer chromatographic-densitometric procedure for the assay of five coxibs, conducted degradation studies in various environments and at different temperatures along with the determination of pharmacokinetic parameters. The results were subjected to chemometric analysis, to investigate and visualize the similarities and differences of the studied coxibs. Samples of the tested drug were also analyzed by UPLC-MS/MS in order to identify degradation products, and determine possible drug degradation pathways. Using the human liver cancer HepG2 cell line, the hepatotoxic effect of the degradation products was also determined. It was observed that all substances were relatively stable under the analyzed conditions and degraded more in acidic than alkaline environments. Robenacoxib is the drug that decomposes the fastest, and cimicoxib turned out to be the most stable. Robenacoxib also showed significant hepatotoxicity at the highest tested concentration, which correlates with the high degree of its degradation, and the probable formation of a more hepatoxic product. The obtained mass spectra of compounds formed as a result of hydrolysis of the protonated drug leading to the formation of several product ions, which enabled us to propose probable degradation pathways.