Diclofenac Potassium in Acute Postoperative Pain and Dysmenorrhoea: Results from Comprehensive Clinical Trial Reports

Comprehensive review of genotoxicity data for diclofenac

Diclofenac is a non-steroidal anti-inflammatory drug discovered several decades ago, which has since been used by an estimated one billion patients and has demonstrated an acceptable safety profile. In support of its marketing approval, a comprehensive set of genotoxicity studies were conducted in vitro and in vivo. Despite the fact that these studies preceded both Good Laboratory Practice (GLP) requirements and International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines on genotoxicity testing, they were conducted using the best scientific principles and are considered appropriate by contemporary standards. In addition to bacterial mutagenicity and mammalian in vitro assays, repeat-dose somatic, germ cell and dominant lethal assays were conducted. These data are made available for the first time to offer researchers an opportunity to review the existing data set that unequivocally demonstrates that diclofenac sodium is not genotoxic. This is further substantiated by long-term bioassay data demonstrating that diclofenac sodium has no carcinogenic potential in rodents. However, more recently, new studies have been published showing a genotoxic potential for diclofenac in novel or modified in vitro test systems. These new publications are discussed in the context of the existing comprehensive data package.

Composing Novel Diclofenac Potassium and l-Proline Salt Cocrystal as a Strategy to Increase Solubility and Dissolution

This research dealt with the multicomponent crystal developed from diclofenac potassium and l-proline to improve the pharmaceutical performance of this anti-inflammatory drug. Slow evaporation of the component mixture at a 1:1 M ratio, supported by ultrasonication, yielded a new salt cocrystal, which was characterized using thermal analysis, Karl Fischer titration, infrared spectrophotometry, powder diffractometry, and single crystal diffractometry. This salt cocrystal was confirmed as a tetrahydrate that comprised diclofenac potassium, l-proline, and water (1:1:4), named DKPH. The new salt cocrystal enhanced the solubility of diclofenac potassium by up to 3.56 folds and accelerated the intrinsic dissolution rate of 3.36 folds. It was supported by the solid and solution phase intermolecular interaction study. A different phase, which indicated a monohydrate form of the salt cocrystal, was found from the low humidity chamber during the isotherm sorption study. However, the tetrahydrate, DKPH, was proven as a stable form under ambient conditions.

Poly(vinyl alcohol boric acid)-Diclofenac Sodium Salt Drug Delivery Systems: Experimental and Theoretical Studies

The main aim of the paper was to simulate the drug release by a multifractal theoretical model, as a valuable method to assess the drug release mechanism. To do this, drug delivery films were prepared by mixing poly(vinyl alcohol boric acid) (PVAB) and diclofenac (DCF) sodium salt drug in different mass ratios from 90/10 to 70/30, in order to obtain drug delivery systems with different releasing rates. The different drug content of the three systems was confirmed by energy-dispersive spectroscopy (EDAX) analysis, and the encapsulation particularities were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and polarized optical microscopy (POM) techniques. The ability of the PVAB matrix to anchor the DCF was assessed by Fourier transform infrared (FTIR) spectroscopy. The in vitro release of the diclofenac sodium salt from the formulations was investigated in biomimetic conditions (pH = 7.4 and 37°C) by UV-Vis spectroscopy, measuring the absorbance of the drug at 275 nm and fitting the results on a previously drawn calibration curve. An estimation of the drug release kinetics was performed by fitting three traditional mathematical models on experimental release data. Further, the drug delivery was simulated by the fractal theory of motion, in which the release dynamics of the polymer-drug complex system is described through various Riccati-type "regimes." To explain such dynamics involved multifractal self-modulation in the form of period doubling, quasiperiodicity, intermittency, etc., as well as multifractal self-modulation of network type. Standard release dynamics were explained by multifractal behaviors of temporary kink type. The good correlation between the traditional mathematical models and the new proposed theoretical model demonstrated the validity of the multifractal model for the investigation of the drug release.

Efficacy and safety of over-the-counter analgesics for primary dysmenorrhea: A network meta-analysis

BACKGROUND

Primary dysmenorrhea is common and troublesome. The comparative efficacy of over-the-counter analgesics (OTCAs) for dysmenorrhea is unclear. This study was aimed at conducting a network meta-analysis to assess the efficacy and safety of 5 OTCAs - naproxen, ibuprofen,diclofenac, aspirin, and ketoprofen - in patients with primary dysmenorrhea.

METHODS

The study was registered with PROSPERO (number: CRD42019133556). The search strategy involved a review of PubMed, Embase, Cochrane Library, Web of Science, and CINAHL for relative randomized controlled trials of the 5 analgesics from the date of database establishment to July 2019. The outputs are presented as odds ratios (ORs), their corresponding 95% confidence intervals (CIs), and the surface under the cumulative ranking area (SUCRA) probabilities.

RESULTS

Thirty-five trials with 4383 participants were included in our study. As for efficacy outcomes, all the included analgesics except aspirin were more effective than placebo in treating dysmenorrhea [naproxen (OR 3.99, 95% CI 2.18-7.30), ibuprofen (OR 10.08, 95% CI 3.29-30.85), diclofenac (OR 11.82, 95% CI 2.66-52.48), and ketoprofen (OR 5.12, 95% CI 1.57-16.69). The OTCAs were superior to the placebo in terms of pain relief in primary dysmenorrhea. Aspirin was less effective than ibuprofen (OR 0.17, 95% CI 0.04-0.73) and diclofenac (OR 1.17, 95% CI 0.02-0.85). The SUCRA curves showed that diclofenac and ibuprofen were the most and second most effective (85.1% and 83.8%, respectively), followed by ketoprofen, naproxen, and aspirin. Regarding safety, there was no significant difference between the 5 OTCAs included and the placebo. Diclofenac versus ibuprofen (OR 4.31, 95% CI 1.18-15.67), ketoprofen versus diclofenac (OR 0.18, 95% CI 0.04-0.78), and ketoprofen versus aspirin (OR 0.41, 95% CI 0.18-0.97) presented statistically significant differences. Ketoprofen and ibuprofen were ranked the best (SUCRA 90.6% and 79.6%), followed by naproxen, aspirin, and diclofenac.

CONCLUSION

Considering the efficacy and safety, ibuprofen is recommended as the optimal OTCA for primary dysmenorrhea. Further well-designed studies that directly compare these analgesics are needed to support our conclusion.