Comparative bioavailability of diclofenac hydroxyethylpyrrolidine vs diclofenac sodium in man

Treatment Satisfaction, Efficacy, and Tolerability of Low-Dose Diclofenac Epolamine Soft Capsules in Acute, Mild, or Moderate Musculoskeletal Pain: A Prospective Open-Label, Single-Arm Interventional Study

INTRODUCTION

The use of oral nonsteroidal anti-inflammatory drugs (NSAIDs) for acute musculoskeletal pain should be at the lowest effective dosage and for the shortest duration to minimize potential adverse effects. This study evaluated treatment satisfaction, effectiveness, and tolerability of a low-dose diclofenac epolamine 12.5-mg soft capsule formulation (DHEP 12.5-mg capsules) using patient-reported outcome measures in a real-life setting over a short period (3 days) in subjects with mild-to-moderate acute musculoskeletal pain.

METHODS

A prospective, open-label, phase IV clinical study in adult outpatients at hospital clinic departments/general practitioner's clinics at eight sites in Italy. The primary efficacy variable was the degree of satisfaction with treatment at 72 ± 7 h after initiation of treatment, assessed using the Overall Satisfaction Question of the Pain Treatment Satisfaction Scale (PTSS) and described by classic descriptive statistics. Secondary objectives were to evaluate the analgesic effect after the first administration and over time; the time to and satisfaction with the onset of pain relief, amount of and duration of pain relief; pain intensity differences over time; and safety and tolerability. The investigator's satisfaction with the treatment was also assessed. Subjects initially took 1-2 capsules of the study treatment and then one or two soft capsules every 4-6 h according to their needs. Not more than six soft capsules were to be taken in any 24-h period.

RESULTS

A total of 182 subjects (mean age, 56.2 years; 54.4% female) took ≥ 1 dose of DHEP capsule and were included in the full analysis set. The most common musculoskeletal conditions were arthralgia (39.0%) and low back pain (23.1%). All subjects completed the study, and 165/182 (90.7%, 95% CI 0.86, 0.95) were satisfied or very satisfied with the treatment at 72 ± 7 h after the first dose (primary efficacy variable). Similar percentages were recorded for treatment satisfaction concerning other efficacy parameters. The onset of the analgesic effect was rapid, with complete pain relief reached after a mean of 49.45 min. Investigators rated their overall treatment satisfaction as 92.9%. Treatment was well tolerated.

CONCLUSIONS

The low-dose (12.5 or 25 mg) oral diclofenac epolamine soft capsules formulation exerted rapid, effective, and safe analgesic activity in patients with mild-to-moderate musculoskeletal pain, with subjects' overall satisfaction with treatment more than 90%.

TRIAL REGISTRATION

EudraCT Number: 2018-004886-15 (Study 18I-Fsg08). Registered 04/09/2018.

Diclofenac Epolamine is Effective in The Treatment of Acute Migraine Attacks. A Randomized, Crossover, Double Blind, Placebo-Controlled, Clinical Study

Hydrosoluble diclofenac epolamine (DHEP) represents an interesting approach to acute migraine attacks, where gastrointestinal motility and drug absorption are often reduced. Its efficacy was investigated in a randomized, crossover, double-blind trial on 155 patients who treated four consecutive mild-to-moderate migraine attacks, either with DHEP (65-mg sachet) or placebo. If pain was not relieved within 1 h, a second dose was given. The total number of treated attacks was 481. A pain-free condition was achieved within 2h in 45.8% and 25.1% of attacks treated, respectively, with DHEP or placebo ( P < 0.0001), with a therapeutic gain of 20.7%. Time to attack resolution, light and noise sensitivity and impact on working ability were significantly reduced by DHEP compared with placebo. Moreover, significantly fewer patients required a second drug dose or a rescue medication when treated with DHEP than with placebo. No adverse reaction was recorded. In conclusion, DHEP was effective and safe for pain relief in patients with an acute mild-to-moderate migraine attack.

Topical nonsteroidal anti-inflammatory drugs for the treatment of pain due to soft tissue injury: diclofenac epolamine topical patch

The objective of this article is to review published clinical data on diclofenac epolamine topical patch 1.3% (DETP) in the treatment of acute soft tissue injuries, such as strains, sprains, and contusions. Review of published literature on topical nonsteroidal anti-inflammatory drugs (NSAIDs), diclofenac, and DETP in patients with acute soft tissue injuries was included. Relevant literature was identified on MEDLINE using the search terms topical NSAIDs, diclofenac, diclofenac epolamine, acute pain, sports injury, soft tissue injury, strain, sprain, and contusion, and from citations in retrieved articles covering the years 1978-2008. Review of published, randomized clinical trials and meta-analyses shows that topical NSAIDs are significantly more effective than placebo in relieving acute pain; the pooled average relative benefit was 1.7 (95% confidence interval, 1.5-1.9). In a limited number of comparisons, topical and oral NSAIDs provided comparable pain relief, but the use of topical agents produced lower plasma drug concentrations and fewer systemic adverse events (AEs). The physical-chemical properties of diclofenac epolamine make it well suited for topical use. In patients with acute soft tissue injuries treated with DETP, clinical data report an analgesic benefit within hours of the first application, and significant pain relief relative to placebo within 3 days. Moreover, DETP displayed tolerability comparable with placebo; the most common AEs were pruritus and other application site reactions. Review of published literature suggests that DETP is generally safe and well tolerated, clinically efficacious, and a rational treatment option for patients experiencing acute pain associated with strains, sprains, and contusions, and other localized painful conditions.

Biowaiver monographs for immediate release solid oral dosage forms: diclofenac sodium and diclofenac potassium

Literature data are reviewed regarding the scientific advisability of allowing a waiver of in vivo bioequivalence (BE) testing for the approval of immediate release (IR) solid oral dosage forms containing either diclofenac potassium and diclofenac sodium. Within the biopharmaceutics classification system (BCS), diclofenac potassium and diclofenac sodium are each BCS class II active pharmaceutical ingredients (APIs). However, a biowaiver can be recommended for IR drug products of each salt form, due to their therapeutic use, therapeutic index, pharmacokinetic properties, potential for excipient interactions, and performance in reported BE/bioavailability (BA) studies, provided: (a) test and comparator contain the same diclofenac salt; (b) the dosage form of the test and comparator is identical; (c) the test product contains only excipients present in diclofenac drug products approved in ICH or associated countries in the same dosage form, for instance as presented in this paper; (d) test drug product and comparator dissolve 85% in 30 min or less in 900 mL buffer pH 6.8, using the paddle apparatus at 75 rpm or the basket apparatus at 100 rpm; and (e) test product and comparator show dissolution profile similarity in pH 1.2, 4.5, and 6.8.

Pharmacokinetics of diclofenac in rats intoxicated with CCL4, and in the regenerating liver

The pharmacokinetics of an intravenous and oral diclofenac dose of 3.2 mg/kg was studied in male Wistar rats under control conditions, 1 and 3 days after liver damage and regeneration induced by an oral injection of CCl(4). One day after CCl(4) administration, indicators of necrosis (alanine aminotransferase), cholestasis (gamma-glutamyl transpeptidase) and regeneration (alpha-fetoprotein) were significantly increased; these effects were reversed after 3 days. In nonintoxicated rats, t(1/2) was 43.83 +/- 4.95 min, V(d) was 0.37 +/- 0.04 l/kg, Cl was 129.21 +/- 9.20 ml/min kg, AUC(i.v.) was 25.62 +/- 1.45 microg/min ml, and AUC(p.o.) was 20.21 +/- 1.03. One day after intoxication, when the liver was damaged and regenerating, the metabolism was decreased: diclofenac t(1/2) was increased to 258.21 +/- 30.80 min but V(d) did not change significantly, therefore Cl was reduced to 32.81 +/- 3.38 ml/min kg. By day 3 after intoxication, liver function, regeneration and pharmacokinetics returned to normal. The results show that liver damage and regeneration increases the bioavailability by decreasing elimination. The present observations suggest that reduction of the pharmacokinetic parameters may lead to drug accumulation in the regenerating-damaged liver with an attendant possible increase in toxic effects. The results in rats, also suggest that once hepatic injury is finished and regeneration is complete, diclofenac can be administered normally.

Clinical pharmacokinetics of diclofenac. Therapeutic insights and pitfalls

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) of the phenylacetic acid class. When given orally the absorption of diclofenac is rapid and complete. Diclofenac binds extensively to plasma albumin. The area under the plasma concentration-time curve (AUC) of diclofenac is proportional to the dose for oral doses between 25 to 150 mg. Substantial concentrations of drug are attained in synovial fluid, which is the proposed site of action for NSAIDs. Concentration-effect relationships have been established for total bound, unbound and synovial fluid diclofenac concentrations. Diclofenac is eliminated following biotransformation to glucoroconjugated and sulphate metabolites which are excreted in urine, very little drug is eliminated unchanged. The excretion of conjugates may be related to renal function. Conjugate accumulation occurs in end-stage renal disease; however, no accumulation is apparent upon comparison of young and elderly individuals. Dosage adjustments for the elderly, children or for patients with various disease states (such as hepatic disease or rheumatoid arthritis) may not be required. Significant drug interactions have been demonstrated for aspirin (acetylsalicylic acid), lithium, digoxin, methotrexate, cyclosporin, cholestyramine and colestipol.

Diclofenac delays healing of gastroduodenal mucosal lesions. Double-blind, placebo-controlled endoscopic study in healthy volunteers

The effects of the water-soluble and delayed-release formulations of a nonsteroidal antiinflammatory drug, diclofenac, on the healing of gastroduodenal mucosal lesions were compared in a double-blind, double cross-over, placebo-controlled endoscopic study conducted in 14 healthy volunteers. Severe endoscopic lesions (petechiae, erosions, ulcers, and esophageal candidiasis) were found only in the group taking the soluble formulation of diclofenac (P less than 0.05 vs placebo). The endoscopic healing of biopsies at one week was delayed by both preparations in comparison to placebo (P less than 0.05 vs placebo). Neither formulation produced significantly more histological inflammation or minor endoscopic lesions (erythema, red striae) than placebo. Both formulations were equally well tolerated and produced no more symptoms than placebo. This study suggests that soluble diclofenac acts topically to delay gastroduodenal healing and produce gastroduodenal injury; it thus provides a model for future studies of the production, perpetuation, and healing of peptic lesions.