Controlled phase III clinical trial of diclofenac potassium liquid-filled soft gelatin capsule for treatment of postoperative dental pain

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.

A pH-sensitive and sustained-release oral drug delivery system: the synthesis, characterization, adsorption and release of the xanthan gum-graft-poly(acrylic acid)/GO-DCFP composite hydrogel

In this study, graphene oxide (GO) was successfully prepared using the improved Hummers method, and the prepared GO powder was dissolved in distilled water and subjected to ultrasonic stripping. Diclofenac potassium (DCFP) was selected as a model drug to systematically evaluate the adsorption mechanism of DCFP by GO. Different reaction models were constructed to fit the adsorption kinetics and adsorption isotherms of DCFP on GO, in order to further explore the underlying adsorption mechanism. The results demonstrated that the pseudo-second-order kinetic model and Freundlich model could better delineate the adsorption process of DCFP by GO. Both π–π stacking and hydrophobic interaction were mainly involved in the adsorption process, and there were electrostatic interaction and hydrogen bonding at the same time. Then, the xanthan gum-graft-poly(acrylic acid)/GO (XG-g-PAA/GO) composite hydrogel was synthesized by in situ polymerization as a slow-release drug carrier. For this reason, a XG-g-PAA/GO–DCFP composite hydrogel was synthesized, and its in vitro drug release and pharmacokinetic data were assessed. The results showed that the synthesized XG-g-PAA/GO composite hydrogel had a certain mechanical strength and uniform color, indicating that GO is evenly distributed in this composite hydrogel. Moreover, the results of a swelling ratio test demonstrated that the swelling ratios of the XG-g-PAA/GO composite hydrogel were significantly increased with increasing pH values, implying that this material is sensitive to pH. The in vitro drug release experiment showed that the cumulative release of DCFP after 96 h was significantly higher in artificial intestinal fluid than in artificial gastric fluid. These findings indicate that the XG-g-PAA/GO–DCFP composite hydrogel exhibits pH sensitivity under physiological conditions. Besides, the results of in vivo pharmacokinetic analysis revealed that the t_1/2 of DCFP group was 2.03 ± 0.35 h, while that of the XG-g-PAA/GO–DCFP composite hydrogel group was 10.71 ± 2.04 h, indicating that the synthesized hydrogel could effectively prolong the drug action time. Furthermore, the AUC_(0–t) of the DCFP group was 53.99 ± 3.18 mg L⁻¹ h⁻¹, while that of the XG-g-PAA/GO–DCFP composite hydrogel group was 116.79 ± 14.72 mg L⁻¹ h⁻¹, suggesting that the bioavailability of DCFP is greatly enhanced by this composite hydrogel. In conclusion, this study highlights that the XG-g-PAA/GO–DCFP composite hydrogel can be applied as a sustained-release drug carrier.

In this study, graphene oxide (GO) was successfully prepared using the improved Hummers method, and the prepared GO powder was dissolved in distilled water and subjected to ultrasonic stripping.

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

We compared the efficacy of diclofenac potassium in unpublished clinical study reports (CSRs) and published reports to examine publication bias, industry bias, and comprehensiveness. Novartis provided CSRs of randomised double-blind trials of diclofenac potassium involving postoperative patients following third molar extraction (3 trials, n=519), gynaecological surgery (3 trials, n=679), and dysmenorrhoea (2 trials, n=711) conducted in 1988–1990. Searches identified published reports of 6 trials. Information from 599/1909 patients was not published; trials with 846/1909 patients were published in a defunct journal. Greater methodological information in CSRs contributed to lesser risk of bias than published trials. Numbers needed to treat (NNT) from CSRs for all six postoperative trials for at least 50% of maximum pain relief over 6 h were 2.2 (95% confidence interval, 1.9–2.6) and 2.1 (1.8–2.4) for 50 and 100 mg diclofenac potassium, respectively. A Cochrane review of published trial data reported NNTs of 2.1 and 1.9, and one comprehensive analysis reported NNTs of 2.2 and 2.1, respectively. All analyses had similar results for patients remedicating within 8 h. No data from dysmenorrhoea CSRs appeared in a Cochrane review. CSRs provide useful information and increase confidence. Stable efficacy estimates with standard study designs reduce the need for updating reviews.

Treatment of Radiation-Induced Oral Mucositis Using a Novel Accepted Taste of Prolonged Release Mucoadhesive Bi-medicated Double-Layer Buccal Films

The aim of this study was to develop a novel double-layer bi-medicated prolonged release mucoadhesive buccal film (MBF) containing lidocaine hydrochloride (LC) and diclofenac potassium (DK). The ultimate goal of the prepared system is the treatment of radiation-induced oral mucositis pain with improved patient acceptance. MBFs were prepared using 3 × 2² randomized full factorial design for film optimization. Nanoemulsion system (NES) was used to mask DK bitter taste. The prepared films were characterized, viz thickness, mass uniformity, surface pH, folding endurance, swelling studies, ex vivo bioadhesive strength, in vitro drug release, and ex vivo permeation. The in vivo evaluation was carried out by testing the anti-inflammatory and analgesic activities on rats followed by a clinical study on patients to prove their acceptance. The optimized MBF composed of 10% w/w HPMC-4KM, 50 mg LC, and 50 mg DK-NES was selected due to prolonged in vitro drug release pattern and ex vivo permeability (95.24 ± 2.14 and 93.48 ± 3.24% in 6 h, respectively). MBF exposed a strong anti-inflammatory effect from 61 to 87% inhibition with a strong analgesic effect when compared to DK® and LC®, respectively. The clinical study revealed that films were accepted by the patients, and the presence of LC on the outer side helped in pain feeling reduction while DK-NES in the inner side facilitated in rapidly relieving the inflammation effect.

Single dose oral diclofenac for acute postoperative pain in adults

BACKGROUND

Diclofenac is a nonsteroidal anti-inflammatory drug, available as a potassium salt (immediate release) or sodium salt (enteric coated to suppress dissolution in the stomach). This review updates an earlier review published in the Cochrane Database of Systematic Reviews (Issue 2, 2009) entitled 'Single dose oral diclofenac for acute postoperative pain in adults'.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of a single oral dose of diclofenac for moderate to severe postoperative pain, using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Oxford Pain Relief Database, two clinical trial registries, and the reference lists of articles. The date of the most recent search was 9 March 2015.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of single dose, oral diclofenac (sodium or potassium) for acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered studies for inclusion in the review, assessed risk of bias, and extracted data. We used the area under the pain relief versus time curve to derive the proportion of participants with at least 50% pain relief over six hours prescribed either diclofenac or placebo. We calculated the risk ratio (RR) and number needed to treat to benefit (NNT). We used information on the use of rescue medication to calculate the proportion of participants requiring rescue medication and the weighted mean of the median time to use. We also collected information on adverse effects.

MAIN RESULTS

This update included three new studies, providing a 26% increase in participants in comparisons between diclofenac and placebo. We included 18 studies involving 3714 participants, 1902 treated with diclofenac and 1007 with placebo. This update has also changed the focus of the review, examining the effects of formulation in more detail than previously. This is a result of increased understanding of the importance of speed of onset in determining analgesic efficacy in acute pain.The largest body of information, for diclofenac potassium 50 mg, in seven studies, produced an NNT for at least 50% of maximum pain relief compared with placebo of 2.1 (95% confidence interval (CI) 1.9 to 2.5) (high quality evidence). There was a graded improvement in efficacy as doses rose from 25 mg to 100 mg, both for participants achieving at least 50% maximum pain relief, and for remedication within 6 to 8 hours. Fast-acting formulations (dispersible products, solutions, and softgel formulations) had a similar efficacy for a 50 mg dose, with an NNT of 2.4 (2.0 to 3.0). Diclofenac sodium in a small number of studies produced a lesser effect, with an NNT of 6.6 (4.1 to 17) for the 50 mg dose.Adverse event rates were low in these single dose studies, with no difference between diclofenac and placebo (moderate quality evidence).

AUTHORS' CONCLUSIONS

Diclofenac potassium provides good pain relief at 25 mg, 50 mg, and 100 mg doses. Diclofenac sodium has limited efficacy and should probably not be used in acute pain.

Assay sensitivity of pain intensity versus pain relief in acute pain clinical trials: ACTTION systematic review and meta-analysis

The magnitude of the effect size of an analgesic intervention can be influenced by several factors, including research design. A key design component is the choice of the primary endpoint. The purpose of this meta-analysis was to compare the assay sensitivity of 2 efficacy paradigms: pain intensity (calculated using summed pain intensity difference [SPID]) and pain relief (calculated using total pain relief [TOTPAR]). A systematic review of the literature was performed to identify acute pain studies that calculated both SPIDs and TOTPARs within the same study. Studies were included in this review if they were randomized, double-blind, placebo-controlled investigations involving medications for postsurgical acute pain and if enough data were provided to calculate TOTPAR and SPID standardized effect sizes. Based on a meta-analysis of 45 studies, the mean standardized effect size for TOTPAR (1.13) was .11 higher than that for SPID (1.02; P = .01). Mixed-effects meta-regression analyses found no significant associations between the TOTPAR - SPID difference in standardized effect size and trial design characteristics. Results from this review suggest that for acute pain studies, utilizing TOTPAR to assess pain relief may be more sensitive to treatment effects than utilizing SPID to assess pain intensity.

PERSPECTIVE

The results of this meta-analysis suggest that TOTPAR may be more sensitive to treatment effects than SPIDs are in analgesic trials examining acute pain. We found that standardized effect sizes were higher for TOTPAR compared to SPIDs.

Three newly approved analgesics: an update

Abstract Since 2008, three new analgesic entities, tapentadol immediate release (Nucynta) diclofenac potassium soft gelatin capsules (Zipsor), and bupivacaine liposome injectable suspension (EXPAREL) were granted US Food and Drug Administration (FDA) approval to treat acute pain. Tapentadol immediate-release is a both a mu-opioid agonist and a norepinephrine reuptake inhibitor, and is indicated for the treatment of moderate to severe pain. Diclofenac potassium soft gelatin capsules are a novel formulation of diclofenac potassium, which is a nonsteroidal anti-inflammatory drug (NSAID), and its putative mechanism of action is through inhibition of cyclooxygenase enzymes. This novel formulation of diclofenac allows for improved absorption at lower doses. Liposomal bupivacaine is a new formulation of bupivacaine intended for single-dose infiltration at the surgical site for postoperative analgesia. Bupivacaine is slowly released from this liposomal vehicle and can provide prolonged analgesia at the surgical site. By utilizing NSAIDs and local anesthetics to decrease the transmission of afferent pain signals, less opioid analgesics are needed to achieve analgesia. Since drug-related adverse events are frequently dose related, lower doses from different drug classes may be employed to reduce the incidence of adverse effects, while producing synergistic analgesia as part of a multimodal analgesic approach to acute pain.

An assessment of the efficacy and safety of diclofenac potassium liquid-filled capsules in patients with various levels of baseline pain intensity

CONTEXT

Diclofenac potassium liquid-filled soft gelatin capsule (DPSGC; Zipsor*) is a novel formulation of diclofenac potassium used to treat mild to moderate acute pain.

OBJECTIVE

To investigate whether DPSGC 25 mg provided significant reduction in pain intensity compared with placebo, regardless of baseline pain intensity, a post hoc analysis was performed of pooled data from two replicate randomized controlled trials (NCT00366444 and NCT00375934) that evaluated the safety and efficacy of DPSGC in postbunionectomy treatment.

METHODS

Patients from the two randomized trials were assigned to one of two subgroups: patients with baseline numerical pain rating scale (NPRS) scores of 4 or greater to less than 7 and those with baseline NPRS scores of 7 or greater. Within each subgroup, efficacy and safety of DPSGC was compared with placebo.

RESULTS

Across the two studies, 73 DPSGC- and 59 placebo-treated patients had baseline pain intensity scores ranging from 4 or greater to less than 7, while 128 DPSGC- and 141 placebo-treated patients had baseline pain intensity scores of 7 or greater. Significantly lower mean 48-hour NPRS scores were observed in the DPSGC group, regardless of baseline pain intensity (P < 0.0001). In both subgroups, at least twice as many patients treated with DPSGC rated the study drug as very good or excellent compared with patients taking placebo. Potential limitations for this post hoc analysis include study design and patient population. As with all studies investigating treatment for pain, the use of rescue medication may also be a potential limitation.

CONCLUSIONS

DPSGC provided significantly greater improvements in pain compared with placebo following bunionectomy, regardless of patients' baseline pain level.

Onset of action of diclofenac potassium liquid-filled capsules in dental surgery patients

OBJECTIVE

Diclofenac potassium soft gelatin capsules (DPSGC) are a low-dose, liquid-filled formulation that uses patented dispersion technology to facilitate rapid and consistent gastrointestinal absorption. Onset of pain relief experienced by patients receiving DPSGC was evaluated in two dental pain studies. Confirmed perceptible pain relief was evaluated in a post hoc analysis from these randomized controlled trials.

RESEARCH DESIGN AND METHODS

Adult patients (n = 514) were enrolled in two multicenter, parallel group, double-blind, placebo-controlled studies. Patients undergoing third molar extraction and experiencing a requisite level of pain (≥50 mm on a 100-mm visual analog scale within 4 hours post-surgery) were randomized to receive single doses of DPSGC 25 mg, 50 mg, 100 mg, or placebo. Pain was assessed at baseline and during 6 hours after dosing. Times to onset of perceptible and meaningful pain relief were recorded using the two-stopwatch method. Confirmed perceptible pain relief was determined in the DPSGC and placebo groups by calculating the median time to onset of perceptible pain relief (first stopwatch) in only those individuals who reported meaningful pain relief (second stopwatch).

RESULTS

More than 80% of patients achieved confirmed perceptible pain relief in the DPSGC groups compared with less than 30% of patients in the placebo group (Study 1 and Study 2, p < 0.0001). The median time to onset of confirmed perceptible pain relief in the two studies was less than 30 minutes for patients receiving any dose of DPSGC and more than 360 minutes in the placebo group (Study 1 and Study 2, p < 0.0001). DPSGC was well tolerated and no serious adverse events were reported. Study design limitations include the short duration of the trial and evaluation of a relatively limited patient population.

CONCLUSIONS

These results indicate that DPSGC was efficacious in providing a rapid onset of confirmed perceptible pain relief within 30 minutes of administration in these single dose postoperative dental pain studies.