Microemulsion for topical delivery of fenoprofen calcium: in vitro and in vivo evaluation.

The aim of this study was to investigate microemulsion (ME) based topical delivery system for fenoprofen calcium (FPCa) to eliminate its oral gastrointestinal adverse effects. ME was prepared by the water titration method using oleic acid as oil phase, tween 80 as a surfactant and propylene glycol as a cosurfactant. Oleic acid was selected as oil phase due to its good solubilizing capacity. ME existence region was determined using pseudo-ternary phase diagrams for preparing different formulations. Six different formulations were selected with various values of oil (25-68%), water (2-3%), and the mixture of surfactant and cosurfactant (1:1) (24-67%). The selected ME formulae were characterized for optical birefringence, transmission electron microscopy (TEM), pH, % transmittance, electronic conductivity, drug content, droplet size, rheological properties and stability evaluation. In vitro release study of FPCa from ME s through the synthetic membrane and hairless rat skin were evaluated. The optimized formula ME5 consisting of 5% w/w FPCa, 60% w/w oleic acid as oil phase, 3% w/w aqueous phase, and 32% w/w of surfactant phase containing Tween 80 and propylene glycol (1: 1) showed the highest transdermal flux and highest skin permeation rate. Finally, the % inhibition of carrageenan-induced rat paw edema of the optimized formula ME5 was highly significant (p < 0.001) as compared to plain gel of FPCa. In conclusion, ME is a promising technique for topical delivery of FPCa.

Topical Delivery of Fenoprofen Calcium via Elastic Nano-vesicular Spanlastics: Optimization Using Experimental Design and In Vivo Evaluation.

The aim of this study was to investigate the potential of surfactant-based nanovesicular system (spanlastics) for topical delivery of fenoprofen calcium (FPCa) to eliminate its oral gastrointestinal adverse effects. FPCa-loaded spanlastics were prepared by thin film hydration (TFH) technique according to a full factorial design to investigate the influence of formulation variables on the drug entrapment efficiency (%EE), particle size (PS), deformability index (DI), and the % drug released after 24 h through the cellulose membrane (Q24h) using Design-Expert® software. The optimized formula (composed of Span 60 and Tween 60 as an edge activator at weight ratio of 8: 2 in presence of Transcutol P as a cosolvent in the hydration media) exhibited the highest %EE (49.91 ± 2.60%), PS of 536.1 ± 17.14 nm, DI of 5.07 ± 0.06 g, and Q24h of 61.11 ± 2.70%; it was also characterized for morphology and physical stability. In vitro release study of FPCa-loaded spanlastic gel and conventional FPCa gel through a synthetic membrane and hairless rat skin were evaluated. The skin permeation study revealed that spanlastic gel exhibited both consistent and prolonged action. Finally, the % inhibition of carrageenan-induced rat paw edema of spanlastic gel was three times higher than the conventional FPCa gel after 24 h. In conclusion, spanlastic-based gel could be a great approach for improving topical delivery of fenoprofen calcium, providing both prolonged and enhanced anti-inflammatory activity in the treatment of arthritis.

A supramolecular topical gel derived from a non-steroidal anti-inflammatory drug, fenoprofen, is capable of treating skin inflammation in mice.

A new series of bioconjugates derived from a non-steroidal anti-inflammatory drug (NSAID), namely fenoprofen, has been synthesised by amidation with various biogenic molecules such as ß-alanine, aminocaproic acid and tyramine with the aim of converting the NSAID into a supramolecular gelator for plausible biomedical applications. One such bioconjugate (2) showed gelation ability with methylsalicylate (MS) and 1% menthol in methyl salicylate (MMS) solvents. These gels were characterized by table top rheology, high resolution-transmission electron microscopy (HR-TEM) and dynamic rheology. Gelator 2 was found to be biostable both in proteolytic enzymes and in blood serum of BALB/c mouse under physiological conditions. It was also found to be biocompatible, as revealed by the methyl thiazolyldiphenyl tetrazolium bromide (MTT) assay in mouse macrophage RAW 264.7 and mouse myoblast C2C12 cells. The anti-inflammatory response (prostaglandin E2 assay, denoted PGE2 assay) of 2 was comparable to that of the parent drug fenoprofen calcium salt. Finally, a topical gel formulation of 2 displayed in vivo self-delivery application in treating imiquimod (IMQ) induced skin inflammation in BALB/c mice.

Anti-nociceptive activity and toxicity evaluation of Cu(II)-fenoprofenate complexes in mice.

The proposed curative properties of copper(II)-non-steroidal anti-inflammatory drugs (NSAIDs) have led to the development of numerous copper(II)-NSAID complexes with enhanced anti-inflammatory activity. In this work, the antinociceptive and toxic effects of two new coordination complexes: Cu2(fen)4(caf)2 [fen: fenoprofenate anion; caf: caffeine] and Cu2(fen)4(dmf)2 [dmf: N-N'-dimethylformamide] were evaluated in mice. The antinociceptive effect was evaluated with two models: acetic acid-induced writhing response and formalin test. For the sub-acute exposure, the complexes were added to the diet at different doses for 28days. Behavioral and functional nervous system parameters in a functional observational battery were assessed. Also, hematological, biochemical and histopathological studies were performed. Cu2(fen)4(caf)2 and Cu2(fen)4(dmf)2 significantly decreased the acetic acid-induced writhing response and the licking time on the late phase in the formalin test with respect to the control and fenoprofen salt groups. The sub-acute exposure to Cu2(fen)4(caf)2 complex increased the motor activity, the number of rearings and the arousal with respect to the control and fenoprofen salt groups. These impaired parameters in mice exposed to Cu2(fen)4(caf)2 can be attributable to the presence of caffeine as stimulating agent. On the other hand, all exposed groups decreased the urine pools in the functional observational battery and increased the plasmatic urea. These effects could be due to the decrease in the glomerular filtration caused by NSAIDs. In conclusion, both complexes Cu2(fen)4(dmf)2 and Cu2(fen)4(caf)2 were more potent antinociceptive agents than fenoprofen salt. Sub-acute exposure to different doses of these complexes did not produce significant changes in the parameters that evaluate toxicity.

Single dose oral fenoprofen for acute postoperative pain in adults.

BACKGROUND: Fenoprofen is a non-steroidal anti-inflammatory drug (NSAID), available in several different countries, but not widely used. OBJECTIVES: To assess the efficacy of single dose oral fenoprofen in acute postoperative pain, and associated adverse events. SEARCH STRATEGY: We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to December 2010. SELECTION CRITERIA: Single oral dose, randomised, double-blind, placebo-controlled trials of fenoprofen for relief of established moderate to severe postoperative pain in adults. DATA COLLECTION AND ANALYSIS: Studies were assessed for methodological quality and data extracted by two review authors independently. Summed total pain relief (TOTPAR) or pain intensity difference (SPID) over 4 to 6 hours was used to calculate the number of participants achieving at least 50% pain relief. These derived results were used to calculate, with 95% confidence intervals, the relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over 4 to 6 hours. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected. MAIN RESULTS: Five studies (696 participants) met the inclusion criteria; 24 participants were treated with fenoprofen 12.5 mg, 23 with fenoprofen 25 mg, 79 with fenoprofen 50 mg, 78 with fenoprofen 100 mg, 146 with fenoprofen 200 mg, 55 with fenoprofen 300 mg, 43 with zomepirac 100 mg, 30 with morphine 8 mg, 77 with codeine 60 mg, and 141 with placebo. Participants had pain following third molar extraction, laparoscopy, minor day surgery and episiotomy. The NNT for at least 50% pain relief over 4 to 6 hours with a single dose of fenoprofen 200 mg compared to placebo was 2.3 (1.9 to 3.0). There were insufficient data to analyse other doses or active comparators, time to use of rescue medication, or numbers of participants needing rescue medication. There was no difference in numbers of participants experiencing any adverse events between fenoprofen 200 mg and placebo. No serious adverse events or adverse event withdrawals were reported in these studies. AUTHORS' CONCLUSIONS: Oral fenoprofen 200 mg is effective at treating moderate to severe acute postoperative pain, based on limited data for at least 50% pain relief over 4 to 6 hours. Efficacy of other doses, other efficacy outcomes, and safety and tolerability could not be assessed.

Chiral inversion of R(-) fenoprofen and ketoprofen enantiomers in cats.

The chiral inversion process is a characteristic metabolic pathway for different aryl-2-propionic acids or profens. Important variations have been observed between these individual compounds as well as between animal species. In this study, R(-) fenoprofen [R(-)FPF] and R(-) ketoprofen [R(-) KTF] were used to investigate their comparative stereoconversion in cats. After intravenous (i.v.) administration of R(-) FPF, the percentage of chiral inversion was 93.20+/-13.70%. A highly significant correlation (r: 0.978) was observed between the clearance of R(-) FPF and the chiral inversion process. After i.v. administration of R(-) KTF, the percentage of inversion was only 36.73+/-2.8%. No correlation between the clearance of R(-) KTF and this process was observed. R(-) FPF was metabolized by the pathways of thioesterification - chiral inversion processes. For R(-) KTF, the competitive metabolic pathways, glucuronidation and hydroxylation may be involved. However, these metabolic steps are saturable or less functional in cats. Moreover, the thioesterification of R(-) KTF in in vitro studies has been shown to be important in carnivores. The lack of correlation between clearance and chiral inversion process of R(-) KTF may be finally explained by deviation of thioesterification to other metabolic pathways of lipids and/or aminoacid conjugation, particulary glicine derivatives.

Enteric coating of fenoprofen calcium reduces gastrointestinal microbleeding.

The effects of plain and enteric-coated fenoprofen calcium (Nalfon, Dista, Indianapolis, Ind.) on gastrointestinal microbleeding were studied in 32 normal male volunteers in a randomized, open-label, parallel trial at two inpatient research facilities. A 1-week placebo (baseline) period preceded 2 weeks of fenoprofen therapy (enteric coated or plain, 600 mg q.i.d.). Fecal blood loss was measured by 51Cr-tagged erythrocyte assay and averaged over days 4 to 7 (baseline) and 11 to 14 and 18 to 21 (active therapy). At one center gastrointestinal irritation was evaluated endoscopically before and after active therapy. Endoscopy showed both formulations to cause mucosal damage not evident by subject-reported symptoms. Four of the 16 subjects developed asymptomatic duodenal ulcers. Mean daily fecal blood loss was significantly lower (P = 0.03) with enteric-coated (mean +/- SD, 1.104 +/- 0.961 ml/day) than with plain fenoprofen calcium (mean +/- SD, 1.686 +/- 0.858 ml/day), suggesting that tolerance of fenoprofen can be improved with administration in an enteric-coated form.

Efficacy of fenoprofen in the treatment of primary dysmenorrhea.

We compared fenoprofen calcium, 200 mg; fenoprofen calcium, 400 mg; aspirin, 650 mg; and a placebo in 85 women for the relief of primary dysmenorrhea in a double-blind, clinical trial. The usefulness of these drugs was judged from data obtained over four consecutive menstrual periods on: restriction of daily activity, pain intensity scores, need for rescue analgesics, withdrawal due to lack of efficacy, and adverse events. Both fenoprofen, 200 mg, and fenoprofen, 400 mg, offered significant (P less than .01) pain relief when compared to placebo and aspirin. Analyses of data on 1, 2 and 3 indicated that aspirin was not significantly different from placebo. The aspirin-treated group reported the greatest number of adverse reactions, but the differences between the four groups were not statistically significant. Our study lends support to the concept of a "plateau analgesic effect" of nonsteroidal antiinflammatory drugs (NSAIDs): fenoprofen, 200 mg, appears to be as effective as fenoprofen, 400 mg. When this type of drug fails to provide relief for a woman suffering from primary dysmenorrhea, switching to another NSAID may be more appropriate than increasing the dosage and the probability of dosage-related side effects.

Dose response to fenoprofen calcium using placebo and codeine as controls.

This paper evaluates the dose-response relationship of several doses of fenoprofen calcium, between 12.5 and 300 mg, and their relationship to 60 mg of codeine sulfate and placebo. Three separate parallel studies are included in this evaluation, including a total of 867 patients. The types of pain were cesarean section, episiotomy wound, uterine cramping, and general surgery. This paper shows that a significant increasing relationship exists between efficacy and dose of fenoprofen, suggesting that relatively larger doses of fenoprofen will achieve greater amounts of efficacy.

Pure red cell aplasia associated with fenoprofen.

A 69-year-old man developed pure red cell aplasia after taking fenoprofen for ten months. The erythroid defect fully reversed after the drug was discontinued and could not be attributed to the patient's previously treated lung carcinoma. This case represents the third example of erythroid aplasia associated with an anti-inflammatory agent and the first instance due to fenoprofen.

Comparison between fenoprofen and ibuprofen in the treatment of soft-tissue rheumatism.

Fenoprofen calcium 600 mg, four times daily, and ibuprofen 400 mg, four times daily, were compared in a double-blind crossover study involving the treatment of soft-tissue rheumatism in fifty patients. After 7 days there was no significant difference between the efficacy of the two drugs with respect to 'pain at rest', 'pain on movement', 'tenderness' or 'sleep disturbance' but fenoprofen was significantly better when considering 'limitation of movement' and 'The physician's assessment of the severity of the condition'. Combining data from Weeks 1 and 2 of treatment, 14 days fenoprofen treatment brought about significant improvements in all of the above parameters. Ibuprofen did not significantly improve 'pain at rest' but did improve the other parameters.

A double-blind comparison of parenteral morphine, placebo, and oral fenoprofen in management of postoperative pain.

A double-blind study comparing parenteral morphine, 8 mg, with parenteral placebo and with oral fenoprofen, 200 mg, for the relief of postoperative pain following outpatient surgery was undertaken in 90 patients. The study drugs were administered within 2 hours of the operation and the Visual Analogue Scale was used to assess pain intensity. Patients given placebos showed minimal change in mean pain intensity, whereas patients who received morphine had significantly less pain at all assessment periods. Pain relief in patients who received fenoprofen was, for the first 2 hours, better than following placebo but not as good as following morphine, but thereafter, there was no significant difference between the morphine and fenoprofen and both were significantly better than placebo. It is concluded that oral analgesics may be a useful alternative to the traditional parenteral analgesics for outpatient surgery.

Fenoprofen and codeine analgesia.

Studies were conducted on postpartum and postoperative patients to estimate the dose-response line of fenoprofen and to contrast it with codeine and placebo. The postpartum patients included women with episiotomy pain and with uterine cramping. This mix allowed contrast of ability of the various pain models to distinguish codeine from placebo. The methodology for the studies was single-dose parallel groups design with interviews conducted by trained nurse observers to obtain subjective responses. More than 850 patients participated in the trial. The results indicate that fenoprofen at doses as low as 12.5 mg has analgesic properties. In each of the five studies, the mean value of 100- and/or 200-mg doses of fenoprofen for the variable sum of the pain intensity difference (SPID) was higher than that of 65 mg codeine. The pooled relative potency calculation based on SPID suggests that 100 mg fenoprofen is approximately equivalent to 60 mg codeine. In their ability to distinguish codeine from placebo, patients with uterine cramp, episiotomy, or surgical pain did not appear to differ.

A double-blind cross-over trial of fenoprofen and phenylbutazone in ankylosing spondylitis.

Fenoprofen, 600 mg, three times daily, was compared with phenylbutazone, 100 mg, three times daily, in 30 patients suffering from ankylosing spondylitis in a double-blind cross-over study. Assessments were made after an initial washout period and after each month-long treatment period. Phenylbutazone significantly improved morning stiffness, finger-to-floor distance, chest expansion, overall joint pain, spinal pain, the physician's assessment of disease activity and ESR. Only chest expansion was significantly improved by fenoprofen, and phenylbutazone was significantly better than fenoprofen in its effects on finger-to-floor distance, morning stiffness, overall joint pain, spinal pain and the physician's assessment of disease activity. Side-effects were of a minor nature apart from one patient who developed rectal bleeding on phenylbutazone which recurred on rechallenging.