Plasma pharmacokinetics and synovial concentrations of S-flurbiprofen plaster in humans

Advancing ophthalmic delivery of flurbiprofen via synergistic chiral resolution and ion-pairing strategies

Flurbiprofen (FB), a nonsteroidal anti-inflammatory drug, is widely employed in treating ocular inflammation owing to its remarkable anti-inflammatory effects. However, the racemic nature of its commercially available formulation (Ocufen®) limits the full potential of its therapeutic activity, as the (S)-enantiomer is responsible for the desired anti-inflammatory effects. Additionally, the limited corneal permeability of FB significantly restricts its bioavailability. In this study, we successfully separated the chiral isomers of FB to obtain the highly active (S)-FB. Subsequently, utilizing ion-pairing technology, we coupled (S)-FB with various counter-ions, such as sodium, diethylamine, trimethamine (TMA), and l-arginine, to enhance its ocular bioavailability. A comprehensive evaluation encompassed balanced solubility, octanol-water partition coefficient, corneal permeability, ocular pharmacokinetics, tissue distribution, and in vivo ocular anti-inflammatory activity of each chiral isomer salt. Among the various formulations, S-FBTMA exhibited superior water solubility (about 1-12 mg/ml), lipid solubility (1< lg Pow < 3) and corneal permeability. In comparison to Ocufen®, S-FBTMA demonstrated significantly higher in vivo anti-inflammatory activity and lower ocular irritability (such as conjunctival congestion and tingling). The findings from this research highlight the potential of chiral separation and ion-pair enhanced permeation techniques in providing pharmaceutical enterprises focused on drug development with a valuable avenue for improving therapeutic outcomes.

Effectiveness and Adherence Rate of S-flurbiprofen Plaster for the Pain Management of Patients With Moderate and End-Stage Knee Osteoarthritis

BACKGROUND

S-flurbiprofen plaster (SFPP) is highly skin permeable and represents a new conservative treatment for knee osteoarthritis (KOA) that can attain considerably higher concentrations in the synovium than topical flurbiprofen. To date, no study has investigated the efficacy and adherence rate of SFPP in patients with end-stage KOA. This study aimed to compare the effectiveness and adherence rate of SFPP for pain management in patients with moderate and end-stage KOA.

METHODS

This retrospective study included a total of 118 patients with KOA (Kellgren-Lawrence classification grades II (n = 29), III (n = 32), and IV (n = 57)). The difference in SFPP use rate, adverse drug reactions rate, whether 50% pain relief occurred, and the percentage of patients who underwent surgical treatment were calculated.

RESULTS

The overall SFPP use rate at one year was 61.0% (88.1% at less than one month, 79.7% at three months, and 61.0% at six months), with no significant differences among Kellgren-Lawrence grade II, III, and IV groups (p = 0.538). Adverse drug reactions such as skin rash (n = 23), skin irritation (n = 8), and gastrointestinal disorders (n = 2) were observed. The one-year SFPP use rate was significantly lower in patients in whom these side effects occurred but did not decrease in patients in whom only a skin rash occurred. Overall, 19 patients underwent surgery after discontinuation of SFPP use. Surgery was statistically selected more by the "over 71 years of age" group (p = 0.038) and the "ineffective" group (p = 0.007).

CONCLUSION

SFPP exerts a comparable therapeutic effect even in end-stage KOA and may be an effective treatment option. Even if patients have end-stage KOA, there are cases in which the patient's background does not allow for surgery positively, such as high perioperative risk or desire for conservative treatment. In such cases, SFPP may be an effective treatment option worth trying.

Physicochemical Properties and Transdermal Absorption of a Flurbiprofen and Lidocaine Complex in the Non-Crystalline Form

Amorphous drug formulations exploiting drug-drug interactions have been extensively studied. This study aims to develop a transdermal system containing an amorphous complex of the nonsteroidal anti-inflammatory drug (NSAID) flurbiprofen (FLU) and lidocaine (LDC) for alleviating chronic pain. The high-viscosity complex between FLU and LDC (Complex) was obtained by heating in ethanol. For the complex, attenuated total reflection-Fourier transform infrared spectroscopy showed a shift in the carboxy-group-derived peak of FLU, and differential scanning calorimetry indicated the endothermic peaks associated with the melting of FLU and LDC disappeared. ¹³C dipolar decoupling and ¹⁵N cross-polarization magic-angle spinning nuclear magnetic resonance measurement suggested the interaction between the carboxyl group of FLU and the secondary amine of LDC. The interaction between the aromatic rings of FLU and LDC contributed to the molecular complex formation. The solubility of FLU from the complex was about 100 times greater than FLU alone. The skin permeation flux of FLU from the complex through the hairless mouse skin was 3.8 times higher than FLU alone in hypromellose gel. Thus, adding LDC to the formulation can be an effective method for enhancing the skin permeation of NSAIDs, which can prove useful for treating chronic pain and inflammatory diseases.

Efficacy and safety of S-flurbiprofen plaster in knee osteoarthritis patients: A 2-week randomized controlled Phase III clinical trial compared to diclofenac gel

Aim

S‐flurbiprofen plaster (SFPP) is a novel topical nonsteroidal anti‐inflammatory drug (NSAID) patch. This study aimed to assess the efficacy and safety of SFPP in knee osteoarthritis (OA) patients compared to diclofenac gel.

Methods

This study was a multicenter, randomized, active‐controlled, open‐label, non‐inferiority phase III trial. There were 311 enrolled patients treated by SFPP or diclofenac gel for 2 weeks. The primary efficacy outcome was the knee pain when rising from the specially arranged chair assessed by visual analog scale (rVAS). The other efficacy outcomes were clinical symptoms, pain on walking, global assessment by both investigator and patient, and use/non‐use of the rescue drugs during the treatment period. Adverse events (AEs) were evaluated as the safety outcome.

Results

The least‐squares mean (95% CI) of ΔrVAS at the end of the study was 41.52 (39.16‐43.88) mm in the SFPP group and 36.01 (33.69‐38.33) mm in the diclofenac gel group, with a between‐group difference of 5.51 (2.20‐8.82), indicating non‐inferiority. There were statistically significant differences between the groups in rVAS, clinical symptoms, pain on walking, and the global assessment by both investigator and patient. The incidence rate of AEs in the SFPP group was 5.8%, and there was no statistically significant difference from that in the diclofenac gel group (5.2%). Most of the AEs were mild, and no AE led to discontinuation.

Conclusion

Non‐inferiority of SFPP to diclofenac gel was demonstrated in the efficacy for pain on rising from a chair. SFPP was also well‐tolerated in knee OA patients.

Comparison of tissue pharmacokinetics of esflurbiprofen plaster with flurbiprofen tablets in patients with knee osteoarthritis: A multicenter randomized controlled trial

This open‐label, multicenter, prospective, randomized controlled trial aimed to determine the effectiveness of esflurbiprofen plaster (SFPP) and flurbiprofen tablets (FPTs) on knee osteoarthritis in patients scheduled for total knee arthroplasty by comparing the transfer of esflurbiprofen and flurbiprofen to tissues and fluids. Thirty‐eight patients were randomly assigned in a 1:1 ratio to receive SFPP or FPT. Both groups were then divided into four subgroups, according to whether they received the final dose of SFPP or FPT at 2, 7, 12, or 24 h before planned surgery. The primary endpoints were the esflurbiprofen concentrations in synovium, synovial fluid, and plasma. Areas under concentration–time curves (AUC_{0–24 h}) of esflurbiprofen were calculated for each group. Pain was assessed using a numeric rating scale (NRS) 7 days before and immediately before surgery. The AUC_{0–24 h} in the synovium were 4401.24 and 4862.70 ng·h/g in the SFPP and FPT groups, respectively. Maximum esflurbiprofen concentrations were observed in the synovium, synovial fluids, and plasma after SFPP application for 12 h. The NRS results indicated a long‐lasting effect of SFPP. The AUC of the synovial esflurbiprofen concentration of SFPP indicated that the SFPP is transferred to the synovium and synovial fluid in high concentration. The efficient deep‐tissue transfer of esflurbiprofen suggests that its pharmacokinetic characteristics differ from those of conventional topical NSAIDs. This study was prospectively registered in the Japan Registry of Clinical Trials (registration number: jRCTs031180228).

Treatment Efficacy of Single Topical NSAID (S-Flurbiprofen Plaster) for Knee Symptoms and Locomotive Dysfunction in Knee Osteoarthritis Patients

Objective:

The aim of this study was to demonstrate the non-inferiority of S-flurbiprofen plaster (SFPP) monotherapy for treating knee osteoarthritis compared with the combination of conventional oral and topical non-steroidal anti-inflammatory drugs (NSAIDs).

Methods:

A total of 222 participants (114, SFPP group; 108, control group) were treated for 4 weeks. The primary endpoint was the change in the degree of pain felt while rising from a chair after 2 and 4 weeks of treatment as determined using the visual analog scale (VAS) . The secondary endpoint was the change in functional scores and test results. Safety was evaluated in terms of the adverse effects.

Results:

The VAS score significantly decreased in both groups after 2 and 4 weeks of treatment. Non-inferiority in the VAS score was established only at 2 weeks. There were no significant differences in the secondary endpoints between the groups. Skin disorders were more frequent in the SFPP group; however, there was no difference in gastrointestinal (GI) adverse effects.

Conclusions:

The therapeutic efficacy of SFPP monotherapy for knee OA, with respect to changes in the VAS, was not shown to be non-inferior to conventional treatment at 4 weeks; however, non-inferiority was established at 2 weeks. The functional improvement in the SFPP group was comparable to that of the control group. No severe GI adverse effects associated with SFPP administration were observed; however, it is necessary to pay more attention to the occurrence of skin disorders with SFPP than with conventional topical NSAIDs.

Effect of Flurbiprofen and S-Flurbiprofen Patches on Multimodal Pain Management After Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

BACKGROUND

Total knee arthroplasty (TKA) is an established procedure for knee osteoarthritis. Multimodal analgesia is reportedly more effective for postoperative analgesia. We investigated the efficacy of 2 patches after TKA.

METHODS

Seventy-nine knees that underwent unilateral TKA for osteoarthritis were included. Oral administration, local periarticular analgesic injection, and patches were adopted for pain management. The knees were randomly assigned to the flurbiprofen patch (FPP), S-flurbiprofen patch (SFPP), and control (no patch) groups. Patch treatment was continued for 14 days. Pain according to the visual analog scale, knee flexion angle, renal dysfunction, gastrointestinal injury, duration of hospitalization, dermatitis, and the rate of using additional oral nonsteroidal anti-inflammatory drugs were compared (from preoperative to postoperative day 14).

RESULTS

The FPP, SFPP, and control groups included 29, 27, and 23 knees, respectively. Visual analog scale was lower in the FPP and SFPP groups than in the control group on days 1 and 3 (day 1: 24.4, 25.0, and 39.4, respectively; day 3: 25.5, 23.3, and 39.3, respectively). Knee flexion angle was larger in the SFPP group than in the control group on days 7 and 14 (day 7: 89.8° and 76.6°, respectively; day 14: 98.3° and 84.2°, respectively). Neither renal dysfunction nor gastrointestinal injury was confirmed. The duration of hospitalization did not differ among the groups. Dermatitis occurred only in the SFPP group. The rate of using additional oral nonsteroidal anti-inflammatory drugs was higher in the control group.

CONCLUSION

Both patches were effective and safe as part of multimodal analgesia for postoperative TKA.

Evaluation of the effects of pregabalin on chondrocyte proliferation and CHAD, HIF-1α, and COL2A1 gene expression

INTRODUCTION

The aim of the present study is to investigate the effects of pregabalin (PGB) on chondrocyte proliferation and collagen type II (COL2A1), hypoxia-inducible factor 1-α (HIF-1α), and chondroadherin (CHAD) gene expression in osteoarthritic chondrocytes.

MATERIAL AND METHODS

Standard primary chondrocyte cultures were prepared using osteochondral tissues that were surgically obtained from 6 patients with gonarthrosis. Cell morphology was evaluated using an inverted microscope, and cell death and proliferation were determined through MTT analysis, which was confirmed by AO/PI staining and statistically evaluated. The expression levels of CHAD, COL2A1, and HIF-1α genes were assessed using gene-specific TaqMan Gene Expression Assays.

RESULTS

MTT analyses showed that PGB administration did not have a negative or toxic effect on cell viability and proliferation in cultured chondrocytes (p < 0.001), but in our morphological evaluation extracellular matrix development was observed to be weaker in cultures treated with PGB. After 24 h of treatment, COL2A1, HIF-1α, and CHAD gene expression decreased in the groups to which PGB was applied compared to gene expression before the experiment (at 0 h); at 48 h, CHAD and HIF-1α expression increased to the same level as the control group, but the expression of COL2A1 continued to decrease.

CONCLUSIONS

Further studies need to be conducted with more participants to prove that there is a negative correlation between extracellular matrix formation and PGB administration. Our preliminary data show that even at low doses and over short-term administration, PGB may affect chondrocyte cells at the gene-expression level.

Effect of naproxen on proliferation and differentiation of primary cell cultures isolated from human cartilage tissue

Non-steroidal anti-inflammatory drugs (NSAIDs) that are applied through oral, injectable or topical routes have been widely used in painful and inflammatory musculoskeletal diseases. The current study aimed to determine whether naproxen, an aryl acetic acid derivative with analgesic and anti-inflammatory effects, has a toxic effect on human chondrocytes. Samples containing monolayer primary chondrocyte cultures were prepared following resection from osteochondral tissues obtained from patients with gonarthrosis. Cell viability, toxicity and proliferation and levels of stage-specific embryonic antigen-1, a precursor to human prechondrocytes, were evaluated spectrophotometrically. The results from the untreated control group were compared with those of the study groups, where naproxen was administered in varying doses (1-1,000 µM). Surface morphologies of the cells were compared using inverted light and environmental scanning electron microscopy. Treatment groups were compared by analysis of variance with Tukey's honest difference post hoc test. P<0.01 was considered to indicate a statistically significant difference. The research revealed significant changes to proliferation and differentiation of chondrocytes in all treatment groups (P<0.01). Naproxen was demonstrated to suppress chondrocyte proliferation and differentiation, which may be an important factor to consider when prescribing this medication to patients.

[Pharmacological action and clinical outcome of newly developed NSAIDs patch, "LOQOA® tape"]

Topical non-steroidal anti-inflammatory drugs (NSAIDs) patches are indispensable for the treatment of musculoskeletal diseases, while they are considered less effective than oral NSAIDs. LOQOA^® tape is a tape-type patch containing esflurbiprofen (SFP) as a major active ingredient with potent cyclooxygenase inhibition and sufficient skin permeability. SFP patch (SFPP) showed higher percutaneous absorption rate, rapid pain relief, and potent anti-inflammatory efficacy comparing with existing NSAIDs patches in rat. SFPP showed dramatically higher synovial fluid and tissue concentration on SFP than that of flurbiprofen (FP) patch after single application to knee osteoarthritis (OA) patients. On the other hand, clinical dosage of SFPP was determined as not more than two patches a day from the estimation of systemic exposure to SFP of SFPP and oral FP. SFPP showed statistically significant differences in pain relief and all the other efficacy end points compared to inactive placebo or FP patch in knee OA patients. Efficacy on OA other than knee joint was also observed. In long-term study of SFPP, using up to two patches a day, a total of 201 patients was included and 161 patients achieved 52-week application. Among drug-related side effects, skin reaction at the application sites was observed in 46.8% and discontinued in 4.3%. Although gastro-intestinal reaction and abnormal changes in laboratory tests related to kidney function were observed as systemic drug-related side effects, most of them were mild in severity. SFPP, the new generation NSAIDs patch, would be one of effective options for the treatment of symptomatic OA patients.

Analgesic effect of S (+)-flurbiprofen plaster in a rat model of knee arthritis: analysis of gait and synovial fluid prostaglandin E2 levels

Objectives

We developed S (+)‐flurbiprofen plaster (SFPP), a novel NSAID patch containing S (+)‐flurbiprofen (SFP), a potent cyclooxygenase (COX) inhibitor. The purpose of this study was to assess efficacy of SFPP by analysing its effect on the gait disturbance and measuring the prostaglandin E₂ (PGE₂) production in synovial fluid in a rat model of knee arthritis.

Methods

Knee inflammation was induced in rats by intra‐articular injection of a yeast suspension. Subsequently, an NSAID patch containing SFP, ketoprofen or loxoprofen was applied over the affected knee. Gait was assessed at 2, 4 and 6 h after application of the patch. The PGE₂ concentration in the synovial fluid was measured after the gait assessment.

Key findings

Application of SFPP (0.125, 0.25, 0.5 or 1 mg/sheet) was followed by a decrease in the visual gait score at all the doses examined. In the case of the other two NSAID patches, only the ketoprofen patch (1 or 2 mg/sheet) and loxoprofen patch (5 mg/sheet) produced a decrease in the visual gait score. All of the NSAID patches decreased the PGE₂ production in the synovial fluid.

Conclusions

These results suggest the potential usefulness of SFPP as an analgesic patch in patients with inflammatory joint pain.

Lowering side effects of NSAID usage in osteoarthritis: recent attempts at minimizing dosage

INTRODUCTION

Osteoarthritis is a burdensome disease that causes progressive damage to articular cartilage. Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the preferred treatments for symptomatic relief. However, NSAIDs can cause serious dose-dependent side effects, which has prompted experts to recommend the minimization of NSAID dosage.

AREAS COVERED

This review focuses on three broad strategies that are currently being investigated or implemented to minimize NSAID dosage: nano-formulation, encapsulation, and topical delivery. The benefits, challenges and current status of these methods are discussed.

EXPERT OPINION

Multiple strategies are under investigation to lower NSAID dosage. There is great potential in developing formulations that utilize more than one of these strategies together. However, there are challenges to developing these lower dose preparations. In order to maximize the clinical potential of the abundance of NSAIDs that are both available and being developed, there is a major need for additional clinical studies directly comparing safety and efficacy of different preparations.

The efficacy and safety of S-flurbiprofen plaster in the treatment of knee osteoarthritis: a phase II, randomized, double-blind, placebo-controlled, dose-finding study

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) patches are convenient for use and show much less gastrointestinal side effects than oral NSAIDs, whereas its percutaneous absorption is not sufficient for the expression of clinical efficacy at satisfactory level. S-flurbiprofen plaster (SFPP) has shown dramatic improvement in percutaneous absorption results from animal and clinical studies. In this study, the efficacy and safety of SFPP were compared with placebo in patients with knee osteoarthritis (OA) to determine its optimal dose. This was a multicenter, randomized, double-blind, parallel-group comparative study.

PATIENTS AND METHODS

Enrolled 509 knee OA patients were treated with placebo or SFPP at 10, 20, or 40 mg applied on the affected site once daily for 2 weeks. The primary endpoint for efficacy was improvement in knee pain on rising from the chair assessed by visual analog scale (VAS). The other endpoints were clinical symptoms, pain on walking, and global assessment by both investigator and patient. Safety was evaluated by observing adverse events (AEs).

RESULTS

VAS change in knee pain from baseline to trial end was dose-dependent, least squares mean was 29.5, 31.5, 32.0, and 35.6 mm in placebo and SFPP 10, 20, and 40 mg, respectively. A significant difference was observed between placebo and SFPP 40 mg (P=0.001). In contrast, the effect of SFPP at a dose ≤20 mg was not significantly different from that of placebo. The proportion of the patients who achieved 50% pain relief was 72.4% in 40 mg and 51.2% in placebo (P<0.001). In all other endpoints, SFPP 40 mg showed significant improvement compared with placebo. The incidence of AEs was not different across all four groups, and no severe AEs were observed.

CONCLUSION

Clinically relevant pain relief was observed in all groups including placebo. Especially 40 mg showed remarkable pain relief in not only primary endpoint but also all the other endpoint with significant differences over placebo. The safety profile of SFPP 40 mg was not different from that of placebo. Therefore, 40 mg was determined as the optimal tested dose.

A minimal impact of long-term S-flurbiprofen plaster application on kidney function in osteoarthritis patients

Background

The number of kidney injury due to nonsteroidal anti-inflammatory drugs (NSAIDs) is the largest among drug-induced kidney diseases. Newly developed NSAID plaster containing S-flurbiprofen (SFP) shows innovative percutaneous absorption. However, systemic exposure to SFP following the repeated application of 80 mg/day was estimated as comparable to that of oral 120 mg/day flurbiprofen and prolonged use of topical NSAIDs is common in clinical practice. Thus, we report the safety focusing on the kidney function after long-term application of SFP plaster (SFPP).

Methods

A total of 201 osteoarthritis patients (mean age; 66.3, 151 females, mean estimated glomerular filtration rate; 74.6 mL/min/1.73 mm²) were applied 40 or 80 mg SFPP for 52 weeks, and kidney function was examined by blood urea nitrogen (BUN), serum creatinine (SCr), eGFR, and urinalysis.

Results

161 (80.1%) patients completed 52-week application. In both groups of 40 and 80 mg, small but statistically significant increases were observed in BUN (mean 1.91 and 1.89 mg/dL, p < 0.05) and SCr (mean 0.019 and 0.022 mg/dL, p < 0.05). Although abnormal changes in laboratory test for renal function were observed in seven patients, all the changes were small and subclinical. Acute kidney injury was observed in two patients. Meanwhile, the investigators denied the relevance of SFPP according to the clinical course.

Conclusion

Toward the end of 52-week application, a statistically significant increase in SCr was observed in both 40 and 80 mg, but increment was small and subclinical. Attention should be paid to kidney function when applying SFPP to patients with multiple risk factors.

The Long-Term Safety of S-Flurbiprofen Plaster for Osteoarthritis Patients: An Open-Label, 52-Week Study

Background and objectives

The newly developed S-flurbiprofen plaster (SFPP) is a tape-type patch that shows innovative percutaneous absorption. This study was designed to evaluate the safety of a long-term 52-week SFPP application to osteoarthritis (OA) patients.

Methods

This was a multi-center, open-label, uncontrolled prospective study that included 201 OA patients. SFPP at 40 mg/day was applied to the site of pain in 101 patients and at 80 mg/day (2 patches) in 100 patients at a total of 301 sites for 52 weeks. The affected sites assessed included the knee (192), lumbar spine (66), cervical spine (26), and others (17). Drug safety was evaluated by medical examination, laboratory tests, and examination of vital signs. Efficacy was evaluated by the patient’s and clinician’s global assessments and clinical symptoms.

Results

Most patients (80.1 %) completed the 52-week SFPP application. The majority of drug-related adverse events (AEs) included mild dermatitis at the application sites and occurred in 46.8 % of the sites. No photosensitive dermatitis was observed. Systemic AEs occurred in 9.0 % of the patients; a serious AE (gastric ulcer hemorrhage) occurred in one patient. No clinically significant changes in the laboratory tests and vital signs were observed. The efficacy evaluation showed an improvement from 2 weeks after the SFPP application, which continued during the 52 weeks’ treatment.

Conclusions

No apparent safety concerns were observed, even during the long-term SFPP application. Therefore, SFPP could be an additional pharmacotherapy in OA treatment.

Chondrocyte proliferation, viability and differentiation is declined following administration of methylphenidate utilized for the treatment of attention-deficit/hyperactivity disorder

PURPOSE

Methylphenidate (MPH) derivative drugs are used because of psychostimulants effects on attention-deficit hyperactivity disorder in children and adults. As far as we know, toxic or anti-proliferative effects of MPH against cartilage tissue were not studied in the literature. The present study was carried out to investigate the possible effects of MPH on the proliferation, viability and differentiation of primary human chondrocytes, in vitro.

METHODS

Monolayer primary chondrocyte cultures were prepared using osteochondral tissue obtained from patients who underwent a total knee prosthesis operation. Stock solution of MPH was prepared and aliquots having 1-1000 µM concentrations of the drug was composed. These solutions were applied to the wells containing cultured chondrocyte samples within the well plates. Control groups were composed of pure chondrocyte culture and no solution was added into them. All groups were evaluated at 24, 48 and 72 h in order to determine the possible negative effects of the drug on the chondrocytes. The data were evaluated by Tukey's honestly significantly different test following analysis of variance.

RESULTS

In the group where MPH was applied, it was found that viability, proliferation and stage-specific embryonic antigen-1 protein expression were decreased in comparison to the control group.

CONCLUSIONS

It was emphasized that clinicians should not disregard the fact that this drug might suppress chondrocyte cell proliferation and chondrogenic differentiation.

Assessing the negative impact of phenyl alkanoic acid derivative, a frequently prescribed drug for the suppression of pain and inflammation, on the differentiation and proliferation of chondrocytes

Background

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed to relieve pain and inflammation. These NSAIDs have also analgesic effects and can be administered via oral, injectable, and topical routes. During inflammation, a number of synovial mediators and cytokines are released which decrease the pH level of the synovial fluid. Administration of acidic NSAIDs further decreases the pH levels and hence contributes to the destruction of the cartilage. To our knowledge, no cellular-based study regarding the chondrotoxicity of phenyl alkanoic acid derivatives on NSAIDs was conducted before. Thus, the aim of this pioneering study was to examine the effect of frequently prescribed NSAIDs, a phenyl alkanoic acid derivative, flurbiprofen, on the proliferation and differentiation of human primer chondrocyte cultures in vitro.

Methods

Primer chondrocyte cultures were prepared from osteochondral tissue obtained during surgery for gonarthrosis. Samples not exposed to the pharmacological agent were used as the control group. The samples were treated with 1, 10, 100, 250, 500, or 1000 μM of the agent for 24, 48, and 72 h. The cell viability, toxicity, and proliferation were assessed with MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) analysis and prechondrocytic precursor stage-specific embryonic antigen-1 (SSEA-1) expression using a commercial ELISA kit spectrophotometrically. The surface morphology of the samples in each group was compared using an inverted light microscope and an environmental scanning electron microscope (ESEM). An analysis of variance was used to compare between-group differences. Tukey’s honest significant difference (HSD) method (95 % confidence interval) was used to evaluate the differences and significance in averages. The alpha significance value was considered <0.01.

Results

Statistically significant cytotoxicity was observed in the treatment groups. NSAID had a significant negative effect on the proliferation and differentiation of chondrocytes as compared to the control group (p < 0.01).

Conclusion

Before administering phenyl alkanoic acid derivatives in the clinical setting, their role in suppressing the proliferation and differentiation of chondrocytes should be taken into account. Thus, caution should be given when prescribing these drugs.

Topical Anti-Inflammatory and Analgesic Effects of Multiple Applications of S(+)-Flurbiprofen Plaster (SFPP) in a Rat Adjuvant-Induced Arthritis Model

Preclinical Research

The aim of this study was to evaluate the efficacy of multiple applications of S(+)‐flurbiprofen plaster (SFPP), a novel Nonsteroidal anti‐inflammatory drug (NSAID) patch, for the alleviation of inflammatory pain and edema in rat adjuvant‐induced arthritis (AIA) model as compared to other NSAID patches. The AIA model was induced by the injection of Mycobacterium butyricum and rats were treated with a patch (1.0 cm × 0.88 cm) containing each NSAID (SFP, ketoprofen, loxoprofen, diclofenac, felbinac, flurbiprofen, or indomethacin) applied to the paw for 6 h per day for 5 days. The pain threshold was evaluated using a flexion test of the ankle joint, and the inflamed paw edema was evaluated using a plethysmometer. cyclooxygenase (COX)−1 and COX‐2 inhibition was evaluated using human recombinant proteins. Multiple applications of SFPP exerted a significant analgesic effect from the first day of application as compared to the other NSAID patches. In terms of paw edema, SFPP decreased edema from the second day after application, Multiple applications of SFPP were superior to those of other NSAID patches, in terms of the analgesic effect with multiple applications. These results suggest that SFPP may be a beneficial patch for providing analgesic and anti‐inflammatory effects clinically. Drug Dev Res 77 : 206–211, 2016. © 2016 The Authors Drug Development Research Published by Wiley Periodicals, Inc.

Efficacy of S-flurbiprofen plaster in knee osteoarthritis treatment: Results from a phase III, randomized, active-controlled, adequate, and well-controlled trial

OBJECTIVES

S-flurbiprofen plaster (SFPP) is a novel non-steroidal anti-inflammatory drug (NSAID) patch, intended for topical treatment for musculoskeletal diseases. This trial was conducted to examine the effectiveness of SFPP using active comparator, flurbiprofen (FP) patch, on knee osteoarthritis (OA) symptoms.

METHODS

This was a phase III, multi-center, randomized, adequate, and well-controlled trial, both investigators and patients were blinded to the assigned treatment. Enrolled 633 knee OA patients were treated with either SFPP or FP patch for two weeks. The primary endpoint was improvement in knee pain on rising from the chair as assessed by visual analogue scale (rVAS). Safety was evaluated through adverse events (AEs).

RESULTS

The change in rVAS was 40.9 mm in SFPP group and 30.6 mm in FP patch group (p < 0.001). The incidence of drug-related AEs at the application site was 9.5% (32 AEs, 29 mild and 3 moderate) in SFPP and 1.6% in FP patch (p < 0.001). Withdrawals due to AE were five in SFPP and one in FP patch.

CONCLUSIONS

The superiority of SFPP in efficacy was demonstrated. Most of AEs were mild and few AEs led to treatment discontinuation. Therefore, SFPP provides an additional option for knee OA therapy.