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

Self-Assembled Multilayer-Modified Needles Simulate Acupuncture and Diclofenac Sodium Delivery for Rheumatoid Arthritis

A novel therapeutic approach combining acupuncture and diclofenac sodium (DS) administration was established for the potential treatment for rheumatoid arthritis (RA). DS is a commonly used anti-inflammatory and analgesic drug but has short duration and adverse effects. Acupoints are critical linkages in the meridian system and are potential candidates for drug delivery. Herein, we fabricated a DS-loaded multilayer-modified acupuncture needle (DS-MMAN) and investigated its capacity for inhibiting RA. This DS-MMAN possesses sustained release properties and in vitro anti-inflammatory effects. Experimental results showed that the DS-MMAN with microdoses can enhance analgesia and efficiently relieve joint swelling compared to the oral or intra-articular administration of DS with gram-level doses. Moreover, the combination of acupoint and DS exerts a synergistic improvement in inflammation and joint damage. Cytokine and T cell analyses in the serum indicated that the application of DS-MMAN suppressed the levels of pro-inflammatory factors and increased the levels of anti-inflammatory factors. Furthermore, the acupoint administration via DS-MMAN could decrease the accumulation of DS in the liver and kidneys, which may express better therapeutic efficiency and low toxicity. The present study demonstrated that the acupuncture needle has the potential to build a bridge between acupuncture and medication, which would be a promising alternative to the combination of traditional and modern medicine.

A New Hyaluronic Emulgel of Hesperetin for Topical Application-An In Vitro Evaluation

The present study aimed to formulate and characterize a hesperetin formulation to achieve adequate deposition and retention of hesperetin in the epidermis as a target for some cosmetic/dermatological actions. To derive the final emulgel, various formulations incorporating different proportions of Polysorbate 80 and hyaluronic acid underwent testing through a Box-Behnken experimental design. Nine formulations were created until the targeted emulgel properties were achieved. This systematic approach, following the principles of a design of experiment (DoE) methodology, adheres to a quality-by-design (QbD) paradigm, ensuring a robust and purposeful formulation and highlighting the commitment to a quality-driven design approach. The emulsions were developed using the phase inversion method, optimizing the emulgel with the incorporation of hyaluronic acid. Physically stable optimized emulgels were evaluated for their globule size, surface charge, viscosity, pH, electrical conductivity, and hesperetin content. These assays, along with the temperature swing test, were used to select the optimal formulation. It was characterized by a droplet size, d[4,3], of 4.02 μm, a Z-potential of -27.8 mV, an O/W sign, a pH of 5.2, and a creamy texture and proved to be stable for at least 2 months at room temperature. Additionally, in vitro release kinetics from the selected emulgel exhibited a sustained release profile of hesperetin. Skin assays revealed adequate retention of hesperetin in the human epidermis with minimum permeation. Altogether, these results corroborate the promising future of the proposed emulgel in cosmetic or dermatological use on healthy or diseased skin.

An Overview of Potential Seaweed-Derived Bioactive Compounds for Pharmaceutical Applications

Nowadays, seaweeds are widely involved in biotechnological applications. Due to the variety of bioactive compounds in their composition, species of phylum Ochrophyta, class Phaeophyceae, phylum Rhodophyta and Chlorophyta are valuable for the food, cosmetic, pharmaceutical and nutraceutical industries. Seaweeds have been consumed as whole food since ancient times and used to treat several diseases, even though the mechanisms of action were unknown. During the last decades, research has demonstrated that those unique compounds express beneficial properties for human health. Each compound has peculiar properties (e.g., antioxidant, antimicrobial, antiviral activities, etc.) that can be exploited to enhance human health. Seaweed's extracted polysaccharides are already involved in the pharmaceutical industry, with the aim of replacing synthetic compounds with components of natural origin. This review aims at a better understanding of the recent uses of algae in drug development, with the scope of replacing synthetic compounds and the multiple biotechnological applications that make up seaweed's potential in industrial companies. Further research is needed to better understand the mechanisms of action of seaweed's compounds and to embrace the use of seaweeds in pharmaceutical companies and other applications, with the final scope being to produce sustainable and healthier products.

Formulation, Optimization and In Vivo Evaluation of Fucoidan-Based Cream with Anti-Inflammatory Properties

Fucoidan is a polysaccharide found in brown alga with glorious potential for pharmacological activities, among which its anti-inflammatory properties have gained meaningful attention. Due to several advantages of formulations for topical application, this study aimed to develop and optimize a fucoidan-based cream formulation and to investigate its anti-inflammatory potential after topical application in vivo. Fucoidan from Fucus vesiculosus L. was used. The cream base consisting of olive oil and Kolliphor RH40 was optimized followed by in vitro agar diffusion and drug release studies. The fucoidan-based cream with 13% Kolliphor P 407, 1% Transcutol P, and 5% PEG400 showed good spreadability, washability, and colloidal stability, and it did not irritate the skin. The kinetics of fucoidan release from the optimized cream exhibited the best fit to the Korsmeyer-Peppas and Higuchi models with R2 > 0.99. Fucoidan release was controlled by drug diffusion and anomalous transport provided by the optimized cream base. The formulation was stable and provided high fucoidan release after storage for 1 year. Topical application of the fucoidan-based cream dose-dependently inhibited carrageenan-induced edema and ameliorated mechanical allodynia in rats. The efficacy of the fucoidan-based cream at a high dose was comparable with the efficacy of diclofenac gel. The fucoidan-based cream could be considered a promising anti-inflammatory formulation.

Emulgel: an effective drug delivery system

BACKGROUND

Emulgels are the emerging drug delivery system nowadays that has become popular for the delivery of hydrophobic drugs. This formulation is considered a novel type of drug delivery system and a mixture of emulsion and gel.

OBJECTIVE

The objective of this review is to throw light on the preparation of emulgels and their evaluation which will conclude how important these dosage forms are. In the coming years, it will be most commonly used because it is easy to use and enhances patient compliance.

CONCLUSION

Emulgels are easily removable, spreadable, thixotropic, greaseless, have a pleasing appearance, emollient, long shelf life, and transparent. In the present era, the emulgels are being used for the delivery of many drugs like analgesics, anti-inflammatory, anti-acne and anti-fungal. Hence, it is of great pharmacological importance and is relatively free of side effects.

Approaching acute pain in emergency settings; European Society for Emergency Medicine (EUSEM) guidelines-part 2: management and recommendations

BACKGROUND

In Europe, healthcare systems and education, as well as the clinical care and health outcomes of patients, varies across countries. Likewise, the management of acute events for patients also differs, dependent on the emergency care setting, e.g. pre-hospital or emergency department. There are various barriers to adequate pain management and factors common to both settings including lack of knowledge and training, reluctance to give opioids, and concerns about drug-seeking behaviour or abuse. There is no single current standard of care for the treatment of pain in an emergency, with management based on severity of pain, injury and local protocols. Changing practices, attitudes and behaviour can be difficult, and improvements and interventions should be developed with barriers to pain management and the needs of the individual emergency setting in mind.

METHODS

With these principles at the forefront, The European Society for Emergency Medicine (EUSEM) launched a programme-the European Pain Initiative (EPI)-with the aim of providing information, advice, and guidance on acute pain management in emergency settings.

RESULTS AND CONCLUSIONS

This article provides treatment recommendations from recently developed guidelines, based on a review of the literature, current practice across Europe and the clinical expertise of the EPI advisors. The recommendations have been developed, evaluated, and refined for both adults and children (aged ≥ 1 year, ≤ 15 years), with the assumption of timely pain assessment and reassessment and the possibility to implement analgesia. To provide flexibility for use across Europe, options are provided for selection of appropriate pharmacological treatment.

Visualization of Epidermal Reservoir Formation from Topical Diclofenac Gels by Raman Spectroscopy

Purpose

This work investigated whether topical pain relief diclofenac gels can form a diclofenac reservoir in the epidermal and dermal layers of human skin.

Methods

Excised human skin samples were treated with three topical diclofenac gels ex vivo and examined using Raman microscopy of transversally microtomed sections. The relative diclofenac concentration in the skin layers was calculated as the ratio of the integrated areas of bands characteristic of diclofenac (~445 cm⁻¹) and skin (Amide I). A customized masking algorithm ensured that only diclofenac-specific signal was mapped in the resulting Raman images.

Results

A heterogenous spatial distribution of diclofenac was clearly visible in both the epidermis and the dermis in all samples, with a markedly higher diclofenac relative content and number of pixels above the detection limit in the epidermis compared to the dermis.

Conclusion

The Raman images evidenced that the studied topical gels deliver diclofenac through the stratum corneum skin barrier and form a drug depot localized in the epidermis. The data are in line with earlier clinical findings that this depot acts like a true reservoir and enables sustained drug release.

Rationale and evidence for the incorporation of heparin into the diclofenac epolamine medicated plaster

OBJECTIVE

The nonsteroidal anti-inflammatory drug (NSAID) diclofenac epolamine (DHEP) formulated as a topical patch has demonstrated efficacy and safety in the localized treatment of acute pain from minor strains, sprains and contusions, and for epicondylitis and knee osteoarthritis. The glycosaminoglycan heparin enhances the activity of topical NSAIDs formulated as a medicated plaster, even in the absence of any significant release of heparin. Therefore, DHEP plus, a new formulation of the DHEP medicated plaster containing a small amount of heparin sodium as excipient, has been developed.

METHODS

We reviewed the pivotal and supportive studies of the clinical development program of the new patch and evaluated the role of heparin as an enhancer in the treatment of localized pain/inflammation of musculoskeletal structures, associated with post-traumatic and/or rheumatic conditions.

RESULTS

The data was consistent with the concept that heparin increased the clinical activity of the DHEP plus medicated plaster versus the reference DHEP medicated plaster through improved bioavailability due to enhanced movement of diclofenac from the plaster. Both DHEP formulations have the same dissolution profile, indicating that heparin does not change the physical and chemical characteristics of the plaster. Permeation testing showed that heparin is not released from the DHEP plus medicated plaster. Efficacy studies showed that the DHEP plus medicated plaster was significantly more effective in reducing pain than the reference marketed DHEP medicated plaster.

CONCLUSIONS

The benefit/risk assessment of DHEP plus 180 mg medicated plaster is favorable, with a safety profile equal to placebo and improved efficacy over the reference marketed DHEP medicated plaster.

Efficacy and safety of loxoprofen sodium topical patch for the treatment of pain in patients with minor acute traumatic limb injuries in Brazil: a randomized, double-blind, noninferiority trial

Posttraumatic injury pain is commonly treated with oral nonsteroidal anti-inflammatory drugs. However, oral nonsteroidal anti-inflammatory drugs cause several adverse events, with topical formulations arising as an important alternative. Therefore, we aimed at evaluating the efficacy and safety of loxoprofen patch (LX-P) in the treatment of patients with posttraumatic pain. This phase III, randomized, double-blind, noninferiority study enrolled Brazilian patients aged 18 to 65 years diagnosed with lower and upper limb posttraumatic injury who were experiencing moderate or severe pain. Patients were assigned to active LX-P or to loxoprofen tablet (LX-T), and pain intensity was measured based on a visual analog scale score variation after 7 days of treatment. Data on clinical symptoms, rescue medication use, and adverse events were also collected. Visual analog scale score variation was compared using a 10% noninferiority margin. Two hundred forty-two patients were randomly assigned to LX-P (n = 123) or to LX-T (n = 119). The results showed a reduction in pain after 7 days of treatment: -49.96 (n = 118; SE 1.7) in the LX-P and -47.71 (n = 117; SE 1.6) in the LX-T groups (difference of -2.25; 95% CI: -5.97 to 1.47; P = 0.23). On the safety analysis, the LX-T group presented twice as many patients with treatment-emergent adverse events as the LX-P group (30.8% and 14.2%, respectively). A sensitivity analysis demonstrated that rescue medication use has not affected the primary end point. This study showed that LX-P has a comparable efficacy to LX-T, but with a better safety profile, being a therapeutic option for the treatment of posttraumatic injury pain.

Topical Administration of Ibuprofen for Injured Athletes: Considerations, Formulations, and Comparison to Oral Delivery

Non-steroidal anti-inflammatory drugs (NSAIDs) are a class of drugs commonly used to treat both the acute and chronic injuries sustained by athletes during training and competition. In many parts of the world, NSAIDs can be purchased over-the-counter and used without any physician oversight. However, the chronic nature of overuse injuries requires NSAIDs to be taken orally for an extended period of time. As a result, they can have significant adverse effects on athletes, namely gastrointestinal (GI), renal, and cardiovascular damage. Dyspepsia and upper GI ulceration and bleeding are of great concern in chronic NSAID use, and as such oral NSAIDs are generally contraindicated in those with a history of peptic ulcers or irritable bowel disease. In the setting of chronic overuse soft tissue or joint disease, topically administered NSAIDs offer an alternate route of administration that has the potential to deliver a similar level of pain and anti-inflammatory relief while bypassing the harmful side effects associated with oral intake. Topically applied NSAIDs are able to achieve high concentrations within the targeted site of action while simultaneously keeping plasma concentrations low, offering several advantages over oral administration. One commonly used generic NSAID is ibuprofen (2-(4-isobutylphenyl)propanoic acid). First synthesized in the 1960s, ibuprofen has since become widely available as an over-the-counter pharmaceutical. In this review, we outline new and different techniques that have been used to deliver ibuprofen into diseased tissues, including supersaturations, microemulsions, gels, nanosystems, and microneedles. We also review relevant clinical trials comparing transdermally delivered ibuprofen to placebo and orally administered ibuprofen.

Application of Quality by Design: Development to Manufacturing of Diclofenac Sodium Topical Gel

The objective of the present study was to develop and optimize generic topical gel formulation of diclofenac sodium through quality by design approaches. The quality target product profile was set for the critical quality attributes of the gel. The key material variables like hydrophilic gelling agent carbopol and penetration enhancer kolliphor were optimized using design of experiments. A central composite design was used considering viscosity and cumulative percent diffusion of the drug after 0.5, 1, 2, 4 and 6 h as responses. The p values for all models generated for different responses were statistically significant (<0.5). Design space was established and verified at the laboratory scale. The predicted and observed values were in close agreement. The robustness of the formula was tested at a higher scale (10X and 200X). The capability index was calculated followed by Monte Carlo simulation and the Cpk values for all the responses were more than 1.33.

Effect of terpenes on transdermal iontophoretic delivery of diclofenac potassium under constant voltage

OBJECTIVE

The aim of the study was to enhance the transdermal delivery of diclofenac potassium (DP) from hydrogels by constant voltage iontophoresis (CVI). The other objective was to establish the safety and efficacy of CVI in rats.

MATERIALS AND METHODS

Hydrogels of DP were developed using hydroxyethyl cellulose as matrix material and geraniol, l-menthol and thymol as iontophoretic efficiency enhancers (IEE). In vitro permeation of hydrogels under CVI (1.5 V) was performed in Franz diffusion cells across porcine skin. The ability of CVI to deliver therapeutic amount of DP in vivo was assessed in rat paw edema model.

RESULTS

CVI significantly (p < 0.05) increased the steady state flux of DP compared to the passive. The hydrogels containing geraniol and l-menthol enhanced the iontophoretic flux of DP by ∼4.75 and ∼4.49 fold, respectively compared to passive control. The in vivo studies indicated that CVI in combination with IEE, significantly reduced (p < 0.05) area under the curve (AUC) of % inflammation compared to passive treatment. An excellent correlation (r = 0.996) was noted between in vitro flux values and AUC of % inflammation.

CONCLUSION

The preclinical studies conclusively demonstrated that CVI in combination with IEE's such as geraniol or l-menthol has the potential to safely deliver therapeutic amounts of DP.

The Effectiveness of Diclofenac Sodium in the Treatment of Mondor's Disease of the Breast: The Topical Patch Compared to the Oral Capsules

Mondor's disease of the breast is a rare, benign sclerosing superficial thrombophlebitis of the subcutaneous veins of the anterior or lateral chest wall, which is treated conservatively. We aim in this study to evaluate the outcome and effectiveness of our treatment protocol using oral diclofenac sodium and topical diclofenac sodium patch in 172 patients. A retrospective database analysis of 172 female patients between January 2001 and December 2010 was done. The treatment protocol consisted of group 1: treatment by oral diclofenac sodium 100 mg once daily for 3 weeks. Group 2: treatment by diclofenac sodium patches for 8 hours twice daily (morning and evening) for 1 week. The patients were instructed to document the time as soon as pain relief is achieved following the patch application and the intake of the oral dose. The incidence rate was 2.49%. Diclofenac sodium patch was statistically found to be significantly better in subsiding the inflammatory process of the veins, relieving the pain, and enhancing faster healing rate. We conclude that diclofenac sodium patch showed a promising role in the treatment of Mondor's disease of the breast by significantly decreasing the inflammatory process due to its transdermal migration action within a short period and the ability to reach a high local concentration. It achieved the best results for rapid relief of pain and disease regression compared to the oral capsules. Therefore, our protocol was changed to implement diclofenac sodium patch as the first choice in treating Mondor's disease of the breast.

Effect of gel properties on transdermal iontophoretic delivery of diclofenac sodium

The aim of the study was to develop hydrogels and investigate the suitability for transdermal delivery of diclofenac sodium (DS) using constant voltage iontophoresis (CVI). Four batches of hydrogels of DS were developed using hydroxylethyl cellulose (HEC) as matrix material and terpenes as penetration enhancers. The hydrogels displayed a viscosity of ~1500 cps at a shear rate of 250 s-1 that was unlikely to change on minute shift in pH or temperature so that the iontophoretic transport would be unaffected. Moreover, the hydrogels were found to possess adequate conductivity at pH 7.4 to enable iontophoretic delivery of DS. In vitro studies indicated that passive transport of DS across porcine skin from hydrogels was comparable (p>0.05) to aqueous solution. The lead hydrogel (F1), containing geraniol was found to enhance the iontophoretic flux of DS by 5.16 fold at 1.5 V compared to passive control. In vivo studies in rats indicated that CVI on application of F1 significantly suppressed (p<0.001) carrageenan induced edema compared to passive treatment throughout the study.

Effects of topical diclofenac plus heparin (DHEP+H plaster) on somatic pain sensitivity in healthy subjects with a latent algogenic condition of the lower limb

OBJECTIVE

To evaluate whether a diclofenac epolamine + heparin topical (plaster) is more effective than diclofenac plaster alone in reducing deep somatic hyperalgesia in subjects without spontaneous pain and whether the effect is linked to or independent of the anti-edematous action of heparin.

DESIGN

Prospective, double-blind, randomized and controlled, four-arm parallel design trial.

SUBJECTS

One hundred and four patients (84 women, 20 men, mean age 42.2 ± 13.3 years), with deep somatic hyperalgesia in one thigh, randomly assigned to one of 4 groups of 26 each.

INTERVENTION

Each group underwent one of the following plaster treatments on one thigh: diclofenac+heparin; diclofenac; heparin; placebo, for 7 days, renewing the plaster every 24 hours.

OUTCOME MEASURES

Before treatment (day 1), at day 4 and day 8, assessment of (a) pressure and electrical pain thresholds of vastus lateralis and overlying subcutis and skin; and (b) structure/thickness of subcutis and muscle with ultrasounds at the same level.

RESULTS

During treatment, in placebo and heparin, no significant threshold changes, except subcutis thresholds which increased slightly (P < 0.02); in diclofenac and diclofenac+heparin, significant increase in all thresholds (0.0001 < P < 0.04). Electrical muscle pain thresholds increased significantly more in diclofenac+heparin than in diclofenac, heparin, and placebo (0.0001 < P < 0.04). In all groups: no edema and thickness changes at ultrasounds in muscle and subcutis.

CONCLUSIONS

Topical diclofenac+heparin is significantly more effective than diclofenac alone in reducing muscle hyperalgesia in subjects without spontaneous pain, independently of the anti-edematous action of heparin. The results provide a rationale for the use of diclofenac+heparin also in algogenic conditions without evident signs of injury/edema/hematoma.

Diclofenac epolamine medicated plaster in the treatment of minor soft tissue injuries: a multicenter randomized controlled trial

OBJECTIVE

To investigate the efficacy and safety of a topical plaster containing diclofenac epolamine (DHEP) 1.3% in the treatment of patients with acute minor soft tissue injuries in China.

RESEARCH DESIGN AND METHODS

This prospective, randomized, double blind, placebo-controlled study had balanced random assignment to DHEP medicated plaster and placebo plaster. A total of 384 patients, aged 18-74 years, with minor soft tissue injury occurring within 72 hours of study entry were enrolled and randomized. Plasters were applied twice daily for seven consecutive days. Outcomes were assessed in three visits over 7 days, in addition to patients' daily self-assessment and an adverse events follow-up visit on day 21.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was the mean change from baseline in pain on movement on a 100 mm Visual Analogue Scale (VAS) after 7 days of treatment. Secondary efficacy endpoints included pain on movement day-by-day evaluation, summed pain intensity difference, overall treatment efficacy, rescue medication consumption, and treatment tolerability.

RESULTS

Reduction in pain on movement after 7 days of treatment, the primary efficacy endpoint, was statistically significantly greater in the DHEP plaster group than with placebo (reduction in VAS pain scores -53.78 ± 16.96 vs -37.02 ± 18.30 for DHEP vs placebo, p < 0.0001). The greater analgesic effect of DHEP plaster was evident by day 1 and increased progressively throughout the treatment period. Global pain relief and overall treatment efficacy were significantly better with DHEP. Both DHEP and placebo plaster were well tolerated with few adverse events, mostly application site reactions.

CONCLUSIONS

A medicated plaster containing DHEP applied to the affected site in Chinese patients with minor soft tissue injury, such as sprains, strains and contusions, was significantly more effective than placebo at reducing pain scores. Onset of action was rapid and the DHEP plaster was safe and well tolerated. The main limitation was the use of a subjective, though validated, self-reported VAS to assess the primary endpoint.

Skin permeability and pharmacokinetics of diclofenac epolamine administered by dermal patch in Yorkshire-Landrace pigs

Purpose

This study compared the pharmacokinetic profile, and systemic and local absorption of diclofenac, following dermal patch application and oral administration in Yorkshire-Landrace pigs.

Patients and methods

Twelve anesthetized, female, Yorkshire-Landrace pigs were randomized to receive either the dermal patch (FLECTOR^® patch, 10 × 14 cm; Alpharma Pharmaceuticals, a subsidiary of Pfizer Inc, New York, NY) or 50 mg oral diclofenac (Voltaren^®; Novartis, East Hanover, NJ). Tissue (skin area of 2 × 2 cm and underlying muscles approximately 2–3 cm in depth) and blood (10 mL) samples were collected at timed intervals up to 11.5 hours after initial patch application or oral administration. The concentrations of diclofenac in plasma, skin, and muscle samples were analyzed using validated ultra performance liquid chromatography tandem mass spectrometric methods.

Results

Peak systemic exposure of diclofenac was very low by dermal application compared with oral administration (maximum concentration [C_max] values of 3.5 vs 9640 ng/mL, respectively). Absorption of diclofenac into underlying muscles beneath the dermal patch was sustained, and followed apparently zero-order kinetics, with the skin serving as a depot with elevated concentrations of diclofenac. Concentrations of diclofenac in muscles beneath the patch application site were similar to corresponding tissues after oral administration (C_max values of 879 and 1160 ng/mL, respectively). In contrast to the wide tissue distribution of diclofenac after oral administration, dermal patch application resulted in high concentrations of diclofenac only on the treated skin and immediate tissue underneath the patch. Low concentrations of diclofenac were observed in the skin and muscles collected from untreated areas contralateral to the site of dermal patch application.

Conclusion

Dermal patch application resulted in low systemic absorption and high tissue penetration of diclofenac compared with oral administration.

Role of ATP-sensitive K+ channels in the antinociception induced by non-steroidal anti-inflammatory drugs in streptozotocin-diabetic and non-diabetic rats

There is evidence that systemic sulfonylureas block diclofenac-induced antinociception in normal rat, suggesting that diclofenac activates ATP-sensitive K(+) channels. However, there is no evidence for the systemic interaction between different non-steroidal anti-inflammatory drugs (NSAIDs) and sulfonylureas in streptozotocin (STZ)-diabetic rats. Therefore, this work was undertaken to determine whether two sulfonylureas, glibenclamide and glipizide, have any effect on the systemic antinociception that is induced by diclofenac (30 mg/kg), lumiracoxib (56 mg/kg), meloxicam (30 mg/kg), metamizol (56 mg/kg) and indomethacin (30 mg/kg) using the non-diabetic and STZ-diabetic rat formalin test. Systemic injections of NSAIDs produced dose-dependent antinociception during the second phase of the test in both non-diabetic and STZ-diabetic rats. Systemic pretreatment with glibenclamide (10 mg/kg) and glipizide (10 mg/kg) blocked diclofenac-induced systemic antinociception in the second phase of the test (P<0.05) in both non-diabetic and STZ-diabetic rats. In contrast, pretreatment with glibenclamide or glipizide did not block lumiracoxib-, meloxicam-, metamizol-, and indomethacin-induced systemic antinociception (P>0.05) in both groups. Results showed that systemic NSAIDs are able to produce antinociception in STZ-diabetic rats. Likewise, data suggest that diclofenac, but not other NSAIDs, activated K(+) channels to induce its systemic antinociceptive effect in the non-diabetic and STZ-diabetic rat formalin test.

Formulation and evaluation of mefenamic acid emulgel for topical delivery

Emulgels have emerged as a promising drug delivery system for the delivery of hydrophobic drugs. The objective of the study was to prepare emulgel of mefenamic acid, a NSAID, using Carbapol 940 as a gelling agent. Mentha oil and clove oil were used as penetration enhancers. The emulsion was prepared and it was incorporated in gel base. The formulations were evaluated for rheological studies, spreading coefficient studies, bioadhesion strength, skin irritation studies, in vitro release, ex vivo release studies, anti-inflammatory activity and analgesic activity. Formulation F2 and F4 showed comparable analgesic and anti-inflammatory activity when they compared with marketed diclofenac sodium gel. So, it can be concluded that topical emulgel of mefenamic acid posses an effective anti-inflammatory and analgesic activity.