Topical agents for the management of musculoskeletal pain

Lidocaine patch for treatment of acute localized pain in the emergency department: a systematic review and meta-analysis

Lidocaine patches are commonly prescribed for acute localized pain. Most of the existing evidence is, however, derived from postoperative or chronic pain. The objective of this study is to assess the efficacy and safety of lidocaine patch compared to placebo patch or nonsteroidal anti-inflammatory drugs (NSAIDs) for acute localized pain. This was a systematic review and meta-analysis of trials randomizing patients with acute localized pain to lidocaine patch versus placebo patch or NSAIDs. The outcomes were change in pain score (any validated scale) from baseline to a specific time endpoint (primary efficacy); adverse events (primary harm), and time to exit the study due to reaching a pain relief target (secondary). We used Cochrane revised tool to assess the risk of bias and GRADE to rate the quality of evidence. The meta-analysis was performed using a random-effects model and Cochrane Q test for heterogeneity. Data were summarized as risk ratios and weighted mean differences with 95% confidence interval (CI). We conducted a comprehensive search of MEDLINE, EMBASE, and other major databases, identifying 10 randomized controlled trials with a total of 523 patients. These trials collectively found that lidocaine patches were more effective in controlling both musculoskeletal and neuropathic pain compared to placebo patches. Due to heterogeneity among the studies, we did not pool the efficacy data. The risk of adverse events was similar between the groups (risk ratio: 0.90; 95% CI: 0.48-1.67; moderate-quality evidence). In the two trials comparing lidocaine patches with NSAIDs, there was no statistically significant difference in pain relief between the treatments. Low to moderate-quality evidence from small trials supports the efficacy and safety of lidocaine patch for the treatment of acute localized pain.

Expert Consensus on Ion Channel Drugs for Chronic Pain Treatment in China

Ion channel drugs have been increasing used for chronic pain management with progress in the development of selective calcium channel modulators. Although ion channel drugs have been proven safe and effective in clinical practice, uncertainty remains regarding its use to treat chronic pain. To standardize the clinical practice of ion channel drug for the treatment of chronic pain, the National Health Commission Capacity Building and Continuing Education Center for Pain Diagnosis and Treatment Special Ability Training Project established an expert group to form an expert consensus on the use of ion channel drugs for the treatment of chronic pain after repeated discussions on existing medical evidence combined with the well clinical experience of experts. The consensus provided information on the mechanism of action of ion channel drugs and their recommendations, caution use, contraindications, and precautions for their use in special populations to support doctors in their clinical decision-making.

Development of a pain self-management intervention framework for people with spinal cord injury

BACKGROUND

 Pain is the most common reason for medical visits to primary health care practitioners. Pain self-management interventions are encouraged and there is no known self-management intervention framework available that clinicians and people with spinal cord injury (PWSCI) can use to guide treatment selection.

AIM

 This study aimed to develop a pain self-management intervention framework for PWSCI.

SETTING

 Online and facilitated in Gauteng, South Africa.

METHODS

 A three-round modified e-Delphi method was used to reach an 80% consensus among a 21-expert panel. Fifty-nine interventions were distributed via REDCap and a final online audio meeting was held to either include or exclude interventions in the final framework. SPSS v27 was used to analyse descriptive data and content analysis was used for qualitative responses.

RESULTS

 The final developed pain self-management framework consists of 56 interventions and includes interventions from multiple health professions to encompass medical, psychological, therapeutic and social interventions. Interventions are also specified for nociceptive and/or neuropathic pain and grouped according to the biopsychosocial model.

CONCLUSION

 The interprofessional framework may be used as a guideline for PWSCI to alleviate pain, as well as assist health professionals in clinical decision-making, by providing them with the freedom to choose acceptable and adequate interventions that may be appropriate to treat the affected individual's pain.Contribution: Pain management is a basic need at the primary healthcare level and PWSCI need access to the broad range of interventions available to manage their pain. The framework highlights the variety of appropriate interventions to guide both health professionals and PWSCI with pain relief options.

Application of hot medicated fomentation for pain alleviation in non-specific low back pain - A randomized controlled clinical trial

BACKGROUND

Non-specific low back pain is a leading contributor to disease burden and works absenteeism worldwide with a lifetime prevalence of 60-70% in industrialized countries. This clinical study aimed to assess the efficacy of hot fomentation with half-baked medicated bread (khubz) compared to hot water bag fomentation to alleviate pain and disability in non-specific low back pain.

METHODS

In this randomized-controlled study, fifty-four patients with low back pain were randomly assigned into two groups to receive either hot fomentation (Takmīd-e-haar) with half-baked medicated bread in the test group or hot water bag fomentation in the control group, on the lumbosacral region daily for 30 min for 15 consecutive days. Patients were assessed statistically using the visual analogue scale (VAS) and Oswestry disability index (ODI) at baseline, 7th and after treatment (15th day).

RESULTS

After the intervention, statistically significant improvements (p < 0.001) were observed in VAS and ODI scores in both the groups on the intragroup comparison. The test treatment showed better efficacy in comparison to the control treatment with a mean difference of 1.75 in VAS (p < 0.0001) and 8.20 in ODI (p = 0.001).

CONCLUSION

The tested intervention showed significantly better efficacy in comparison to the hot water bag fomentation probably due to the analgesic (musakkin-i-alam), anti-inflammatory (muḥallil-i-awrām), and demulcent (mulaṭṭif) properties of the ingredients of tested Unani formulation in addition to the effects of heat. It may therefore be concluded that medicated fomentation is an effective, safer, feasible, and less expensive regimen for patients with non-specific low back pain.

TRIAL REGISTRATION

The Clinical Trials Registry-India (CTRI/2020/03/024107).

Localized, on-demand, sustained drug delivery from biopolymer-based materials

INTRODUCTION

Local drug delivery facilitiates higher concentrations of drug molecules at or near the treatment site to enhance treatment efficiency and reduce drug toxicity and other systemic side effects. However, local drug delivery systems face challenges in terms of encapsulation, delivery, and controlled release of therapeutics.

AREAS COVERED

We provide an overview of naturally derived biopolymer-based drug delivery systems for localized, sustained, and on-demand treatment. We introduce the advantages and limitations of these systems for drug encapsulation, delivery, and local release, as well as recent applications.

EXPERT OPINION

Naturally derived biopolymers like cellulose, silk fibroin, chitosan, alginate, hyaluronic acid, and gelatin are good candidates for localized drug delivery because they are readily chemically modified, biocompatible, biodegradable (with the generation of metabolically compatible degradation products), and can be processed in aqueous and ambient environments to maintain the bioactivity of various therapeutics. The tradeoff between the effective treatment dosage and the response by local healthy tissue should be balanced during the design of these delivery systems. Future directions will be focused on strategies to design tunable and controlled biodegradation rates, as well as to explore commercial utility in substituting biopolymer-based systems for currently utilized synthetic polymers for implants for drug delivery.

From Chemical Burn to Below Knee Amputation: Amputation Secondary to Application of Over-the-Counter Topical Analgesic With Menthol and Methyl Salicylate

Topical analgesics and topical rubefacients are widely used to control acute as well as chronic pain every day. Due to their availability without a prescription, consumers often overlook any potentially harmful effects and consider them largely benign. Here, we present a rare case of chemical burn triggered by a typical over-the-counter (OTC) analgesic containing menthol and methyl salicylate resulting in chemical burn, complicated by necrotizing infection treated by below the knee amputation.

Evaluation of antipsoriatic activity of gel containing Pongamia pinnata extract on Imiquimod-induced psoriasis

Background

Pongamia pinnata (Fabaceae) is among those categories of plants mentioned in Ayurveda and traditionally known to use in several types of disease and disorders. The objective of the present work was to investigate the anti-psoriatic activity of Pongamia pinnata leaves extracts in Herbal gel formulation.

Results

Hydroalcoholic leaves extract of Pongamia pinnata was first subjected to phytochemical screening and quantification of phytoconstituents. Herbal gel was prepared containing Pongamia pinnata extracts using Carbopol 934 as gelling agent. The prepared gel formulations were studied for pH, viscosity, Spreadability and in vitro diffusion studies. The imiquimod-induced psoriatic mouse model, showed a prominent anti-psoriatic activity of the extract as evident through index grading. Treatment with extract confirmed a noteworthy reduction in psoriasis in the treated groups as there was a considerable diminution in the thickness and scaling of skin.

Conclusions

Lack of proper treatment and disadvantages associated with allopathic medicines pave the way to extensive research in natural products with anti-psoriatic activity. The present research scientifically justified the anti-psoriatic activity of the Hydroalcoholic extracts of Pongamia pinnata leaves.

The possibilities of using topical nonsteroidal anti-inflammatory drugs in the complex pain syndrome therapy of musculoskeletal system diseases

Diseases of the peripheral joints (osteoarthritis OA) and the spine are the most common pathology among other chronic conditions. One of the most common diseases characterized by degenerative periarticular changes with various clinical manifestations is periarthritis. Unlike OA, periarthritis is characterized by a discrepancy between active and passive movements, increased pain during strictly defined movements, the absence of joint swelling or local swelling in the projection of the affected tendon. As the basic therapy of OA (step 1), it is recommended to prescribe locally nonsteroidal anti-inflammatory drugs (NSAIDs), as drugs with less systemic adverse effects. Local NSAIDs have a sufficient analgesic effect in knee joints OA. Among topical NSAIDs for reducing pain in knee joints OA and periarticular tissues, diclofenac gel (Voltaren Emulgel 2%) is approved for use, the effectiveness of which has been demonstrated in many studies. To achieve maximum effect, the gel is applied according to the instructions for use of the drug: 2 ml on the anterior, posterior and lateral surfaces of the knee 2 times a day (every 12 hours) for 4 weeks.

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.

Polymeric Gels and Their Application in the Treatment of Psoriasis Vulgaris: A Review

Psoriasis is a chronic skin disease, and it is especially characterized by the occurrence of red, itchy, and scaly eruptions on the skin. The quality of life of patients with psoriasis is decreased because this disease remains incurable, despite the rapid progress of therapeutic methods and the introduction of many innovative antipsoriatic drugs. Moreover, many patients with psoriasis are dissatisfied with their current treatment methods and the form with which the drug is applied. The patients complain about skin irritation, clothing stains, unpleasant smell, or excessive viscosity of the preparation. The causes of these issues should be linked with little effectiveness of the therapy caused by low permeation of the drug into the skin, as well as patients’ disobeying doctors’ recommendations, e.g., concerning regular application of the preparation. Both of these factors are closely related to the physicochemical form of the preparation and its rheological and mechanical properties. To improve the quality of patients’ lives, it is important to gain knowledge about the specific form of the drug and its effect on the safety and efficacy of a therapy as well as the patients’ comfort during application. Therefore, we present a literature review and a detailed analysis of the composition, rheological properties, and mechanical properties of polymeric gels as an alternative to viscous and greasy ointments. We discuss the following polymeric gels: hydrogels, oleogels, emulgels, and bigels. In our opinion, they have many characteristics (i.e., safety, effectiveness, desired durability, acceptance by patients), which can contribute to the development of an effective and, at the same time comfortable, method of local treatment of psoriasis for patients.

Comprehensive Review of Topical Analgesics for Chronic Pain

PURPOSE OF REVIEW

Topical analgesics are a non-opioid option for the treatment of chronic pain conditions including neuropathic pain, musculoskeletal pain, and osteoarthritis. There are many topical medications available; however their efficacy is variable. This article reviews the various topical analgesics, their mechanisms of action, and their efficacy.

RECENT FINDINGS

Studies have found topical NSAIDs are useful in treating acute musculoskeletal pain syndromes (strains and sprains) and show some efficacy in treating hand and knee osteoarthritis (Derry et al. Cochrane Database Syst Rev 5:CD008609, 2017). Topical capsaicin 8% has been shown to be efficacious in the treatment of postherpetic neuralgia, painful diabetic peripheral neuropathy, and HIV-neuropathy (Derry et al. Cochrane Database Syst Rev 1:CD007393, 2017). Topical lidocaine has been widely studied and found to reduce pain in patients with postherpetic neuralgia (Knezevic et al. Pain Manag 7:537-58, 2017). Although many other topical analgesics are available, there is limited data to support the efficacy of other agents. Topical analgesics are a relatively benign treatment for chronic pain conditions including neuropathic pain, musculoskeletal, and myofascial pain. There is evidence to support the use of topical NSAIDs, high concentration topical capsaicin, and topical lidocaine for various painful conditions.

[Effectiveness of Topical NSAIDs in a Gastric Cancer Patient with Bone Metastasis Pain during Therapy with Opioids and Oral NSAIDs]

Cancer patients often suffer from severe pain related to bone metastasis. We encountered a patient in whom the addition of topical non-steroidal anti-inflammatory drugs (NSAIDs) for persistent pain related to bone metastasis during therapy with opioids and oral NSAIDs reduced pain, improving activities of daily living (ADL). Fentanyl patches, celecoxib, denosumab, and topical NSAIDs (loxoprofen tape, felbinac) were administered to a 72-year-old patient with gastric cancer and pain related to bone metastasis. Pain control was favorable, with a numerical rating scale (NRS) score of 2 and Japanese version Support Team Assessment Schedule (STAS-J) score of 1. Intervention by pharmacists for the use of topical NSAIDs decreased both the NRS and STAS-J scores to zero, improving ADL. The results suggest that topical NSAIDs relieve bone-metastasis-related pain, improving ADL. When bone-metastasis-related pain is localized, the prescription of topical NSAIDs should be considered, and positive intervention by pharmacists regarding their usage should be promoted.

Topical agents: a thoughtful choice for multimodal analgesia

For over a thousand years, various substances have been applied to the skin to treat pain. Some of these substances have active ingredients that we still use today. However, some have been discontinued due to their harmful effect, while others have been long forgotten. Recent concerns regarding the cardiovascular and renal risk from nonsteroidal anti-inflammatory drugs, and issues with opioids, have resulted in increasing demand and attention to non-systemic topical alternatives. There is increasing evidence of the efficacy and safety of topical agents in pain control. Topical analgesics are great alternatives for pain management and are an essential part of multimodal analgesia. This review aims to describe essential aspects of topical drugs that physicians should consider in their practice as part of multimodal analgesia. This review describes the mechanism of popular topical analgesics and also introduces the most recently released and experimental topical medications.

Development and Antimicrobial Evaluation of Eruca Sativa Oil Nanoemulgel with Determination of the Oil Antioxidant, Sun Protection Factor and Elastase Inhibition

OBJECTIVES

This project aims to develop a bio-natural nano-product with Cosmeceutical and pharmaceutical applications.

METHODS

E. sativa oil was evaluated for its anti-oxidant, sun protection factor and elastase inhibition. Then, nanoemulgel formulations were prepared for E. sativa oil through the combination of nanoemulsion with hydrogel. E. sativa nanoemulsion formulations were prepared by the help of a selfemulsification technique. After this, the optimum formulation was mixed with Carbopol to produce the nanoemulgel. Anti-bacterial and anti-fungal activities were evaluated.

RESULTS

Nanoemulsion occurred when the size of the droplets was 195.29 nm with the lowest polydispersibility index 0.207. The results of antioxidant, anti-elastase and SPF activities for E. sativa oil were 2.10 µg/ml, 25.1 µg/ml and an SPF value of 5.57, respectively. In addition, in the anti-bacterial test for Staphylococcus aureus, it was found that nanoemulgel has an inhibition zone of 2.1 cm in diameter. According to the MRSA, the inhibition zone was 1.5 cm.

CONCLUSION

E. Sativa oil could be a promising candidate in cosmeceutical and pharmaceutical preparations.

Efficacy of a topical gabapentin gel in a cisplatin paradigm of chemotherapy-induced peripheral neuropathy

BACKGROUND

Chemotherapy induced peripheral neuropathy (CIPN) has been attributed to chemotherapeutic agents such as cisplatin which adversely affect disease outcome leading to increased cancer related morbidity. The clinical efficacy of systemic gabapentin in neuropathic pain management is limited by central side-effects in addition to a scarceness of conclusive evidence of its efficacy in CIPN management. The topical route therefore may provide a relatively safe alternative for neuropathic pain treatment in general and CIPN in particular.

METHODS

Cisplatin induced neuropathic nociception was established in rats after a single weekly cisplatin injection (3.0 mg/kg, intraperitoneally) for 4 weeks. The evoked neuropathic sensation of allodynia was assessed by plantar application of von Frey monofilaments as the paw withdrawal threshold (PWT), whereas the expression of heat-hypoalgesia was determined on a hot-plate as paw withdrawal latency (PWL). Gabapentin gel (10% w/w) was applied three-times daily on the hind paws while in a concurrent systemic study, gabapentin was administered daily (75 mg/kg, intraperitoneally) for 4 weeks. To assess any evidence of neurological adverse symptoms of cisplatin and the central side-effect propensity of systemic or topical gabapentin, evaluation of motor coordination (rotarod test) and gait (footprint analysis) were performed.

RESULTS

Cisplatin invoked a progressive development of neuropathic hind paw allodynia (decreased PWT, days 7-28) and heat hypoalgesia (increased PWL, days 21-28). Topical gabapentin significantly delayed the expression of both allodynia on protocol days 21 and 28 and heat-hypoalgesia (day 28). Systemic gabapentin displayed a comparative anti-neuropathic predisposition through a sustained suppression of tactile allodynia on days 14 and 21-28 as well as thermal hypoalgesia (days 21 and 28). Systemic gabapentin also impaired motor coordination and gait thus affirming its clinically documented central side effects, but these outcomes were not evident after topical treatment.

CONCLUSIONS

Both topical and systemic gabapentin exhibit a propensity to attenuate CIPN in a cisplatin paradigm. Gabapentin applied topically may therefore provide an adjunctive or alternative route for CIPN management upon cessation of systemic medications due to intolerable side-effects.

[Pain therapy for children and adolescents with hemophilia : Recommendations by an expert panel]

BACKGROUND

Children and adolescents with severe hemophilia commonly suffer from acute and chronic pain as a consequence of hemophilia-related bleeding. Intervention-related pain also plays a major role. Despite its high prevalence in this patient group, hemophilia-related pain is not always adequately addressed and sufficiently treated.

OBJECTIVES

This paper discusses how to improve pain management for children and adolescents (0-18 years) with hemophilia and which specific features in this population should influence decisions in pain management.

MATERIALS AND METHODS

An expert panel discussed challenges in pain treatment in children and adolescents with hemophilia. Recommendations are based on evidence and clinical experience.

RESULT

Pain management in children with hemophilia needs improvement. Children with hemophilia are at risk of developing chronic pain and of suffering traumatization due to insufficient pain management. Pain therapy can be challenging in these children as both their age and the underlying disease limit the options in particular in pain medication. The expert panel developed recommendations to improve pain management in children with hemophilia.

Formulation Development and Evaluation of Diphenhydramine Nasal Nano-Emulgel

The aim of present study is to formulate diphenhydramine nasal nano-emulgels, having lipophilic nano-sized interior droplets, with better penetration for targeted controlled delivery to mucous membrane. Different diphenhydramine (DPH) nasal nano-emulgels were developed having propylene glycol and olive oil (as permeation enhancers) by using RSM for optimization and then evaluated for physico-chemical characteristics and thermal stability. In-vitro drug release through cellophane membrane was conducted and results were analyzed statistically. Further, gelation, mucoadhesive stress, and ex-vivo and histopathological studies were performed on optimized formulation by using goat nasal membrane. Among all formulations, E2 showed maximum DPH release at higher concentration olive oil (4%) and lower concentration propylene glycol (PG) (25%) within 4 h. All formulations have followed first-order kinetics and drug release mechanism was Fickian diffusion. Analysis of variance (ANOVA) and multiple linear regression analysis (MLRA) were used to compare results among formulations and 3D surface plots were constructed also. Optimized formulation showed immediate prolong gelation in artificial nasal mucosa and excellent mucoadhesive property (72.5 ± 1.5 dynes/cm²). Approximately 97.1% optimized formulation was permeated through membrane within 4 h, having a high flux rate (33.19 ± 0.897 μg/cm²/min) with diffusion coefficient (0.000786 ± 4.56 × 10^-5 cm²/min) while drug contents remained on mucosal membrane for 24 h. Histopathologically, change on intra-mucosal surface of excised membrane was observed due to passage of drug through it. In summary, combination of PG and olive oil in nasal DPH nano-emulgel can be utilized successfully for targeted controlled delivery. The optimized formulation has excellent permeability and prolonged residence time on mucosal surface, which prove its good anti-histaminic activity in case of allergic rhinitis.

Management of chronic neuropathic pain with single and compounded topical analgesics

The goal of our review was to emphasize important aspects that physicians should take into consideration when prescribing topical analgesics as part of chronic neuropathic pain treatment. We discuss the dermatopharmacokinetics and microstructural components of the skin, differences between topical and transdermal drug delivery, and topical medication effects on peripheral neuropathy and central sensitization. Even though the US FDA approved topical analgesics are 8%-capsaicin and 5%-lidocaine patches for treating postherpetic neuralgia, there are many other studies conducted on the efficacy of topical ketamine cream, clonidine gel, topical gabapentin, topical baclofen and topical phenytoin for peripheral neuropathic pain, either alone or in combination with other formulations. Furthermore, we discuss new compounded topical analgesics that are becoming more popular and that are showing promising results in the management of chronic peripheral neuropathies. However, more studies are needed for elucidation of the role of topical analgesics and their effects, especially when combined with other treatments.

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.

Skin penetration and tissue permeation after topical administration of diclofenac

OBJECTIVE

Topical delivery of drugs is an alternative to oral administration, often with similar efficacy but potentially a more favorable tolerability profile. However, topical formulations need to be able to penetrate the skin and permeate to the target areas in quantities sufficient to exert a therapeutic effect. Many factors can affect this process, including the physicochemical properties of the drug, the formulation used, and the site and mode of application. It is believed that measurement of drug concentrations at the sites of action may be an indicator of their likely efficacy. This review addresses these issues, with reference to topically administered diclofenac in osteoarthritis.

METHODS

Articles relevant to this review were identified after a systematic search of Medline and Embase, using the key words "diclofenac", "topical administration" and "osteoarthritis" in the search strategy.

RESULTS

The sparse data available indicate that topical diclofenac can penetrate and permeate to deeper tissues, with a lower plasma to tissue ratio than oral diclofenac. The tissue diclofenac levels after topical delivery are sustained over time (at least several hours). However, there is not enough data to establish how diclofenac levels in the joint compare with IC₅₀ levels (50% of the maximum inhibition of prostaglandin synthesis) established following oral administration.

CONCLUSIONS

After topical application, diclofenac can penetrate the skin and permeate to deeper tissues, where it reaches a concentration that appears to be sufficient to exert a therapeutic effect. More robust methods are required for in vivo characterization to better estimate the clinical efficacy of topically applied drugs.

Pharmacologic Therapies in Musculoskeletal Conditions

Musculoskeletal conditions are common, and there are many options for pharmacologic therapy. Unfortunately, there is not strong evidence for the use of many of these medications. Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) are generally first-line medications for most musculoskeletal pain, but there is more evidence these medications are not as safe as once thought. Other analgesic and antispasmodic medications can be effective for acute pain but generally are not as effective for chronic pain. Antidepressants and anticonvulsants can be more effective for chronic or neuropathic pain. Topical formulations of NSAIDs can be effective for pain with fewer side effects.

A highly sensitive LC-MS/MS method for determination of ketoconazole in human plasma: Application to a clinical study of the exposure to ketoconazole in patients after topical administration

A simple, rapid and highly sensitive LC-MS/MS method was developed and validated for the determination of ketoconazole in human plasma. Sample preparation was accomplished through a single step liquid-liquid extraction by ethyl acetate. The chromatography separation was carried out on a Hedera CN (150mm×2.1mm, 5μm) column with isocratic elution using acetonitrile and 10mM ammonium acetate containing 0.1% formic acid (45:55, v/v) as the mobile phase. The flow rate was 0.5mL/min. Detection was performed in the positive ion electrospray ionization mode using multiple reaction monitoring of the transitions of 531.2→489.3 and 286.1→217.1 for ketoconazole and letrozole (the internal standard), respectively. The method exhibited good linearity over the concentration range of 0.01-12ng/mL for ketoconazole. The intra- and inter-batch precision and accuracy of ketoconazole were all within the acceptable criteria. The method was successfully applied to a clinical study of the exposure to ketoconazole in Chinese seborrheic dermatitis patients after topical administration of two ketoconazole formulations of foam and lotion, respectively. The study results showed that there was little systemic absorption of ketoconazole in patients for the two formulations, and the ketoconazole foam and lotion are safe therapeutic drugs for seborrheic dermatitis patients.

Skin sample preparation by collagenase digestion for diclofenac quantification using LC-MS/MS after topical application

BACKGROUND

Skin is the target site to evaluate the pharmacokinetic parameters of topical applications. Sample preparation is one of the influential steps in the bioanalysis of drugs in the skin. Evaluation of dermatopharmacokinetics at preclinical stage is challenging due to lack of proper sample preparation method. There is a need for an efficient sample preparation procedure for quantification of drugs in the skin using LC-MS/MS.

RESULTS

The skin samples treated with collagenase followed by homogenization using a bead beater represents a best-fit method resulting in uniform homogenate for reproducible results.

CONCLUSION

A new approach involving enzymatic treatment and mechanical homogenization techniques were evaluated for efficient sample preparation of skin samples in the bioanalysis.

Evaluation of the Percutaneous Absorption of Ketamine HCl, Gabapentin, Clonidine HCl, and Baclofen, in Compounded Transdermal Pain Formulations, Using the Franz Finite Dose Model

Objective. This study evaluates the ability of four commonly used analgesics (ketamine HCl, gabapentin, clonidine HCl, and baclofen), when incorporated into two transdermal compounding bases, Lipoderm and Lipoderm ActiveMax, to penetrate human cadaver trunk skin in vitro , using the Franz finite dose model.

Design. In vitro experimental study .

Methods. Ketamine HCl 5% w/w, gabapentin 10% w/w, clonidine HCl 0.2% w/w, and baclofen 2% w/w were compounded into two transdermal bases, Lipoderm and Lipoderm ActiveMax. Each compounded drug formulation was tested on skin from three different donors and three replicate skin sections per donor. The Franz finite dose model was used in this study to evaluate the percutaneous absorption and distribution of drugs within each formulation.

Results. Rapid penetration to peak flux was detected for gabapentin and baclofen at approximately 1 hour after application. Clonidine HCl also had a rapid penetration to peak flux occurring approximately 1 hour after application and had a secondary peak at approximately 40 hours. Ketamine HCl exhibited higher overall absorption rates than the other drugs, and peaked at 6–10 hours. Similar patterns of drug distribution within the skin were also observed using both transdermal bases.

Conclusions. This study suggests that the combination of these 4 analgesic drugs can be successfully delivered transdermally, using either Lipoderm or Lipoderm ActiveMax. Compounded transdermal drug preparations may then provide physicians with an alternative to traditional oral pain management regimens that can be personalized to the specific patient with the potential for enhanced pain control.

Skin Matters: A Review of Topical Treatments for Chronic Pain. Part Two: Treatments and Applications

In Part One of this two-part series, we discussed skin physiology and anatomy as well as generalities concerning topical analgesics. This modality of therapy has lesser side effects and drug-drug interactions, and patients tolerate this form of therapy better than many oral options. Unfortunately, this modality is not used as often as it could be in chronic pain states, such as that from neuropathic pain. Part Two discusses specific therapies, local anesthetics, and other drugs, as well as how a clinician might use specific aspects of a patient's neuropathic pain presentation to help guide them in the selection of a topical agent.

Alternative methods of pain management for the older adult population: Review of topical pain medications

The older adult population is one of the fastest growing age groups in the United States. As this population continues to expand, determining the safest way to provide pain management has become increasingly important. More than 50% of community-dwelling older adults experience pain on a daily basis, and up to 83% of those in assisted living facilities experience persistent pain. Pain is exceedingly challenging to treat safely and effectively in the elderly because of the physiologic changes that occur as people age. In addition, many nonnarcotic medications with analgesic properties are listed in both the 2012 American Geriatrics Society Beers Criteria for Potentially Inappropriate Medication Use in Older Adults and the Pharmacy Quality Alliance high-risk medications lists. An approach to the growing challenge of managing pain in the elderly that is gaining popularity among community-dwelling patients is the use of topical pain medications. The goal of this article is to review some of the available literature regarding the use of various topical analgesics alone or in combination, and to discuss their known or theoretical mechanisms of peripheral pain modulation. Commercially available or compounded topical pain medications may be used to replace or augment doses of oral medications in an effort to decrease the risk of adverse drug events for older adult patients. When prescribing topical pain medications physicians should consider the nature of the pain targeted, the type of analgesia expected from each ingredient, the potential for systemic absorption, and related side effects.

Development and characterization of sorbitan monostearate and sesame oil-based organogels for topical delivery of antimicrobials

The current study explains the development of sorbitan monostearate and sesame oil-based organogels for topical drug delivery. The organogels were prepared by dissolving sorbitan monostearate in sesame oil (70°C). Metronidazole was used as a model antimicrobial. The formulations were characterized using phase contrast microscopy, infrared spectroscopy, viscosity, mechanical test, and differential scanning calorimetry. Phase contrast microscopy showed the presence of needle-shaped crystals in the organogel matrix. The length of the crystals increased with the increase in the sorbitan monostearate concentration. XRD studies confirmed the amorphous nature of the organogels. Viscosity study demonstrated shear thinning behavior of the organogels. The viscosity and the mechanical properties of the organogels increased linearly with the increase in the sorbitan monostearate concentration. Stress relaxation study confirmed the viscoelastic nature of the organogels. The organogels were biocompatible. Metronidazole-loaded organogels were examined for their controlled release applications. The release of the drug followed zero-order release kinetics. The drug-loaded organogels showed almost similar antimicrobial activity against Escherichia coli when compared to the commercially available Metrogyl® gel. In gist, it can be proposed that the developed organogels had sufficient properties to be used for controlled delivery of drugs.

Randomized clinical trial of peganum oil for knee osteoarthritis

Osteoarthritis affects about 50% of people aged older than 65 years. Pain is the most important symptom in this disease. Today public interest in the use of complementary medicine, especially traditional herbal medicines has increased. The present study was designed to investigate the efficacy of traditional preparation of Peganum harmala L oil on patients with knee osteoarthritis. The product has been analyzed and standardized by high-performance liquid chromatography. A double blind controlled randomized clinical trial consisting of 54 patients were performed. Patients rubbed the drug or control (olive oil) on the knee 4 drops 3 times a day for 4 weeks. The patients were asked to fill out the Western Ontario and McMaster Universities Arthritis Index and Visual Analogue Scale questionnaires at week 0 and 4. The adapted results from the questionnaires showed that pain and difficulty in function were significantly decreased in Peganum oil group after 4 weeks. There was no significant difference in stiffness change between 2 groups.

Topical NSAID formulations

OBJECTIVE

This article reviews topical nonsteroidal anti-inflammatory drug (NSAID) formulations available in the United States, including advantages and disadvantages, therapeutic usefulness, adverse effects, and formulation considerations.

RESULTS

In the United States, several topical NSAID products are approved to treat painful conditions including diclofenac sodium 1% gel (Voltaren Gel®; Endo Pharmaceuticals), diclofenac sodium topical solution 1.5% w/w in 45.5% dimethyl sulfoxide (PENNSAID®; Mallinckrodt, Inc.), and diclofenac epolamine 1.3% (Flector Patch®; Alpharma Pharmaceuticals LLC, a subsidiary of Pfizer, Inc.). Recent studies suggest topical diclofenac preparations are effective for osteoarthritis pain and suggest the efficacy of topical formulations is similar to that achieved with oral NSAID formulations. All NSAID formulations contain the same boxed warnings regarding cardiovascular and renal toxicity; however, topical NSAIDs are proposed to have a more favorable safety profile than oral NSAIDs due to the low serum concentrations achieved with topical NSAID formulations.

CONCLUSIONS

Topical NSAIDs have been shown to be beneficial from both a therapeutics and adverse effect perspective, and are increasingly recommended in treatment guidelines.

Reversal of monoarthritis-induced affective disorders by diclofenac in rats

BACKGROUND

Nonsteroidal anti-inflammatory drugs are effective for arthritic pain, but it is unknown whether they also benefit anxiety and depression that frequently coexist with pain. Using the monoarthritis model, the authors evaluated the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in structures implicated in both sensorial and emotional pain spheres, and it was verified whether analgesia can reverse monoarthritis-mediated affective responses.

METHODS

Monoarthritis was induced in male rats by complete Freund's adjuvant injection. Allodynia (ankle-bend test), mechanical hyperalgesia (paw-pinch test), anxiety- and depression-like behaviors (elevated zero maze and forced swimming tests, respectively), and ERK1/2 phosphorylation (Western blot) in the spinal cord, paragigantocellularis nucleus, locus coeruleus, and prefrontal cortex were evaluated at 4, 14, and 28 days postinoculation (n = 6 per group). Changes in these parameters were evaluated after induction of analgesia by topical diclofenac (n = 5 to 6 per group).

RESULTS

Despite the pain hypersensitivity and inflammation throughout the testing period, chronic monoarthritis (28 days) also resulted in depressive- (control [mean ± SEM]: 38.3 ± 3.7 vs. monoarthritis: 51.3 ± 2.0; P < 0.05) and anxiogenic-like behaviors (control: 36.8 ± 3.7 vs. monoarthritis: 13.2 ± 2.9; P < 0.001). These changes coincided with increased ERK1/2 activation in the spinal cord, paragigantocellularis, locus coeruleus, and prefrontal cortex (control vs. monoarthritis: 1.0 ± 0.0 vs. 5.1 ± 20.8, P < 0.001; 0.9 ± 0.0 vs. 1.9 ± 0.4, P < 0.05; 1.0 ± 0.3 vs. 2.9 ± 0.6, P < 0.01; and 1.0 ± 0.0 vs. 1.8 ± 0.1, P < 0.05, respectively). Diclofenac decreased the pain threshold of the inflamed paw and reversed the anxio-depressive state, restoring ERK1/2 activation levels in the regions analyzed.

CONCLUSION

Chronic monoarthritis induces affective disorders associated with ERK1/2 phosphorylation in paragigantocellularis, locus coeruleus, and prefrontal cortex which are reversed by diclofenac analgesia. (Anesthesiology 2014; 120:1476-90).

Recent advances in gel technologies for topical and transdermal drug delivery

Transdermal drug delivery systems are a constant source of interest because of the benefits that they afford in overcoming many drawbacks associated with other modes of drug delivery (i.e. oral, intravenous). Because of the impermeable nature of the skin, designing a suitable drug delivery vehicle that penetrates the skin barrier is challenging. Gels are semisolid formulations, which have an external solvent phase, may be hydrophobic or hydrophilic in nature, and are immobilized within the spaces of a three-dimensional network structure. Gels have a broad range of applications in food, cosmetics, biotechnology, pharmatechnology, etc. Typically, gels can be distinguished according to the nature of the liquid phase, for example, organogels (oleogels) contain an organic solvent, and hydrogels contain water. Recent studies have reported other types of gels for dermal drug application, such as proniosomal gels, emulgels, bigels and aerogels. This review aims to introduce the latest trends in transdermal drug delivery via traditional hydrogels and organogels and to provide insight into the latest gel types (proniosomal gels, emulgels, bigels and aerogels) as well as recent technologies for topical and transdermal drug delivery.

Rhododendron tomentosum (Ledum palustre). A review of traditional use based on current research

Rhododendron tomentosum Harmaja (previously: Ledum palustre) is a fragrant evergreen shrub found in peaty soils in northern Europe, Asia and North America, commonly referred to as wild rosemary, marsh tea, marsh rosemary or northern Labrador tea. At least since the eighteenth century it has been used in ethnomedicine for the treatment of various ailments, such as rheumatism, cough, cold and insect bites, as well as a repellent. The essential oil of wild rosemary with the rich polyphenolic fraction possesses analgesic, anti-inflammatory, antimicrobial, antiviral, antifungal and insecticidal potential, demonstrated by in vivo and in vitro studies. In addition, recent scientific research reported the promising antidiabetic, antioxidant and anticancer properties. This review summarizes the information concerning taxonomy, botany, ecology, chemical composition, biological activities, toxicology and traditional and contemporary application of Rhododendron tomentosum plants.

Optimization of Metronidazole Emulgel

The purpose of the present study was to develop and optimize the emulgel system for MTZ (Metronidazole), a poorly water soluble drug. The pseudoternary phase diagrams were developed for various microemulsion formulations composed of Capmul 908 P, Acconon MC8-2, and propylene glycol. The emulgel was optimized using a three-factor, two-level factorial design, the independent variables selected were Capmul 908 P, and surfactant mixture (Acconon MC8-2 and gelling agent), and the dependent variables (responses) were a cumulative amount of drug permeated across the dialysis membrane in 24 h (Y₁) and spreadability (Y₂). Mathematical equations and response surface plots were used to relate the dependent and independent variables. The regression equations were generated for responses Y₁ and Y₂. The statistical validity of the polynomials was established, and optimized formulation factors were selected. Validation of the optimization study with 3 confirmatory runs indicated a high degree of prognostic ability of response surface methodology. Emulgel system of MTZ was developed and optimized using 2³ factorial design and could provide an effective treatment against topical infections.

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.

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.

Self-management programs for chronic musculoskeletal pain conditions: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effectiveness of self-management programs on pain and disability for chronic musculoskeletal pain conditions by systematic review.

METHODS

A search of randomized controlled trials was conducted in Medline and Embase from 1970s to 2010. Two reviewers independently selected trials, conducted critical appraisal of the methodological quality, and extracted the data. Meta-analyses were performed using all time-points meta-analysis (ATM).

RESULTS

Nineteen trials met inclusion criteria. For arthritis, the findings of this study showed that self-management programs have small to moderate effects in improving pain and disability at the long-term level, but the medium-term effect for disability is not significant. For chronic back pain, there is insufficient evidence to determine the effectiveness of self-management programs.

CONCLUSION

The encouraging evidence of this study indicates that it is recommended to provide self-management programs to adult patients with arthritis. Further research is needed on self-management for chronic back pain.

PRACTICE IMPLICATIONS

Self-management is a safe, community-based and effective way for patients with arthritis to manage pain and disability. Core skills of self-management should be delivered using multiple approaches.

Gastrointestinal tolerability of diclofenac epolamine topical patch 1.3%: a pooled analysis of 14 clinical studies

OBJECTIVE

The purpose of this investigation was to evaluate the gastrointestinal (GI) tolerability profile of diclofenac epolamine topical patch 1.3% (DETP) during short-term treatment in patients with mild-to-moderate pain.

DESIGN

Fourteen clinical trials of DETP were examined; 10 placebo-controlled studies were further integrated for analyses. All adverse event (AE) data were coded to the Medical Dictionary for Regulatory Activities.

OUTCOME MEASURES

Frequency of GI AEs was summarized by treatment, preferred term, sex, and age group.

RESULTS

The percentage of patients reporting GI AEs were similar between patients treated with the DETP and placebo, with only 3 of the 10 placebo-controlled trials reporting events in >2% of patients; there was no significant difference between DETP and placebo for any preferred GI term. The most common GI AE reported for both treatment groups was nausea (1.5% DETP, 1.1% placebo). There was no significant difference between treatment groups and sex in the number of reported events and no noted difference between age groups.

CONCLUSION

This study provides evidence that DETP is a topical nonsteroidal anti-inflammatory drug that is a well-tolerated treatment option, demonstrating a low incidence of GI AEs across 14 clinical trials, making it a possible alternative to short-term oral NSAIDs, which are commonly associated with GI complications.