Transdermal and Topical Drug Administration in the Treatment of Pain

Topical and transdermal botanical formulations of the Chinese pharmacopoeia-A review

In pharmaceutics, ingredients are classified as active ingredients and excipients. In topical/transdermal phytomedicines, an ingredient may serve both functions. Published information on these dual-purpose ingredients and their pharmacological relevance is limited. An intriguing scenario arises in traditional Chinese medicine (TCM) formulations, where active ingredients and excipients are undifferentiated. This study analyzes ingredients in TCM topical/transdermal formulations, aiming at harmonization of understanding of TCMs. The most commonly recorded ingredients from such formulations in the Chinese pharmacopoeia 2020 (ChP 2020) are reviewed, aiming at developing innovative topical/transdermal phytomedicines. Current editions of Chinese historical documents were reviewed to explore the principles underlying the use of these ingredients. TCM formulations containing botanical drugs for topical/transdermal application were selected from the ChP 2020. The use of botanical materials in TCM formulations is guided by the "Jun-Chen-Zuo-Shi" principle rooted in Yin-Yang and the five elements' theories. In the ChP 2020, 155 botanical drugs, along with 40 excipients (from the "procedure" section, focusing on processing and technical parameters), were identified from 34 botanical formulations intended for topical/transdermal application. Pungent and aromatic botanical materials were the most frequently recorded. Adhesive plasters were the most commonly recorded TCM dosage form, employing specific matrix blends. This new perspective of study reveals the prevalence of pungent and aromatic botanical materials, the common use of adhesive plasters, multifunctional properties of botanical oils, and formulation adaptability in TCM topical/transdermal products. These insights should inform novel formulation designs for both pharmaceutical and phytopharmacological research.

Efficacy of topical drug application to manage in-office bleaching sensitivity: a systematic review and meta-analysis of randomized clinical trials

OBJECTIVES

To answer whether the topical drug application can reduce in-office tooth bleaching sensitivity without impairing the color change.

MATERIALS AND METHODS

This review was registered on PROSPERO (CRD42024524171). Two reviewers screened PubMed, Web of Science, Scopus, Embase, and clinicaltrials.gov in March 2024 independently for randomized clinical trials investigating the efficacy of topical drug application to manage in-office tooth bleaching sensitivity. The risk of bias was assessed using Cochrane's Risk of Bias tool (RoB2). Certainty of the evidence was assessed using the Grading of Recommendations: Assessment, Development, and Evaluation tool (GRADE). The meta-analyses evaluated the bleaching sensitivity and color change with RevMan 5.4 software.

RESULTS

334 articles were retrieved. The final sample was composed of four articles. Tested drugs were Otosporin, Eugenol, Ibuprofen with arginine, and Dipyrone. The meta-analysis evidenced no difference in bleaching sensitivity up to 1 h (MD, -0.39; 95% CI, -0.89, 0.11), 24 h (MD, -0.26, 95% CI, -0.71, 0.18), or 48 h (MD, 0.00, 95% CI, -0.16, 0.16). Meta-analysis for color change evidenced no difference for color change (MD, 0.03; 95% IC, -0.56, 0.61). The risk of bias was low. The certainty of the evidence was rated moderate for bleaching sensitivity and high for color change.

CONCLUSIONS

Although topical drug application did not impair color change, it was ineffective in reducing in-office tooth bleaching sensitivity.

CLINICAL RELEVANCE

topical drug application on dental enamel is not an effective approach in reducing bleaching sensitivity, but several modifications can be made in future studies to possibly achieve a better outcome.

Alkaloids as drug leads in Alzheimer's treatment: Mechanistic and therapeutic insights

Alzheimer's disease (AD) has few effective treatment options and continues to be a major global health concern. AD is a neurodegenerative disease that typically affects elderly people. Alkaloids have potential sources for novel drug discovery due to their diverse chemical structures and pharmacological activities. Alkaloids, natural products with heterocyclic nitrogen-containing structures, are considered potential treatments for AD. This review explores the neuroprotective properties of alkaloids in AD, focusing on their ability to regulate pathways such as amyloid-beta aggregation, oxidative stress, synaptic dysfunction, tau hyperphosphorylation, and neuroinflammation. The FDA has approved alkaloids such as acetylcholinesterase inhibitors like galantamine and rivastigmine. This article explores AD's origins, current market medications, and clinical applications of alkaloids in AD therapy. This review explores the development of alkaloid-based drugs for AD, focusing on pharmacokinetics, blood-brain barrier penetration, and potential adverse effects. Future research should focus on the clinical evaluation of promising alkaloids, developing recently discovered alkaloids, and the ongoing search for novel alkaloids for medical treatment. A pharmaceutical option containing an alkaloid may potentially slow down the progression of AD while enhancing its symptoms. This review highlights the potential of alkaloids as valuable drug leads in treating AD, providing a comprehensive understanding of their mechanisms of action and therapeutic implications.

Plasma concentrations of buprenorphine administered via matrix-type transdermal patches applied at three different anatomical locations in healthy adult horses

Background

Anatomical location-dependent differences in transdermal opioid penetration are well described in human patients. Although this has been investigated in horses with fentanyl, there is no literature available on location-dependent plasma buprenorphine concentrations when administered as a transdermal matrix-type patch.

Objective

This study aims to compare the plasma concentrations achieved from the matrix-type transdermal buprenorphine patches placed at different anatomical sites (metacarpus, gaskin, and ventral tail base) in healthy adult horses.

Study design

This is a randomized experimental study with a Latin square design.

Methods

Six adult horses were given each of three treatments with a minimum 10-day washout period. For each treatment, two 20 μg h-1 matrix-type buprenorphine patches were applied to the ventral aspect of the tail base (TailTDP), metacarpus region (MetacarpusTDP), or gaskin region (GaskinTDP). Whole blood samples (for determination of buprenorphine concentration) and physiological variables were collected before (0 h) and at 0.5, 2, 4, 6, 8, 10, 12, 16, 24, 32, 48, 56, 72, 96 and 120 h after patches were applied. The patches were removed 96 h following placement and were analyzed for residual buprenorphine content. Buprenorphine concentrations were measured in plasma by LC-MS/MS. A mixed-effects model was used to analyze the physiological variables.

Results

Between the three treatment groups, there was no change in physiological variables across timepoints as compared to baseline and when compared to each other in a single horse and between horses (p > 0.3). When comparing all three locations, the buprenorphine uptake was observed to be more consistent with respect to measurable plasma concentrations >0.1 ng ml-1 when applied to the ventral aspect of the tail base. In the TailTDP group, the mean plasma buprenorphine concentrations were >0.1 ng ml-1 from 2 to 32 h. The highest group mean was 0.25 ng ml-1 noted at 4 h.

Conclusions

The metacarpal and gaskin regions presented more erratic and inconsistent buprenorphine uptake and plasma concentrations as compared to the ventral aspect of the tail base. Further research must be directed at investigating the optimal dose, achievable duration of analgesia, change in measurable plasma concentrations, and behavioral and systemic effects.

Anti-inflammatory effects of the Thai herbal remedy Yataprasen and biflavonoids isolated from Putranjiva roxburghii in RAW264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Yataprasen is a topical Thai herbal remedy for the treatment of musculoskeletal pain and is included in Kumpe Thart Phra Narai, the first Thai textbook of traditional medicine. The herbal preparation is made from a hydroethanolic extract of a mixture of 13 medicinal plants, of which Putranjiva roxburghii Wall. leaves are the major ingredient.

AIM OF THE STUDY

In this study, we investigated the underlying mechanism of action for the anti-inflammatory effects of the Yataprasen remedy, its main ingredients, and the phytochemicals isolated from P. roxburghii leaves.

MATERIALS AND METHODS

The anti-inflammatory effects of the Yataprasen remedy, along with its main ingredients, including the leaves of Baliospermum solanifolium (Burm.) Suresh, Melia azedarach L., P. roxburghii, Senna siamea (Lam.) Irwin & Barneby, and Tamarindus indica L. were determined by measuring prostaglandin E2 (PGE2) secretion, nitric oxide (NO) production, and the synthesis of inflammatory biomarkers in lipopolysaccharide (LPS)-treated RAW264.7 macrophage cells. The active ingredients of the P. roxburghii leaves were separated by chromatography and spectroscopic measurements were used to identify their chemical structures.

RESULTS

Ethanol extracts of the Yataprasen remedy and some of its ingredients significantly suppressed LPS-induced PGE2 secretion and NO production in a dose-dependent manner. Treatment of RAW264.7 cells with ethanolic extracts of the Yataprasen remedy (50 μg/mL) significantly inhibited LPS-induced mRNA expression of TNF-α, COX-2, iNOS, and NF-κB. Among the plant ingredient extracts, P. roxburghii leaf extract exhibited the highest inhibitory effects on LPS-induced TNF-α and iNOS expression. Moreover, T. indica leaf extract showed the highest activity on the inhibition of LPS-induced COX-2 and NF-κB expression. Putraflavone, podocarpusflavone A, and amentoflavone were isolated biflavonoids from P. roxburghii leaf extract and showed the inhibitory effects on LPS-induced PGE2 secretion and NO synthesis in RAW264.7 cells. Of the isolated biflavonoids, amentoflavone exhibited the strongest anti-inflammatory activity by inhibiting the expression of TNF-α, COX-2, and iNOS.

CONCLUSION

The results support reported the anti-inflammatory effects of the Yataprasen remedy, which are associated with the downregulation of proinflammatory mediators. P. roxburghii, along with its biflavonoids, are the impact components that contribute to the anti-inflammatory effects of the herbal remedy.

Evidence of Cannabidiol Effectiveness Associated or Not with Tetrahydrocannabinol in Topical Administration: A Scope Review

Cannabis sativa is a plant of the Cannabaceae family, whose molecular composition is known for its vast pharmacological properties. Cannabinoids are the molecules responsible for Cannabis sativa potential effects, especially tetrahydrocannabinol and cannabidiol. Scientific development has shown interest in the potential of cannabidiol in various health conditions, as it has demonstrated lower adverse events and great pharmacological potential, especially when administered topically. The present study aims to carry out a scoping review, focusing on the use of cannabidiol, in vivo models, for topical administration. Thus, the methodological approach used by the Joanna Briggs Institute was applied, and the studies were selected based on previously established inclusion criteria. Even though more information regarding the dose to achieve pharmacological potential is still needed, cannabidiol demonstrated potential in treating and preventing different conditions, such as glaucoma, atopic dermatitis, epidermolysis bullosa, and pyoderma gangrenosum.

Comparaison of Efficacy and Safety of Fentanyl Transdermal Patch with Oral Ketorolac for Pain Management in Dry Socket: A Randomized Clinical Trial

Objectives

The aim of this study was to compare the efficacy and safety of transdermal Fentanyl patch with oral Ketorolac for pain management in dry socket patients.

Study design

Sixty patients who were diagnosed with dry socket (VAS > 40 mm) were recruited in this prospective randomized controlled trial. Patients were divided into two groups. Group1 (n = 30) Transdermal Fentanyl patch (25mcg/hr) was given and in Group 2 (n = 30) Ketorolac 10 mg Oral tablet was prescribed for pain management. The primary endpoint was the mean pain scores within 72 h evaluated by visual analog scale (VAS). Secondary measures included the safety and tolerability, amount of rescue medication (analgesic and antiemetic) and effectiveness of treatment interventions by Brief Pain Inventory Questionnaire (BPI).

Results

The mean VAS pain scores were significantly less in group 1 (Fentanyl) as compared to group 2 (ketorolac) on all follow-up days. Significant difference was noted in the mean amount of rescue analgesic medication. It was 2.16 + 1.53 in group 1 and 8.50 + 3.98 in group 2. Side effects were seen in both the groups. Nausea (46%) and vomiting (43%) were reported in group 1 while headache (36.6%) and epigastric pain (53.3%) in group 2.

Conclusions

Thus, transdermal Fentanyl was better in pain control than Ketorolac with less need for rescue analgesic medication in dry socket.

A review on natural biopolymers in external drug delivery systems for wound healing and atopic dermatitis

Despite the advantages of topical administration in the treatment of skin diseases, current marketed preparations face the challenge of the skin's barrier effect, leading to low therapeutic effectiveness and undesirable side effects. Hence, in recent years the management of skin wounds, the main morbidity-causing complication in hospital environments, and atopic dermatitis, the most common inflammatory skin disease, has become a great concern. Fortunately, new, more effective, and safer treatments are already under development, with chitosan, starch, silk fibroin, agarose, hyaluronic acid, alginate, collagen, and gelatin having been used for the development of nanoparticles, liposomes, niosomes and/or hydrogels to improve the delivery of several molecules for the treatment of these diseases. Biocompatibility, biodegradability, increased viscosity, controlled drug delivery, increased drug retention in the epidermis, and overall mitigation of adverse effects, contribute to an effective treatment, additionally providing intrinsic antimicrobial and wound healing properties. In this review, some of the most recent success cases of biopolymer-based drug delivery systems as part of nanocarriers, semi-solid hydrogel matrices, or both (hybrid systems), for the management of skin wounds and atopic dermatitis, are critically discussed, including composition and in vitro, ex vivo and in vivo characterization, showing the promise of these external drug delivery systems.

Update on Treating Painful Diabetic Peripheral Neuropathy: A Review of Current US Guidelines with a Focus on the Most Recently Approved Management Options

Painful diabetic peripheral neuropathy (DPN) is a highly prevalent and disabling complication of diabetes that is often misdiagnosed and undertreated. The management of painful DPN involves treating its underlying cause via lifestyle modifications and intensive glucose control, targeting its pathogenesis, and providing symptomatic pain relief, thereby improving patient function and health-related quality of life. Four pharmacologic options are currently approved by the US Food and Drug Administration (FDA) to treat painful DPN. These include three oral medications (duloxetine, pregabalin, and tapentadol extended release) and one topical agent (capsaicin 8% topical system). More recently, the FDA approved several spinal cord stimulation (SCS) devices to treat refractory painful DPN. Although not FDA-approved specifically to treat painful DPN, tricyclic antidepressants, serotonin/norepinephrine reuptake inhibitors, gabapentinoids, and sodium channel blockers are common first-line oral options in clinical practice. Other strategies may be used as part of individualized comprehensive pain management plans. This article provides an overview of the most recent US guidelines for managing painful DPN, with a focus on the two most recently approved treatment options (SCS and capsaicin 8% topical system), as well as evidence for using FDA-approved and guideline-supported drugs and devices. Also discussed are unmet needs for this patient population, and evidence for potential future treatments for painful DPN, including drugs with novel mechanisms of action, electrical stimulation devices, and nutraceuticals.

Evaluation of physical variables, thermal nociceptive threshold testing and pharmacokinetics during placement of transdermal buprenorphine matrix-type patch in healthy adult horses

Background

Matrix type transdermal buprenorphine patches have not been investigated in horses and may provide an effective means of providing continuous pain control for extended period and eliminating venous catheterization.

Objective

Assessment of the physiological variables (heart rate, respiratory rate, body temperature) and thermal nociceptive threshold testing, and describing the pharmacokinetic profile of transdermal buprenorphine matrix-type patch (20 μg h-1 and 40 μg h-1 dosing) in healthy adult horses.

Study design

Randomised experimental study with a Latin-square design.

Methods

Six adult healthy horses received each of the three treatments with a minimum 10 day washout period. BUP0 horses did not receive a patch (control). BUP20 horses received one patch (20 μg h-1) applied on the ventral aspect of the tail base resulting in a dose of 0.03-0.04 μg kg-1 h-1. BUP40 horses received two patches placed alongside each other (40 μg h-1) on the tail base resulting in a dose of 0.07-0.09 μg kg-1 h-1. Whole blood samples (for determination of buprenorphine concentration), physiological variables and thermal threshold testing were performed before (0 h) and at 2, 4, 8, 12, 16, 24, 32, 40, 48, 56, 64, 72, and 96 h after patch application. The patches were removed 72 h following placement and were analyzed for residual buprenorphine content.

Results

Between the three groups, there was no change in physiological variables across timepoints as compared to baseline (p > 0.1). With the higher dose, there was a significant increase in thermal thresholds from baseline values from 2 h until 48 h and these values were significantly higher than the group receiving the lower patch dose for multiple timepoints up to 40 h. 40 μg h-1 patch led to consistent measurable plasma concentrations starting at 2 h up to 96 h, with the mean plasma concentrations of > 0.1 ng/ml from 4 h to 40 h.

Conclusions

20 μg h-1 and 40 μg h-1 patch doses were well tolerated by all horses. At higher dose, plasma buprenorphine concentrations were more consistently measurable and blunted thermal thresholds for 48 h vs. 32 h with 20 μg h-1 dosing as compared to control.

Pharmacological Topical Therapy for Intra-Oral Post Traumatic Trigeminal Neuropathic Pain: A Comprehensive Review

Background: The efficacy of topical treatments in alleviating neuropathic pain is well-established. However, there is a paucity of research on topical interventions designed specifically for intra-oral application, where the tissue composition differs from that of exposed skin. Methods: This comprehensive review endeavors to assess the extant evidence regarding the efficacy of topical treatments in addressing neuropathic pain within the oral cavity. Utilizing combinations of search terms, we conducted a thorough search across standard electronic bibliographic databases-MEDLINE (via PubMed), Embase, Google Scholar, and Up to Date. The variables under scrutiny encompassed topical treatment, local intervention, chronic oral and orofacial pain, and neuropathic pain. All pertinent studies published in the English language between 1992 and 2022 were included in our analysis. Results: Fourteen relevant manuscripts were identified, primarily consisting of expert opinions and case reports. The comprehensive review suggests that topical treatments, especially when applied under a stent, could be effective in mitigating neuropathic pain in the oral area. However, it is crucial to conduct further studies to confirm these preliminary results. The limitations of the reviewed studies, mainly the reliance on expert opinions, small sample sizes, inconsistent study designs, and a lack of long-term follow-up data, highlight the need for more rigorous research. Conclusions: Although initial findings indicate topical treatments may be effective for oral neuropathic pain, the limitations of current studies call for more thorough research. Further comprehensive studies are essential to validate the efficacy of these treatments, standardize procedures, and determine long-term results. This will provide clearer guidance for treating chronic neuropathic pain in the oral cavity.

The efficacy of a transdermal hydrogel patch containing betamethasone dipropionate for treatment of chronic hand eczema: A single-blind, randomized and controlled trial

BACKGROUND

Topical corticosteroids under occlusion have been used to enhance the treatment of eczema. However, no study has investigated the efficacy of a steroid-containing transdermal patch for the treatment of chronic hand eczema.

METHODS

We conducted a randomized, controlled, assessor-blinded trial to determine the efficacy of a transdermal patch containing betamethasone dipropionate compared to topical betamethasone dipropionate ointment in the treatment of mild to moderate chronic hand eczema. The patients were included and assigned to receive either the transdermal patch once daily at night or the ointment twice daily for a period of 8 weeks. The outcomes were assessed using the Hand Eczema Severity Index (HECSI), Physical Global Assessment (PGA) score, self-reported compliance, level of patient satisfaction, quality of life, and side effects.

RESULTS

Fifty-six patients completed this study. At 8 weeks, there was a significant reduction in the HECSI scores in both the transdermal patch and topical ointment groups compared to those measured at baseline (14.61 to 1.86, p < 0.001; 18.46 to 3.43, p < 0.001, respectively) without a statistically significant difference between the two groups. Similarly, the two groups did not show any significant difference in the PGA scores, quality of life and side effects. However, the transdermal patch group reported better compliance and a higher level of patient satisfaction than the topical ointment group.

CONCLUSION

The transdermal corticosteroid patch has proven to be a safe and effective treatment, comparable to topical corticosteroids, after 8 weeks of use. Its sustained-release properties, along with once-daily use, can improve patient satisfaction and promote greater adherence to the treatment.

TRIAL REGISTRATION

This study was registered with the Thai Clinical Trials Registry (www.

CLINICALTRIALS

in.th) under registration number TCTR20220413003.

Evidence for the involvement of keratinocyte-derived microvesicle particles in the photosensitivity associated with xeroderma pigmentosum type A deficiency

Photosensitivity can be due to numerous causes. The photosensitivity associated with deficiency of xeroderma pigmentosum type A (XPA) has been previously shown to be associated with excess levels of the lipid mediator platelet-activating factor (PAF) generated by the keratinocyte. As PAF has been reported to trigger the production of subcellular microvesicle particles (MVP) due to the enzyme acid sphingomyelinase (aSMase), the goal of these studies was to discern if PAF and aSMase could serve as therapeutic targets for the XPA deficiency photosensitivity. HaCaT keratinocytes lacking XPA generated greater levels of MVP in comparison to control cells. Mice deficient in XPA also generated enhanced MVP levels in skin and in plasma in response to UV radiation. Use of a genetic strategy with mice deficient in both XPA and PAF receptors revealed that these mice generated less MVP release as well as decreased skin erythema and cytokine release compared to XPA knockout mice alone. Finally, the aSMase inhibitor imipramine blocked UV-induced MVP release in HaCaT keratinocytes, as well as XPA knockout mice. These studies support the concept that the photosensitivity associated with XPA involves PAF- and aSMase-mediated MVP release and provides a potential pharmacologic target in treating this form of photosensitivity.

Novel Therapeutic Hybrid Systems Using Hydrogels and Nanotechnology: A Focus on Nanoemulgels for the Treatment of Skin Diseases

Topical and transdermal drug delivery are advantageous administration routes, especially when treating diseases and conditions with a skin etiology. Nevertheless, conventional dosage forms often lead to low therapeutic efficacy, safety issues, and patient noncompliance. To tackle these issues, novel topical and transdermal platforms involving nanotechnology have been developed. This review focuses on the latest advances regarding the development of nanoemulgels for skin application, encapsulating a wide variety of molecules, including already marketed drugs (miconazole, ketoconazole, fusidic acid, imiquimod, meloxicam), repurposed marketed drugs (atorvastatin, omeprazole, leflunomide), natural-derived compounds (eucalyptol, naringenin, thymoquinone, curcumin, chrysin, brucine, capsaicin), and other synthetic molecules (ebselen, tocotrienols, retinyl palmitate), for wound healing, skin and skin appendage infections, skin inflammatory diseases, skin cancer, neuropathy, or anti-aging purposes. Developed formulations revealed adequate droplet size, PDI, viscosity, spreadability, pH, stability, drug release, and drug permeation and/or retention capacity, having more advantageous characteristics than current marketed formulations. In vitro and/or in vivo studies established the safety and efficacy of the developed formulations, confirming their therapeutic potential, and making them promising platforms for the replacement of current therapies, or as possible adjuvant treatments, which might someday effectively reach the market to help fight highly incident skin or systemic diseases and conditions.

Design, Development and In-Vitro Characterization of Insulin Loaded Topical Pluronic-Lecithin Based Organogel Formulation for the Management of Diabetic Wound

AIM

To develop and characterize the topical insulin-loaded organogel formulation for the management of diabetic wounds.

OBJECTIVES

To formulate and evaluate organogel of insulin that can serve as a topical administration for promoting enhanced wound healing in diabetic patients by providing sustained and localized delivery of drug to the wound site.

METHODOLOGY

The insulin organogel formulated by the micro-emulsion method involves mixing the "aqueous and oil phases" at high shear. Physical and chemical properties, as well as an in vitro study with a Franz diffusion chamber, were used to evaluate the prepared organogel.

RESULTS

All formulations proved to be off-white, homogeneous, washable, and had a pH between 6 and 6.5; moreover, they were non-irritating and skin-compatible. Formulations F1-F6 had viscosity ranging from 2058 to 3168 cps, spreadability ranges of 0.35 to 0.52 g*cm/s, and gel transition ranges of 28.33 to 35.33 °C. In formulations F1-F3, the concentration of lecithin was gradually increased, and in formulations F4-F6, the concentration of PF-127 was increased, resulting in a decrease in gel transition temperature, an increase in viscosity, and a gradual change in spreadability. The higher-viscosity formulations were much more stable and had better drug release. All formulations were fitted to a kinetic model belonging to first-order kinetics. However, after examining the parameter evaluation, it was found that the formulations F2 and F6 were better suited to the kinetic model and were consistent with the first-order and Higuchi models in Korsmeyer-Peppas F2 (r2 = 0.9544 and n = 1.0412); F6 (r2 = 0.9019 and n = 1.0822), which was a confirmation of the sustainability of the release system with matrix diffusion and drug delivery mechanisms that were based on the Super-Case II transport.

CONCLUSION

Further research and clinical trials are needed to validate its efficacy, optimize the formulation, and establish its long-term safety. Topical insulin organogel has the potential to revolutionize diabetic wound management by improving healing outcomes, reducing complications, and raising the standard of living for those who have diabetes.

Lidocaine induces apoptosis in head and neck squamous cell carcinoma through activation of bitter taste receptor T2R14

Head and neck squamous cell carcinomas (HNSCCs) have high mortality and significant treatment-related morbidity. It is vital to discover effective, minimally invasive therapies that improve survival and quality of life. Bitter taste receptors (T2Rs) are expressed in HNSCCs, and T2R activation can induce apoptosis. Lidocaine is a local anesthetic that also activates bitter taste receptor 14 (T2R14). Lidocaine has some anti-cancer effects, but the mechanisms are unclear. Here, we find that lidocaine causes intracellular Ca2+ mobilization through activation of T2R14 in HNSCC cells. T2R14 activation with lidocaine depolarizes mitochondria, inhibits proliferation, and induces apoptosis. Concomitant with mitochondrial Ca2+ influx, ROS production causes T2R14-dependent accumulation of poly-ubiquitinated proteins, suggesting that proteasome inhibition contributes to T2R14-induced apoptosis. Lidocaine may have therapeutic potential in HNSCCs as a topical gel or intratumor injection. In addition, we find that HPV-associated (HPV+) HNSCCs are associated with increased TAS2R14 expression. Lidocaine treatment may benefit these patients, warranting future clinical studies.

Application of surface-layer matrix-assisted laser desorption/ionization mass spectrometry imaging to pharmaceutical-loaded poly(ester urea) films

Polymer thin films are often used in transdermal patches as a method of continuous drug administration for patients with chronic illness. Understanding the drug segregation and distribution within these films is important for monitoring proper drug release over time. Surface-layer matrix-assisted laser desorption/ionization mass spectrometry imaging (SL-MALDI-MSI) is a unique analytical technique that provides an optical representation of chemical compositions that exist at the surface of polymeric materials. Solvent-free sublimation is employed for application of matrix to the sample surface, so that only molecules in direct contact with the matrix layer are detected. Here, these methodologies are utilized to visualize variations in drug concentration at both the air and substrate interface in pharmaceutical-loaded polymer films.

Therapeutic Potential for Beta-3 Adrenoreceptor Agonists in Peripheral Arterial Disease and Diabetic Foot Ulcers

Annually, peripheral arterial disease is estimated to cost over USD 21 billion and diabetic foot disease an estimated at USD 9-13 billion. Mirabegron is a TGA-approved beta-3 adrenoreceptor agonist, shown to be safe and effective in the treatment of overactive bladder syndrome by stimulating bladder smooth muscle relaxation. In this review, we discuss the potential use of beta-3 adrenoreceptor agonists as therapeutic agents repurposed for peripheral arterial disease and diabetic foot ulcers. The development of both conditions is underpinned by the upregulation of oxidative stress pathways and consequential inflammation and hypoxia. In oxidative stress, there is an imbalance of reactive oxygen species and nitric oxide. Endothelial nitric oxide synthase becomes uncoupled in disease states, producing superoxide and worsening oxidative stress. Agonist stimulation of the beta-3 adrenoreceptor recouples and activates endothelial nitric oxide synthase, increasing the production of nitric oxide. This reduces circulating reactive oxygen species, thus decreasing redox modification and dysregulation of cellular proteins, causing downstream smooth muscle relaxation, improved endothelial function and increased angiogenesis. These mechanisms lead to endothelial repair in peripheral arterial disease and an enhanced perfusion in hypoxic tissue, which will likely improve the healing of chronic ulcers.

Depolymerized Chitosan-g-[Poly(MMA-co-HEMA-cl-EGDMA)] Based Nanogels for Controlled Local Release of Bupivacaine

This study is designed to formulate and characterize chitosan-based nanogels that provide the controlled delivery of anesthetic drugs, such as bupivacaine (BPV), for effective postoperative pain management over prolonged periods of time. Drug carriers of chitosan/poly (MMA-co-HEMA-cl-EGDMA) (CsPMH) nanogels were prepared by varying the composition of comonomers such as MMA, HEMA, and redox initiator CAN. The nanogels were then characterized using FTIR, TGA, SEM, and TEM. The CsPMH nanogels showed greater encapsulation efficiencies from 43.20-91.77%. Computational studies were also conducted to evaluate the interaction between the drug and CsPMH nanoparticles. Finally, BPV-loaded nanoparticles were used to examine their in vitro release behavior. At pH 7.4, all the drug carriers displayed the "n" value around 0.7, thus the BPV release follows anomalous diffusion. Drug carrier 7 demonstrated a steady and sustained release of BPV for approximately 24 h and released about 91% of BPV, following the K-P mechanism of drug release. On the other hand, drug carrier 6 exhibited controlled release for approximately 12 h and released only 62% of BPV.

Topical Delivery Systems Effectively Transport Analgesics to Areas of Localized Pain via Direct Diffusion

Topical delivery systems (TDSs) enable the direct transport of analgesics into areas of localized pain and thus minimize the side effects of administration routes that rely on systemic drug distribution. For musculoskeletal pain, clinicians frequently prescribe topical products containing lidocaine or diclofenac. This study assessed whether drug delivery from a TDS into muscle tissue occurs mainly via direct diffusion or systemic transport. An investigational TDS containing 108 mg lidocaine (SP-103, 5.4% lidocaine), a commercially available TDS containing 36 mg lidocaine (ZTlido®, 1.8% lidocaine), and a topical pain relief gel (Pennsaid®, 2% diclofenac) were tested. Using open flow microperfusion (OFM), interstitial fluid from the dermis, subcutaneous adipose tissue (SAT), and muscle was continuously sampled to assess drug penetration in all tissue layers. Ex vivo and in vivo experiments showed a higher diffusive transport of lidocaine compared to diclofenac. The data showed a clear contribution of diffusive transport to lidocaine concentration, with SP-103 5.4% resulting in a significantly higher lidocaine concentration in muscle tissue than commercially available ZTlido® (p = 0.008). These results indicate that SP-103 5.4% is highly effective in delivering lidocaine into muscle tissue in areas of localized pain for the treatment of musculoskeletal pain disorders (e.g., lower back pain).

Synergistic wound repair effects of a composite hydrogel for delivering tumor-derived vesicles and S-nitrosoglutathione

Treating chronic wounds requires transition from proinflammatory M1 to anti-inflammatory M2 dominant macrophages. Based on the role of tumor extracellular vesicles (tEVs) in regulating the phenotypic switching from M1 to M2 macrophages, we propose that tEVs may have a beneficial impact on alleviating the overactive inflammatory microenvironment associated with refractory wounds. On the other hand, as a nitric oxide donor, S-nitrosoglutathione (GSNO) can regulate inflammation, promote angiogenesis, enhance matrix deposition, and facilitate wound healing. In this study, a guar gum-based hydrogel with tEVs and GSNO was designed for the treatment of diabetic refractory wounds. This hybrid hydrogel was formed through the phenyl borate bonds, which can automatically disintegrate in response to the high reactive oxygen species (ROS) level at the site of refractory diabetic wounds, releasing tEVs and GSNO. We conducted a comprehensive evaluation of this hydrogel in vitro, which demonstrated excellent performance. Meanwhile, using a full-thickness excision model in diabetic mice, the wounds exposed to the therapeutic hydrogel healed completely within 21 days. The increased closure rate was associated with macrophage polarization and collagen deposition, accelerated fibroblast proliferation, and increased angiogenesis in the regenerating tissues. Therefore, this multifunctional hybrid hydrogel appears to be promising for clinical applications.

Painful diabetic peripheral neuropathy of the feet: integrating prescription-strength capsaicin into office procedures

Prescription-strength (8%) capsaicin topical system is a US FDA-approved treatment for painful diabetic peripheral neuropathy of the feet. A 30 min application of the capsaicin 8% topical system can provide sustained (up to 3 months) local pain relief by desensitizing and reducing TRPV1-expressing cutaneous fibers. Capsaicin is not absorbed systemically; despite associated application-site discomfort, capsaicin 8% topical system is well tolerated, with no known drug interactions or contraindications, and could offer clinical advantages over oral options. Capsaicin 8% topical system are not for patient self-administration and require incorporation into office procedures, with the added benefit of treatment compliance. This article reviews existing literature and provides comprehensive, practical information regarding the integration of capsaicin 8% topical systems into office procedures.

Efficacy of topical versus oral analgesic medication compared to a placebo in injured athletes: A systematic review with meta-analysis

BACKGROUND

Athletes are injured frequently and often take analgesic medication. Moreover, athletes commonly use non-prescription topical and oral medications with little guidance. Despite wide use, relatively few studies exist on the efficacy of pain medication in injured athletes compared to a placebo.

OBJECTIVE

To determine efficacy of topical or oral medications in pain reduction compared to a placebo in injured athletes.

STUDY DESIGN

A systematic review and meta-analysis.

METHODS

We conducted an electronic search using Medline/Pubmed, Web of Science, Ovid, and SportDiscus for all literature relating to topical or oral medications in athletes for pain management post-injury. Two reviewers screened the studies and measured their quality. To determine efficacy, we calculated the Hedges' g value. We created forest plots with 95% CI to graphically summarize the meta-analyses.

RESULTS

There was a significant pooled effect size reflecting a reduction in pain outcomes for the topical treatment versus placebo (g = -0.64; 95% CI [-0.89, -0.39]; p < 0.001). There was not a significant reduction in pain outcomes for the oral treatment versus placebo (g = -0.26; 95% CI [-0.60, 0.17]; p = 0.272).

CONCLUSION

Topical medications were significantly better at reducing pain compared to oral medications versus a placebo in injured athletes. These results are different when compared to other studies that used experimentally induced pain versus musculoskeletal injuries. The results from our study suggest that athletes should use topical medications for pain reduction, as it is more effective, and there are less reported adverse effects compared to oral medication.

Deep Eutectic Solvents Based on L-Arginine and 2-Hydroxypropyl-β-Cyclodextrin for Drug Carrier and Penetration Enhancement

By selecting L-arginine as the hydrogen bond acceptor (HBA) and 2-hydroxypropyl-β-cyclodextrin (2HPβCD) as the hydrogen bond donor (HBD), deep eutectic solvents (DESs) with various water content were prepared at the 4:1 mass ratio of L-arginine to 2HPβCD with 40 to 60% of water, and were studied for its application in transdermal drug delivery system (TDDS). The hydrogen bond networks and internal chemistry structures of the DESs were measured by attenuated total reflection Fourier transform infrared (ATR-FTIR) and 1H-nuclear magnetic resonance spectroscopy (1H-NMR), which demonstrated the successful synthesis of DESs. The viscosity of DES was decreased from 10,324.9 to 3219.6 mPa s, while glass transition temperature (Tg) of the DESs was increased from - 60.8 to - 51.4 °C, as the added water was increased from 45 to 60%. The solubility of ibuprofen, norfloxacin, and nateglinide in DES with 45% of water were increased by 79.3, 44.1, and 3.2 times higher than that in water, respectively. The vitro study of transdermal absorption of lidocaine in DESs showed that the cumulative amounts of lidocaine reached 252.4 µg/cm2, 226.1 µg/cm2, and 286.1 µg/cm2 at 8 h for DESs with 45%, 50%, and 60% of water, respectively. The permeation mechanism of DES with lower content of water (45%) was mainly by changing the fluidization of lipids, while changing the secondary structure of keratin in stratum corneum (SC) at higher water content (50% and 60%). These nonirritant and viscous fluid like DESs with good drug solubility and permeation enhancing effects have broad application prospect in the field of drug solubilization and transdermal drug delivery system.

Shang-Ke-Huang-Shui and coptisine alleviate osteoarthritis in the knee of monosodium iodoacetate-induced rats through inhibiting CXCR4 signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Shang-Ke-Huang-Shui (SKHS) is a classic traditional Chinese medicine formula originally from the southern China city of Foshan. It has been widely used in the treatment of osteoarthritis (OA) but underlying molecular mechanisms remain unclear.

AIM OF STUDY

Recently, activation of C-X-C chemokine receptor type 4 (CXCR4) signaling has been reported to induce cartilage degradation in OA patients; therefore, inhibition of CXCR4 signaling has becoming a promising approach for OA treatment. The aim of this study was to validate the cartilage protective effect of SKHS and test whether the anti-OA effects of SKHS depend on its inhibition on CXCR4 signaling. Additionally, CXCR4 antagonist in SKHS should be identified and its anti-OA activity should also be tested in vitro and in vivo.

METHODS

The anti-OA effects of SKHS and the newly identified CXCR4 antagonist was evaluated by monosodium iodoacetate (MIA)-induced rats. The articular cartilage surface was examined by hematoxylin and eosin (H&E) staining and Safranin O-Fast Green (S-F) staining whereas the subchondral bone was examined by micro-CT. CXCR4 antagonist screenings were conducted by molecular docking and calcium response assay. The CXCR4 antagonist was characterized by UPLC/MS/MS. The bulk RNA-Seq was conducted to identify CXCR4-mediated signaling pathway. The expression of ADAMTS4,5 was tested by qPCR and Western blot.

RESULTS

SKHS protected rats from MIA-induced cartilage degradation and subchondral bone damage. SKHS also inhibited CXCL12-indcued ADAMTS4,5 overexpression in chondrocytes through inhibiting Akt pathway. Coptisine has been identified as the most potent CXCR4 antagonist in SKHS. Coptisine reduced CXCL12-induced ADAMTS4,5 overexpression in chondrocytes. Furthermore, in MIA-induced OA model, the repaired cartilage and subchondral bone were observed in the coptisine-treated rats.

CONCLUSION

We first report here that the traditional Chinese medicine formula SKHS and its predominate phytochemical coptisine significantly alleviated cartilage degradation as well as subchondral bone damage through inhibiting CXCR4-mediated ADAMTS4,5 overexpression. Together, our work has provided an important insight of the molecular mechanism of SKHS and coptisine for their treatment of OA.

Recent advances in dosage form design for the elderly: a review

INTRODUCTION

With the increase in the elderly population and the prevalence of multiple medical conditions, medication adherence, and efficacy have become crucial for the effective management of their health. The aging population faces unique challenges that need to be addressed through advancements in drug delivery systems and formulation technologies.

AREAS COVERED

The current review highlights the recent advances in dosage form design for older individuals, with consideration of their specific physiological and cognitive changes. Various dosage forms, such as modified-release tablets/capsules, chewable tablets, and transdermal patches, can be tailored to meet the specific needs of elderly patients. Advancements in drug delivery systems, such as nanotherapeutics, additive manufacturing (three-dimensional printing), and drug-food combinations, improve drug delivery and efficacy and overcome challenges, such as dysphagia and medication adherence.

EXPERT OPINION

Regulatory guidelines and considerations are crucial in ensuring the safe utilization of medications among older adults. Important factors to consider include geriatric-specific guidelines, safety considerations, labeling requirements, clinical trial considerations, and adherence and accessibility considerations.

Looking Back to Move Forward: The Current State of Research on the Clinical Applications of Camphor- and Menthol-Containing Agents

Topically applied compounds containing camphor and menthol have been used to alleviate pain, cold symptoms, and pruritus, historically predominantly in East Asia. Being not studied well, they are less recognized in Western medicine. Given the commonality of pain, pruritus, and cold symptoms in addition to the growing need for non-opioid treatment options, the authors investigated clinical applications of such compounds for their over-counter usage. The purpose was to analyze current clinical research and applications regarding the use of these topical agents. This study involved a bibliometric analysis of peer-reviewed articles, published in English and indexed in PubMed from 2010 to 2022, pertaining to camphor- and menthol-containing compounds. There were 103 results, of which 15 (14.6%) articles were related to the treatment of disorders related to health, such as upper respiratory infection, pain, and pruritus. Excluded were "non-research" articles (e.g., letters to the editor), articles that do not involve human subjects, reports of improper application or misuse (e.g., ingestion), and articles pertaining to intraoral, intranasal, and ophthalmic agents. Of these articles, the originating journals, respective journal impact factor scores, publication years, study designs, and study topics were identified. Underlying trends and themes regarding clinically relevant research on these compounds were subsequently discerned. Based on this analysis, topical agents containing camphor and menthol are potentially effective at treating pain, upper respiratory infection symptoms, and pruritus in addition to potentially functioning as an antimicrobial. However, with a limited number of studies addressing these compounds' uses in each application, no definitive recommendation can be made regarding their use. Given the promising results of earlier studies, the authors recommend that more primary research, particularly randomized, double-blind controlled studies, be done regarding clinical applications of these substances.

Strategies for Improving Transdermal Administration: New Approaches to Controlled Drug Release

In this work, we aim to address several strategies to improve transdermal drug delivery, such as iontophoresis, sonophoresis, electroporation and micron. We also propose a review of some transdermal patches and their applications in medicine. TDDs (transdermal patches with delayed active substances) are multilayered pharmaceutical preparations that may contain one or more active substances, of which, systemic absorption is achieved through intact skin. The paper also presents new approaches to the controlled release of drugs: niosomes, microemulsions, transfersomes, ethosomes, but also hybrid approaches nanoemulsions and microns. The novelty of this review lies in the presentation of strategies to improve the transdermal administration of drugs, combined with their applications in medicine, in light of pharmaceutical technological developments.

Systemically Acting Diclofenac Sodium Patch for Control of Low Back Pain: A Randomized, Double-Blind, Placebo-Controlled Study in Japan

INTRODUCTION

Nonsteroidal antiinflammatory drugs (NSAIDs) are commonly used for pain disorders such as low back pain and exist in multiple formulations; however, no systemically acting transdermal formulations are available for low back pain. Transdermal formulations can be safely administered even to patients with trouble swallowing or at risk of aspiration, and without regard to the effect of food on drug absorption. Unlike locally acting formulations, systemically acting transdermal formulations need not be applied at the target site, so dosing is simple and the burden is not on one area of the skin. A patch with the systemically acting NSAID diclofenac sodium is approved in Japan for treatment of cancer-related pain, and we hypothesized that it would be useful for controlling low back pain.

METHODS

This randomized, double-blind, placebo-controlled study aimed to evaluate the efficacy and safety of diclofenac sodium patch in Japanese patients with low back pain. Eligible patients were randomized to receive diclofenac sodium patch 75 mg or 150 mg or placebo once daily for 2 weeks. The primary endpoint was pain intensity assessed on a visual analog scale (VAS).

RESULTS

Primary analysis of the primary endpoint showed that both doses of the diclofenac sodium patch (150 mg and 75 mg) were superior to placebo in terms of absolute change from baseline in mean 3-day VAS score after 2 weeks' treatment; the mean difference between the active and placebo treatments in this variable was -5.67 [95% confidence interval (CI) -9.34 to -2.00] mm in the 150 mg group and -5.68 (95% CI -9.34 to -2.01) mm in the 75 mg group. Most adverse events were mild. No serious adverse events occurred.

CONCLUSION

In Japanese patients, diclofenac sodium patch is effective for the relief of low back pain and is well tolerated.

TRIAL REGISTRATION

JPRN number, JPRN-JapicCTI-205134.

Patterns and Trends in Pharmacological Treatment for Outpatients with Postherpetic Neuralgia in Six Major Areas of China, 2015-2019

The aim of this study was to assess the patterns and trends of pharmacological treatment for outpatients with postherpetic neuralgia (PHN) in China in the period 2015-2019. Prescription data for outpatients with PHN were extracted from the database of the Hospital Prescription Analysis Program of China according to the inclusion criteria. The trends in yearly prescriptions and corresponding costs were analyzed and stratified by drug class and specific drugs. A total of 19,196 prescriptions from 49 hospitals in 6 major regions of China were included for analysis. The yearly prescriptions increased from 2534 in 2015 to 5676 in 2019 (p = 0.027), and the corresponding expenditures increased from CNY 898,618 in 2015 to CNY 2,466,238 in 2019 (p = 0.027). Gabapentin and pregabalin are the most commonly used drugs for PHN, and more than 30% of these two drugs were combined with mecobalamin. Opioids were the second most frequently prescribed drug class, and oxycodone accounted for the largest share of the cost. Topical drugs and TCAs are rarely used. The frequent use of pregabalin and gabapentin was in accordance with current guidelines; however, the use of oxycodone raised concerns about rationality and economic burden. The results of this study may benefit the allocation of medical resources and management for PHN in China and other countries.

Recent Advances in the Application of ATRP in the Synthesis of Drug Delivery Systems

Advances in atom transfer radical polymerization (ATRP) have enabled the precise design and preparation of nanostructured polymeric materials for a variety of biomedical applications. This paper briefly summarizes recent developments in the synthesis of bio-therapeutics for drug delivery based on linear and branched block copolymers and bioconjugates using ATRP, which have been tested in drug delivery systems (DDSs) over the past decade. An important trend is the rapid development of a number of smart DDSs that can release bioactive materials in response to certain external stimuli, either physical (e.g., light, ultrasound, or temperature) or chemical factors (e.g., changes in pH values and/or environmental redox potential). The use of ATRPs in the synthesis of polymeric bioconjugates containing drugs, proteins, and nucleic acids, as well as systems applied in combination therapies, has also received considerable attention.

Newfangled Topical Film-Forming Solution for Facilitated Antifungal Therapy: Design, Development, Characterization, and In Vitro Evaluation

Luliconazole is a broad-spectrum topical antifungal agent that acts by altering the synthesis of fungi cell membranes. Literature suggests that the recurrence of fungal infection can be avoided by altering the pH of the site of infection. Studies have also suggested that fungi thrive by altering skin pH to be slightly acidic, i.e., pH 3-5. The current study is aimed to design, develop, characterize, and evaluate an alkaline pH-based antifungal spray solution for antifungal effects. Luliconazole was used as an antifungal agent and an alkaline spray was formulated for topical application by using Eudragit RS 100, propylene glycol (PG), water, sodium bicarbonate, and ethanol via solubilization method. Herein, sodium bicarbonate was used as an alkalizing agent. Based on DSC, FTIR, PXRD, scanning electron microscopy (SEM), and rheological analysis outcomes, the drug (luliconazole) and polymer were found to be compatible. F-14 formulation containing 22% Eudragit RS 100 (ERS), 1.5% PG, and 0.25% sodium bicarbonate was optimized by adopting the quality by design approach by using design of experiment software. The viscosity, pH, drying time, volume of solution post spraying, and spray angle were, 14.99 ± 0.21 cp, 8 pH, 60 s, 0.25 mL ± 0.05 mL, and 80 ± 2, respectively. In vitro drug diffusion studies and in vitro antifungal trials against Candida albicans revealed 98.0 ± 0.2% drug diffusion with a zone of inhibition of 9 ± 0.12 mm. The findings of the optimized luliconazole topical film-forming solution were satisfactory, it was compatible with human skin, and depicted sustained drug release that suggests promising applicability in facilitated topical antifungal treatments.

Oleic acid-based vesicular nanocarriers for topical delivery of the natural drug thymoquinone: Improvement of anti-inflammatory activity

The topical administration of a drug compound remains the first choice for the treatment of many local skin ailments. Many skin diseases can be treated by applying the active formulation directly to the skin, but unfortunately some drugs are unable to overcome the stratum corneum and exert their pharmacological action. An example is thymoquinone, a naturally derived drug obtained from Nigella sativa L. and potentially effective in the treatment of inflammatory and oxidative skin conditions. Since its physico-chemical properties are not suitable for overcoming the stratum corneum, we wanted to circumvent the problem by proposing new lipid-based nanovesicles called "oleoethosomes", made up of naturally derived ingredients, for its delivery. Among several formulations of oleoethosomes, the sample made up of 2% (w/w) oleic acid:PL90G 1:1 (molar ratio), and ethanol 15% showed the best physico-chemical characteristics and above all it showed the capacity to contain a suitable amount of thymoquinone (2 mg/ml). The formulation was tested in vitro on stratum corneum and viable epidermis membranes confirming its ability to induce the passage of thymoquinone through the human stratum corneum and to act as a permeation enhancer. In fact, it showed thymoquinone permeation values of 22.63 ± 1.49% regarding the applied drug amount. Oleoethosomes were compared with oleosomes, another kind of naturally derived nanosystems but free of ethanol. The experimental data confirmed that ethanol was an important component that enhanced the activity of the oleoethosomes when tested on the skin of healthy volunteers. The thymoquinone-loaded oleoethosome treatment demonstrated a significantly greater extent of anti-inflammatory activity than the treatment with thymoquinone-loaded oleosomes or the conventional dosage form of the drug. These in vivo results confirmed the synergic effect between oleic acid and ethanol on the lipid and protein compartments of the outermost skin layer, thus promoting a greater penetration capacity.

Formulation and Evaluation of the In Vitro Performance of Topical Dermatological Products Containing Diclofenac Sodium

The selection of an appropriate vehicle in a semi-solid topical product is of utmost importance since the vehicle composition and microstructure can potentially cause changes in drug-vehicle or vehicle-skin interactions and affect drug release and subsequent permeation into and across skin. Hence, the aim of this study was to evaluate different semi-solid formulations containing diclofenac sodium for the physicochemical and structural performance of excipients used and various physiological factors governing permeation of drugs applied to skin. The formulations (emulsion, emulgel, gel, and ointment) were prepared using conventional excipients and were found to be homogenous and stable. Rheological analysis demonstrated characteristic shear-thinning and viscoelastic behavior of formulations. The mean release rate of the gel formulation (380.42 ± 3.05 µg/cm²/h^0.5) was statistically higher compared to all other formulations. In vitro permeation using human skin showed a significantly greater extent of drug permeation and retention for the emulgel formulation (23.61 ± 1.03 µg/cm² and 47.95 ± 2.47 µg/cm², respectively). The results demonstrated that the different formulations influenced product performance due to their inherent properties. The findings of this study demonstrated that a comprehensive physicochemical and structural evaluation is required to optimize the in vitro performance for dermatological formulations depending on the intended therapeutic effect.

Synthesis of enhanced lipid solubility of indomethacin derivatives for topical formulations

Indomethacin is a nonselective nonsteroidal anti-inflammatory drug with serious side effects such as depression, hallucination, and gastrointestinal irritation. This study aims to enhance indomethacin lipid solubility of indomethacin derivative to use it for the topical formulation since topical formulation may lower the unwanted side effects. The lipid solubility was achieved by adding various alkyl groups (methyl, ethyl, propyl, and isopropyl) to the drug via an ester linkage. The measured log p of these compounds was higher compared to the underivatized indomethacin. Furthermore, an ointment of each ester was formulated and was tested on mice skin using Franz diffusion. The best absorption was observed for methyl indomethacin with threefold increase in permeability compared to indomethacin. This study approves using derivatized indomethacin as a topical formulation with improved efficacy compared to the present gel formulation in the market.

Compritol-Based Nanostrucutured Lipid Carriers (NLCs) for Augmentation of Zolmitriptan Bioavailability via the Transdermal Route: In Vitro Optimization, Ex Vivo Permeation, In Vivo Pharmacokinetic Study

Migraine is a severe neurovascular disease manifested mainly as unilateral throbbing headaches. Triptans are agonists for serotonin receptors. Zolmitriptan (ZMP) is a biopharmaceutics classification system (BCS) class III medication with an absolute oral bioavailability of less than 40%. As a result, our research intended to increase ZMP bioavailability by developing transdermal nanostructured lipid carriers (NLCs). NLCs were prepared utilizing a combination of hot melt emulsification and high-speed stirring in a 3² full factorial design. The studied variables were liquid lipid type (X₁) and surfactant type (X₂). The developed NLCs were evaluated in terms of particle size (Y₁, nm), polydispersity index (Y₂, PDI), zeta potential (Y₃, mV), entrapment efficacy (Y₄, %) and amount released after 6 h (Q6h, Y₅, %). At 1% Mygliol as liquid lipid component and 1% Span 20 as surfactant, the optimized formula (NLC9) showed a minimum particle size (138 ± 7.07 nm), minimum polydispersity index (0.39 ± 0.001), acceptable zeta potential (−22.1 ± 0.80), maximum entrapment efficiency (73 ± 0.10%) and maximum amount released after 6 h (83.22 ± 0.10%). The optimized formula was then incorporated into gel preparation (HPMC) to improve the system stability and ease of application. Then, the pharmacokinetic study was conducted on rabbits in a cross-over design. The calculated parameters showed a higher area under the curve (AUC_0–24, AUC_0–∞ (ng·h/mL)) of the developed ZMP-NLCs loaded gel, with a 1.76-fold increase in bioavailability in comparison to the orally administered marketed product (Zomig^®). A histopathological examination revealed the safety of the developed nanoparticles. The declared results highlight the potential of utilizing the proposed NLCs for the transdermal delivery of ZMP to improve the drug bioavailability.

The Usefulness of In Vitro Percutaneous Absorption Experiments Applying the Infinite Dose Technique to Predict In Vivo Plasma Levels: Comparison of Model-Predicted and Observed Plasma Concentrations of Nortriptyline in Rats

The aims of this study were to evaluate the feasibility of a nortriptyline (NT) formulation for transdermal administration and to assess the usefulness of an estimated kinetic parameter (kout) using the in vitro infinite dose technique to predict in vivo plasma levels when used in combination with pharmacokinetic parameters. To do so, a simple one-compartment model was used to describe the transport of a permeant across a membrane (skin). This model provides relatively simple expressions for the amount of permeant in the skin, the cumulative amount of permeant that crosses the skin, and the flux of permeant, for both the infinite and the finite dose regimens. Transdermal administration of the formulated NT gel to rats resulted in plasma levels of approximately 150 ng/mL between 8 and 30 h post-administration. These levels were higher than the minimum concentration of 40 ng/mL recommended for smoking cessation therapy and slightly higher than the upper limit of the therapeutic range for the treatment of depression in humans. The one-compartment model used to describe transport across the skin was connected to a two-compartment pharmacokinetic model used to predict NT plasma concentrations in rats using the kout determined in vitro and the values of other pharmacokinetic parameters obtained in vivo. The predicted concentrations were close to the observed plasma levels and the time profiles were similar for both types of data. These results show the usefulness of the kout parameter determined in vitro to predict plasma concentrations of drugs administered percutaneously.

Pharmacokinetics of lanoconazole in human skin after repeated topical application

Drug disposition after topical application to the skin has not been fully elucidated, especially after repeated application. We conducted a clinical trial to evaluate the pharmacokinetics in the stratum corneum of healthy adults after repeated application of lanoconazole cream as a model drug. We applied 25 mg of 1% lanoconazole cream onto the pre-specified areas on the participants' back once daily for 5 days. The stratum corneum was sampled twice on each study day using a standardized tape-stripping method, and the amount of lanoconazole contained in the samples was quantified using the tandem mass spectrometry method. The obtained data were used to evaluate lanoconazole pharmacokinetics in the stratum corneum. The amount of lanoconazole in the stratum corneum after once daily repeated administration reached a steady state on day 3, and it was eliminated from the stratum corneum with a half-life of approximately 11 h after discontinuing application.

Open-Label Adhesion Performance Study of a Prescription Lidocaine Topical System 1.8% versus Three Lidocaine-Containing Over-the-Counter Patches in Healthy Subjects

Purpose

Patients and Methods

Results

Conclusion

Preparation of Terbinafin-Encapsulated Solid Lipid Nanoparticles Containing Antifungal Carbopol® Hydrogel with Improved Efficacy: In Vitro, Ex Vivo and In Vivo Study

The present research was aimed to develop a terbinafin hydrochloride (TH)-encapsulated solid lipid nanoparticles (SLNs) hydrogel for improved antifungal efficacy. TH-loaded SLNs were obtained from glyceryl monostearate (lipid) and Pluronic® F68 (surfactant) employing high-pressure homogenization. The ratio of drug with respect to lipid was optimized, considering factors such as desired particle size and highest percent encapsulation efficiency. Lyophilized SLNs were then incorporated in the hydrogel prepared from 0.2–1.0% w/v carbopol 934P and further evaluated for rheological parameters. The z-average, zeta potential and polydispersity index were found to be 241.3 nm, −15.2 mV and 0.415, respectively. The SLNs show a higher entrapment efficiency of about 98.36%, with 2.12 to 6.3602% drug loading. SEM images, XRD and the results of the DSC, FTIR show successful preparation of SLNs after freeze drying. The TH-loaded SLNs hydrogel showed sustained drug release (95.47 ± 1.45%) over a period of 24 h. The results reported in this study show a significant effect on the zone of inhibition than the marketed formulation and pure drug in Candida albicans cultures, with better physical stability at cooler temperatures. It helped to enhance skin deposition inthe ex vivostudy and improved, in vitro and in vivo, the antifungal activity.

A Narrative Review of the Potential Roles of Lipid-Based Vesicles (Vesiculosomes) in Burn Management

Burn injuries can have a lasting effect on people’s quality of life, as they negatively impact their physical and mental health. Then, they are likely to suffer psychological problems as a result. A serious problem is that deep burns are more challenging to treat due to their slow healing rate and susceptibility to microbial infection. Conventional topical medications used for burn treatment are sometimes ineffective because they cannot optimize their ability of transcutaneous absorption at the targeted site and accelerate healing. However, nanotechnology offers excellent prospects for developing current medical wound therapies and is capable of addressing issues such as low drug stability, water solubility, permeability, and bioavailability. The current review focuses on lipid-based vesicles (vesiculosomes) as an example of advanced delivery systems, showing their potential clinical applications in burn wound management. Vesiculosomes may help overcome impediments including the low bioavailability of active agents, offering the controlled release of drugs, increased drug stability, fewer side effects, and reduced dosing frequency, which will ultimately improve therapeutic efficacy and patient compliance. We discuss the application of various types of vesiculosomes such as liposomes, niosomes, ethosomes, cubosomes, transfersomes, and phytosomes in burn healing therapy, as these demonstrate superior skin penetration compared to conventional burn topical treatment. We also highlight their noteworthy uses in the formulation of natural products and discuss the current status as well as future perspectives of these carriers in burn management. Furthermore, the burn treatment options currently available in the market are also summarized.

Pain management with transdermal drug administration: A review

Pain management is an urgent issue to solve with complex mechanisms. Localized acute pain requires rapid and accurate delivery of drugs with less distribution in the blood circulation while chronic pain requires controlled release of drugs with long drug retention time. The transdermal route, a promising way with high patient compliance was known for painless delivery, long drug retention time, stable blood concentration, easily controlled dosage and release rate as well as the fewer side effects. This review presents transdermal route for pain management according to the different sites of action which drugs aim to reach, and illustrates different analgesic mechanisms, dosage forms, transdermal enhancements and clinical applications. In addition, the review concludes the difference of pain types and presents the future aims of pain management, thereby providing a reference for researches focusing on percutaneous analgesia.

Efficacy of topical cannabinoids in the management of pain: a systematic review and meta-analysis of animal studies

BACKGROUND/IMPORTANCE

Cannabinoids are emerging as an alternative pain management option, preliminarily supported by preclinical and clinical studies. Unwanted side effects from oral or inhaled cannabinoids remain, however, a major barrier to widespread use. Peripherally acting cannabinoids (eg, topically applied) may circumvent these side effects while providing localized pain management.

OBJECTIVE

Our purpose was to systematically review the literature on the effectiveness of peripherally acting cannabinoids for pain management.

EVIDENCE REVIEW

We searched MEDLINE, EMBASE, CENTRAL, CINAHL, and PubMed databases. Included studies examined the effect of topical/peripherally administered cannabinoids on pain ratings in humans, as well as pain-related outcomes in animals (eg, paw withdrawal). Due to a lack of trials, human studies were summarized in a narrative synthesis. Separate meta-analyses were performed for animal studies using radiant tail flick or paw withdrawal outcomes.

FINDINGS

Our search yielded 1182 studies following removal of duplicates, with 46 studies (6 human, 40 animal) included. Human studies (one randomized controlled trial and five case studies/series) reported no adverse events to topical cannabinoids and preliminary evidence of decreased pain ratings. Animal studies reporting tail flick (5) (2.81, 95% CI 1.93 to 3.69, p<0.001) and mechanical withdrawal (11) (2.74, 95% CI 1.82 to 3.67, p<0.001) reported prolonged responses (analgesia) in peripheral cannabinoid groups compared with controls.

CONCLUSIONS

Preclinical animal studies provided low-quality evidence for peripherally administered cannabinoids to provide regional, antinociceptive effects. The scarcity of high-quality human studies underscores the need to translate preclinical evidence into well-controlled human trials.

Topical Medicine Potency of Musa paradisiaca var. sapientum (L.) kuntze as Oral Gel for Wound Healing: An In Vitro, In Vivo Study

OBJECTIVE

 Topical application of ambonese banana (Musa paradisiaca var. sapientum (L.) kuntze) stem sap gel (GEGPA) on the socket wound area showed an increase in the expression of platelet-derived growth factor-BB, while decrease in the expression of matrix metalloproteinase-2 and 9. The aim of this study is to achieve standard formulation of GEGPA through stability, viscosity, distribution area, and drugs release for oral gel wound healing.

MATERIALS AND METHODS

 This is an in vitro and in vivo study with the randomized posttest only control group design. The gel was formulated according to the composition of each group by adding hydroxypropyl methylcellulose (HPMC), Lexgard, propylene glycol, and cold water to obtain 100 g of gel. Observations were made through the following tests: stability, viscosity, distribution area, drug release, and histopathological analysis of tooth extraction wound healing.

STATISTICAL ANALYSIS

 Data were analyzed using a one-way analysis of variance (α = 0.05) with GraphPad Prism-8 statistical software.

RESULTS

 The study showed that the GEGPA formulation was stable against changes in consistency, color, smell, homogeneity, and pH value. There is a significant difference between groups with respect to viscosity (p = 0.0001), adhesion (p = 0.004), dispersion (p = 0.000), and fibroblast cell numbers on days 3 and 5 (p = 0.007 and p = 0.001). There is no interaction between the active ingredients and the gel base of all formulations. Formulation 3 had better properties in terms of viscosity, broad distribution, and drug release compared with other groups. Application of GEGPA to tooth extraction wounds showed a significant proliferation of fibroblast cells on days 3 and 5.

CONCLUSIONS

 The formulation of M. paradisiaca var. sapientum (L.) kuntze extract with HPMC and propylene glycol obtained a gel preparation, GEGPA, that was organoleptically stable and met the topical gel standard for wounds in the oral cavity.

Stockton M, Signaigo A. A Topical Botanical Ointment for Self-Reported Hip and/or Knee Pain: A Randomized Placebo-Controlled Clinical Trial

Joint pain is a common ailment among adults worldwide. Six men and 14 women (aged 51 ± 10 years) with self-reported joint pain were randomly assigned, using a cross-over design, to a botanical ointment (Yeahhh Baby!®) or placebo, twice daily for 14 days. Subjects completed questionnaires regarding their joint pain and discomfort (eg, WOMAC and subjective pain using a visual analog scale [VAS]) each evening and underwent a washout period of two weeks before crossing into the other condition. Pain and discomfort scores improved for subjects when using Yeahhh Baby!® ointment from day 1 to the average of days 2-15. For certain measures, similar, albeit insignificant, improvements were noted when subjects used the placebo—demonstrating the powerful placebo effect. Specifically, with Yeahhh Baby!® ointment, effects were noted for WOMAC pain ( P = .008), WOMAC physical function ( P = .024), WOMAC total ( P = .019), and VAS mood interference ( P = .042). The most pronounced improvement was noted for WOMAC pain ( P = .048), with a 25% reduction observed with Yeahhh Baby!®, with a 10% reduction noted for placebo. These findings indicate that, as compared to a placebo, Yeahhh Baby!® ointment may provide relief to individuals suffering from joint pain in their knees and/or hips.

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.