Advanced Analgesic Drug Delivery and Nanobiotechnology

Exosomes as natural nanocarrier-based drug delivery system: recent insights and future perspectives

Exosomes are nanosized (size ~ 30-150 nm) natural vesicular structures released from cells by physiological processes or pathological circumstances. Exosomes are growing in popularity as a result of their many benefits over conventional nanovehicles, including their ability to escape homing in the liver or metabolic destruction and their lack of undesired accumulation before reaching their intended targets. Various therapeutic molecules, including nucleic acids, have been incorporated into exosomes by different techniques, many of which have shown satisfactory performance in various diseases. Surface-modified exosomes are a potentially effective strategy, and it increases the circulation time and produces the specific drug target vehicle. In this comprehensive review, we describe composition exosomes biogenesis and the role of exosomes in intercellular signaling and cell-cell communications, immune responses, cellular homeostasis, autophagy, and infectious diseases. In addition, we discuss the role of exosomes as diagnostic markers, and their therapeutic and clinical implications. Furthermore, we addressed the challenges and outstanding developments in exosome research and discuss future perspectives. In addition to the current status of exosomes as a therapeutic carrier, the lacuna in the clinical development lifecycles along with the possible strategies to fill the lacuna have been addressed.

Multidisciplinary approach, continuous care and opioid management in cancer pain: case series and review of the literature

Underlying cancer pain has heterogenous aetiologies and mechanisms. It requires detailed and comprehensive pain assessment, combined with personalized treatment. A multidisciplinary team is essential to providing the best management of cancer pain at every disease stage, improving the quality of life and outcomes in patients with cancer. This narrative literature review emphasizes the value of providing all patients with multidisciplinary pain management in their preferred care setting. Real-life experiences are also reported to witness the efforts of physicians to properly manage cancer pain. This article is part of the Management of breakthrough cancer pain Special Issue: https://www.drugsincontext.com/special_issues/management-of-breakthrough-cancer-pain.

The Role of Cryoprotective Agents in Liposome Stabilization and Preservation

To improve liposomes’ usage as drug delivery vehicles, cryoprotectants can be utilized to prevent constituent leakage and liposome instability. Cryoprotective agents (CPAs) or cryoprotectants can protect liposomes from the mechanical stress of ice by vitrifying at a specific temperature, which forms a glassy matrix. The majority of studies on cryoprotectants demonstrate that as the concentration of the cryoprotectant is increased, the liposomal stability improves, resulting in decreased aggregation. The effectiveness of CPAs in maintaining liposome stability in the aqueous state essentially depends on a complex interaction between protectants and bilayer composition. Furthermore, different types of CPAs have distinct effective mechanisms of action; therefore, the combination of several cryoprotectants may be beneficial and novel attributed to the synergistic actions of the CPAs. In this review, we discuss the use of liposomes as drug delivery vehicles, phospholipid–CPA interactions, their thermotropic behavior during freezing, types of CPA and their mechanism for preventing leakage of drugs from liposomes.

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.

Lornoxicam-Loaded Chitosan-Decorated Nanoemulsion: Preparation and In Vitro Evaluation for Enhanced Transdermal Delivery

Nanoemulsions are promising drug delivery systems for the administration of poorly soluble drugs like lornoxicam (LRX) by oral or parenteral routes. Such formulations work perfectly for transdermal delivery of lornoxicam-type drugs. It has also been established that formulating such a delivery system is highly dependent on the presence, type, and concentration of excipients taking part in the formulation. The inherent characteristics of nanoemulsion (NE), i.e., smaller globule size and excipient nature, facilitate the drug's passage through skin. The current study was aimed at the development of an NE-based formulation of LRX to improve the drug solubility in vitro as well as to enhance drug skin permeation to promote therapeutic outcome in appropriate time. Spontaneous self-emulsification technique was utilized to develop optimized LRX-encapsulated NE-based formulations. ATR-FTIR spectra of the pure drug and various formulations did not show any interaction between the drug and various formulation excipients showing compatibility. Globule size for stable formulations ranged between 63-168 nm. These formulations were characterized for viscosity, surface tension, pH, drug encapsulation efficiency, in vitro drug release, and drug skin permeation studies. Chitosan-decorated optimized NE formulation of LRX showed about 58.82% cumulative drug release, showing an anomalous non-Fickian diffusion mechanism of drug release. Drug encapsulation efficiency, in vitro drug release, and skin permeation studies exhibited promising results. An appreciable drug entrapment efficiency was exhibited by optimized NE formulations LRX-6, 71.91 ± 3.17% and C-LRX, 65.25 ± 4.89%. Permeability parameters like enhancement ratio (Er), permeability constant (Kp), and steady state flux (Jss) showed higher values and exhibited good results based on formulation type. The selected promising formulation type "LRX-6" showed significantly different results as compared to other formulations (LRX-4, 5, and 7). The skin permeation property of the LRX-6 formulation was compared to similar chitosan-based formulations and was found to have better skin permeation results than chitosan-based formulations. This study clearly exhibited that an LRX-containing NE-based formulation can be formulated to form a stable drug delivery system. Such formulations are promising in terms of physicochemical characteristics, improved solubility, and high skin permeation potential.

Analgesia in the Initial Management of Acute Pancreatitis: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

BACKGROUND

The optimal analgesic strategy for patients with acute pancreatitis (AP) remains unknown.

OBJECTIVE

The present systematic review and meta-analysis aims to compare the efficacy of different analgesic modalities trialled in AP.

METHODS

A systematic search of PubMed, MEDLINE, EMBASE, CENTRAL, SCOPUS and Web of Science conducted up until June 2021, identified all randomised control trials (RCTs) comparing analgesic modalities in AP. A pooled analysis was undertaken of the improvement in pain scores as reported on visual analogue scale (VAS) on day 0, day 1 and day 2.

RESULTS

Twelve RCTs were identified including 542 patients. Seven trial drugs were compared: opiates, non-steroidal anti-inflammatories (NSAIDs), metamizole, local anaesthetic, epidural, paracetamol, and placebo. Across all modalities, the pooled VAS scores showed global improvement from baseline to day 2. Epidural analgesia appears to provide the greatest improvement in VAS within the first 24 h but is equivalent to opiates by 48 h. Within 24 h, NSAIDs offered similar pain-relief to opiates, while placebo also showed equivalence to other modalities but then plateaued. Local anaesthetics demonstrated least overall efficacy. VAS scores for opiate and non-opiate analgesics were comparable at baseline and day 1. The identified RCTs demonstrated significant statistical and methodological heterogeneity in pain-relief reporting.

CONCLUSIONS

There is remarkable paucity of level 1 evidence to guide pain management in AP with small datasets per study. Epidural administration appears effective within the first 24 h of AP although infrequently used and featured in only a single RCT. NSAIDs are an effective opiate sparing alternative during the first 24 h.

Doxorubicin-loaded, pH-sensitive Albumin Nanoparticles for Lung Cancer Cell Targeting

In recent decades, scientific and medical communities have continuously sought new methods and chemistries to improve the treatment of cancer. Among many types of nanoparticles considered as carriers for drug delivery, the protein ones count among the safest. The present study aimed to investigate the physicochemical and biological effects of the supplementation of albumin nanoparticles with doxorubicin (DOX). DOX was co-precipitated with albumin in a desolvation process and entrapped inside the cross-linked albumin nanoparticles, where it disrupted the protein structure at various levels: (a) it reduced the particle size distribution homogeneity; (b) it extended the peptide bond length; (c) it lowered the thermal stability of albumin; (d) it lowered the crystallinity of the protein. Physicochemical mechanisms underlying these changes are discussed. The drug release was incomplete under the physiological conditions, but the nanoparticles fully released their chemotherapeutic payload when pH was decreased by a single unit from the physiological value. Because the extracellular pH of tumors is usually by a single pH unit lower than that of healthy tissues, this environmentally responsive drug delivery system composed of albumin nanoparticles may be applicable in the targeting of cancer cells. In vitro assays against human lung cancer cells demonstrated that DOX released from albumin nanoparticles had a four times higher apoptotic activity than the equivalent concentration of free DOX. The ability of albumin to prevent the agglomeration of partially hydrophobic DOX and release it at a sustained, zero-order rate over the first 12 h of incubation, with no burst effect, explains this ability to augment the activity of DOX against the lung cancer cells.

The Factors Determining the Skin Penetration and Cellular Uptake of Nanocarriers: New Hope for Clinical Development

The skin provides a protective barrier against toxic environments and also offers a valuable route for topical drug delivery. The stratum corneum (SC) is the outermost layer of the skin and serves as the major barrier to chemical transfer through the skin. The human skin barrier is particularly difficult to overcome because of the complex composition and structure of the SC. Nanoparticulate carriers have gained widespread attention in topical drug delivery due to their tunable and versatile properties. The present review summarizes the main factors involved in skin penetration of nanocarriers containing the drug. Employment of nanotechnology in topical delivery has grown progressively during recent years; however, it is important to monitor the skin penetration of nanocarriers prior to their use to avoid possible toxic effects. Nanocarriers can act as a means to increase skin permeation of drugs by supporting direct interaction with the SC and increasing the period of permanence on the skin. Skin penetration is influenced by the physicochemical characteristics of nanocarriers such as composition, size, shape, surface chemistry, as well as skin features. Considering that the target of topical systems based on nanocarriers is the penetration of therapeutic agents in the skin layers, so a detailed understanding of the factors influencing skin permeability of nanocarriers is essential for safe and efficient therapeutic applications.

Cuminum cyminum L.-Mediated Synthesis of Silver Nanoparticles: Their Characterization and Effect on Formalin-Induced Nociceptive Response in Male Rats

In this study, a simple, low-cost, rapid, and eco-friendly approach for the biosynthesis of silver nanoparticles (AgNPs) using the aqueous extract of Cuminum cyminum L. (cumin) seed (CcAgNPs) was developed. Also, the anti-nociceptive properties of these synthesized AgNPs were evaluated in vivo. The CcAgNPs characterized using Ultraviolet-visible (UV-Vis) spectrophotometer, X-ray diffraction analysis (XRD), Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM). The analysis of phytochemical components in the aqueous extract of cumin seeds showed high concentrations of total phenols and ascorbic acid and low concentrations of total flavonoids. The analysis of phytochemical components and FTIR spectroscopy confirmed the presence of functional groups responsible for the bioreduction of Ag⁺ to AgNPs. The UV-Vis absorbance spectrum of CcAgNPs showed a maximum wavelength at 442 nm. The analysis of TEM images showed a spherical shape with a size of less than 50 nm, while XRD spectra revealed the crystallinity of CcAgNPs. The analysis of anti-nociceptive properties of CcAgNPs showed that the first phase of formalin-induced pain was significantly reduced in the groups receiving 200, 500, and 1000 mg/kg CcAgNPs compared with the controls and the group receiving 300 mg/kg of sodium salicylate (SS300). The second phase of formalin pain was also significantly reduced in the groups receiving 200 and 500 mg/kg CcAgNPs compared to the controls and SS300 group. Overall, we introduced a new AgNPs synthesized from cumin seeds (CcAgNPs) and showed their anti-nociceptive properties in the formalin-induced pain.

Microemulsion-based gel for the transdermal delivery of rasagiline mesylate: In vitro and in vivo assessment for Parkinson's therapy

Rasagiline mesylate (RSM) is a selective and irreversible monoamine oxidase B inhibitor used for the treatment of Parkinson's disease (PD). However, its unfavorable biopharmaceutical properties, such as extensive degradation in the gastrointestinal tract and first-pass metabolism are responsible for its low oral bioavailability and suboptimal therapeutic efficacy. Here, we report the feasibility of delivering RSM via the transdermal route using RSM containing microemulsion-based gel (RSM-MEG) to achieve effective management of PD. Our in vitro skin permeation studies of RSM-MEG showed significantly higher (at least ~1.5-fold) permeation across rat skin compared to the conventional RSM hydrogel. Our skin irritation studies in rabbits showed that RSM-MEG is safe for transdermal application. Finally, using the rat model of rotenone-induced Parkinsonism, we demonstrated that the topical application of RSM-MEG was equally effective in reversing PD symptoms when compared to oral RSM therapy. Thus, our study confirmed the feasibility and potential of transdermal delivery of RSM via simple topical application of RSM-MEG, and this approach could be an alternative therapeutic intervention for the treatment of Parkinson's disease.

Fabrication of Alginate-Based O/W Nanoemulsions for Transdermal Drug Delivery of Lidocaine: Influence of the Oil Phase and Surfactant

Transdermal drug delivery of lidocaine is a good choice for local anesthetic delivery. Microemulsions have shown great effectiveness for the transdermal transport of lidocaine. Oil-in-water nanoemulsions are particularly suitable for encapsulation of lipophilic molecules because of their ability to form stable and transparent delivery systems with good skin permeation. However, fabrication of nanoemulsions containing lidocaine to provide an extended local anesthetic effect is challenging. Hence, the aim of this study was to address this issue by employing alginate-based o/w nanocarriers using nanoemulsion template that is prepared by combined approaches of ultrasound and phase inversion temperature (PIT). In this study, the influence of system composition such as oil type, oil and surfactant concentration on the particle size, in vitro release and skin permeation of lidocaine nanoemulsions was investigated. Structural characterization of lidocaine nanoemulsions as a function of water dilution was done using DSC. Nanoemulsions with small droplet diameters (d < 150 nm) were obtained as demonstrated by dynamic light scattering (DLS) and cryo-TEM. These nanoemulsions were also able to release 90% of their content within 24-h through PDMS and pig skin and able to the drug release over a 48-h. This extended-release profile is highly favorable in transdermal drug delivery and shows the great potential of this nanoemulsion as delivery system.

Ketamine-polymer based drug delivery system for prolonged analgesia: recent advances, challenges and future prospects

Introduction: With a sharp increase in NSAIDs and opioid use for chronic pain conditions associated with traumatic injuries and diseases, there has been an escalated risk of life-threatening side effects (cardiac and respiratory malfunction), inadvertent overdose, and even death. Their short duration of action and toxicity induces the need to develop extended-release analgesic drug formulations based on safe drugs like ketamine.Areas covered: This review presents progressive breakthroughs in pain control strategies for augmenting patient's comfort and minimizing unnecessary adverse effects associated with NSAIDs and opioids. Advantages of using ketamine, a dissociative anesthetic and potent analgesic over opioids have been elaborated here for the development of advanced sustained-release analgesic drug formulations based on ketamine and polymers (hydrogels, microparticles, and nanoparticles) as mainstream systems. These systems can be very promising in the resource-constrained healthcare set-up where frequent drug dosing at short time intervals is extremely challenging. PubMed, Embase, Google Scholar electronic databases, and clinical websites were used for conducting extensive research.Expert opinion: Controlled drug release analgesic systems can significantly reduce the burden of repeated drug dosing and opioid drug dependency, maximizing the function of analgesic drugs for clinical translation, and improving the quality of life of those living with pain.

Biocompatibility and Pharmacological Effects of Innovative Systems for Prolonged Drug Release Containing Dexketoprofen in Rats

The present study reports on the in vivo biocompatibility investigation and evaluation of the effects of liposomes containing dexketoprofen in somatic sensitivity in rats. Method: The liposomes were prepared by entrapping dexketoprofen in vesicular systems stabilized with chitosan. The in vivo biocompatibility was evaluated after oral administration in white Wistar rats: Group I (DW): distilled water 0.3 mL/100 g body weight; Group II (DEX): dexketoprofen 10 mg/kg body weight (kbw); Group III (nano-DEX): liposomes containing dexketoprofen 10 mg/kbw. Blood samples were collected from caudal lateral vein one day and seven days after the substance administration, to assess the eventual hematological, biochemical, and immunological changes. The investigation of somatic pain reactivity was performed using the hot plate test, to count the latency time response evoked by the thermal paws’ noxious stimulation. Results: Original liposomes entrapping dexketoprofen, with mean size of 680 nm and good stability, were designed. Laboratory analysis indicated no substantial variances between the three treated groups. The treatment with liposomes containing dexketoprofen resulted in a prolongation of the latency time response, statistically significant in the interval between 90 min and 10 h, in the hot plate test. Conclusions: The use of liposomes with dexketoprofen proved a good in vivo biocompatibility in rats and prolonged analgesic effects in the hot plate test.

Exploration of Nanoethosomal Transgel of Naproxen Sodium for the Treatment of Arthritis

BACKGROUND

The present work aimed to develop an ethosomal gel of naproxen sodium for the amelioration of rheumatoid arthritis.

OBJECTIVE

In the present work, we have explored the potential of ethosomes to deliver naproxen into deeper skin strata. Further, the anti-inflammatory efficacy of naproxen ethosomal formulation was assessed using the carrageenan-induced rat paw edema model.

METHODS

Naproxen sodium nanoethosomes were prepared using different proportions of lipoid S100 (50mg-200mg), ethanol (20-50%) and water, and were further characterized on the basis of vesicle morphology, entrapment efficiency, zeta potential, in-vitro drug release and ex-vivo permeation studies.

RESULTS

The optimized ethosomal formulation was found to have 129 ± 0.01 nm particle size, 0.295 Polydispersity Index (PDI), -3.29 mV zeta potential, 88% entrapment efficiency and 96.573% drug release in 24 hours. TEM and SEM analysis of the optimized formulation showed slightly smooth spherical structures. The Confocal laser scanning microscopy showed that ethosomes could easily infiltrate into deeper dermal layers (upto 104.9μm) whereas the hydroalcoholic solution of the drug could penetrate up to 74.9μm. Further, the optimized ethosomal formulation was incorporated into 1% carbopol 934 gel base and optimized wherein the transdermal flux was found to be approximately 10 times more than the hydroethanolic solution. Also, the in-vivo pharmacodynamic study of the optimized ethosomal gel exhibited a higher percentage inhibition of swelling paw edema than marketed diclofenac gel.

CONCLUSION

The ethosomal gel was successfully developed and has shown the potential to be a good option for the replacement of conventional therapies of rheumatoid arthritis.

Role of Nanobiotechnology in Drug Delivery

This chapter is a brief overview of use of nanobiotechnology in drug delivery. Several types of nanoparticles are available. Nanoparticulate formulations of normally used drugs have increased efficacy due to improved absorption and require lower dosage with less side effects than standard formulations. Nanobiotechnology also facilitates targeted drug delivery of anticancer drugs, which is important for the management of cancer. Nanoparticles also facilitate crossing of biological barriers in the human body for drug delivery to targeted organs, for example, crossing the blood-brain barrier to reach the brain. Nanobiotechnology applications in delivery of biological therapies are expanding in areas such as cell and gene therapies, siRNAs, and monoclonal antibodies. Some nanoparticles can carry more than one therapeutic molecule enabling multimodal therapy and combination with physical modalities such as radiotherapy in cancer. Nanorobotics is developing with applications in drug delivery, particularly for cancer. Other anticipated developments in this area include use of nanotechnology for creating intelligent drug release devices.

Chitosan-collagen based film for controlled delivery of a combination of short life anesthetics

The present research was undertaken to develop a chitosan-collagen film for controlled delivery of combinations of local anesthetics. The film has been prepared by casting which is a versatile, rapid and low-cost approach distinguished by high reproducibility. The mechanical, morphological, and physicochemical properties of the films and the impact of the drug loading were evaluated. We showed that the formulations have a good combination of strength and flexibility with high water permeability. Surface morphology investigation indicates a variation in roughness depending on the loaded compound. Release studies were performed in controlled environments and the data processed by the Higuchi model to assess the dynamics of the release. The local anesthetics, lidocaine, tetracaine, and benzocaine, were uniformly distributed within the matrix and released in a rate and magnitude specific for the drug concentration and combination tunable in a range time from 6 h to 24 h. The films dissolve completely in the physiological environment within 24 h without leaving any toxic metabolites as both of the components are recognized as safe. In vitro cytotoxicity and cell proliferation tests performed on human dermal fibroblast demonstrate the biocompatibility and lack of cytotoxicity of the prepared formulations.

Lipid-based carriers for the delivery of local anesthetics

INTRODUCTION

There is a clinical need for pharmaceutical dosage forms devised to prolong the acting time of local anesthetic (LA) agents or to reduce their toxicity. Encapsulation of LA in drug delivery systems (DDSs) can provide long-term anesthesia for inpatients (e.g. in immediate postsurgical pain control, avoiding the side effects from systemic analgesia) and diminished systemic toxicity for outpatients (in ambulatory/dentistry procedures). The lipid-based formulations described here, such as liposomes, microemulsions, and lipid nanoparticles, have provided several nanotechnological advances and therapeutic alternatives despite some inherent limitations associated with the fabrication processes, costs, and preclinical evaluation models.

AREAS COVERED

A description of the currently promising lipid-based carriers, including liposomes, microemulsions, and nanostructured lipid carriers, followed by a systematic review of the existing lipid-based formulations proposed for LA. Trends in the research of these LA-in-DDS are then exposed, from the point of view of administration route and alternatives for non-traditionally administered LA molecules.

EXPERT OPINION

Considering the current state and potential future developments in the field, we discuss the reasons for why dozens of formulations published every year fail to reach clinical trials; only one lipid-based formulation for the delivery of local anesthetic (Exparel®) has been approved so far.