Lamotrigine loaded PLGA nanoparticles intended for direct nose to brain delivery in epilepsy: pharmacokinetic, pharmacodynamic and scintigraphy study

Epilepsy Treatment and Diagnosis Enhanced by Current Nanomaterial Innovations: A Comprehensive Review

Epilepsy is a complex disease in the brain. Complete control of seizure has always been a challenge in epilepsy treatment. Currently, clinical management primarily involves pharmacological and surgical interventions, with the former being the preferred approach. However, antiepileptic drugs often exhibit low bioavailability due to inherent limitations such as poor water solubility and difficulty penetrating the blood-brain barrier (BBB). These issues significantly reduce the drugs' effectiveness and limit their clinical application in epilepsy treatment. Additionally, the diagnostic accuracy of current imaging techniques and electroencephalography (EEG) for epilepsy is suboptimal, often failing to precisely localize epileptogenic tissues. Accurate diagnosis is critical for the surgical management of epilepsy. Thus, there is a pressing need to enhance both the therapeutic outcomes of epilepsy medications and the diagnostic precision of the condition. In recent years, the advancement of nanotechnology in the biomedical sector has led to the development of nanomaterials as drug carriers. These materials are designed to improve drug bioavailability and targeting by leveraging their large specific surface area, facile surface modification, ability to cross the BBB, and high biocompatibility. Furthermore, nanomaterials have been utilized as contrast agents in imaging and as materials for EEG electrodes, enhancing the accuracy of epilepsy diagnoses. This review provides a comprehensive examination of current research on nanomaterials in the treatment and diagnosis of epilepsy, offering new strategies and directions for future investigation.

Mucoadhesive chitosan-poly (lactic-co-glycolic acid) nanoparticles for intranasal delivery of quetiapine - Development & characterization in physiologically relevant 3D tissue models

Quetiapine hemifumarate (QF) delivery to the CNS via conventional formulations is challenging due to poor solubility and lower oral bioavailability (9 %). Similarly, many other second-generation antipsychotics, such as olanzapine, clozapine, and paliperidone, have also shown low oral bioavailability of <50 %. Hence, the present work was intended to formulate QF-loaded biodegradable PLGA-NPs with appropriate surface charge modification through poloxamer-chitosan and investigate its targeting potential on RPMI-2650 cell lines to overcome the limitations of conventional therapies. QF-loaded poloxamer-chitosan-PLGA in-situ gel (QF-PLGA-ISG) was designed using emulsification and solvent evaporation techniques. Developed QF-PLGA-ISG were subjected to evaluation for particle size, PDI, zeta potential, ex-vivo mucoadhesion, entrapment efficiency (%EE), and drug loading, which revealed 162.2 nm, 0.124, +20.5 mV, 52.4 g, 77.5 %, and 9.7 %, respectively. Additionally, QF-PLGA formulation showed >90 % release within 12 h compared to 80 % of QF-suspension, demonstrating that the surfactant with chitosan-poloxamer polymers could sustainably release medicine across the membrane. Ex-vivo hemolysis study proved that developed PLGA nanoparticles did not cause any hemolysis compared to negative control. Further, in-vitro cellular uptake and transepithelial permeation were assessed using the RPMI-2650 nasal epithelial cell line. QF-PLGA-ISG not only improved intracellular uptake but also demonstrated a 1.5-2-fold increase in QF transport across RPMI-2650 epithelial monolayer. Further studies in the EpiNasal™ 3D nasal tissue model confirmed the safety and efficacy of the developed QF-PLGA-ISG formulation with up to a 4-fold increase in transport compared to plain QF after 4 h. Additionally, histological reports demonstrated the safety of optimized formulation. Finally, favorable outcomes of IN QF-PLGA-ISG formulation could provide a novel platform for safe and effective delivery of QF in schizophrenic patients.

Nanotherapeutics for Alleviating Anesthesia-Associated Complications

Current management of anesthesia-associated complications falls short in terms of both efficacy and safety. Nanomaterials with versatile properties and unique nano-bio interactions hold substantial promise as therapeutics for addressing these complications. This review conducts a thorough examination of the existing nanotherapeutics and highlights the strategies for developing prospective nanomedicines to mitigate anesthetics-related toxicity. Initially, general, regional, and local anesthesia along with the commonly used anesthetics and related prevalent side effects are introduced. Furthermore, employing nanotechnology to prevent and alleviate the complications of anesthetics is systematically demonstrated from three aspects, that is, developing 1) safe nano-formulization for anesthetics; 2) nano-antidotes to sequester overdosed anesthetics and alter their pharmacokinetics; 3) nanomedicines with pharmacodynamic activities to treat anesthetics toxicity. Finally, the prospects and challenges facing the clinical translation of nanotherapeutics for anesthesia-related complications are discussed. This work provides a comprehensive roadmap for developing effective nanotherapeutics to prevent and mitigate anesthesia-associated toxicity, which can potentially revolutionize the management of anesthesia complications.

Intranasal administration of antiseizure medications in chronic and emergency treatment: Hopes and challenges

Despite the availability of many antiseizure medications (ASMs), 30 % of patients experience pharmacoresistant seizures. High-throughput screening methods undoubtedly remain one of the most important approaches for discovering new molecules to treat seizures. However, the costly and time-consuming nature of drug development prompts us to explore alternative strategies to counteract drug-resistant seizures. One such approach is to consider intranasal administration of known molecules for seizure treatment. In the case of treating epileptic seizures, administering ASMs intranasally may enhance treatment effectiveness and minimize adverse effects. A good example of changes in drug administration is the intranasal administration of fentanyl, which has become a clinical standard in the emergency setting to treat moderate to severe pain in adults and children. This review discusses the utilization of intranasally administered ASMs for both acute and chronic seizures. It addresses various targeted pharmacokinetic approaches, challenges and prospects associated with these regimens. Brief neuroanatomical and molecular rationale for nose-to-brain drug transport is also presented. Furthermore, recent preclinical studies validating the efficacy and brain distribution following intranasal administration of the most commonly used drugs in chronic treatment are also discussed.

Nanotechnological advances in the treatment of epilepsy: a comprehensive review

Epilepsy is one of the most prevalent chronic neurological disorders characterized by frequent unprovoked epileptic seizures. Epileptic seizures can develop from a broad range of underlying abnormalities such as tumours, strokes, infections, traumatic brain injury, developmental abnormalities, autoimmune diseases, and genetic predispositions. Sometimes epilepsy is not easily diagnosed and treated due to the large diversity of symptoms. Undiagnosed and untreated seizures deteriorate over time, impair cognition, lead to injuries, and can sometimes result in death. This review gives details about epilepsy, its classification on the basis of International League Against Epilepsy, current therapeutics which are presently offered for the treatment of epilepsy. Despite of the fact that more than 30 different anti-epileptic medication and antiseizure drugs are available, large number of epileptic patients fail to attain prolonged seizure independence. Poor onsite bioavailability of drugs due to blood brain barrier poses a major challenge in drug delivery to brain. The present review covers the limitations with the state-of-the-art strategies for managing seizures and emphasizes the role of nanotechnology in overcoming these issues. Various nano-carriers like polymeric nanoparticles, dendrimers, lipidic nanoparticles such as solid lipid nanoparticles, nano-lipid carriers, have been explored for the delivery of anti-epileptic drugs to brain using oral and intranasal routes. Nano-carries protect the encapsulated drugs from degradation and provide a platform to deliver controlled release over prolonged periods, improved permeability and bioavailability at the site of action. The review also emphasises in details about the role of neuropeptides for the treatment of epilepsy.

Nose to Brain Delivery of Transferrin conjugated PLGA nanoparticles for clonidine

The present work focuses on the development of surface modified transferrin PLGA nanoparticles loaded with clonidine for nose to brain delivery. The CLD-Tf-PLGA-NPs were developed using double emulsification, followed by solvent evaporation and characterization. Particle size, PDI and Zeta potential of the nanoparticles was 199.5 ± 1.36 nm, 0.291, -17.4 ± 6.29 mV respectively with EE% 86.2 ± 2.12 %, and DL%, 7.8 ± 0.48 %. TEM, SEM and FTIR analysis were carried out to confirm the size and transferrin coating over the surface of nanoparticles. In-vitro drug release profile were studied in PBS (pH 7.4) and SNF (pH 5.5) for 72 h and highest release was observed in PBS 89.54 ± 3.17 %. Cellular assays were conducted on Neuro-2a cells to check the cytotoxicity and uptake of Tf-modified PLGA nanoparticles and the cell viability% was obtained to be 61.85 ± 4.48 % even at maximum concentration (40Cmax) with uptake of approximately 97 %. Histopathological studies were also performed to identify the cytotoxicity on nasal epithelium along with in-vivo biodistribution and pharmacodynamics studies to assess the concentration of drug in the mice brain and behavioural responses after intranasal delivery of surface modified nanoparticles. The results showed significant increase in concentration of drug in brain and behavioural improvements in mice (p < 0.05).

Polysorbate 80 surface modified PLGA nanoparticles: an in-vitro evaluation of cellular uptake and cytotoxicity on neuro-2a cells

AIM

Present study focuses on the development of P80 coated PLGA Nanoparticles loaded with drugs, paroxetine (P80-Par-PLGA-NPs) and clonidine (P80-CLD-PLGA-NPs) for in-vitro evaluation of Cellular Uptake & Cytotoxicity on Neuro-2a cells.

METHOD

P80-Par-PLGA-NPs and P80-CLD-PLGA-NPs were developed and characterised for zeta size, potential, PDI, EE%, DL%, TEM, SEM, FTIR, DSC, in-vitro release, cytotoxicity, histopathological and cell uptake studies using rhodamine loaded P80-NPs.

RESULT

Mean particle diameter of P80-Par-PLGA-NPs and P80-CLD-PLGA-NPs was 204; 182.7 nm, ZP of -21.8; -18.72 mV and 0.275; 0.341 PDI, respectively. TEM and SEM images revealed homogenous surface morphology. In-vitro drug release showed sustained and complete release in 72 h. Cell viability (>90%) at Cmax and no cytotoxicity in histopathology was observed. Significant higher uptake (96.9%) of P80-modified-NPS was observed as compared to unmodified-NPs (81%) (p < 0.05).

CONCLUSION

The finding clearly indicated a higher cell uptake of drugs via surface modified P80-coated PLGA-NPs as compared to unmodified particles.

Lamotrigine-Loaded Poloxamer-Based Thermo-Responsive Sol-Gel: Formulation, In Vitro Assessment, Ex Vivo Permeation, and Toxicology Study

The present study aimed to prepare, characterize, and evaluate a thermo-responsive sol-gel for intranasal delivery of lamotrigine (LTG), which was designed for sustained drug delivery to treat epilepsy. LTG sol-gel was prepared using the cold method by changing the concentrations of poloxamer 407 and poloxamer 188, which were used as thermo-reversible polymers. The optimized formulations of sol-gel were analyzed for clarity, pH, viscosity, gelation temperature, gelation time, spreadability, drug content, in vitro drug release studies, ex vivo permeation studies, and in vivo toxicological studies. FTIR, XRD, and DSC were performed to determine the thermal stability of the drug and polymers. The prepared formulations had a clear appearance in sol form; they were liquid at room temperature and became gel at temperatures between 31 °C and 36 °C. The pH was within the range of the nasal pH, between 6.2 and 6.4. The drug content was found to be between 92% and 94%. In vitro drug release studies indicated that the formulations released up to 92% of the drug within 24 h. The FTIR, DSC, and XRD analyses showed no interaction between the drug and the polymer. A short-term stability study indicated that the formulation was stable at room temperature and at 4-8 °C. There was a slight increase in viscosity at room temperature, which may be due to the evaporation of the vehicle. A histological study indicated that there were no signs of toxicity seen in vital organs, such as the brain, kidney, liver, heart, and spleen. It can be concluded from the above results that the prepared intranasal sol-gel for the delivery of LTG is safe for direct nose-to-brain delivery to overcome the first-pass effect and thus enhance bioavailability. It can be considered an effective alternative to conventional drug delivery for the treatment of epilepsy.

Understanding Lamotrigine's Role in the CNS and Possible Future Evolution

The anti-epileptic drug lamotrigine (LTG) has been widely used to treat various neurological disorders, including epilepsy and bipolar disorder. However, its precise mechanism of action in the central nervous system (CNS) still needs to be determined. Recent studies have highlighted the involvement of LTG in modulating the activity of voltage-gated ion channels, particularly those related to the inhibition of neuronal excitability. Additionally, LTG has been found to have neuroprotective effects, potentially through the inhibition of glutamate release and the enhancement of GABAergic neurotransmission. LTG's unique mechanism of action compared to other anti-epileptic drugs has led to the investigation of its use in treating other CNS disorders, such as neuropathic pain, PTSD, and major depressive disorder. Furthermore, the drug has been combined with other anti-epileptic drugs and mood stabilizers, which may enhance its therapeutic effects. In conclusion, LTG's potential to modulate multiple neurotransmitters and ion channels in the CNS makes it a promising drug for treating various neurological disorders. As our understanding of its mechanism of action in the CNS continues to evolve, the potential for the drug to be used in new indications will also be explored.

Intranasal Polymeric and Lipid-Based Nanocarriers for CNS Drug Delivery

Nanomedicine is currently focused on the design and development of nanocarriers that enhance drug delivery to the brain to address unmet clinical needs for treating neuropsychiatric disorders and neurological diseases. Polymer and lipid-based drug carriers are advantageous for delivery to the central nervous system (CNS) due to their safety profiles, drug-loading capacity, and controlled-release properties. Polymer and lipid-based nanoparticles (NPs) are reported to penetrate the blood–brain barrier (BBB) and have been extensively assessed in in vitro and animal models of glioblastoma, epilepsy, and neurodegenerative disease. Since approval by the Food and Drug Administration (FDA) of intranasal esketamine for treatment of major depressive disorder, intranasal administration has emerged as an attractive route to bypass the BBB for drug delivery to the CNS. NPs can be specifically designed for intranasal administration by tailoring their size and coating with mucoadhesive agents or other moieties that promote transport across the nasal mucosa. In this review, unique characteristics of polymeric and lipid-based nanocarriers desirable for drug delivery to the brain are explored in addition to their potential for drug repurposing for the treatment of CNS disorders. Progress in intranasal drug delivery using polymeric and lipid-based nanostructures for the development of treatments of various neurological diseases are also described.

Translational Considerations in the Development of Intranasal Treatments for Epilepsy

Epilepsy is a common and serious neurological disorder, to which a high proportion of patients continue to be considered "drug-resistant", despite the availability of a host of anti-seizure drugs. Investigation into new treatment strategies is therefore of great importance. One such strategy is the use of the nose to deliver drugs directly to the brain with the help of pharmaceutical formulation to overcome the physical challenges presented by this route. The following review explores intranasal delivery of anti-seizure drugs, covering the link between the nose and seizures, pathways from the nose to the brain, current formulations in clinical use, animal seizure models and their proposed application in studying intranasal treatments, and a critical discussion of relevant pre-clinical studies in the literature.

Lipid nanoparticles strategies to modify pharmacokinetics of central nervous system targeting drugs: Crossing or circumventing the blood-brain barrier (BBB) to manage neurological disorders

The main limitation to the success of central nervous system (CNS) therapies lies in the difficulty for drugs to cross the blood-brain barrier (BBB) and reach the brain. Regarding its structure and enzymatic complexity, crossing the BBB is a challenge, although several alternatives have been identified. For instance, the use of drugs encapsulated in lipid nanoparticles has been described as one of the most efficient approaches to bypass the BBB, as they allow the passage of drugs through this barrier, improving brain bioavailability. In particular, solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been a focus of research related to drug delivery to the brain. These systems provide protection of lipophilic drugs, improved delivery and bioavailability, having a major impact on treatments outcomes. In addition, the use of lipid nanoparticles administered via routes that transport drugs directly into the brain seems a promising solution to avoid the difficulties in crossing the BBB. For instance, the nose-to-brain route has gained considerable interest, as it has shown efficacy in 3D human nasal models and in animal models. This review addresses the state of the art on the use of lipid nanoparticles to modify the pharmacokinetics of drugs employed in the management of neurological disorders. A description of the structural components of the BBB, the role of the neurovascular unit and limitations for drugs to entry into the CNS is first addressed, along with the developments to increase drug delivery to the brain, with a special focus on lipid nanoparticles. In addition, the obstacle of BBB complexity in the creation of new effective drugs for the treatment of the most prevalent neurological disorders is also addressed. Finally, the proposed strategies for lipid nanoparticles to reach the CNS, crossing or circumventing the BBB, are described. Although promising results have been reported, especially with the nose-to-brain route, they are still ongoing to assess its real efficacy in vivo in the management of neurological disorders.

Direct nose to the brain nanomedicine delivery presents a formidable challenge

This advanced review describes the anatomical and physiological barriers and mechanisms impacting nanomedicine translocation from the nasal cavity directly to the brain. There are significant physiological and anatomical differences in the nasal cavity, olfactory area, and airflow reaching the olfactory epithelium between humans and experimentally studied species that should be considered when extrapolating experimental results to humans. Mucus, transporters, and tight junction proteins present barriers to material translocation across the olfactory epithelium. Uptake of nanoparticles through the olfactory mucosa and translocation to the brain can be intracellular via cranial nerves (intraneuronal) or other cells of the olfactory epithelium, or extracellular along cranial nerve pathways (perineural) and surrounding blood vessels (perivascular, the glymphatic system). Transport rates vary greatly among the nose to brain pathways. Nanomedicine physicochemical properties (size, surface charge, surface coating, and particle stability) can affect uptake efficiency, which is usually less than 5%. Incorporation of therapeutic agents in nanoparticles has been shown to produce pharmacokinetic and pharmacodynamic benefits. Assessment of adverse effects has included olfactory mucosa toxicity, ciliotoxicity, and olfactory bulb and brain neurotoxicity. The results have generally suggested the investigated nanomedicines do not present significant toxicity. Research needs to advance the understanding of nanomedicine translocation and its drug cargo after intranasal administration is presented. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials.

Eudragit S-100 Surface Engineered Nanostructured Lipid Carriers for Colon Targeting of 5-Fluorouracil: Optimization and In Vitro and In Vivo Characterization

5-Fluorouracil (5-FU) is the most preferred chemotherapeutic agent in the management of colon cancer but is associated with poor therapeutic efficacy and lack of site specificity. Hence, it was aimed to employ Eudragit S100 surface engineered 5-FU nanostructured lipid carriers for the spatial and temporal release of the drug for the treatment of colon cancer. Hot high-pressure homogenization (HPH) technique was employed in the preparation of 5-FU-NLCs. The optimization of 5-FU-NLCs was performed using a Quality by Design (QbD) approach. A 3² factorial design was employed wherein the relationship between independent variables [amount of oleic acid (X₁) and concentration of Tween®80 (X₂)] and dependent variables [particle size (Y₁) and % entrapment efficiency (Y₂)] was studied. Optimized 5-FU-NLCs were surface treated to obtain Eudragit S100-coated 5-FU-NLCs (EU-5-FU-NLCs). The evaluation parameters for 5-FU-NLCs and EU-5-FU-NLCs included surface morphology, particle size, PDI, and zeta potential. In vitro release from EU-5-FU-NLCs revealed a selective and controlled 5-FU release in the colonic region for 24 h. In vitro cytotoxicity (MTT assay) was performed against Caco-2 cancer cells, wherein EU-5-FU-NLCs exhibited a 2-fold greater cytotoxic potential in comparison to a 5-FU solution (5-FU-DS). Oral administration of EU-5-FU-NLCs in Albino Wistar rats depicted a higher C_max (2.54 folds) and AUC (11 folds) as well as prolonged T_max (16 folds) and MRT (4.32 folds) compared to 5-FU-DS confirming higher bioavailability along with the spatial and temporal release in the colonic region. Thus, a multifaceted strategy involving abridgement of nanotechnology along with surface engineering is introduced for effective chemotherapy of colon cancer via oral administration of 5-FU with uncompromised safety and higher efficacy.Graphical abstract.