Brain Bioavailability Research Articles

Brain Targeting of Duloxetine HCL via Intranasal Delivery of Loaded Cubosomal Gel: In vitro Characterization, ex vivo Permeation, and in vivo Biodistribution Studies.

PurposeDuloxetine (DLX) is dual serotonin and norepinephrine reuptake inhibitor suffering from limited bioavailability (≈ 40%) due to extensive hepatic metabolism. This work aims to formulate and evaluate DLX intranasal thermoreversible cubosomal gels to enhance its bioavailability and ensure efficient brain targeting.Materials and MethodsCubo-gels were prepared by 33 central composite design with three independent factors, lipid ratio (glycerol monooleate: glycerol tripalmitate), Pluronic F127%, and Pluronic F68%. The prepared formulations were evaluated for their particle size (PS), gelling temperature (GT), entrapment efficiency (EE%), and in vitro release. The cubo-gel with the highest desirability (0.88) was chosen as the optimized formulation. DLX cubo-gel was evaluated using differential scanning calorimetry, Fourier-transform infrared spectroscopy, X-ray powder diffraction, and transmission electron microscopy. Cytotoxicity study, ex vivo permeation study and in vivo bio-distribution study were conducted to evaluate the safety and efficacy of brain targeting.ResultsThe optimum cubo-gel was composed of 3.76 lipid ratio, 20% w/v PF127, and 5% w/v PF68. It had PS of 265.13 ± 9.85 nm, GT of 32 ± 0.05°C, EE% of 98.13 ± 0.50%, and showed controlled release behavior where 33% DLX was released within 6 hrs. The plain in situ cubo-gel had a significantly higher IC50 compared to DLX solution and DLX-loaded in situ cubo-gel. The ex vivo permeation study showed 1.27 enhancement in the drug permeation from DLX in situ cubo-gel. According to the in vivo bio-distribution study in plasma and brain, the intranasal DLX in situ cubo-gel showed a 1.96 fold improvement in brain bioavailability compared to the intranasal solution. Its BTE% and DTP% were 137.77 and 10.5, respectively, indicating efficient brain targeting after intranasal administration.ConclusionAccordingly, intranasal DLX in situ cubo-gel can be considered as an innovative nano-carrier delivery system for bioavailability enhancement and efficient brain targeting of DLX to maximize its effect.

Ischemic brain treated with 6-gingerol loaded mucoadhesive nanoemulsion via intranasal delivery and their comparative pharmacokinetic effect in brain

Background6-Gingerol (GRL), as an antioxidant nonvolatile, phenolic component of ginger showed a capable function in the treatment of cerebral ischemia but their poor solubility and low absorption gives low bioavailability in the brain. PurposeThe main purpose of proposed study is to develop a novel GRL-loaded-nanoemulsion (GRL-NE) and converted to mucoadhesive nanoemulsion (GRL-MNE) for intranasal delivery to brain. MethodsAqueous microtitration method was used to formulate GRL-NE using Lauroglycol 90, Tween 80 and PEG-400 as the oil phase, surfactant, and co-surfactant with the help of CS converted into mucoadhesive-GRL-MNE was evaluated for morphology, physicochemically, stability in terms of thermodynamic, release (in vitro), mucoadhesive potency, and nasal permeation (ex-vivo) to enhance brain bioavailability and other PK-parameters. ResultsOpt-GRL-MNE showed mean globule-size (94.89 ± 2.61 nm), PDI (0.129 ± 0.091) and +ve ZP (1.892 ± 0.068 mV). Excellent mucoadhesive-nature of GRL-MNE as compared with GRL-S was found with their retention time (1.27 min) and m/z: 295.3764/137.0763 for GRL, alongwith a retention time (1.12 min) and m/z: 294.3126/137.1802 for Nonivamide (internal standard; IS). 1.0–1000.0 ng/mL linear range, % inter-and-intraday accuracy (94.12–98.97%) and CV (2.06–4.04%) were calculated. A highly significant (p < 0.001) results were found for enhanced Cmax with their area under curve (AUC)0–24 of based on i.n. and i.v. treated-groups of rats. Moreover, significantly results were observed for neurobehavioral and biochemical assessment with their histopathological assessment and reduction of infarction-volume in MCAO-induced brain-ischemic model after the delivered GRL-MNE via intranasal route. ConclusionGRL-MNE showed a significant (p < 0.001) role for the improvement of brain-bioavailability in the treatment of cerebral ischemia with improving their neuroprotection at very low-dose of GRL.

Mixed Amphiphilic Polymeric Nanoparticles of Chitosan, Poly(vinyl alcohol) and Poly(methyl methacrylate) for Intranasal Drug Delivery: A Preliminary In Vivo Study.

Intranasal (i.n.) administration became an alternative strategy to bypass the blood–brain barrier and improve drug bioavailability in the brain. The main goal of this work was to preliminarily study the biodistribution of mixed amphiphilic mucoadhesive nanoparticles made of chitosan-g-poly(methyl methacrylate) and poly(vinyl alcohol)-g-poly(methyl methacrylate) and ionotropically crosslinked with sodium tripolyphosphate in the brain after intravenous (i.v.) and i.n. administration to Hsd:ICR mice. After i.v. administration, the highest nanoparticle accumulation was detected in the liver, among other peripheral organs. After i.n. administration of a 10-times smaller nanoparticle dose, the accumulation of the nanoparticles in off-target organs was much lower than after i.v. injection. In particular, the accumulation of the nanoparticles in the liver was 20 times lower than by i.v. When brains were analyzed separately, intravenously administered nanoparticles accumulated mainly in the “top” brain, reaching a maximum after 1 h. Conversely, in i.n. administration, nanoparticles were detected in the “bottom” brain and the head (maximum reached after 2 h) owing to their retention in the nasal mucosa and could serve as a reservoir from which the drug is released and transported to the brain over time. Overall, results indicate that i.n. nanoparticles reach similar brain bioavailability, though with a 10-fold smaller dose, and accumulate in off-target organs to a more limited extent and only after redistribution through the systemic circulation. At the same time, both administration routes seem to lead to differential accumulation in brain regions, and thus, they could be beneficial in the treatment of different medical conditions.

Transport of PEGylated-PLA nanoparticles across a blood brain barrier model, entry into neuronal cells and in vivo brain bioavailability

Treatments of neurodegenerative diseases (NDDs) are severely hampered by the presence of the blood-brain barrier (BBB) precluding efficient brain drug delivery. The development of drug nanocarriers aims at increasing the brain therapeutic index would represent a real progress in brain disease management. PEGylated polyester nanoparticles (NPs) are intensively tested in clinical trials for improved drug delivery. Our working hypothesis was that some surface parameters and size of NPs could favor their penetration across the BBB and their neuronal uptake. Polymeric material PEG-b-PLA diblocks were synthesized by ring opening polymerisation (ROP) with PEG2000 or PEG5000. A library of polymeric PEG-b-PLA diblocks NPs with different physicochemical properties was produced. The toxicity, endocytosis and transcytosis through the brain microvascular endothelial cells were monitored as well as the neuronal cells uptake. In vitro results lead to the identification of favourable surface parameters for the NPs endocytosis into vascular endothelial cells. NPs endocytosis took place mainly by macropinocytosis while transcytosis was partially controlled by their surface chemistry and size. In vivo assays on a zebrafish model showed that the kinetic of NPs in circulation is dependent on PEG coating properties. In vivo findings also showed a low but similar translocation of PEG-b-PLA diblocks NPs to the CNS, regardless of their properties. In conclusion, modulation of surface PEG chain length and NPs size impact the endocytosis rate of NPs but have little influence on cell barriers translocation; while in vivo biodistribution is influenced by surface PEG chain density.

Abstract 6220: KDM1A inhibition sensitizes glioblastoma cells to temozolomide therapy through DNA damage and apoptosis pathway modulation

Abstract Background: Glioblastoma (GBM) is the most common brain tumor. Despite advancements in multimodal treatment strategies, GBM patients exhibit a dismal prognosis with a median survival of 20 months and a 5-year survival rate post diagnosis of 13%. Standard of care consists of surgical resection, external beam radiation therapy, and adjuvant chemotherapy with temozolomide (TMZ). Despite heavy investment in therapy, GBM patients inevitably experience tumor progression and eventually succumb to their disease. Recently, we showed that lysine-specific histone demethylase 1A (KDM1A), an epigenetic modifier, is overexpressed in GBM. In this study, we tested the hypothesis that KDM1A is essential for DNA damage response (DDR) and inhibition of KDM1A sensitizes GBM to TMZ therapy. Methods: KDM1A knockout (KDM1A-KO) cells were generated using the CRISPR/Cas9 system and knockdown cells were generated using KDM1A specific shRNA (KDM1A-KD). We studied the effect of KDM1A-KO, -KD, or pharmacological KDM1A inhibitors (NCD-38 and NCL-1) on TMZ sensitization using Cell Titer-Glo luminescent cell viability assay, and survival assays. Apoptosis was determined using Caspase 3/7 and TUNEL assays. Mechanistic studies were conducted using RNA-seq, RT-qPCR, and Western blot analysis. Furthermore, the in vivo efficacy of KDM1A inhibitor and TMZ therapy was studied using orthotopic models of GBM using both male and female mice. Results: Cell viability and survival assays demonstrated that knockout/knockdown or inhibition of KDM1A sensitized patient derived glioma stem cells (GSCs) to TMZ treatment. Further, combination of NCD-38 or NCL-1 and TMZ significantly increased the apoptosis of GSCs. RNA-seq analysis revealed the modulation of DDR and apoptotic pathways following combination therapy. Pharmacokinetics (PK) and brain bioavailability studies showed that NCD-38 has favorable PK properties and exhibited a significant penetration through the blood brain barrier. Importantly, combination of NCD-38 and TMZ significantly reduced the in vivo tumor progression and improved the overall survival of both male and female mice compared to single drug treatment in GBM orthotopic models. Conclusions: Our results provide evidence that KDM1A knockdown/inhibition sensitizes GBM to TMZ therapy via modulation of DDR and that the use of KDM1A inhibitor in conjunction with TMZ could serve as a novel therapy for GBM patients. Citation Format: Bridgitte E. Palacios, Prabhakar Pitta Venkata, Yihong Chen, Salvador Alejo, Yi He, Suryavathi Viswanadhapalli, Uday Pratap, Junhao Liu, Xiaonan Li, Takayoshi Suzuki, Siyuan Zheng, Andrew Brenner, Ratna Vadlamudi, Gangadhara Sareddy. KDM1A inhibition sensitizes glioblastoma cells to temozolomide therapy through DNA damage and apoptosis pathway modulation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6220.

Pharmacokinetic, pharmacodynamic, and neurochemical investigations of lamotrigine-pentylenetetrazole kindled mice to ascertain it as a reliable model for clinical drug-resistant epilepsy.

BackgroundPentylenetetrazole kindling has long been used for the screening of investigational antiseizure drugs. The presence of lamotrigine, at a very low dose, does not hamper kindling in mice; rather it modifies this epileptogenesis process into drug‐resistant epilepsy. The lamotrigine‐pentylenetetrazole kindled mice show resistance to lamotrigine, phenytoin, and carbamazepine. It may also be possible that other licensed antiseizure drugs, like the mentioned drugs, remain ineffective in this model; therefore, this was the subject of this study.MethodsSwiss albino mice were kindled with pentylenetetrazole for 35 days in the presence of either methylcellulose vehicle or lamotrigine (subtherapeutic dose, ie, 5 mg/kg). Vehicle vs lamotrigine‐kindled mice were compared in terms of (a) resistance/response toward nine antiseizure drugs applied as monotherapies and two drug combinations; (b) lamotrigine bioavailability in blood and brain; (c) blood‐brain barrier integrity; and (d) amino acids and monoamines in the cerebral cortex and hippocampus.ResultsLamotrigine vs vehicle‐kindled mice are similar (or not significantly different P > .05 from each other) in terms of (a) response toward drug combinations; (b) lamotrigine bioavailability; and (c) blood‐brain barrier integrity except for, significantly (P < .05) reduced taurine and increased glutamate in the cerebral cortex and hippocampus. Aside from these, lamotrigine‐kindled mice show significant (P < .05) resistant to lamotrigine (15 mg/kg), levetiracetam (40 mg/kg); carbamazepine (40 mg/kg), zonisamide (100 mg/kg), gabapentin (224 mg/kg), pregabalin (30 mg/kg), phenytoin (35 mg/kg), and topiramate (300 mg/kg).ConclusionLamotrigine‐pentylenetetrazole kindling takes longer to develop (~5 weeks) in comparison to lamotrigine‐amygdale (~4 weeks) and lamotrigine‐corneal (~2 weeks) kindling models. However, drug screening through this model may yield superior drugs with novel antiseizure mechanisms.

Retromer stabilization results in neuroprotection in a model of Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis (ALS) is a fatal disease characterized by the degeneration of upper and lower motor neurons (MNs). We find a significant reduction of the retromer complex subunit VPS35 in iPSCs-derived MNs from ALS patients, in MNs from ALS post mortem explants and in MNs from SOD1G93A mice. Being the retromer involved in trafficking of hydrolases, a pathological hallmark in ALS, we design, synthesize and characterize an array of retromer stabilizers based on bis-guanylhydrazones connected by a 1,3-phenyl ring linker. We select compound 2a as a potent and bioavailable interactor of VPS35-VPS29. Indeed, while increasing retromer stability in ALS mice, compound 2a attenuates locomotion impairment and increases MNs survival. Moreover, compound 2a increases VPS35 in iPSCs-derived MNs and shows brain bioavailability. Our results clearly suggest the retromer as a valuable druggable target in ALS.

The enhanced protective effects of salvianic acid A: A functionalized nanoparticles against ischemic stroke through increasing the permeability of the blood-brain barrier

Ischemic stroke is the leading cause of disability and death worldwide. Currently, the only proven treatment for ischemic stroke is restoring the cerebral blood supply. In addition, some of the tissue is damaged during the subsequent reperfusion because of the overproduction of reactive oxygen species (ROS). Furthermore, antioxidant therapies have shown promise in preclinical studies for the treatment of ischemia-reperfusion injury. However, their therapeutic efficacy has been limited because of their low bioavailability in brain. To resolve this issue, we synthesized ROS-responsive, fan-shaped dendrimer nanoparticles (NPs) and conjugated them with a blood-brain barrier (BBB)-targeting peptide, COG1410, and salvianic acid A (SA), which is an effective antioxidant in ischemic stroke. The BBB targeting peptide acts as a ligand of the nanocarrier system and penetrates the BBB through the endocytosis of the ligand receptor. The results showed that T-SA-NPs not only target and accumulate in the infarct area, they also reduce over 2 times of the infarct area and reverse the behavioral deficits in MCAO mice, which illustrates that these NPs have an effective therapeutic effect on the ischemic stroke. In addition, these NPs had no toxicity in any organs of the body. Importantly, the present study provides an alternative strategy for delivering antioxidants to the brain and achieving targeted therapy of ischemic stroke.

Brain delivery of supplemental docosahexaenoic acid (DHA): A randomized placebo-controlled clinical trial.

BackgroundPast clinical trials of docosahexaenoic Acid (DHA) supplements for the prevention of Alzheimer's disease (AD) dementia have used lower doses and have been largely negative. We hypothesized that larger doses of DHA are needed for adequate brain bioavailability and that APOE4 is associated with reduced delivery of DHA and eicosapentaenoic acid (EPA) to the brain before the onset of cognitive impairment.Methods33 individuals were provided with a vitamin B complex (1 mg vitamin B12, 100 mg of vitamin B6 and 800 mcg of folic acid per day) and randomized to 2,152 mg of DHA per day or placebo over 6 months. 26 individuals completed both lumbar punctures and MRIs, and 29 completed cognitive assessments at baseline and 6 months. The primary outcome was the change in CSF DHA. Secondary outcomes included changes in CSF EPA levels, MRI hippocampal volume and entorhinal thickness; exploratory outcomes were measures of cognition.FindingsA 28% increase in CSF DHA and 43% increase in CSF EPA were observed in the DHA treatment arm compared to placebo (mean difference for DHA (95% CI): 0.08 µg/mL (0.05, 0.10), p<0.0001; mean difference for EPA: 0.008 µg/mL (0.004, 0.011), p<0.0001). The increase in CSF EPA in non-APOE4 carriers after supplementation was three times greater than APOE4 carriers. The change in brain volumes and cognitive scores did not differ between groups.InterpretationDementia prevention trials using omega-3 supplementation doses equal or lower to 1 g per day may have reduced brain effects, particularly in APOE4 carriers. Trial Registration: NCT02541929.FundingHNY was supported by R01AG055770, R01AG054434, R01AG067063 from the National Institute of Aging and NIRG-15-361854 from the Alzheimer's Association, and MGH by the L. K. Whittier Foundation. This work was also supported by P50AG05142 (HCC) from the National Institutes of Health. Funders had no role in study design, data collection, data analysis, interpretation, or writing of the report.

Genetically modified macrophages accomplish targeted gene delivery to the inflamed brain in transgenic Parkin Q311X(A) mice: importance of administration routes

Cell-based drug delivery systems have generated an increasing interest in recent years. We previously demonstrated that systemically administered macrophages deliver therapeutics to CNS, including glial cell line-derived neurotrophic factor (GDNF), and produce potent effects in Parkinson’s disease (PD) mouse models. Herein, we report fundamental changes in biodistribution and brain bioavailability of macrophage-based formulations upon different routes of administration: intravenous, intraperitoneal, or intrathecal injections. The brain accumulation of adoptively transferred macrophages was evaluated by various imaging methods in transgenic Parkin Q311(X)A mice and compared with those in healthy wild type littermates. Neuroinflammation manifested in PD mice warranted targeting macrophages to the brain for each route of administration. The maximum amount of cell-carriers in the brain, up to 8.1% ID/g, was recorded followed a single intrathecal injection. GDNF-transfected macrophages administered through intrathecal route provided significant increases of GDNF levels in different brain sub-regions, including midbrain, cerebellum, frontal cortex, and pons. No significant offsite toxicity of the cell-based formulations in mouse brain and peripheral organs was observed. Overall, intrathecal injection appeared to be the optimal administration route for genetically modified macrophages, which accomplished targeted gene delivery, and significant expression of reporter and therapeutic genes in the brain.

Liposome Consolidated with Cyclodextrin Provides Prolonged Drug Retention Resulting in Increased Drug Bioavailability in Brain.

Although butylidenephthalide (BP) is an efficient anticancer drug, its poor bioavailability renders it ineffective for treating drug-resistant brain tumors. However, this problem is overcome through the use of noninvasive delivery systems, including intranasal administration. Herein, the bioavailability, drug stability, and encapsulation efficiency (EE, up to 95%) of BP were improved by using cyclodextrin-encapsulated BP in liposomal formulations (CDD1). The physical properties and EE of the CDD1 system were investigated via dynamic light scattering, transmission electron microscopy, UV–Vis spectroscopy, and nuclear magnetic resonance spectroscopy. The cytotoxicity was examined via MTT assay, and the cellular uptake was observed using fluorescence microscopy. The CDD1 system persisted for over 8 h in tumor cells, which was a considerable improvement in the retention of the BP-containing cyclodextrin or the BP-containing liposomes, thereby indicating a higher BP content in CDD1. Nanoscale CDD1 formulations were administered intranasally to nude mice that had been intracranially implanted with temozolomide-resistant glioblastoma multiforme cells, resulting in increased median survival time. Liquid chromatography–mass spectrometry revealed that drug biodistribution via intranasal delivery increased the accumulation of BP 10-fold compared to oral delivery methods. Therefore, BP/cyclodextrin/liposomal formulations have potential clinical applications for treating drug-resistant brain tumors.

Intranasal delivery of topiramate nanoemulsion: Pharmacodynamic, pharmacokinetic and brain uptake studies

Epilepsy is the noncommunicable and chronic central nervous system disorder characterized by frequent, unprovoked seizures, or electrical disturbances in the brain. Topiramate is used as an antiepileptic drug for the treatment of partial onset seizures, generalized seizures and Lennox-Gastaut Syndrome. Topiramate, a BCS class II drug, has a relatively low bioavailability. It is also a substrate of P-glycoprotein and Blood Brain Barrier restricts its entry into the brain. This investigation was aimed to prepare O/W nanoemulsion delivery system of topiramate to improve its brain bioavailability. Topiramate loaded nanoemulsion was prepared by phase titration method. It was consisting of 2% w/w Capmul MCM C8, 32% w/w Tween 20:Carbitol (2:1) and 66% w/w water. It was characterized for globule size, viscosity, polydispersibility index, zeta potential, pH, conductivity values, transmittance and TEM. Pharmacodynamic, pharmacokinetic and brain drug uptake study was carried out using wistar albino rats post intranasal and oral administration. Topiramate loaded nanoemulsion was having a globule size of 4.73±0.52nm. It was stable for six months. Brain uptake of topiramate post intranasal administration of topiramate loaded nanoemulsion was significantly (P<1.86×10-8) higher when it was compared with oral administration of topiramate loaded nanoemulsion. This study indicates that intranasal administration of topiramate containing nanoemulsion could be an encouraging approach for the treatment of epilepsy to minimize the dose of topiramate in direction to avoid dose related adverse events.

In vitro and in vivo evaluation of organic solvent-free injectable melatonin nanoformulations

Melatonin is a neurohormone with potenial therapeutic effects in many diseases including neonatal hypoxic-ischemic (HI) brain injury. Due to limited solubility in water there is currently no clinically available melatonin formulation for parenteral use. Clinical use of melatonin has thus relied on oral administration, which in many cases is hampered by low and variable bioavailability. In animal treatment studies of neonatal HI, this issue have been circumvented by using parenteral administration of melatonin dissolved in ethanol (EtOH) or dimethyl sulfoxide (DMSO), solvents that are potentially neurotoxic, especially to the newborn brain. Thus, there is an urgent need for a non-toxic injectable melatonin formulation. The aim of this study was to develop such a formulation comprised of melatonin and biocompatible lipid-based nanoparticles with improved melatonin bioavailability. We herein report the development and characterization of an injectable system composed of melatonin and liposomes (LP) or oil-in-water nanoemulsions (NE). Nanoparticle characterization confirmed physicochemical stability over a week and an improvement with respect to melatonin solubilization in water (2.6 mg/mL in our injectable system). Determination of the in vitro release kinetics showed a prolonged release when melatonin is solubilized in nanoparticles (T1/2: 81 min vs 50 min vs 26 min for melatonin-LP, melatonin-NE, and melatonin-EtOH respectively). The pharmacokinetic (PK) parameters were confirmed in vivo in adult rats as similar melatonin levels detected in blood and indicated higher bioavailability in brain after intravenous administration of melatonin nanoformulations (10 mg/kg) in comparison to the free-melatonin administration. In conclusion, we have developed an organic solvent-free injectable formulation for melatonin by utilizing FDA-approved components, as a safe alternative for facilitating the potential of melatonin against variety of pathological conditions.

In Silico Pharmacogenetics CYP2D6 Study Focused on the Pharmacovigilance of Herbal Antidepressants.

The annual increase in depression worldwide together with an upward trend in the use of alternative medicine as treatment asks for developing reliable safety profiles of herbal based medicine. A considerable risk on adverse reactions exists when herbal remedies are combined with prescription medication. Around 25% of the drugs, including many antidepressants, depend on the activity of CYP2D6 for their metabolism and corresponding efficacy. Therefore, probing CYP2D6 inhibition by the active substances in herbal based medicine within the wild-type enzyme and clinically relevant allelic variants is crucial to avoid toxicity issues. In this in silico study several compounds with herbal origin suggested to have antidepressant activity were analyzed on their CYP2D6 wild-type and CYP2D6*53 inhibition potential using molecular docking. In addition, several pharmacokinetic properties were evaluated to assess their probability to cross the blood brain barrier and subsequently reach sufficient brain bioavailability for the modulation of central nervous system targets as well as characteristics which may hint toward potential safety issues.

Niosomes for nose-to-brain delivery of bromocriptine: Formulation development, efficacy evaluation and toxicity profiling

The present study aimed to formulate stable non-ionic surfactant vesicles incorporating Bromocriptine Mesylate (BCM) to enhance brain uptake via the direct nose to brain pathway. The optimized formulation prepared by ethanol injection method exhibited a size of 180 ± 4.5 nm, % encapsulation of 75.8 ± 3.6 and zeta potential of −14.2 ± 1.8 mV. Ex vivo study demonstrated 6.4 times enhancement in permeation across goat nasal mucosa at 24 h as compared to BCM drug suspension. The relative brain bioavailability, drug targeting efficiency and direct transport percentage of intranasal (i.n) niosomes was found to be 1045.51%, 1118.10% and 91.06% respectively, suggesting enhanced CNS targeting via the direct olfactory pathway. Group treated with BCM niosomes i.n revealed a marked attenuation of cataleptic time along with reduced lipid oxidation and restored Glutathione (GSH) levels in the brain. Sub-acute toxicity studies carried out for 28 days revealed no mortality or toxicologically significant changes. The combination of above results proved that BCM niosomes were safe to be administered i.n displaying manifold enhancement in brain distribution and improved pharmacodynamic behavior with 10 times dose reduction. Thus, such a system could be positively exploited as an alternative to oral delivery in the management of Parkinson's Disease (PD).

Design of temozolomide-loaded proliposomes and lipid crystal nanoparticles with industrial feasible approaches: comparative assessment of drug loading, entrapment efficiency, and stability at plasma pH

Temozolomide is a drug approved for treating glioblastomas, which has 100% oral bioavailability but gets degraded at physiological pH thus having very short half-life and only 20–30% brain bioavailability. Due to its amphiphilic nature, reported nanoformulations exhibits poor drug loading. The objective of this work was to formulate lipid-based drug delivery systems to enhance the brain bioavailability by prolonging the drug release and circulation time of the drug to overcome the limitations of the existing therapies and possible reduction of side effects. The size of the nanocarriers obtained was less than 300 nm and the PDI obtained was less than 0.3. The designed formulation showed higher entrapment efficiency as compared to the other reported nanocarriers of temozolomide. The designed formulations showed prolonged drug release from 12 to 20 h compared to 6 h for the pure drug. About 95% of the pure drug was degraded at plasma pH at the end of 12 h, whereas only 68% and 77% was degraded when entrapped inside the lipid crystal nanoparticles and proliposomes respectively. Further, pharmacokinetic and animal studies can confirm the potential of these for improvement of brain bioavailability.

Quantification and Evaluations of Catechin Hydrate Polymeric Nanoparticles Used in Brain Targeting for the Treatment of Epilepsy.

To formulate novel chitosan (CS)-coated–PLGA–nanoparticles (NPs) using a central composite design approach and use them in order to improve brain bioavailability for catechin hydrate (CH) through direct nose-to-central nervous system (CNS) delivery for the evaluation of a comparative biodistribution study of CH by the newly developed ultra high performance liquid chromatography mass spectroscopy and mass spectroscopy (UHPLC-MS/MS) method in the treatment of epilepsy. For PLGA–NPs’ preparation, a double emulsion-solvent evaporation method was used, where a four-factor, three-level central composite design was used to obtain the best nanoformulation. For the optimization, four independent variables were chosen, that is, PLGA, polyvinyl alcohol (PVA), sonication time, and temperature. The optimized PLGA–NPs were further coated with chitosan and assessed for drug release, nasal permeation study, as well as a comparative pharmacokinetic and pharmacodynamic study. Independent and dependent variables helped to optimize the best nanoformulation based on the composition of PLGA (50.0 mg), PVA (1.10%), sonication time (90.0 s), and temperature (25.0 °C). The values of dependent variables were observed, such as polydispersity index (PDI), particle size, and zeta potential (ZP)—that is, 0.106 ± 0.01, 93.46 ± 3.94 nm, and −12.63 ± 0.08 mV, respectively. The ZPs of CS-coated PLGA–NPs were changed from negative to positive value with some alteration in the distribution of particle size. Excellent mucoadhesive-nature of CS–CH–PLGA–NPs as compared with CH–S and CH–PLGA–NPs was seen, with a retention time of 0.856 min and m/z of 289.23/245.20 for CH, together with a retention time of 1.04 min and m/z of 301.21/151.21 for Quercetin as an internal standard (IS). For a linear range (1–1000 ng mL−1), % accuracy (93.07–99.41%) and inter- and intraday % precision (0.39–4.90%) were determined. The improved Cmax with area under curve (AUC)0–24 was found to be highly significant (p < 0.001) in Wistar rats’ brain as compared with the i.n. and i.v. treated group based on the pharmacokinetics (PK) results. Furthermore, CS–CH–PLGA–NPs were found to be more significant (p < 0.001) for the treatment of seizure threshold rodent models, that is, increasing current electroshock and pentylenetetrazole-induced seizures. A significant role of CS–CH–PLGA–NPs was observed, that is, p < 0.001, for the enhancement of brain bioavailability and the treatment of epilepsy.

A bioanalytical UHPLC based method used for the quantification of Thymoquinone-loaded-PLGA-nanoparticles in the treatment of epilepsy

To formulate a nanoformulation (PLGA-NPs) and to improve brain bioavailability for thymoquinone (THQ) through intranasal (i.n.) drug delivery, using a newly UHPLC-PDA developed the method and validated. Five different THQ-PLGA-NPs (THQ-N1 to THQ-N5) were prepared by emulsion solvent evaporation method. A new UHPLC method developed and validated for biodistribution studies in the rat’s brain, lungs and plasma. Optimized-THQ-N1-NPs showed a particle size of 97.36 ± 2.01 nm with a low PDI value of 0.263 ± 0.004, ZP of − 17.98 ± 1.09, EE of 82.49 ± 2.38% and DL of 5.09 ± 0.13%. THQ-N1-NPs showed sustained release pattern via in vitro release profile. A bioanalytical method was developed by UHPLC-PDA and validated for the evaluation of pharmacokinetics parameters, biodistribution studies, brain drug-targeting potential (89.89 ± 9.38%), and brain-targeting efficiency (8075.00 ± 113.05%) studies through intranasal administration which showed an improved THQ-brain- bioavailability, compared to i.v. Moreover, THQ-PLGA-NPs improved the seizure threshold treatment i.e. epilepsy increasing current electroshock (ICES) rodent models induced seizures in rats. A significant role of THQ-PLGA-NPs with high brain targeting efficiency of the nanoformulations was established. The reported data supports the treatment of epilepsy.

Donepezil, a cholinesterase inhibitor used in Alzheimer's disease therapy, is actively exported out of the brain by abcb1ab p-glycoproteins in mice

Polymorphisms in the drug transporter gene ABCB1 predict the treatment response of selected antidepressants and limit anticonvulsive medication's effectiveness. The ABCB1 locus encodes the energy-dependent transporter P-glycoprotein (P-gp) of the blood brain barrier (BBB), which serves as an efflux pump of its substrates in the expressing tissues of vertebrates. One experimental setup to determine a posteriori the P-gp substrate status is the use of the double abcb1ab knock-out (KO) mice model. Since so far, P-gp substrate status of donepezil, a cholinesterase inhibitor wildly used in Alzheimer's disease therapy was inconclusive, we performed subcutanous (s.c.), continuous injections over 11 days in double abcb1ab KO and P-gp competent wildtype (WT) mice. Both in brain and in testis concentrations of donepezil were significantly higher in P-gp deficient mice compared to WT controls (2.39 and 2.24 times respectively). In conclusion, in mice donepezil's brain bioavailability depends on P-gp.

Deferoxamine and Curcumin Loaded Nanocarriers Protect Against Rotenone-Induced Neurotoxicity.

Reduced glutathione and excess free iron within dopaminergic, substantia nigra neurons in Parkinson's disease (PD) can drive accumulation of toxic hydroxyl radicals resulting in sustained oxidative stress and cellular damage. Factors such as brain penetrance and bioavailability have limited the advancement of potential antioxidant and iron chelator therapies for PD. This study aimed to develop novel nanocarrier delivery systems for the antioxidant curcumin and/or iron chelator deferoxamine (DFO) to protect against rotenone-induced changes in cell viability and oxidative stress in SH-SY5Y cells. Nanocarriers of curcumin and/or DFO were prepared using Pluronic F68 (P68) with or without dequilinium (DQA) by modified thin-film hydration. Cell viability was assessed using an MTT assay and oxidative stress was measured using thiobarbituric acid reactive substances and cellular antioxidant activity assays. All formulations demonstrated high encapsulation efficiency (65-96%) and nanocarrier size was <200 nm. 3-h pretreatment with P68 or P68+DQA nanocarriers containing various concentrations of curcumin and/or DFO significantly protected against rotenone-reduced cell viability. The addition of DFO to curcumin-loaded P68+DQA nanocarriers resulted in increased protection by at least 10%. All nanoformulations significantly protected against rotenone-induced lipid peroxidation (p < 0.0001). The addition of DQA, which targets mitochondria, resulted in up to 65% increase in cellular antioxidant activity. In nearly all preparations, the combination of 10 μM curcumin and 100 μM DFO had the most antioxidant activity. This study demonstrates for the first time the formulation and delivery using P68 and P68+DQA curcumin and/or DFO nanocarriers to protect against oxidative stress induced by a rotenone PD model. This strategy to combine antioxidants with iron chelators may provide a novel approach to fully utilise their therapeutic benefit for PD.