A study of rivastigmine liposomes for delivery into the brain through intranasal route

Laronidase-loaded liposomes reach the brain and other hard-to-treat organs after noninvasive nasal administration

Mucopolysaccharidosis type I (MPS I) is caused by a lack of the lysosomal enzyme α-L-iduronidase (IDUA), responsible for the degradation of the glycosaminoglycans (GAGs) dermatan and heparan sulfate, leading to multisystemic signs and symptoms. Enzyme replacement therapy (ERT) is a treatment that consists of weekly intravenous administrations of laronidase, a recombinant version of IDUA. However, ERT has limited access to certain tissues, such as bone, cartilage, and brain, and laronidase fails to trespass the BBB. In this sense, this study reports the development and characterization of laronidase-loaded liposomes for the treatment of MPS I mice. Liposomal complexes were obtained by the thin film formation method followed by microfluidization. The main characterization results showed mean vesicle size of 103.0 ± 3.3 nm, monodisperse populations of vesicles, zeta potential around + 30.0 ± 2.1 mV, and mucoadhesion strength of 5.69 ± 0.14 mN. Treatment of MPS I mice fibroblasts showed significant increase in enzyme activity. Nasal administration of complexes to MPS I mice resulted in significant increase in laronidase activity in the brain cortex, heart, lungs, kidneys, eyes, and serum. The overall results demonstrate the feasibility of nasal administration of laronidase-loaded liposomes to deliver enzyme in difficult-to-reach tissues, circumventing ERT issues and bringing hope as a potential treatment for MPS I.

Development and validation of high-performance liquid chromatography method for the simultaneous quantification of rivastigmine hydrogen tartrate and asiaticoside co-loaded in niosomes: A Box-Behnken design approach

Rivastigmine hydrogen tartrate (RHT), a reversible cholinesterase inhibitor, is considered as the first-line therapy for mild to moderate Alzheimer's disease. Asiaticoside (AS), a pentacyclic triterpenoid saponin, is well known as cognitive enhancer due to its antioxidant effect. Based on the hypothesis of their synergistic therapeutic potential, RHT and AS were co-encapsulated in niosomal formulation. A simple, precise, and accurate high-performance liquid chromatography method was developed for simultaneous quantitative analysis. The chromatographic parameters were optimized by Box-Behnken experimental design. The separation was performed on a reversed-phase Phenomenex C18 (150 mm × 4.6 mm, 5 μm) column at 30 °C under the UV detection of 210 nm. The optimized mobile phase consisted of a mixture of 20 mM potassium dihydrogen phosphate buffer (pH 2.6) and acetonitrile (72:28 % v/v) under the isocratic mode at the flow rate of 0.9 mL/min. The developed method was fully validated under the ICH guidelines and could be successfully applied for simultaneous quantitative analysis of RHT and AS in niosomal formulation.

A Comprehensive Study on Nanoparticle Drug Delivery to the Brain: Application of Machine Learning Techniques

The delivery of drugs to specific target tissues and cells in the brain poses a significant challenge in brain therapeutics, primarily due to limited understanding of how nanoparticle (NP) properties influence drug biodistribution and off-target organ accumulation. This study addresses the limitations of previous research by using various predictive models based on collection of large data sets of 403 data points incorporating both numerical and categorical features. Machine learning techniques and comprehensive literature data analysis were used to develop models for predicting NP delivery to the brain. Furthermore, the physicochemical properties of loaded drugs and NPs were analyzed through a systematic analysis of pharmacodynamic parameters such as plasma area under the curve. The analysis employed various linear models, with a particular emphasis on linear mixed-effect models (LMEMs) that demonstrated exceptional accuracy. The model was validated via the preparation and administration of two distinct NP formulations via the intranasal and intravenous routes. Among the various modeling approaches, LMEMs exhibited superior performance in capturing underlying patterns. Factors such as the release rate and molecular weight had a negative impact on brain targeting. The model also suggests a slightly positive impact on brain targeting when the drug is a P-glycoprotein substrate.

Intranasal Drug Delivery by Nanotechnology: Advances in and Challenges for Alzheimer's Disease Management

Alzheimer's disease, a progressive neurodegenerative condition, is characterized by a gradual decline in cognitive functions. Current treatment approaches primarily involve the administration of medications through oral, parenteral, and transdermal routes, aiming to improve cognitive function and alleviate symptoms. However, these treatments face limitations, such as low bioavailability and inadequate permeation. Alternative invasive methods, while explored, often entail discomfort and require specialized assistance. Therefore, the development of a non-invasive and efficient delivery system is crucial. Intranasal delivery has emerged as a potential solution, although it is constrained by the unique conditions of the nasal cavity. An innovative approach involves the use of nano-carriers based on nanotechnology for intranasal delivery. This strategy has the potential to overcome current limitations by providing enhanced bioavailability, improved permeation, effective traversal of the blood-brain barrier, extended retention within the body, and precise targeting of the brain. The comprehensive review focuses on the advancements in designing various types of nano-carriers, including polymeric nanoparticles, metal nanoparticles, lipid nanoparticles, liposomes, nanoemulsions, Quantum dots, and dendrimers. These nano-carriers are specifically tailored for the intranasal delivery of therapeutic agents aimed at combatting Alzheimer's disease. In summary, the development and utilization of intranasal delivery systems based on nanotechnology show significant potential in surmounting the constraints of current Alzheimer's disease treatment strategies. Nevertheless, it is essential to acknowledge regulatory as well as toxicity concerns associated with this route; meticulous consideration is required when engineering a carrier. This comprehensive review underscores the potential to revolutionize Alzheimer's disease management and highlights the importance of addressing regulatory considerations for safe and effective implementations. Embracing this strategy could lead to substantial advancements in the field of Alzheimer's disease treatment.

Intramuscularly Administered PLGA Microparticles for Sustained Release of Rivastigmine: In Vitro, In Vivo and Histological Evaluation

Rivastigmine is an acetylcholinesterase (AchE) and butyrylcholinesterase (BchE) inhibitor drug approved by the US Food and Drug Administration (FDA) for the treatment of mild to moderate dementia of Alzheimer's type. However, its first-pass metabolism and gastrointestinal side effects negatively affect the tolerability and efficacy of oral therapy. These adverse effects could be avoided with the use of a sustained -release formulation as an intramuscular (IM) administration system. The objective of this work was to develop polylactic co-glycolic acid (PLGA) microparticles for the sustained release of rivastigmine and to evaluate its stability during storage, tissue tolerance, in vitro release, and in vivo pharmacokinetics after its IM administration. The microparticles were made by the solvent evaporation emulsion method. A series of formulation parameters (the type of polymer used, the amount of polymer used, the initial amount of rivastigmine, and the volume of PVA 0.1% w/v) were studied to achieve an encapsulation efficiency (EE) and a rivastigmine load of 54.8 ± 0.9% and 3.3 ± 0.1%, respectively. The microparticles, whose size was 56.1 ± 2.8 μm, had a spherical shape and a smooth surface. FT-IR analysis showed that there is no chemical interaction between rivastigmine and the polymer. PLGA microparticles maintain rivastigmine retained and stable under normal (5 ± 3 °C) and accelerated storage (25 ± 2 °C and 60 ± 5 % RH) conditions for at least 6 months. The microparticles behaved as a sustained release system both in vitro and in vivo compared to non-encapsulated rivastigmine. The IM administration of the formulation in rats did not produce significant tissue damage. However, it is necessary to reproduce the experiments with multiple doses to rule out a negative effect in terms of tolerability in chronic treatment. To the best of our knowledge, this study is the only one that has obtained the sustained release of rivastigmine from PLGA microparticles after IM administration in an in vivo model.

Formulation, optimization and evaluation of amisulpride-loaded niosomal intranasal gel for brain targeting

Aim: To develop stable non-ionic surfactant vesicles containing amisulpride (AMS) to improve brain uptake via nose to brain mechanism. Methods: Niosomes were developed using a modified ethanol injection technique, optimized using 32 factorial design and evaluated for the vesicle size (VS), percent encapsulation efficiency (EE), zeta potential (ZP) and % cumulative drug release (%CDR). Results: Optimized niosomes (Span-60: cholesterol ratio 0:1) showed 191.4 nm VS, 84.25% EE, -38.2 ZP and 81.31% CDR. In situ gel with these niosomes displayed 78% CDR. TEM analysis revealed spherical niosomes. Pharmacokinetic and brain tissue distribution studies in rats showed enhanced plasma and brain concentrations, indicating successful brain targeting. Conclusion: This strategy demonstrates improved AMS permeation via the nasal cavity, enhancing bioavailability for treating schizophrenia.

Nanotechnology-empowered therapeutics targeting neurodegenerative diseases

Neurodegenerative diseases are posing pressing health issues due to the high prevalence among aging populations in the 21st century. They are evidenced by the progressive loss of neuronal function, often associated with neuronal necrosis and many related devastating complications. Nevertheless, effective therapeutical strategies to treat neurodegenerative diseases remain a tremendous challenge due to the multisystemic nature and limited drug delivery to the central nervous system. As a result, there is a pressing need to develop effective alternative therapeutics to manage the progression of neurodegenerative diseases. By utilizing the functional reconstructive materials and technologies with specific targeting ability at the nanoscale level, nanotechnology-empowered medicines can transform the therapeutic paradigms of neurodegenerative diseases with minimal systemic side effects. This review outlines the current applications and progresses of the nanotechnology-enabled drug delivery systems to enhance the therapeutic efficacy in treating neurodegenerative diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Nanomedicine in the Management of Alzheimer's Disease: State-of-the-Art

Alzheimer's disease (AD) is a deadly, progressive, and irreversible brain condition that impairs cognitive abilities. Globally, it affects 32.6 million individuals, and if no viable therapies are available by 2050, that figure might rise to 139 million. The current course of treatment enhances cognitive abilities and temporarily relieves symptoms, but it does not halt or slow the disease's development. Additionally, treatments are primarily offered in conventional oral dosage forms, and conventional oral treatments lack brain specialization and cause adverse effects, resulting in poor patient compliance. A potential nanotechnology-based strategy can improve the bioavailability and specificity of the drug targeting in the brain. Furthermore, this review extensively summarizes the applications of nanomedicines for the effective delivery of drugs used in the management of AD. In addition, the clinical progress of nanomedicines in AD is also discussed, and the challenges facing the clinical development of nanomedicines are addressed in this article.

Intranasal delivery of nanoliposomal SN-38 for treatment of diffuse midline glioma

OBJECTIVE

Diffuse midline gliomas, including diffuse intrinsic pontine gliomas (DIPGs), are among the most malignant and devastating childhood brain cancers. Despite aggressive treatment, nearly all children with these tumors succumb to their disease within 2 years of diagnosis. Due to the anatomical location of the tumors within the pons, surgery is not a treatment option, and distribution of most systematically administered drugs is limited by the blood-brain barrier (BBB). New drug delivery systems that bypass the BBB are desperately needed to improve outcomes of DIPG patients. Intranasal delivery (IND) is a practical and noninvasive drug delivery system that bypasses the BBB and delivers the drugs to the brain through the olfactory and trigeminal neural pathways. In this study, the authors evaluated the efficacy of nanoliposomal (LS) irinotecan (CPT-11) and an active metabolite of CPT-11, 7-ethyl-10-hydroxycamptothecin (SN-38), using IND in DIPG patient-derived xenograft models.

METHODS

In vitro responses to LS-CPT-11 and LS-SN-38 in DIPG cells were evaluated with cell viability, colony formation, and apoptosis assays. The cellular uptakes of rhodamine-PE (Rhod)-labeled LS-CPT-11 and LS-SN-38 were analyzed with fluorescence microscopy. Mice bearing DIPG patient-derived xenografts were treated with IND of LS-control (empty liposome), LS-CPT-11, or LS-SN-38 by IND for 4 weeks. In vivo responses were measured for tumor growth by serial bioluminescence imaging and animal subject survival. The concentration of SN-38 in the brainstem tumor administered by IND was determined by liquid chromatography-mass spectrometry (LC-MS). Immunohistochemical analyses of the proliferative and apoptotic responses of in vivo tumor cells were performed with Ki-67 and TUNEL staining.

RESULTS

LS-SN-38 inhibited DIPG cell growth and colony formation and increased apoptosis, outperforming LS-CPT-11. Rhod-labeled LS-SN-38 showed intracellular fluorescence signals beginning at 30 minutes and peaking at 24 hours following treatment. LC-MS analysis revealed an SN-38 concentration in the brainstem tumor of 0.66 ± 0.25 ng/ml (5.43% ± 0.31% of serum concentration). IND of LS-SN-38 delayed tumor growth and significantly prolonged animal survival compared with IND of LS-control (p < 0.0001) and LS-CPT-11 (p = 0.003). IND of LS-SN-38 increased the number of TUNEL-positive cells and decreased the Ki-67-positive cells in the brainstem tumor.

CONCLUSIONS

This study demonstrates that IND of LS-SN-38 bypasses the BBB and enables efficient and noninvasive drug delivery to the brainstem tumor, providing a promising therapeutic approach for treating DIPG.

Surface-tailoring of emulsomes for boosting brain delivery of vinpocetine via intranasal route: in vitro optimization and in vivo pharmacokinetic assessment

Vinpocetine (VNP), a semisynthetic active pharmaceutical ingredient, is used for oral management of cerebrovascular diseases because of its ability to enhance the blood flow to the brain. However, despite that, the therapeutic application of VNP is restricted due to its reduced bioavailability and diminished brain levels that could be attributed to its low aqueous solubility, short half-life, and presystemic metabolism exposure. Accordingly, the goal of this work was to explore the ability of surface-tailored intranasal emulsomes to boost brain delivery of the drug. A 3²2¹ factorial design was implemented to explore the impact of phospholipid (PL) to solid lipid weight ratio, PL to cholesterol molar ratio, and type of solid lipid on vesicle size, zeta potential, drug entrapment, and release efficiency of the new developed VNP emulsomes. Tailoring of the optimized emulsomal surface formulation was performed using either cationization or PEGylation approaches to boost blood–brain barrier penetration. The pharmacokinetic assessment in rats showed significantly improved bioavailability of VNP emulsomal formulations compared to the oral market product. Additionally, surface-tailored emulsomes exhibited significantly higher brain levels compared to the optimized emulsomes. Based on these findings, the proposed surface-tailored emulsomes could be considered as a promising platform for achieving high brain levels of VNP following intranasal administration.

Targeting the Pathological Hallmarks of Alzheimer's Disease Through Nanovesicleaided Drug Delivery Approach

INTRODUCTION

Nanovesicle technology is making a huge contribution to the progress of treatment studies for various diseases, including Alzheimer's disease (AD). AD is the leading neurodegenerative disorder characterized by severe cognitive impairment. Despite the prevalence of several forms of anti-AD drugs, the accelerating pace of AD incidence cannot becurbed, and for rescue, nanovesicle technology has grabbed much attention.

METHODOLOGY

Comprehensive literature search was carried out using relevant keywords and online database platforms. The main concepts that have been covered included a complex pathomechanism underlying increased acetylcholinesterase (AchE) activity, β-amyloid aggregation, and tau-hyperphosphorylation forming neurofibrillary tangles (NFTs) in the brain, which are amongst the major hallmarks of AD pathology. Therapeutic recommendations exist in the form of AchE inhibitors, along with anti-amyloid and anti-tau therapeutics, which are being explored at a high pace. The degree of the therapeutic outcome, however, gets restricted by the pharmacological limitations. Susceptibility to peripheral metabolism and rapid elimination, inefficiency to cross the blood-brain barrier (BBB) and reach the target brain site are the factors that lower the biostability and bioavailability of anti-AD drugs. The nanovesicle technology has emerged as a route to preserve the therapeutic efficiency of the anti-AD drugs and promote AD treatment. The review hereby aims to summarize the developments made by the nanovesicle technology in aiding the delivery of synthetic and plant-based therapeutics targeting the molecular mechanism of AD pathology.

CONCLUSION

Nanovesicles appear to efficiently aid in target-specific delivery of anti-AD therapeutics and nullify the drawbacks posed by free drugs, besides reducing the dosage requirement and the adversities associated. In addition, the nanovesicle technology also appears to uplift the therapeutic potential of several phyto-compounds with immense anti-AD properties. Furthermore, the review also sheds light on future perspectives to mend the gaps that prevail in the nanovesicle-mediated drug delivery in AD treatment strategies.

Lipid-Based Nanocarriers via Nose-to-Brain Pathway for Central Nervous System Disorders

Neurodegenerative disorders are distinguished by the gradual deterioration of the nervous system's structure and function due to oxidative stress, mitochondrial dysfunction, protein misfolding, excitotoxicity, and neuroinflammation. Among these NDs, Alzheimer's disease, Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis characterized an increasing dysfunction and loss of neuronal structure leading to neuronal cell death. Although there is currently no drug to totally reverse the effects of NDs, such novel formulations and administration routes are developed for better management and nose-to-brain delivery is one of delivery for treating NDs. This review aimed to highlight advances in research on various lipid based nanocarriers such as liposomes, solid lipid nanoparticles, nanostructured lipid carriers, microemulsion, nanoemulsion, and cubosomes which are reported to treat and alleviate the symptoms of NDs via nose-to-brain route. The challenges during clinical translation of lipid nanocarriers from bench to bed side is also discussed.

Study of Valproic Acid Liposomes for Delivery into the Brain through an Intranasal Route

Intranasal drug transport through the olfactory route to the brain is an effective drug route for increased absorption and bioavailability of the drug. The objective of this study was to increase the penetration of valproic acid as an anticonvulsant into a delivery system comprising liposomes. Valproic acid liposomes were prepared by a thin-layer hydration technique using soybean phosphatidylcholine and cholesterol as the main ingredients. The formulations were evaluated for diameter size, entrapment efficiency (EE), zeta potential, polydispersity index, and morphology. ex vivo permeation using sheep nasal mucosa and in vivo efficacy were assessed by performing a pharmacokinetic study in Wistar albino rats following intranasal administration of the formulations in comparison with pure drug. The mean size particle of optimized liposomes ranged from 90 to 210 nm with a low polydispersity index (<0.5). The EE of optimized liposomes was between 60% and 85%, increasing the concentration of phosphatidylcholine added to the formula. Transmission electron microscopy observations (40,000×) showed that valproic acid liposomes have a spherical molecular shape and a particle size of below 250 nm. The ex vivo and in vivo results showed that liposomal formulations provided enhanced brain exposure. Among the formulations studied, Formula 4 (F4) showed greater uptake of valproic acid into the brain than plasma. The high brain targeting efficiency index for F4 indicated the preferential transport of the drug to the brain. The study demonstrated the successful formulation of surface-modified valproic acid liposomes for nasal delivery with brain targeting potential.

Intranasal delivery of phenytoin-loaded nanoparticles to the brain suppresses pentylenetetrazol-induced generalized tonic clonic seizures in an epilepsy mouse model

In this work we describe the preparation and characterization of lecithin-chitosan nanoparticles (L₁₀C_i⁺), and investigate their ability to deliver the anti-epileptic drug phenytoin (PHT) to mouse brain following intranasal (IN) administration. L₁₀C_i⁺ were retained in the nasal cavity compared to PHT in PEG200 solution (PHT/PEG), which suffered immediate nasal drainage. PHT was detected in the brain after 5 min of IN administration reaching a maximum of 11.84 ± 2.31 %ID g^-1 after 48 hours. L₁₀C_i⁺ were associated with a higher brain/plasma ratio (C_b/p) compared to the experimental control comprising free PHT injected via the intraperitoneal route (PHT-IP) across all tested time points. Additionally, L₁₀C_i⁺ led to lower PHT accumulation in the liver and spleen compared to PHT-IP, which is vital for lowering the systemic side effects of PHT. The relatively high drug targeting efficiency (DTE%) of 315.46% and the drug targeting percentage (DTP%) of 68.29%, combined with the increasing anterior-to-posterior gradient of PHT in the brain confirmed the direct nose-to-brain transport of PHT from L₁₀C_i⁺. Electroencephalogram (EEG) analysis was used to monitor seizure progression. L₁₀C_i⁺ resulted in a complete seizure suppression after 4 hours of administration, and this inhibition persisted even with an 8-fold reduction of the encapsulated dose compared to the required PHT-IP dose to achieve a similar inhibitory effect due to systemic loss. The presented findings confirm the possibility of using L₁₀C_i⁺ as a non-invasive delivery system of PHT for the management of epilepsy using reduced doses of PHT.

Nose-to-brain delivery: exploring newer domains for glioblastoma multiforme management

Glioblastoma multiforme (GBM) is the most common and aggressive form of the primary brain tumors in humans. The intricate pathophysiology, the development of resistance by tumor cells, and the inability of the drugs to effectively cross the blood-brain and blood-tumor barriers result in poor prognosis for GBM patients, with a median survival time of only 1 to 2 years. Nose-to-brain delivery offers an attractive, noninvasive strategy to enhance drug penetration or transport novel drug/gene carriers into the brain. Although the exact mechanism of intranasal delivery remains elusive, the olfactory and trigeminal nerve pathways have been found to play a vital role in circumventing the traditional barriers of brain targeting. This review discusses the intranasal pathway as a novel domain for delivering drugs and nanocarriers encapsulating drugs/genes, as well as stem cell carriers specifically to the glioma cells. Considering the fact that most of these studies are still in preclinical stage, translating such intranasal delivery strategies from bench to bedside would be a critical step for better management and prognosis of GBM. Graphical abstract.

Pharmacokinetic and pharmacodynamic evaluation of nasal liposome and nanoparticle based rivastigmine formulations in acute and chronic models of Alzheimer's disease

With the increasing aging population and progressive nature of the disease, Alzheimer's disease (AD) poses to be an oncoming epidemic with limited therapeutic strategies. It is characterized by memory loss, behavioral instability, impaired cognitive function, predominantly, cognitive inability manifested due to the accumulation of β-amyloid, with malfunctioned cholinergic system. Rivastigmine, a reversible dual cholinesterase inhibitor, is a more tolerable and widely used choice of drug for AD. However, rivastigmine being hydrophilic and undergoing the first-pass metabolism exhibits low CNS bioavailability. Nanoformulations including liposomes and PLGA nanoparticles can encapsulate hydrophilic drugs and deliver them efficiently to the brain. Besides, the nasal route is receiving considerable attention recently, due to its direct access to the brain. Therefore, the present study attempts to evaluate the pharmacokinetic and pharmacodynamic properties of nasal liposomal and PLGA nanoparticle formulations of rivastigmine in acute scopolamine-induced amnesia and chronic colchicine induced cognitive dysfunction animal models, and validate the best formulation by employing pharmacokinetic and pharmacodynamic (PK-PD) modeling. Nasal liposomal rivastigmine formulation showed the best pharmacokinetic features with rapid onset of action (Tmax = 5 min), higher Cmax (1489.5 ± 620.71), enhanced systemic bioavailability (F = 118.65 ± 23.54; AUC = 35,921.75 ± 9559.46), increased half-life (30.92 ± 8.38 min), and reduced clearance rate (Kel (1/min) = 0.0224 ± 0.006) compared to oral rivastigmine (Tmax = 15 min; Cmax = 56.29 ± 27.05; F = 4.39 ± 1.82; AUC = 1663.79 ± 813.54; t1/2 = 13.48 ± 5.79; Kel (1/min) = 0.0514 ± 0.023). Further, the liposomal formulation significantly rescued the memory deficit induced by scopolamine as well as colchicine superior to other formulations as assessed in Morris water maze and passive avoidance tasks. PK-PD modeling demonstrated a strong correlation between the pharmacokinetic parameters and acetylcholinesterase inhibition of liposomal formulation.

Systematic development of lectin conjugated microspheres for nose-to-brain delivery of rivastigmine for the treatment of Alzheimer's disease

The current study focuses on development of nasal mucoadhesive microspheres for nose-to-brain delivery of rivastigmine for Alzheimer treatment. A systematic development was employed for optimization of the formulation and process parameters influential on the quality attributes of the microspheres. The risk assessment study revealed major influence of the polymer concentration (ethylcellulose: chitosan), the concentration of surfactant solution (polyvinyl alcohol), and stirring speed as the critical factors for optimization of the microspheres. These factors were systematically optimized using Box-Behnken design and microspheres were evaluated for the particle size, entrapment efficiency, and in vitro drug release as the response variables. The optimized microspheres containing 4.4% wt/vol polymers, 1% wt/vol surfactant, and stirring speed at 1500 rpm showed particle size of 19.9 µm, entrapment efficiency of 77.8%, and drug release parameters as T_80% of 7.3 h. The surface modification of microspheres was performed with lectin by carbodiimide activation reaction and confirmed by difference in surface charge before and after chemical functionalization by zeta potential measurement which was found to be - 25.7 mV and 20.5 mV, respectively. Ex vivo study for bioadhesion strength evaluation on goat nasal mucosa indicated a significant difference (p < 0.001) between the plain (29%) and lectin functionalized microspheres (64%). In vivo behavioral and biochemical studies in the rats treated with lectin functionalized microspheres showed markedly better memory-retention vis-à-vis test and pure drug solution treated rats (p < 0.001). In a nutshell, the present studies showed successful development of nasal microspheres for enhanced brain delivery of rivastigmine for Alzheimer's treatment.

Design, development and in-vitro/in-vivo evaluation of intranasally delivered Rivastigmine and N-Acetyl Cysteine loaded bifunctional niosomes for applications in combinative treatment of Alzheimer's disease

The present investigation explores the potential of novel dual drug-loaded niosomes for nasal delivery of Rivastigmine (RIV) and N-Acetyl Cysteine (NAC) to the brain. The dual niosomes showed a particle size of 162.4 nm and % entrapment efficiencies of 97.7% for RIV and 85.9% for NAC. The niosomes were statistically validated using Box-Behnken experimental design (BBD) with good significance. Ultrastructural and chemical characterization of the niosomes using various analytical techniques like Fourier Transform Infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Transmission electron microscopy (TEM) showcased drug-excipient compatibility and robust stability of 6 months in a liquid state at 4-8 °C. The dual drug-loaded niosomes showed a sustained drug release pattern up to 2 days. Acetylcholinesterase (AChE) and DPPH (1, 1-diphenyl-2- picrylhydrazyl) enzyme inhibition assays showed a better combinative effect than the free drug solutions. A 2-day nasal permeation proved the effectiveness and biocompatibility of the niosomes. In-vivo pharmacokinetic and organ biodistribution studies revealed a better drug profile and greater distribution of the niosomes in the brain compared to other organs, thereby indicating a direct nose-to-brain delivery of the niosomes.

Alzheimer's Disease Targeted Nano-Based Drug Delivery Systems

Alzheimer's disease (AD) is the most common neurodegenerative disease, and is part of a massive and growing health care burden that is destroying the cognitive function of more than 50 million individuals worldwide. Today, therapeutic options are limited to approaches with mild symptomatic benefits. The failure in developing effective drugs is attributed to, but not limited to the highly heterogeneous nature of AD with multiple underlying hypotheses and multifactorial pathology. In addition, targeted drug delivery to the central nervous system (CNS), for the diagnosis and therapy of neurological diseases like AD, is restricted by the challenges posed by blood-brain interfaces surrounding the CNS, limiting the bioavailability of therapeutics. Research done over the last decade has focused on developing new strategies to overcome these limitations and successfully deliver drugs to the CNS. Nanoparticles, that are capable of encapsulating drugs with sustained drug release profiles and adjustable physiochemical properties, can cross the protective barriers surrounding the CNS. Thus, nanotechnology offers new hope for AD treatment as a strong alternative to conventional drug delivery mechanisms. In this review, the potential application of nanoparticle based approaches in Alzheimer's disease and their implications in therapy is discussed.

In Situ-Forming Microparticles for Controlled Release of Rivastigmine: In Vitro Optimization and In Vivo Evaluation

In this work, sucrose acetate isobutyrate (SAIB) and polylactic co-glycolic acid (PLGA) were used alone or in combination as a matrix-former (MF) to prepare long-acting injectable rivastigmine (RV) in situ-forming microparticles (ISM). RV-ISM were prepared by the emulsification of an internal phase, containing the drug and the matrix former(s), into an external oily phase containing a stabilizer. The statistical design, Central Composite Design (CCD), was adopted as a quality by design (QbD) approach to optimize the formulation of RV-ISM systems. The fabricated RV-ISM systems was designed to minimize the initial burst drug release and maximize the sustainment of RV release from the ISM and ease of injection. The influence of critical formulation variables such as the matrix-former to drug (MF/D) ratio and SAIB to PLGA (S/P) ratio in the internal phase with respect to critical quality attributes (CQAs), such as the percentage drug release within the first day (Q₁), the time required for 50% drug release (T_50%) and the rate of injection, were studied using the CCD. The optimal RV-ISM system with the highest desirability value (0.74) was predicted to have an MF/D ratio of 11.7:1 (w/w) and an S/P ratio of 1.64:1 (w/w). The optimal RV-ISM system was assessed for its release profile, injectability, rheological properties, morphology, effect on cell viability, tolerance to γ-sterilization and in vivo performance in male albino rabbits. In vitro release studies revealed that the optimal RV-ISM system released 100% of its drug content throughout a release period of 30 days with only 15.5% drug release within the first day (Q₁) and T_50% of 13.09 days. Moreover, the optimal system showed a high injection rate of 1.012 mL/min, pseudoplastic flow, uniform spherical globules with homogenous particle size, minimal cytotoxicity and high tolerability to γ-sterilization. In vivo pharmacokinetic (PK) studies revealed that the rate of absorption of RV from the optimal RV-ISM system was controlled compared to a drug solution following either intramuscular (IM) or subcutaneous (SC) injection. Furthermore, the optimal RV-ISM was found to follow flip-flop PK with poor correlation between in vitro release and in vivo findings. These findings suggest that the optimal RV-ISM is a promising tool to achieve a sustained release therapy for RV; however, further investigation is still required to optimize the in vivo performance of RV-ISM.

Nanoparticlized System: Promising Approach for the Management of Alzheimer's Disease through Intranasal Delivery

Alzheimer's disease (AD) is a neurodegenerative brain problem and responsible for causing dementia in aged people. AD has become most common neurological disease in the elderly population worldwide and its treatment remains still challengeable. Therefore, there is a need of an efficient drug delivery system which can deliver the drug to the target site. Nasal drug delivery has been used since prehistoric times for the treatment of neurological disorders like Alzheimer's disease (AD). For delivering drug to the brain, blood brain barrier (BBB) is a major rate limiting factor for the drugs. The desired drug concentration could not be achieved through the conventional drug delivery system. Thus, nanocarrier based drug delivery systems are promising for delivering drug to brain. Nasal route is a most convenient for targeting drug to the brain. Several factors and mechanisms need to be considered for an effective delivery of drug to the brain particularly AD. Various nanoparticlized systems such as nanoparticles, liposomes, exosomes, phytosomes, nanoemulsion, nanosphere, etc. have been recognized as an effective drug delivery system for the management of AD. These nanocarriers have been proven with improved permeability as well as bioavailability of the anti-Alzheimer's drugs. Some novel drug delivery systems of anti-Alzheimer drugs are under investigation of different phase of clinical trials. Present article highlights on the nanotechnology based intranasal drug delivery system for the treatment of Alzheimer's disease. Furthermore, consequences of AD, transportation mechanism, clinical updates and recent patents on nose to brain delivery for AD have been discussed.

The New Frontiers in Neurodegenerative Diseases Treatment: Liposomal-Based Strategies

In the last decade, the onset of neurodegenerative (ND) diseases is strongly widespread due to the age increase of the world population. Despite the intensive investigations boosted by the scientific community, an efficacious therapy has not been outlined yet. The drugs commonly used are only able to relieve symptom severity; following their oral or intravenous administration routes, their effectiveness is strictly limited due to their low ability to reach the Central Nervous System (CNS) overcoming the Blood Brain Barrier (BBB). Starting from these assumptions, the engineered-nanocarriers, such as lipid-nanocarriers, are suitable agents to enhance the delivery of drugs into the CNS due to their high solubility, bioavailability, and stability. Liposomal delivery systems are considered to be the ideal carriers, not only for conventional drugs but also for neuroprotective small molecules and green-extracted compounds. In the current work, the LP-based drug delivery improvements in in vivo applications against ND disorders were carefully assessed.

Nano Carrier Drug Delivery Systems for the Treatment of Neuropsychiatric Disorders: Advantages and Limitations

Neuropsychiatric diseases are one of the main causes of disability, affecting millions of people. Various drugs are used for its treatment, although no effective therapy has been found yet. The blood brain barrier (BBB) significantly complicates drugs delivery to the target cells in the brain tissues. One of the problem-solving methods is the usage of nanocontainer systems. In this review we summarized the data about nanoparticles drug delivery systems and their application for the treatment of neuropsychiatric disorders. Firstly, we described and characterized types of nanocarriers: inorganic nanoparticles, polymeric and lipid nanocarriers, their advantages and disadvantages. We discussed ways to interact with nerve tissue and methods of BBB penetration. We provided a summary of nanotechnology-based pharmacotherapy of schizophrenia, bipolar disorder, depression, anxiety disorder and Alzheimer's disease, where development of nanocontainer drugs derives the most active. We described various experimental drugs for the treatment of Alzheimer's disease that include vector nanocontainers targeted on β-amyloid or tau-protein. Integrally, nanoparticles can substantially improve the drug delivery as its implication can increase BBB permeability, the pharmacodynamics and bioavailability of applied drugs. Thus, nanotechnology is anticipated to overcome the limitations of existing pharmacotherapy of psychiatric disorders and to effectively combine various treatment modalities in that direction.

Assessments of regenerative potential of silymarin nanoparticles loaded into chitosan conduit on peripheral nerve regeneration: a transected sciatic nerve model in rat

PURPOSE

It is compulsory to make a tension-free, end-to-end repair in transected injuries. However, when it comes to longer defects, placement of an autograft or nerve conduits is required. The present study was designed to assess regenerative potential of silymarin nanoparticles loaded into chitosan conduit on peripheral nerve regeneration in a transected sciatic nerve model in rat.

METHODS

In NML group left sciatic nerve was exposed through a gluteal muscle incision and after careful hemostasis skin was closed. In TSC group left sciatic nerve was transected and stumps were fixed in adjacent muscle. In CTN group, 10-mm sciatic nerve defects were bridged using a chitosan. In CTN/NSLM group, 10-mm sciatic nerve defects were bridged using a chitosan conduit and 100 µL silymarin nanoparticles were administered into the conduit. The regenerated fibers were studied 4, 8, and 12 weeks after surgery. Assessment of nerve regeneration was based on behavioral, functional, biomechanical, histomorphometric, and immuohistochemical criteria.

RESULTS

The behavioral, functional, electrophysiological, and biomechanical studies confirmed significant recovery of regenerated axons in CTN/NSLM group (P < 0.05). Quantitative morphometric analyses of regenerated fibers showed number and diameter of myelinated fibers in CTN/NSLM group were significantly higher than in CTN group (P < 0.05).

DISCUSSION

This demonstrated potential of using chitosan-silymarin nanoparticles in peripheral nerve regeneration without limitations of donor-site morbidity associated with isolation of autograft. It is also cost saving and may have clinical implications for surgical management of patients after peripheral nerve transection.

Management of epileptic disorders using nanotechnology-based strategies for nose-to-brain drug delivery

INTRODUCTION

Epilepsy, a major neurological disorder affects about 1% of the Indian population. The discovery of noninvasive strategies for epilepsy presents a challenge for the scientists. Different types of nose-to-brain dosage-forms have been studied for epilepsy management. It aims to give new perspectives for developing new and existing anti-epileptic drugs. Combining nanotechnology with nose-to-brain approach can help in promoting the treatment efficacy by site-specific delivery. Also, it will minimize the side-effects and patient noncompliance observed in conventional administration routes. Peptide delivery can be an interesting approach for the management of epilepsy. Drug-loaded intranasal nanoformulations exhibit diverse prospective potentials in the management of epilepsy. Considering that, nanotherapy using nose-to-brain delivery as a prospective technique for the efficient management of epilepsy is reviewed.

AREAS COVERED

The authors have compiled all recently available data pertaining to the nose-to-brain delivery of therapeutics using nanotechnological strategies. The fundamental mechanism of nose-to-brain delivery, claims for intranasal delivery and medical devices for epilepsy are discussed.

EXPERT OPINION

Drug-loaded intranasal nanoformulations exhibit different prospective potentials in the management of epilepsy. Considering the foregoing research done in the field of nanotechnology, globally, authors propose nose-to-brain delivery of nanoformulations as a potential technique for the efficient management of epilepsy.

Bioinspired lipid-polysaccharide modified hybrid nanoparticles as a brain-targeted highly loaded carrier for a hydrophilic drug

Lipid-polysaccharide modified biohybrid nanoparticles (NPs) are eminent drug carriers for brain targeting, owing to their ability to prolong the circulation time and penetrate the blood brain barrier (BBB). Biohybrid NPs particular interest arises from their potential to mimic biological components. Herein, we prepared bioinspired lipid polymeric NPs, either naked or surface modified by a synthesized biocompatible dextran-cholic acid (DxC). The nanoprecipitation method was tailored to allow the assembly of the multicomponent NPs in a single step. Modulating the solvent/antisolvent system provided lipid polymer hybrid NPs in the size of 111.6 ± 11.4 nm size. The NPs encapsulated up to 92 ± 1.2% of a hydrophilic anti-Alzheimer drug, rivastigmine (Riv). The brain uptake, biodistribution and pharmacokinetics studies, proved the efficient fast penetration of the bioinspired surface modified NPs to the brain of healthy albino rats. The modified nanocarrier caused a 5.4 fold increase in brain targeting efficiency compared to the drug solution. Furthermore, the presence of DxC increased Riv's brain residence time up to 40 h. The achieved results suggest that the fabricated biohybrid delivery system was able to circumvent the BBB and is expected to minimize Riv systemic side effects.

Can Bottom-Up Synthetic Biology Generate Advanced Drug-Delivery Systems?

Creating a magic bullet that can selectively kill cancer cells while sparing nearby healthy cells remains one of the most ambitious objectives in pharmacology. Nanomedicine, which relies on the use of nanotechnologies to fight disease, was envisaged to fulfill this coveted goal. Despite substantial progress, the structural complexity of therapeutic vehicles impedes their broad clinical application. Novel modular manufacturing approaches for engineering programmable drug carriers may be able to overcome some fundamental limitations of nanomedicine. We discuss how bottom-up synthetic biology principles, empowered by microfluidics, can palliate current drug carrier assembly limitations, and we demonstrate how such a magic bullet could be engineered from the bottom up to ultimately improve clinical outcomes for patients.

Dermal pharmacokinetics of rivastigmine-loaded liposomes: an ex vivo-in vivo correlation study

The aim of the present study was to develop a topical liposomal formulation as a transdermal delivery of rivastigmine for the treatment of Alzheimer's disease as an alternative to the oral dosage form and to achieve smooth continuous drug delivery and maintain plasma levels within the therapeutic window. Rivastigmine-loaded liposomes were prepared by a thin layer hydration technique that was applied in ex vivo-in vivo correlation study. Permeability parameters through rat skin in ex vivo study and pharmacokinetic parameters in the in vivo study were evaluated. The ex vivo permeation study showed that liposomes provided steady-state flux 0.11 ± 0.01 mg/cm.h that were more than 2-fold the aqueous control. In the in vivo experiments, after topical application of optimized rivastigmine liposomes, the C_max 208 ng/ml and AUC_0-24 3605 (ng.h/ml) were also significantly higher than the control group (both p < 0.01). A point-to-point significant linear correlation was found between ex vivo and in vivo parameters, meaning in vivo pharmacokinetic parameters can be predicted by ex vivo permeation parameters. These data suggest that a liposomal formulation could be an effective carrier to enhance rivastigmine permeation through the skin and maintain plasma levels within the therapeutic window.

Bi-functional sterically hindered phenol lipid-based delivery systems as potential multi-target agents against Alzheimer's disease via an intranasal route

New lipid-based nanomaterials and multi-target directed ligands (MTDLs) based on sterically hindered phenol, containing a quaternary ammonium moiety (SHP-s-R, with s = 2,3) of varying hydrophobicity (R = CH2Ph and CnH2n+1, with n = 8, 10, 12, 16), have been prepared as potential drugs against Alzheimer's disease (AD). SHP-s-R are inhibitors of human cholinesterases with antioxidant properties. The inhibitory potency of SHP-s-R and selectivity ratio of cholinesterase inhibition were found to significantly depend on the length of the methylene spacer (s) and alkyl chain length. The compound SHP-2-16 showed the best IC50 for human AChE and the highest selectivity, being 30-fold more potent than for human BChE. Molecular modeling of SHP-2-16 binding to human AChE suggests that this compound is a dual binding site inhibitor that interacts with both the peripheral anionic site and catalytic active site. The relationship between self-assembly parameters (CMC, solubilization capacity, aggregation number), antioxidant activity and a toxicological parameter (hemolytic action on human red blood cells) was investigated. Two sterically hindered phenols (SHP-2-Bn and SHP-2-R) were loaded into L-α-phosphatidylcholine (PC) nanoparticles by varying the SHP alkyl chain length. For the brain AChE inhibition assay, PC/SHP-2-Bn/SHP-2-16 nanoparticles were administered to rats intranasally at a dose of 8 mg kg-1. The Morris water maze experiment showed that scopolamine-induced AD-like dementia in rats treated with PC/SHP-2-Bn/SHP-2-16 nanoparticles was significantly reduced. This is the first example of cationic SHP-phospholipid nanoparticles for inhibition of brain cholinesterases realized by the use of intranasal administration. This route has promising potential for the treatment of AD.

Pharmacotechnical Development of a Nasal Drug Delivery Composite Nanosystem Intended for Alzheimer's Disease Treatment

Direct nose-to-brain delivery has been raised as a non-invasive powerful strategy to deliver drugs to the brain bypassing the blood-brain barrier (BBB). This study aimed at preparing and characterizing an innovative composite formulation, associating the liposome and hydrogel approaches, suitable for intranasal administration. Thermosensitive gel formulations were obtained based on a mixture of two hydrophilic polymers (Poloxamer 407, P407 and Poloxamer 188, P188) for a controlled delivery through nasal route via liposomes of an active pharmaceutical ingredient (API) of potential interest for Alzheimer’s disease. The osmolarity and the gelation temperature (T° sol-gel) of formulations, defined in a ternary diagram, were investigated by rheometry and visual determination. Regarding the issue of assays, a mixture composed of P407/P188 (15/1%, w/w) was selected for intranasal administration in terms of T° sol-gel and for the compatibility with the olfactory mucosal (280 ± 20 mOsmol, pH 6). Liposomes of API were prepared by the thin film hydration method. Mucoadhesion studies were performed by using mucin disc, and they showed the good natural mucoadhesive characteristics of in situ gel formulations, which increased when liposomes were added. The study demonstrated successful pharmacotechnical development of a promising API-loaded liposomes in a thermosensitive hydrogel intended for nasal Alzheimer’s disease treatment.

Preparation, Optimization, and Evaluation of Methoxy Poly(ethylene glycol)-co-Poly(ε-caprolactone) Nanoparticles Loaded by Rivastigmine for Brain Delivery

The objective of this study was to formulate and investigate the neuropharmacokinetics and pharmacodynamics of rivastigmine (Riv) loaded methoxy poly(ethylene glycol)-co-poly(ε-caprolactone) (MPEG-PCL) nanoparticles (Riv-NPs) in rats after IV administration. The MPEG-PCL was synthesized via ring-opening polymerization of ε-caprolactone by MPEG and used to prepare Riv-NPs by the nanoprecipitation method. Response surface D-optimal design was applied to optimize Riv-NPs drug delivery system. The optimized formulation showed a particle size (PS) of 98.5 ± 2.1 nm, drug loading (DL) of 19.2 ± 1.1%, and sustained release behavior of the drug. Moreover, the optimized Riv-NPs were characterized by AFM and DSC analyses. A simple and sensitive HPLC-DAD method for bioanalysis was developed and successfully applied to the pharmacokinetic study. The neuropharmacokinetic study in rats indicated that the integration plot was linear, and the brain uptake clearance of the drug-loaded in MPEG-PCL NPs was significantly higher than the free drug. Furthermore, results of pharmacodynamic studies using the Morris water maze test demonstrated faster regain of memory loss with Riv-NPs when compared to the free drug solution. The results revealed that the mentioned biodegradable nanoparticle holds promise as a suitable drug carrier for brain drug delivery.

Progress and perspectives of brain-targeting lipid-based nanosystems via the nasal route in Alzheimer's disease

Since health care systems dedicate substantial resources to Alzheimer's disease (AD), it poses an increasing challenge to scientists and health care providers worldwide, especially that many decades of research in the medical field revealed no optimal effective treatment for this disease. The intranasal administration route seems to be a preferable route of anti-AD drug delivery over the oral one as it demonstrates an ability to overcome the related obstacles reflected in low bioavailability, limited brain exposure and undesired pharmacokinetics or side effects. This delivery route can bypass the systemic circulation through the intraneuronal and extraneuronal pathways, providing truly needleless and direct brain drug delivery of the therapeutics due to its large surface area, porous endothelial membrane, the avoidance of the first-pass metabolism, and ready accessibility. Among the different nano-carrier systems developed, lipid-based nanosystems have become increasingly popular and have proven to be effective in managing the common symptoms of AD when administered via the nose-to-brain delivery route, which provides an answer to circumventing the BBB. The design of such lipid-based nanocarriers could be challenging since many factors can contribute to the quality of the final product. Hence, according to the authors, it is recommended to follow the quality by design methodology from the early stage of development to ensure high product quality while saving efforts and costs. This review article aims to draw attention to the up-to-date findings in the field of lipid-based nanosystems and the potential role of developing such forms in the management of AD by means of the nose-to-brain delivery route, in addition to highlighting the significant role of applying QbD methodology in this development.

Interpreting non-linear drug diffusion data: Utilizing Korsmeyer-Peppas model to study drug release from liposomes

The aim of this work was to clarify the dynamics behind the influence of ionic strength on the changes in drug release from large unilamellar vesicles (LUVs). For this purpose, we have investigated the transport of two different model drugs (caffeine and hydrocortisone) formulated into liposomes through different types of barriers with different retention properties (regenerated cellulose and the newly introduced biomimetic barrier, Permeapad®). Drug release from liposomes was studied utilizing the standard Franz diffusion cells. LUV dispersions were exposed to the isotonic, hypotonic and hypertonic environment (difference of 300 mOsm/kg between the initial LUVs and the environment) and experimental data treated with both linear and non-linear (Korsmeyer-Peppas) regression models. To alter the rigidity of the liposomal membranes, cholesterol was introduced in the liposomal barriers (up to 25% w/w). Korsmeyer-Peppas model was proven to be suited to analyse experimental data throughout the experimental time frame, providing important additive information in comparison to standard linear approximation. The obtained results are highly relevant as they improve the interpretation of drug release kinetics from LUVs under osmotic stress. Moreover, the findings can be utilized in the development of liposomal formulations intended for nose-to-brain targeted drug delivery.

Liposome delivery systems for the treatment of Alzheimer's disease

Alzheimer's disease (AD) will affect around 115 million people worldwide by the year 2050. It is associated with the accumulation of misfolded and aggregated proteins (β-amyloid and tau) in the senile plaques and neurofibrillary tangles found in the brain. Currently available drugs for AD only temporarily alleviate symptoms and do not slow the inevitable progression of this disease. New drugs are required that act on key pathologies in order to arrest or reverse cognitive decline. However, there has been a spectacular failure rate in clinical trials of conventional small molecule drugs or biological agents. Targeted nanoliposomes represent a viable and promising drug delivery system for AD that have not yet reached clinical trials. They are biocompatible, highly flexible, and have the potential to carry many different types of therapeutic molecules across the blood-brain barrier (BBB) and into brain cells. They can be tailored to extend blood circulation time and can be directed against individual or multiple pathological targets. Modifications so far have included the use of brain-penetrating peptides, together with Aβ-targeting ligands, such as phosphatidic acid, curcumin, and a retro-inverted peptide that inhibits Aβ aggregation. Combining several modifications together into multifunctional liposomes is currently a research area of great interest. This review focuses on recent liposomal approaches to AD therapy, including mechanisms involved in facilitating their passage across the BBB, and the evaluation of new therapeutic agents for blocking Aβ and/or tau aggregation.

Therapeutic strategies and nano-drug delivery applications in management of ageing Alzheimer's disease

In recent years, the incidental rate of neurodegenerative disorders has increased proportionately with the aging population. Alzheimer's disease (AD) is one of the most commonly reported neurodegenerative disorders, and it is estimated to increase by roughly 30% among the aged population. In spite of screening numerous drug candidates against various molecular targets of AD, only a few candidates - such as acetylcholinesterase inhibitors are currently utilized as an effective clinical therapy. However, targeted drug delivery of these drugs to the central nervous system (CNS) exhibits several limitations including meager solubility, low bioavailability, and reduced efficiency due to the impediments of the blood-brain barrier (BBB). Current advances in nanotechnology present opportunities to overcome such limitations in delivering active drug candidates. Nanodrug delivery systems are promising in targeting several therapeutic moieties by easing the penetration of drug molecules across the CNS and improving their bioavailability. Recently, a wide range of nano-carriers, such as polymers, emulsions, lipo-carriers, solid lipid carriers, carbon nanotubes, metal based carriers etc., have been adapted to develop successful therapeutics with sustained release and improved efficacy. Here, we discuss few recently updated nano-drug delivery applications that have been adapted in the field of AD therapeutics, and future prospects on potential molecular targets for nano-drug delivery systems.

Phyto-Therapeutic and Nanomedicinal Approaches to Cure Alzheimer's Disease: Present Status and Future Opportunities

Alzheimer's disease (AD) is characterized by cognitive inability manifested due to the accumulation of β-amyloid, formation of hyper phosphorylated neurofibrillary tangles, and a malfunctioned cholinergic system. The degeneration integrity of the neuronal network can appear long after the onset of the disease. Nanotechnology-based interventions have opened an exciting area via theranostics of AD in terms of tailored nanomedicine, which are able to target and deliver drugs across the blood-brain barrier (BBB). The exciting interface existing between medicinal plants and nanotechnology is an emerging marvel in medicine, which has delivered promising results in the treatment of AD. In order to assess the potential applications of the medicinal plants, their derived components, and various nanomedicinal approaches, a review of literature was deemed as necessary. In the present review, numerous phytochemicals and various feats in nanomedicine for the treatment of AD have been discussed mechanistically for the first time. Furthermore, recent trends in nanotechnology such as green synthesis of metal nanoparticles with reference to the treatment of AD have been elaborated. Foreseeing the recent progress, we hope that the interface of medicinal plants and nanotechnology will lead to highly effective theranostic strategies for the treatment of AD in the near future.

Ursolic acid loaded intra nasal nano lipid vesicles for brain tumour: Formulation, optimization, in-vivo brain/plasma distribution study and histopathological assessment

The aim was to formulate an optimized ursolic acid (UA) loaded lipid vesicle using formulation by design approach (FbD) for improving the drug targeting by nasal route for brain tumor. Three factors were evaluated at three different levels using anethole (terpene) (A), ethanol (B) and phospholipid90 G (C) as independent variables and their individual and combined effects were observed for PDI (Y1), vesicle size (Y2) and encapsulation efficiency (Y3) to select an optimal system (UALVopt). The optimized formulation was further converted into gel and evaluated for drug release, nasal permeation study, brain/plasma uptake and histopathology study. The UALVopt formulation containing anethole as terpene (1% as A), ethanol (2.6% as B) and phospholipid90 G (8.8 mg as C) showed low PDI (0.212), vesicle size (115.56 nm) and high entrapment efficiency (76.42%). The in-vitro drug release and ex-vivo permeation study results revealed prolonged drug release and permeation. The brain/blood ratio for UALVGopt remained significantly higher at all the time points with respect to UALVopt indicating higher and prolonged retention of drug at site of action. The histopathological study of the nasal mucosa and brain confirmed non-toxic nature of developed formulation. The formulation UALVGopt could serve as a better alternative for the brain targeting via the intranasal route which in turn could subsequently improve its efficacy.

Surface-Modified Nanocarriers for Nose-to-Brain Delivery: From Bioadhesion to Targeting

In the field of nasal drug delivery, nose-to-brain delivery is among the most fascinating applications, directly targeting the central nervous system, bypassing the blood brain barrier. Its benefits include dose lowering and direct brain distribution of potent drugs, ultimately reducing systemic side effects. Recently, nasal administration of insulin showed promising results in clinical trials for the treatment of Alzheimer’s disease. Nanomedicines could further contribute to making nose-to-brain delivery a reality. While not disregarding the need for devices enabling a formulation deposition in the nose’s upper part, surface modification of nanomedicines appears the key strategy to optimize drug delivery from the nasal cavity to the brain. In this review, nanomedicine delivery based on particle engineering exploiting surface electrostatic charges, mucoadhesive polymers, or chemical moieties targeting the nasal epithelium will be discussed and critically evaluated in relation to nose-to-brain delivery.

Effects of Silymarin-Loaded Nanoparticles on HT-29 Human Colon Cancer Cells

Background and objective: Previous studies have demonstrated the anti-cancer effects of silymarin (SLM). However, the low bioavailability of SLM has restricted its use. This study investigated the toxic effect of nanostructured SLM encapsulated in micelles (Nano-SLM) on the growth of the HT-29 human colon cancer cell line. Materials and methods: HT-29 cells were treated with 25 μM/mL of SLM or Nano-SLM for 48 h. MTT and colony formation assays were used to assess the cytotoxicity and proliferation of HT-29 cells, respectively. The cells were stained with annexin V/PI for assessment of apoptosis. Results: MTT assays revealed that Nano-SLM treatment was able to exert a more pronounced toxic effect on the HT-29 cells as compared to free SLM treatment (p < 0.01). In the Nano-SLM-treated cells, colony numbers were significantly reduced in comparison to the free SLM-treated cells (p < 0.01). Apoptotic and necrotic indexes of Nano-SLM-treated HT-29 cells were also significantly increased in comparison to those of the free SLM-treated cells (p < 0.01). The viability, proliferation and apoptosis of healthy cells (NIH-3T3 cells) were not changed in response to Nano-SLM or SLM. Conclusions: Our results indicate that Nano-SLM enhances the anti-cancer effects of SLM against human colon cancer cells.

A Stability Indicating HPLC Assay Method for Analysis of Rivastigmine Hydrogen Tartrate in Dual-Ligand Nanoparticle Formulation Matrices and Cell Transport Medium

The objective of this study was to develop and validate a method for quantitative analysis of rivastigmine hydrogen tartrate (RHT) in dual-ligand polymeric nanoparticle formulation matrices, drug release medium, and cellular transport medium. An isocratic HPLC analysis method using a reverse phase C₁₈ column and a simple mobile phase without buffer was developed, optimised, and fully validated. Analyses were carried out at a flow rate of 1.5 mL/min at 50°C and monitored at 214 nm. This HPLC method exhibited good linearity, accuracy, and selectivity. The recovery (accuracy) of RHT from all matrices was greater than 99.2%. The RHT peak detected in the samples of a forced degradation study, drug loading study, release study, and cellular transport study was pure and free of matrix interference. The limit of detection (LOD) and limit of quantification (LOQ) of the assay were 60 ng/mL and 201 ng/mL, respectively. The method was rugged with good intra- and interday precision. This stability indicating HPLC method was selective, accurate, and precise for analysing RHT loading and its stability in nanoparticle formulation, RHT release, and cell transport medium.