Development and Evaluation of pH-Responsive Cyclodextrin-Based in situ Gel of Paliperidone for Intranasal Delivery

Review of Intranasal Active Pharmaceutical Ingredient Delivery Systems

In recent decades, there has been an increased interest in the development of intranasal delivery systems for active pharmaceutical ingredients (APIs) not only for treating local nasal diseases but also for treating systemic diseases, central nervous system (CNS) disorders, and vaccine delivery. The nasal cavity possesses a unique set of anatomical characteristics for delivering active pharmaceutical ingredients, but there are several limitations that recent research in the field of the intranasal administration of APIs aims to overcome. For the effective delivery of nasal preparations, active pharmaceutical ingredients are incorporated into various micro- and nanosystems. Some of the most commonly encountered API delivery systems in the scientific literature include liposomal systems, polymer particles with mucoadhesive properties, in situ gels, nano- and microemulsions, and solid lipid particles. This article provides a review of research on the development of nasal preparations for treating local nasal cavity diseases (in particular, for antibiotic delivery), systemic diseases (analgesics, drugs for cardiovascular diseases, antiviral and antiemetic drugs), CNS disorders (Alzheimer's disease, Parkinson's disease, epilepsy, schizophrenia, depression), and vaccine delivery. The literature data show that active research is underway to reformulate drugs of various pharmacotherapeutic groups into a nasal form.

pH-Sensitive In Situ Gel of Mirtazapine Invasomes for Rectal Drug Delivery: Protruded Bioavailability and Anti-Depressant Efficacy

The present research emphasizes fabrication alongside the assessment of an innovative nano-vesicular membranous system known as invasomes (NVMs) laden with Mirtazapine for rectal administration. This system could circumvent the confines of orally administered counterparts regarding dose schedules and bioavailability. Mirtazapine invasomes were tailored by amalgamating phospholipid, cineole, and ethanol through a thin-film hydration approach rooted in the Box-Behnken layout. Optimization of composition parameters used to fabricate desired NVMs' physicochemical attributes was undertaken using the Design-Expert® program. The optimal MRZ-NVMs were subsequently transformed to a pH-triggered in situ rectal gel followed by animal pharmacodynamic and pharmacokinetic investigations relative to rectal plain gel and oral suspension. The optimized NVMs revealed a diameter size of 201.3 nm, a z potential of -28.8 mV, an entrapment efficiency of 81.45%, a cumulative release within 12 h of 67.29%, and a cumulative daily permeated quantity of 468.68 µg/cm2. Compared to the oral suspension, pharmacokinetic studies revealed a 2.85- and 4.45-fold increase in calculated rectal bioavailability in circulation and brain, respectively. Pharmacodynamic and immunohistopathology evaluations exposed superior MRZ-NVMs attributed to the orally administered drug. Consequently, rectal MRZ-NVMs can potentially be regarded as a prospective nanoplatform with valuable pharmacokinetics and tolerability assets.

Advances and future perspectives of intranasal drug delivery: A scientometric review

Intranasal drug delivery is as a noninvasive and efficient approach extensively utilized for treating the local, central nervous system, and systemic diseases. Despite numerous reviews delving into the application of intranasal drug delivery across biomedical fields, a comprehensive analysis of advancements and future perspectives remains elusive. This review elucidates the research progress of intranasal drug delivery through a scientometric analysis. It scrutinizes several challenges to bolster research in this domain, encompassing a thorough exploration of entry and elimination mechanisms specific to intranasal delivery, the identification of drugs compatible with the nasal cavity, the selection of dosage forms to surmount limited drug-loading capacity and poor solubility, and the identification of diseases amenable to the intranasal delivery strategy. Overall, this review furnishes a perspective aimed at galvanizing future research and development concerning intranasal drug delivery.

The prescription design and key properties of nasal gel for CNS drug delivery: A review

Central nervous system (CNS) diseases are among the major health problems. However, blood-brain barrier (BBB) makes traditional oral and intravenous delivery of CNS drugs inefficient. The unique direct connection between the nose and the brain makes nasal administration a great potential advantage in CNS drugs delivery. However, nasal mucociliary clearance (NMCC) limits the development of drug delivery systems. Appropriate nasal gel viscosity alleviates NMCC to a certain extent, gels based on gellan gum, chitosan, carbomer, cellulose and poloxamer have been widely reported. However, nasal gel formulation design and key properties for alleviating NMCC have not been clearly discussed. This article summarizes gel formulations of different polymers in existing nasal gel systems, and attempts to provide a basis for researchers to conduct in-depth research on the key characteristics of gel matrix against NMCC.

Study on the Nasal Drug Delivery System of NMD Liposomes In Situ Thermosensitive Gel

Nimodipine (NMD) is a 1,4-dihydropyridine calcium antagonist that is effective in the prevention and treatment of cerebral arterial vasospasm and cerebral ischemic injury caused by subarachnoid hemorrhage. Since the drug itself is highly insoluble in water and has low oral bioavailability, while injectable formulations may cause pain and inflammation, the blood-brain barrier (BBB) prevents the effective delivery of therapeutic agents to the brain tissue. Therefore, in the present study, NMD liposomes were prepared by ethanol injection and innovatively lyophilised and loaded into temperature-sensitive in situ gels for intranasal administration as sprays to deliver drugs to brain tissues bypassing the blood-brain barrier. The optimal gel formulation was obtained by screening in which liposomes were divided into lecithin, cholesterol, and NMD in the ratio of 40:10: 1; Pluronic P407, Pluronic P188, Tween 80, polyvinyl ketone and ethyl nipagin in the ratio of (180:20:3:1:1); Pluronic P407, Pluronic P188, Tween 80, polyvinyl ketone, and ethyl nipagin in the ratio of (180:20:3:1:1). The prepared flow gel can form a solidified gel after a temperature of 31.07-32.07°C and a time of 58.51-59.89 s. Meanwhile, the NMD liposome gel formulation achieved sustained release over 56 h. The pharmacokinetic results of the developed NMD liposomal temperature-sensitive in situ gel and NMD temperature-sensitive in situ gel showed that liposomal nasal mucosal in situ gel is a more effective brain-targeted drug delivery system for NMD.

Nasal Absorption Enhancement of Mometasone Furoate Nanocrystal Dispersions

Purpose

We designed a 0.05% mometasone furoate (MF) nanocrystal dispersion and investigated whether the application of MF nanocrystals in nasal formulations enhanced local absorption compared to traditional nasal MF formulations (CA-MF).

Methods

MF nanocrystal dispersions (MF-NPs) were prepared by bead milling MF microcrystal dispersions (MF-MPs) consisting of MF, 2-hydroxypropyl-β-cyclodextrin, methylcellulose, and purified water. Pluronic F-127 combined with methylcellulose, Pluronic F-68, or carbopol was used as a base for in situ gelation (thickener). MF concentrations were measured using high-performance liquid chromatography, and nasal absorption of MF was evaluated in 6 week-old male Institute of Cancer Research (ICR) mice.

Results

The particle size range of MF prepared with the bead mill treatment was 80-200 nm, and the nanoparticles increased the local absorption of MF, which was higher than that of CA-MF and MF-MPs. In addition, unlike the results obtained in the small intestine and corneal tissue, the high absorption of nanocrystalline MF in the nasal mucosa was related to a pathway that was not derived from energy-dependent endocytosis. Moreover, the application of the in situ gelling system attenuated the local absorption of MF-NPs, owing to a decrease in drug diffusion in the dispersions.

Conclusion

We found that nanoparticulation of MF enhances local intranasal absorption, and nasal bioavailability is higher than that of CA-MF. In addition, we demonstrate that viscosity regulation is an important factor in the design of nasal formulations based on MF nanocrystals. These findings provide insights for the design of novel nanomedicines with enhanced nasal bioavailability.

Thermoresponsive Gel-loaded Oxcarbazepine Nanosystems for Nose- To-Brain Delivery: Enhanced Antiepileptic Activity in Rats

BACKGROUND

Oxcarbazepine (OXC) is a frequently prescribed antiepileptic drug for managing focal and generalized seizures. Its therapeutic benefits are limited by its dose-dependent side effects. Nose-to-brain delivery is a novel route for improving the efficacy of antiepileptics. Drug encapsulation in mucoadhesive nanoparticles offers even more advantages for the nasal route.

OBJECTIVE

The study aimed to develop oxcarbazepine-loaded chitosan nanoparticles (OXC-NP) added to a mucoadhesive thermo-reversible gel for intranasal delivery and enhancement of antiepileptic activity.

METHODS

The formulation was optimized based on entrapment efficiency, polydispersity index, particle size, zeta potential, and in vitro release analysis. The therapeutic efficacy of OXC-NP was assessed in an epileptic rat model and compared to intranasal OXC and oral OXC.

RESULTS

The optimized OXC-NPs with chitosan exhibited particle size, zeta potential, and entrapment efficiency of 189 nm, + 31.4 mV ± 2.5 and 97.6% ± 0.14, respectively. The release of OXC was prolonged, reaching 47.1% after 6 h and 55% after 24 h. Enhanced antiepileptic activity of OXC-NP was manifested as decreased seizure score and prolonged survival. Halting of hippocampal TNF-α and IL-6 together with upregulated IL-10 could explain its anti-inflammatory mechanisms.

CONCLUSIONS

Intranasal OXC-NP-loaded in situ gel represents a promising formulation for enhanced antiepileptic potential achieved at low drug concentrations.

Nose-to-brain drug delivery for the treatment of CNS disease: New development and strategies

Delivering drugs to the brain has always been a challenging task due to the restrictive properties of the blood-brain barrier (BBB). Intranasal delivery is therefore emerging as an efficient method of administration, making it easy to self-administration and thus provides a non-invasive and painless alternative to oral and parenteral administration for delivering therapeutics to the central nervous system (CNS). Recently, drug formulations have been developed to further enhance this nose-to-brain transport, primarily using nanoparticles (NPs). Therefore, the purposes of this review are to highlight and describe the anatomical basis of nasal-brain pathway and provide an overview of drug formulations and current drugs for intranasal administration in CNS disease.

Current and future directions of drug delivery for the treatment of mental illnesses

Mental illnesses including anxiety disorders, autism spectrum disorder, post-traumatic stress disorder, schizophrenia, depression, and others exact an immense toll on the healthcare system and society at large. Depression alone impacts 21 million adults and costs over $200 billion annually in the United States. However, pharmaceutical strategies to treat mental illnesses are lagging behind drug development in many other disease areas. Because many of the shortcomings of therapeutics for mental illness relate to delivery problems, drug delivery technologies have the potential to radically improve the effectiveness of therapeutics for these diseases. This review describes the current pharmacotherapeutic approaches to treating mental illnesses as well as drug delivery approaches that have improved existing therapies. Approaches to improve drug bioavailability, provide controlled release of therapeutics, and enable drug targeting to the central nervous system (CNS) will be highlighted. Moreover, next-generation delivery approaches such as environmentally-controlled release and interval/sequential drug release will be addressed. Based on the evolving landscape of the treatment of mental illnesses, the nascent field of drug delivery in mental health has tremendous potential for growth in terms of both economic and patient impact.

Investigating the Targeting Power to Brain Tissues of Intranasal Rasagiline Mesylate-Loaded Transferosomal In Situ Gel for Efficient Treatment of Parkinson's Disease

Rasagiline mesylate (RSM) is a hydrophilic drug with poor oral bioavailability (36%) because of hepatic first-pass metabolism. The present study focuses on delivering RSM directly to the brain through its inclusion within transferosomal in situ gel administered through the intranasal (IN) route. Transferosomes were formed by the thin-film hydration method with the aid of Design-Expert^® software by varying the edge activator (EA) type in the absence or presence of cholesterol. By desirability calculations, the optimum formulation was composed of phosphatidylcholine and sodium deoxycholate as an EA (5:1% w/w) with no cholesterol. The optimum formulation was 198.63 ± 34.98 nm in size and displayed an entrapment efficiency of 95.73 ± 0.09%. Transmission electron microscopy revealed discrete and spherical vesicles. Optimized transferosomes were further incorporated into an in situ gel composed of 0.5% pectin, 15% Pluronic^® F-127, and 5% Pluronic^® F-68 and tested for the in vivo performance. The systemic as well as brain kinetics were assessed in rats by comparing the IN-administered in situ gel to the IV aqueous solution. The optimum in situ gel showed safety and biocompatibility on rats' nasal mucosa with enhanced brain bioavailability (131.17%). Drug targeting efficiency and direct transport percentage indices (304.53% and 67.16%, respectively) supported successful brain targeting offering direct nose-to-brain drug delivery.

Polymeric Biomaterials for Topical Drug Delivery in the Oral Cavity: Advances on Devices and Manufacturing Technologies

There are several routes of drug administration, and each one has advantages and limitations. In the case of the topical application in the oral cavity, comprising the buccal, sublingual, palatal, and gingival regions, the advantage is that it is painless, non-invasive, allows easy application of the formulation, and it is capable of avoiding the need of drug swallowing by the patient, a matter of relevance for children and the elderly. Another advantage is the high permeability of the oral mucosa, which may deliver very high amounts of medication rapidly to the bloodstream without significant damage to the stomach. This route also allows the local treatment of lesions that affect the oral cavity, as an alternative to systemic approaches involving injection-based methods and oral medications that require drug swallowing. Thus, this drug delivery route has been arousing great interest in the pharmaceutical industry. This review aims to condense information on the types of biomaterials and polymers used for this functionality, as well as on production methods and market perspectives of this topical drug delivery route.

Formulation considerations for improving intranasal delivery of CNS acting therapeutics

One of the principal impediments for the treatment of neurological conditions is the lack of ability of most of the medicinal agents to evade the blood–brain barrier. Among all the novel approaches to bypass the blood–brain barrier, nose to brain transport is the most patient compliant, non-invasive and effective approach. It directly transports drugs to the CNS via the trigeminal and olfactory nerves present in the nasal cavity. This review article focuses on anatomy and physiology of nasal cavity, potential of intranasal drug delivery, mechanisms of drug transport to brain, its advantages and limitations, novel intranasal formulations, marketed products, factors affecting nose to brain transport, formulation consideration of intranasal products and the future perspectives of CNS targeting via intranasal drug administration.

Nose-to-Brain Delivery of Therapeutic Peptides as Nasal Aerosols

Central nervous system (CNS) disorders, such as psychiatric disorders, neurodegeneration, chronic pain, stroke, brain tumor, spinal cord injury, and many other CNS diseases, would hugely benefit from specific and potent peptide pharmaceuticals and their low inherent toxicity. The delivery of peptides to the brain is challenging due to their low metabolic stability, which decreases their duration of action, poor penetration of the blood-brain barrier (BBB), and their incompatibility with oral administration, typically resulting in the need for parenteral administration. These challenges limit peptides’ clinical application and explain the interest in alternative routes of peptide administration, particularly nose-to-brain (N-to-B) delivery, which allows protein and peptide drugs to reach the brain noninvasively. N-to-B delivery can be a convenient method for rapidly targeting the CNS, bypassing the BBB, and minimizing systemic exposure; the olfactory and trigeminal nerves provide a unique pathway to the brain and the external environment. This review highlights the intranasal delivery of drugs, focusing on peptide delivery, illustrating various clinical applications, nasal delivery devices, and the scope and limitations of this approach.

Advances and Challenges in Intranasal Delivery of Antipsychotic Agents Targeting the Central Nervous System

Treatment of central nervous system (CNS) disorders is challenging using conventional delivery strategies and routes of administration because of the presence of the blood–brain barrier (BBB). This BBB restricts the permeation of most of the therapeutics targeting the brain because of its impervious characteristics. Thus, the challenges of delivering the therapeutic agents across the BBB to the brain overcoming the issue of insufficient entry of neurotherapeutics require immediate attention for recovering from the issues by the use of modern platforms of drug delivery and novel routes of administration. Therefore, the advancement of drug delivery tools and delivering these tools using the intranasal route of drug administration have shown the potential of circumventing the BBB, thereby delivering the therapeutics to the brain at a significant concentration with minimal exposure to systemic circulation. These novel strategies could lead to improved efficacy of antipsychotic agents using several advanced drug delivery tools while delivered via the intranasal route. This review emphasized the present challenges of delivering the neurotherapeutics to the brain using conventional routes of administration and overcoming the issues by exploring the intranasal route of drug administration to deliver the therapeutics circumventing the biological barrier of the brain. An overview of different problems with corresponding solutions in administering therapeutics via the intranasal route with special emphasis on advanced drug delivery systems targeting to deliver CNS therapeutics has been focused. Furthermore, preclinical and clinical advancements on the delivery of antipsychotics using this intranasal route have also been emphasized.

Convolutions in the rendition of nose to brain therapeutics from bench to bedside: Feats & fallacies

Brain, a subtle organ of multifarious nature presents plethora of physiological, metabolic and bio-chemical convolutions that impede the delivery of biomolecules and thereby resulting in truncated therapeutic outcome in pathological conditions of central nervous system (CNS). The absolute bottleneck in the therapeutic management of such devastating CNS ailments is the BBB. Another pitfall is the lack of efficient technological platforms (due to high cost and low approval rates) as well as limited clinical trials (due to failures of neuro‑leads in late-stage pipelines) for CNS disorders which has become a literal brain drain with poorest success rates compared to other therapeutic areas, owing to time consuming processes, tremendous convolutions and conceivable adverse effects. With the advent of intranasal delivery (via direct N2B or indirect nose to blood to brain), several novel drug delivery carriers viz. unmodified or surface modified nanoparticle based carriers, lipid based colloidal nanocarriers and drysolid/liquid/semisolid nanoformulations or delivery platforms have been designed as a means to deliver therapeutic agents (small and large molecules, peptides and proteins, genes) to brain, bypassing BBB for disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), epilepsy, schizophrenia and CNS malignancies primarily glioblastomas. Intranasal application offers drug delivery through both direct and indirect pathways for the peripherally administered psychopharmacological agents to CNS. This route could also be exploited for the repurposing of conventional drugs for new therapeutic uses. The limited clinical translation of intranasal formulations has been primarily due to existence of barriers of mucociliary clearance in the nasal cavity, enzyme degradation and low permeability of the nasal epithelium. The present review literature aims to decipher the new paradigms of nano therapeutic systems employed for specific N2B drug delivery of CNS drugs through in silico complexation studies using rationally chosen mucoadhesive polymers (exhibiting unique physicochemical properties of nanocarrier's i.e. surface modification, prolonging retention time in the nasal cavity, improving penetration ability, and promoting brain specific delivery with biorecognitive ligands) via molecular docking simulations. Further, the review intends to delineate the feats and fallacies associated with N2B delivery approaches by understanding the physiological/anatomical considerations via decoding the intranasal drug delivery pathways or critical factors such as rationale and mechanism of excipients, affecting the permeability of CNS drugs through nasal mucosa as well as better efficacy in terms of brain targeting, brain bioavailability and time to reach the brain. Additionally, extensive emphasis has also been laid on the innovative formulations under preclinical investigation along with their assessment by means of in vitro /ex vivo/in vivo N2B models and current characterization techniques predisposing an efficient intranasal delivery of therapeutics. A critical appraisal of novel technologies, intranasal products or medical devices available commercially has also been presented. Finally, it could be warranted that more reminiscent pharmacokinetic/pharmacodynamic relationships or validated computational models are mandated to obtain effective screening of molecular architecture of drug-polymer-mucin complexes for clinical translation of N2B therapeutic systems from bench to bedside.

Intranasal Zolmitriptan-Loaded Bilosomes with Extended Nasal Mucociliary Transit Time for Direct Nose to Brain Delivery

This study aimed at delivering intranasal zolmitriptan directly to the brain through preparation of bilosomes incorporated into a mucoadhesive in situ gel with extended nasal mucociliary transit time. Zolmitriptan-loaded bilosomes were constructed through a thin film hydration method applying Box-Behnken design. The independent variables were amount of sodium deoxycholate and the amount and molar ratio of cholesterol/Span® 40 mixture. Bilosomes were assessed for their entrapment efficiency, particle size and in vitro release. The optimal bilosomes were loaded into mucoadhesive in situ gel consisting of poloxamer 407 and hydroxypropyl methylcellulose. The systemic and brain kinetics of Zolmitriptan were evaluated in rats by comparing intranasal administration of prepared gel to an IV solution. Statistical analysis suggested an optimized bilosomal formulation composition of sodium deoxycholate (5 mg) with an amount and molar ratio of cholesterol/Span® 40 mixture of 255 mg and 1:7.7, respectively. The mucoadhesive in situ gel containing bilosomal formulation had a sol-gel temperature of 34.03 °C and an extended mucociliary transit time of 22.36 min. The gelling system possessed enhanced brain bioavailability compared to bilosomal dispersion (1176.98 vs. 835.77%, respectively) following intranasal administration. The gel revealed successful brain targeting with improved drug targeting efficiency and direct transport percentage indices. The intranasal delivery of mucoadhesive in situ gel containing zolmitriptan-loaded bilosomes offered direct nose-to-brain drug targeting with enhanced brain bioavailability.

Applications of innovative technologies to the delivery of antipsychotics

Psychosis is a high-incidence pathology associated with a profound alteration in the perception of reality. The limitations of drugs available on the market have stimulated the search for alternative solutions to achieve effective antipsychotic therapies. In this review, we evaluate innovative formulations of antipsychotic drugs developed through the application of modern pharmaceutical technologies, including classes of micro and nanocarriers, such as lipid formulations, polymeric nanoparticles (NPs), solid dispersions, and cyclodextrins (CDs). We also consider alternative routes of administration to the oral and parenteral ones currently used. Improved solubility, stability of preparations, and pharmacokinetic (PK) and pharmacodynamic (PD) parameters confirm the potential of these new formulations in the treatment of psychotic disorders.

Progress in nasal drug delivery systems

Most of the available drugs are usually administered orally (e.g. in tablets or capsules) or by parenteral injection in the case of substances being destroyed in the gastric environment or not being absorbed. However, this bears disadvantages as many people have trouble swallowing tablets and parenteral injection requires trained personnel and/or a reasonably sterile environment to minimize the possibility of contamination. Thus, as an easy to use alternative nasal drug delivery was developed. Drug delivery systems are used to achieve a reproducible high drug concentration. These systems overcome various disadvantages leading to stabilization of the drug, advanced drug transport, improvement of the physicochemical properties of the drug like water solubility, and increase of drug uptake and bioavailability. In addition, properties such as bad taste or smell of the drug are masked. Nasal drug delivery systems are suitable for use both locally and systemically. In the last five years, the development and progression of nasal drug delivery systems has gained importance due to their numerous advantages. This work gives an overview of the basics, such as structure and function of the nose, as well as a short introduction to local and systemic application of drugs. Furthermore, selected drug delivery systems are explained with examples of active ingredients, as well as additional possibilities to increase nasal drug uptake and factors influencing the absorption.

Versatile Nasal Application of Cyclodextrins: Excipients and/or Actives?

Cyclodextrins (CDs) are oligosaccharides widely used in the pharmaceutical field. In this review, a detailed examination of the literature of the last two decades has been made to understand the role of CDs in nasal drug delivery systems. In nasal formulations, CDs are used as pharmaceutical excipients, as solubilizers and absorption promoters, and as active ingredients due to their several biological activities (antiviral, antiparasitic, anti-atherosclerotic, and neuroprotective). The use of CDs in nasal formulations allowed obtaining versatile drug delivery systems intended for local and systemic effects, as well as for nose-to-brain transport of drugs. In vitro and in vivo models currently employed are suitable to analyze the effects of CDs in nasal formulations. Therefore, CDs are versatile pharmaceutical materials, and due to the continual synthesis of new CDs derivatives, the research on the new nasal applications is an interesting field evolving in the coming years, to which Italian research will still contribute.

Biomaterials for Drugs Nose-Brain Transport: A New Therapeutic Approach for Neurological Diseases

In the last years, neurological diseases have resulted in a global health issue, representing the first cause of disability worldwide. Current therapeutic approaches against neurological disorders include oral, topical, or intravenous administration of drugs and more invasive techniques such as surgery and brain implants. Unfortunately, at present, there are no fully effective treatments against neurodegenerative diseases, because they are not associated with a regeneration of the neural tissue but rather act on slowing the neurodegenerative process. The main limitation of central nervous system therapeutics is related to their delivery to the nervous system in therapeutic quantities due to the presence of the blood-brain barrier. In this regard, recently, the intranasal route has emerged as a promising administration site for central nervous system therapeutics since it provides a direct connection to the central nervous system, avoiding the passage through the blood-brain barrier, consequently increasing drug cerebral bioavailability. This review provides an overview of the nose-to-brain route: first, we summarize the anatomy of this route, focusing on the neural mechanisms responsible for the delivery of central nervous system therapeutics to the brain, and then we discuss the recent advances made on the design of intranasal drug delivery systems of central nervous system therapeutics to the brain, focusing in particular on stimuli-responsive hydrogels.

Drug release from hydroxypropylcellulose gels cannot be statistically predicted from their viscometric and initial viscoelastic properties

This study questioned whether rheological properties can predict drug (metronidazole) release from Hydroxypropylcellulose (HPC) platforms. Viscometric and viscoelastic properties of aqueous, alcohols/diols and mixed solvent HPC solutions and gels were determined using viscometry and oscillatory analysis. Drug release was conducted at pH 7.4 under sink conditions. Relationships between rheological parameters and drug release were modelled using multiple linear stepwise regression. Viscometry identified ethanol and water as good solvents for HPC. Diol solvents were predicted to exhibit greater interactions with HPC (COSMO modelling) but possessed lowest intrinsic viscosities. Pentanediol or ethylene glycol prepared gels exhibited greatest elasticity. No relationships were observed between dilute solution properties and initial gel viscoelasticity. Drug release from HPC gels occurred via gel erosion and diffusion. No relationships were observed between initial gel viscoelasticity and drug release and thus, for gel platforms that undergo erosion in aqueous media, drug release cannot be predicted from initial gel viscoelasticity.

Innovative coenzyme Q10-loaded nanoformulation as an adjunct approach for the management of moderate periodontitis: preparation, evaluation, and clinical study

Periodontal diseases are worldwide chronic inflammatory conditions that are associated with heavy production of reactive oxygen species followed by damage of the tooth-supporting tissues. Although the mechanical approach of scaling and root planing (SRP) for removing of plaque is considered as the key element for controlling periodontitis, the anatomical complexity of the teeth hinders accessibility to deeper points. The aim of this study was to design a micellar nanocarrier of coenzyme Q10 (Q₁₀) to support the management of moderate periodontitis. Q₁₀ was formulated in nanomicelles (NM_Q10) and evaluated regarding encapsulation efficiency, loading efficiency, percent yield, hydrodynamic size (D_h), polydispersity index (PDI), and zeta potential (ζ potential). NM_Q10 was incorporated to in situ gelling systems and the in vitro release of Q₁₀ was studied. A clinical study including evaluation of periodontal parameters and biochemical assay of total antioxidant capacity (T-AOC) and lipid peroxide was achieved. Results revealed that Q₁₀ was efficiently entrapped in spherical-shaped stable NM_Q10 with D_h, PDI, and ζ potential of 154.0 nm, 0.108, and - 31.67 mV, respectively. The clinical study revealed that SRP only exhibited improvement of the periodontal parameters. Also, assay of T-AOC and lipid peroxide revealed that their values diminished by 21.5 and 23.8%, respectively. On the other hand, SRP combined with local application of NM_Q10 resulted in a significant management of the periodontal parameters, and likewise, the assayed biomarkers proved enhanced antioxidant activity over SRP alone. In conclusion, NM_Q10 can be suggested as a promising nanosystem as an approach to support the management of chronic periodontitis. Such results could be used to conduct larger clinical studies. Graphical abstrac.

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.

Stimuli-responsive In situ gelling system for nose-to-brain drug delivery

The diagnosis and treatment of neurological ailments always remain an utmost challenge for research fraternity due to the presence of BBB. The intranasal route appeared as an attractive and alternative route for brain targeting of therapeutics without the intrusion of BBB and GI exposure. This route directly and effectively delivers the therapeutics to different regions of the brain via olfactory and trigeminal nerve pathways. However, shorter drug retention time and mucociliary clearance curtail the efficiency of the intranasal route. The in situ mucoadhesive gel overthrow the limitations of direct nose-to-brain delivery by not only enhancing nasal residence time but also minimizing the mucociliary clearance and enzymatic degradation. This delivery system further improves the nasal absorption as well as bioavailability of drugs in the brain. The in situ mucoadhesive gel is a controlled and sustained release system that facilitates the absorption of various proteins, peptides and other larger lipophilic and hydrophilic moieties. Owing to multiple benefits, in situ gelling system has been widely explored to target the brain via nasal route. However, very few review works are reported which explains the application of in situ nasal gel for brain delivery of CNS acting moieties. Hence, in this piece of work, we have initially discussed the global statistics of neurological disorders reported by WHO and other reputed organizations, nasal anatomy, mechanism and challenges of nose-to-brain drug delivery. The work mainly focused on the use of different stimuli-responsive polymers, specifically thermoresponsive, pH-responsive, and ion triggered systems for the development of an effective and controlled dosage form, i.e., in situ nasal gel for brain targeting of bioactives. We have also highlighted the origin, structure, nature and phase transition behavior of the smart polymers found suitable for nasal administration, including poloxamer, chitosan, EHEC, xyloglucan, Carbopol, gellan gum and DGG along with their application in the treatment of neurological disorders. The article is aimed to gather all the information of the past 10 years related to the development and application of stimuli-responsive in situ nasal gel for brain drug delivery.

Nose-to-brain delivery of antipsychotics using nanotechnology: a review

INTRODUCTION

Orally-administered antipsychotics are effective in the management of psychosis-related disorders although generation-specific adverse drug reactions (ADRs) significantly hinder clinical outcomes, driven by issues such as patient non-compliance. Direct nose-to-brain (N2B) delivery of antipsychotics via the olfactory epithelium could avert peripheral ADRs by maximizing cerebral drug concentrations, and reducing drug levels in the periphery. However, there exist physicochemical challenges related to psychotropic drugs, alongside biochemical barriers associated with targeting the olfactory region. Nanotechnological approaches present a viable strategy for the development of intranasal antipsychotic formulations where drug stability, mucosal absorption and cerebrospinal fluid (CSF)-bioavailability can be optimized.

AREAS COVERED

This review explores the unique anatomical features of the nasal cavity as a pathway for antipsychotic drug delivery to the brain. Nanocarrier-based approaches to encapsulate antipsychotics, and enhance stability, absorption and bioavailability are explored. The aim of this review is to determine current knowledge gaps for direct N2B psychotropic drug delivery, and identify clinically acceptable strategies to overcome them.

EXPERT OPINION

The olfactory epithelium may be the most effective and direct administration route for antipsychotic delivery to the central nervous system (CNS). This research is novel and has the potential to revolutionize the mode of delivery of neurological medicines to the CNS in the future.

Cyclodextrin complexes: Perspective from drug delivery and formulation

Cyclodextrins (CDs) have been widely investigated as a unique pharmaceutical excipient for past few decades and is still explored for new applications. They are highly versatile oligosaccharides which possess multifunctional characteristics, and are mainly used to improve the physicochemical stability, solubility, dissolution rate, and bioavailability of drugs. Stability constant, factors affecting complexation, techniques to enhance complexation efficiency, the preparation methods for molecular inclusion complexes and release of guest molecules are discussed in brief. In addition, different CD derivatives and their pharmacokinetics are elaborated. Further, the significance of CD complex in aqueous solubility, dissolution and bioavailability, stability, and taste masking is explained. The recent advancement of CDs in developing various drug delivery systems is enlightened. Indeed, the potential of CDs by means of inclusion complex formation have widen the applicability of these materials in various drug delivery systems including ocular, osmotic, mucoadhesive, transdermal, nasal, and targeted delivery systems. Feasibility studies have been performed on the benefit of these cyclic oligomers as nanocarriers, a strategy that can modify the drugs with improved physicochemical properties. Studies also demonstrated the feasibility of CDs to self-assemble in the form of stable nanoaggregates, which may extend the scope of CDs in drug delivery to the continually expanding list of new drug entities.

In Situ-Based Gels for Nose to Brain Delivery for the Treatment of Neurological Diseases

In situ-based gel drug delivery systems that can bypass the blood-brain barrier, deliver the therapeutics to the desired site, reduce peripheral toxicity and control drug release kinetics have been developed. Some of the therapeutics used to treat neurological diseases suffer from poor bioavailability. Preclinical reports from several researchers have proven that the delivery of drugs to the brain via the nose-to-brain route using in situ gels holds great promise. However, safety issues on the toxicity of the nasal mucosa, transportation of the drugs to specific brain regions and determination of the required dose are factors that must be considered when designing these gels. This review will be focused on in situ-based gels that are used for the delivery of therapeutics via the nose-to-brain route, preclinical reports and challenges.