Preparation, characterization, and optimization of asenapine maleate mucoadhesive nanoemulsion using Box-Behnken design: In vitro and in vivo studies for brain targeting

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.

Fabrication of acetazolamide loaded leciplex for intraocular delivery: Optimization by 32 full factorial design, in vitro, ex vivo and in vivo pharmacodynamics

The complex structure of the eye poses challenges in delivering drugs effectively, which can be circumvented by employing nanotechnologies. The present study aimed to prepareacetazolamide-loadedleciplex (ACZ - LP) using a simple one-step fabrication approach followed byoptimization employing a 32 Full Factorial Design. The ACZ - LP demonstrated high entrapment efficiency (93.25 ± 2.32 %), average diameter was recorded around 171.03 ± 3.32 with monodisperse size distribution and zeta potential of 41.33 ± 2.10 mV. Invitro release and ex vivo permeation studies of prepared formulation demonstrated an initial burst release in 1 h followed by sustained release pattern as compared to plain acetazolamide solution. Moreover, an ex vivo corneal drug retention (27.05 ± 1.20 %) and in vitro mucoadhesive studies with different concentration of mucin indicated strong electrostatic bonding confirming the mucoadhesive characteristics of the formulation. Additionally, the histopathological studies ensured that the formulation was non-irritant and nontoxic while and HET-CAM ensured substantial tolerability of the formulation. The in vivo pharmacodynamic investigation carried out on a rabbit model demonstrated that treatment with ACZ - LP resulted in a significant and prolonged reduction in intraocular pressure as compared to plain acetazolamide solution, acetazolamide oral tablet, and Brinzox®. In summary, the ACZ - LP is anefficient and versatile drug delivery approach which demonstrates significant potential in controlling glaucoma.

To see or not to see: In vivo nanocarrier detection methods in the brain and their challenges

Nanoparticles have a great potential to significantly improve the delivery of therapeutics to the brain and may also be equipped with properties to investigate brain function. The brain, being a highly complex organ shielded by selective barriers, requires its own specialized detection system. However, a significant hurdle to achieve these goals is still the identification of individual nanoparticles within the brain with sufficient cellular, subcellular, and temporal resolution. This review aims to provide a comprehensive summary of the current knowledge on detection systems for tracking nanoparticles across the blood-brain barrier and within the brain. We discuss commonly employed in vivo and ex vivo nanoparticle identification and quantification methods, as well as various imaging modalities able to detect nanoparticles in the brain. Advantages and weaknesses of these modalities as well as the biological factors that must be considered when interpreting results obtained through nanotechnologies are summarized. Finally, we critically evaluate the prevailing limitations of existing technologies and explore potential solutions.

Nose-to-Brain Drug Delivery and Physico-Chemical Properties of Nanosystems: Analysis and Correlation Studies of Data from Scientific Literature

Background

In the last few decades, nose-to-brain delivery has been investigated as an alternative route to deliver molecules to the Central Nervous System (CNS), bypassing the Blood-Brain Barrier. The use of nanotechnological carriers to promote drug transfer via this route has been widely explored. The exact mechanisms of transport remain unclear because different pathways (systemic or axonal) may be involved. Despite the large number of studies in this field, various aspects still need to be addressed. For example, what physicochemical properties should a suitable carrier possess in order to achieve this goal? To determine the correlation between carrier features (eg, particle size and surface charge) and drug targeting efficiency percentage (DTE%) and direct transport percentage (DTP%), correlation studies were performed using machine learning.

Methods

Detailed analysis of the literature from 2010 to 2021 was performed on Pubmed in order to build "NANOSE" database. Regression analyses have been applied to exploit machine-learning technology.

Results

A total of 64 research articles were considered for building the NANOSE database (102 formulations). Particle-based formulations were characterized by an average size between 150-200 nm and presented a negative zeta potential (ZP) from -10 to -25 mV. The most general-purpose model for the regression of DTP/DTE values is represented by Decision Tree regression, followed by K-Nearest Neighbors Regressor (KNeighbor regression).

Conclusion

A literature review revealed that nose-to-brain delivery has been widely investigated in neurodegenerative diseases. Correlation studies between the physicochemical properties of nanosystems (mean size and ZP) and DTE/DTP parameters suggest that ZP may be more significant than particle size for DTP/DTE predictability.

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

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

Versatile Nanoparticulate Systems as a Prosperous Platform for Targeted Nose-Brain Drug Delivery

The intranasal route has proven to be a reliable and promising route for delivering therapeutics to the central nervous system (CNS), averting the blood-brain barrier (BBB) and avoiding extensive first-pass metabolism of some drugs, with minimal systemic exposure. This is considered to be the main problem associated with other routes of drug delivery such as oral, parenteral, and transdermal, among other administration methods. The intranasal route maximizes drug bioavailability, particularly those susceptible to enzymatic degradation such as peptides and proteins. This review will stipulate an overview of the intranasal route as a channel for drug delivery, including its benefits and drawbacks, as well as different mechanisms of CNS drug targeting using nanoparticulate drug delivery systems devices; it also focuses on pharmaceutical dosage forms such as drops, sprays, or gels via the nasal route comprising different polymers, absorption promoters, CNS ligands, and permeation enhancers.

Fabrication of architectonic nanosponges for intraocular delivery of Brinzolamide: An insight into QbD driven optimization, in vitro characterization, and pharmacodynamics

The intricate structure of the eye poses difficulties in drug targeting, which can be surmounted with the help of nanoformulation strategies. With this view, brinzolamide nanosponges (BNS) were prepared using the emulsion solvent evaporation technique and optimized via Box-Behnken statistical design. The optimized BNS were further incorporated into a poloxamer 407 in situ gel (BNS-ISG) and evaluated. The optimized BNS showed spherical morphology, entrapment efficiency of 83.12 ± 1.2 % with particle size of 114 ± 2.32 nm and PDI of 0.11 ± 0.01. The optimized BNS-ISG exhibited a pseudoplastic behavior and depicted a gelling temperature and gelation time of 35 ± 0.5 °C and 10 ± 2 s respectively. In-vitro release and ex- vivo permeation studies of BNS-ISG demonstrated a sustained release pattern as compared to Brinzox®. Additionally, the HET-CAM and in vitro cytotoxicity studies (using SIRC cell line) ensured that the formulation was non-irritant and nontoxic for ophthalmic delivery. The in vivo pharmacodynamic study using rabbit model depicted that BNS-ISG treatment significantly lowers the intra ocular pressure for prolonged period of time when compared with Brinzox®. In conclusion, the BNS-ISG is an efficient and scalable drug delivery system with significant potential as the targeted therapy of posterior segment eye diseases.

Preparation, in vitro and in vivo evaluation of a novel mitiglinide microemulsions

This study aimed to prepare an o/w mitiglinide microemulsion (MTGME) to improve the drug solubility and bioavailability. The formulation of o/w MTGME was optimized by the solubility study of drug, pseudo-ternary phase diagram and Box-Behnken design successively. MTGME was characterized by dynamic laser light scattering (DLS), zeta potential and transmission electron microscopy (TEM), moreover, the storage stability, pharmacodynamics and pharmacokinetics were investigated. The optimal prescription for MTGME consisted of Maisine 35-1 (oil), Cremophor EL (surfactant) and propylene glycol (PG, cosurfactant). MTGME with a spherical dimension of 58.1 ± 5.86 nm was stable when stored at 4 °C for 3 months. The blood glucose levers (BGL) of diabetic mice were uniformly and significantly decreased by intragastric (i.g.) administration of 1-4 mg/kg MTGME, in which BGL (i.g. 4 mg/kg MTGME) was reduced by 69% during 24 h. The pharmacokinetics study of MTGME (i.g., 20 mg/kg) in Wistar rats showed higher plasma drug concentration (Cmax, 2.9 folds), larger area under curve (AUC, 4.6 folds) and oral bioavailability than those of MTG suspensions. Generally, the MTGME (o/w) showed good effect on controlling hyperglycemia. Therefore, microemulsion can be used as an effective oral drug delivery system to improve the bioavailability of MTG.

A Nanoemulgel for Nose-to-Brain delivery of Quetiapine - QbD-Enabled formulation development & in-vitro characterization

Second-generation antipsychotics, quetiapine hemifumarate (QF), exhibited highly active against negative and positive signs of psychosis. However, contemporary reports have shown that long-term therapy with QF causes lethal thrombocytopenia and leukopenia. Hence, to circumvent the drawbacks of available therapies, the current work aimed to design a QF-loaded biodegradable nanoemulsion (QF-NE) with suitable surface charge modification by poloxamer-chitosan and evaluate its targeting efficiency against RPMI-2650 cell lines. QF-loaded poloxamer-chitosan in-situ gel (QF-Nanoemulgel) was formulated through the O/W emulsification aqueous titration technique and optimized using the QbD approach. Optimized QF-Nanoemulgel subjected to evaluate for globule size, PDI, zeta potential, %T, viscosity, %EE, and ex-vivo mucoadhesive strength were found to be 15.0 ± 0.3 nm, 0.05 ± 0.001, -18.3 ± 0.2 mV, 99.8 ± 0.8 %, 13.5 ± 2.1 cP, 69.0 ± 1.5 %, and 43.7 ± 1.5 g, respectively. QF-Nanoemulgel revealed sustained release and obeyed zero-order kinetics compared to QF-NE and QF-suspension. Additionally, nanoformulations treated blood samples did not cause hemolytic activity compared to drug and negative control after 10 h treatment. Further, in-vitro cytotoxicity, cellular uptake, and permeation of 12.5 and 25 μM QF-Nanoemulgel were assessed on RPMI-2650 cells and discovered nontoxic with 0.55 ± 0.02 µg and 1.1 ± 0.04 µg cellular permeation, respectively, which ensured the safety and potency of QF-Nanogel. Current research revealed the successful development of intranasal QF-Nanoemulgel as a novel dosage form for the safe and effective delivery of QF in schizophrenia patients.

Oral administration of Huanglian-Houpo herbal nanoemulsion loading multiple phytochemicals for ulcerative colitis therapy in mice

How to achieve stable co-delivery of multiple phytochemicals is a common problem. This study focuses on the development, optimization and characterization of Huanglian-HouPo extract nanoemulsion (HLHPEN), with multiple components co-delivery, to enhance the anti-ulcerative colitis (UC) effects. The formulation of HLHPEN was optimized by pseudo-ternary phase diagram combined with Box-Behnken design. The physicochemical properties of HLHPEN were characterized, and its anti-UC activity was evaluated in DSS-induced UC mice model. Based on preparation process optimization, the herbal nanoemulsion HLHPEN was obtained, with the droplet size, PDI value, encapsulation efficiency (EE) for 6 phytochemicals (berberine, epiberberine, coptisine, bamatine, magnolol and honokiol) of 65.21 ± 0.82 nm, 0.182 ± 0.016, and 90.71 ± 0.21%, respectively. The TEM morphology of HLHPEN shows the nearly spheroidal shape of particles. The optimized HLHPEN showed a brownish yellow milky single-phase and optimal physical stability at 25 °C for 90 days. HLHPEN exhibited the good particle stability and gradual release of phytochemicals in SGF and SIF, to resist the destruction of simulated stomach and small intestine environment. Importantly, the oral administration of HLHPEN significantly restored the shrunk colon tissue length and reduced body weight, ameliorated DAI value and colon histological pathology, decreased the levels of inflammatory factors in DSS-induced UC mice model. These results demonstrated that HLHPEN had a significant therapeutic effect on DSS-induced UC mice, as a potential alternative UC therapeutic agent.

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.

Zein-maltodextrin nanocomplex based dissolving microneedle: A promising approach for Paliperidone palmitate delivery

Researchers are looking at microneedle devices as a possible solution to the problems with poor patient compliance and severe gastrointestinal side effects associated with conventional oral or injectable techniques for treating schizophrenia. Microneedles (MNs) may be an effective approach for transdermal drug delivery of antipsychotic drugs. We fabricated polyvinyl alcohol (PVA) microneedles loaded with paliperidone palmitate (PLDN) nanocomplex and studied their therapeutic potency for schizophrenia. We demonstrated that PLDN nanocomplex-loaded MNs had a pyramidal shape with high mechanical strength, which allowed us to successfully deliver PLDN into the skin and improve permeation behavior ex-vivo. Microneedling enhanced the concentration of PLDN in plasma and brain tissue as compared with the plain drug as observed. In addition, the therapeutic effectiveness was significantly improved by MNs with the capability of extended release. According to the findings of our study, the nanocomplex-loaded microneedle-mediated transdermal delivery of PLDN has the potential to be a novel treatment for schizophrenia.

Nose-to-Brain Targeting via Nanoemulsion: Significance and Evidence

Background: Non-invasive and patient-friendly nose-to-brain pathway is the best-suited route for brain delivery of therapeutics as it bypasses the blood–brain barrier. The intranasal pathway (olfactory and trigeminal nerves) allows the entry of various bioactive agents, delivers a wide array of hydrophilic and hydrophobic drugs, and circumvents the hepatic first-pass effect, thus targeting neurological diseases in both humans and animals. The olfactory and trigeminal nerves make a bridge between the highly vascularised nasal cavity and brain tissues for the permeation and distribution, thus presenting a direct pathway for the entry of therapeutics into the brain. Materials: This review portrays insight into recent research reports (spanning the last five years) on the nanoemulsions developed for nose-to-brain delivery of actives for the management of a myriad of neurological disorders, namely, Parkinson’s disease, Alzheimer’s, epilepsy, depression, schizophrenia, cerebral ischemia and brain tumours. The information and data are collected and compiled from more than one hundred Scopus- and PubMed-indexed articles. Conclusions: The olfactory and trigeminal pathways facilitate better biodistribution and bypass BBB issues and, thus, pose as a possible alternative route for the delivery of hydrophobic, poor absorption and enzyme degradative therapeutics. Exploring these virtues, intranasal nanoemulsions have proven to be active, non-invasiveand safe brain-targeting cargos for the alleviation of the brain and other neurodegenerative disorders.

Formulation and Characterization of a Novel Palm-Oil-Based α-Mangostin Nano-Emulsion (PO-AMNE) as an Antimicrobial Endodontic Irrigant: An In Vitro Study

Aim: To formulate and characterize a palm-oil-in-water-based α-Mangostin nano-emulsion (PO-AMNE) endodontic irrigant, in order to evaluate its antibacterial efficacy against Enterococcus faecalis, Staphylococcus epidermidis, and Candida albicans biofilms, as well as its capacity to remove smear layer. Methods: The solubility of α-Mangostin in various oils was determined and selected, surfactants and co-surfactants were used for the nano-emulsion trial. PO-AMNE was prepared and optimized. The MIC was performed, and the antimicrobial efficacy was estimated against biofilms. The optimized 0.2% PO-AMNE irrigant antimicrobial efficacy in a tooth model was done using colony-forming units. The treated teeth were processed by scanning electron microscopic examination for debris and smear layer removal. An Alamar Blue assay was used to evaluate cell viability. The optimization of the PO-AMNE irrigant was performed using Box–Behnken statistical design. Results: The optimized 0.2% PO-AMNE irrigant was found to have a particle size of 340.9 nm with 0.246 PDI of the dispersed droplets, and a zeta potential (mV) of −27.2 ± 0.7 mV. The MIC values showed that 0.2% PO-AMNE (1.22 ± 0.02) were comparable to 2% CHX (1.33 ± 0.01), and 3.25% NaOCl (2.2 ± 0.09) had the least inhibition for E. faecalis. NaOCl (3.25%) showed the maximum inhibition of S. epidermidis (0.26 ± 0.05), whereas 0.2% PO-AMNE (1.25 ± 0.0) was comparable to 2% CHX (1.86 ± 0.07). For C. albicans, 2% CHX (8.12 ± 0.12) showed the least inhibition as compared to 0.2% PO-AMNE (1.23 ± 0.02) and 3.25% NaOCl (0.59 ± 0.02). The 0.2% PO-AMNE irrigant was then evaluated for its antimicrobial efficacy against the three biofilms, using colony-forming units. The 0.2% PO-AMNE was comparable to both 3.25% NaOCl and 2% CHX in inhibiting the growth of biofilms. The 0.2% PO-AMNE and 17% EDTA eliminated the smear layer with the lowest mean scores (p < 0.001). Finally, 0.2% PO-AMNE was shown to be biocompatible when compared to 17% EDTA, 3.25% NaOCl, and 2% CHX in immortalized oral keratinocyte cells. Conclusion: Overall, the formulated 0.2% PO-AMNE irrigant was an effective antimicrobial and biocompatible which could combat endodontic-infection-related polymicrobial biofilms.

Nose-to-brain delivery of paliperidone palmitate poloxamer-guar gum nanogel: Formulation, optimization and pharmacological studies in rats

Oral delivery of paliperidone palmitate (PPD), a potent antipsychotic agent, has been reported with a potential risk of very serious drug-induced adverse events such as tachycardia, hyperprolactinemia, sexual dysfunction, and neutropenia. Alternatively, the potential of nasal delivery has also been explored to treat CNS complications by delivering the medicines directly to the brain bypassing the blood-brain barrier. Hence, the objectives of current work were to formulate, design, optimize, and investigate the therapeutic potency of PPD-loaded intranasal in-situ gel (PPGISG) in the treatment of schizophrenia. PPD-nanoemulsion (PNE) was fabricated using water titration technique, was further optimized via Box-Behnken design. Furthermore, the optimized PNE was evaluated for parameters such as globule size, polydispersity index, zeta potential, and % entrapment efficiency were found to be 21.44±1.58nm, 0.268±0.02, -25.56±1.6mV, and 99.89±0.25%, respectively. PNE was further converted to PPGISG utilizing two polymers, poloxamer, and guar gum. Simultaneously, ex-vivo permeation for PNE, PPGISG, and PPD-suspension was found to be 211.40±4.8, 297.89±3.9 and 98.66±1.6μg/cm², respectively. While PPGISG nanoparticles showed 1.58 and 5.65-folds more J_ss than PNE and PPD-suspension. Behavioral studies confirmed that no extrapyramidal symptoms were observed in experimental animals post intranasal administration. Finally, the outcomes of the in-vivo hemato-compatibility study proved that intranasal formulation did not cause any alteration in leukocytes, RBCs, and neutrophils count. Therefore, intranasal delivery of PPGISG can be considered a novel tool for the safe delivery of PPD in schizophrenic patients.

Nanosystems for Brain Targeting of Antipsychotic Drugs: An Update on the Most Promising Nanocarriers for Increased Bioavailability and Therapeutic Efficacy

Orally administered antipsychotic drugs are the first-line treatment for psychotic disorders, such as schizophrenia and bipolar disorder. Nevertheless, adverse drug reactions jeopardize clinical outcomes, resulting in patient non-compliance. The design formulation strategies for enhancing brain drug delivery has been a major challenge, mainly due to the restrictive properties of the blood-brain barrier. However, recent pharmacokinetic and pharmacodynamic in vivo assays confirmed the advantage of the intranasal route when compared to oral and intravenous administration, as it allows direct nose-to-brain drug transport via neuronal pathways, reducing systemic side effects and maximizing therapeutic outcomes. In addition, the incorporation of antipsychotic drugs into nanosystems such as polymeric nanoparticles, polymeric mixed micelles, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, nanoemulgels, nanosuspensions, niosomes and spanlastics, has proven to be quite promising. The developed nanosystems, having a small and homogeneous particle size (ideal for nose-to-brain delivery), high encapsulation efficiency and good stability, resulted in improved brain bioavailability and therapeutic-like effects in animal models. Hence, although it is essential to continue research in this field, the intranasal delivery of nanosystems for the treatment of schizophrenia, bipolar disorder and other related disorders has proven to be quite promising, opening a path for future therapies with higher efficacy.

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.

Drug Nanocrystals: Focus on Brain Delivery from Therapeutic to Diagnostic Applications

The development of new drugs is often hindered by low solubility in water, a problem common to nearly 90% of natural and/or synthetic molecules in the discovery pipeline. Nanocrystalline drug technology involves the reduction in the bulk particle size down to the nanosize range, thus modifying its physico-chemical properties with beneficial effects on drug bioavailability. Nanocrystals (NCs) are carrier-free drug particles surrounded by a stabilizer and suspended in an aqueous medium. Due to high drug loading, NCs maintain a potent therapeutic concentration to produce desirable pharmacological action, particularly useful in the treatment of central nervous system (CNS) diseases. In addition to the therapeutic purpose, NC technology can be applied for diagnostic scope. This review aims to provide an overview of NC application by different administration routes, especially focusing on brain targeting, and with a particular attention to therapeutic and diagnostic fields. NC therapeutic applications are analyzed for the most common CNS pathologies (i.e., Parkinson's disease, psychosis, Alzheimer's disease, etc.). Recently, a growing interest has emerged from the use of colloidal fluorescent NCs for brain diagnostics. Therefore, the use of NCs in the imaging of brain vessels and tumor cells is also discussed. Finally, the clinical effectiveness of NCs is leading to an increasing number of FDA-approved products, among which the NCs approved for neurological disorders have increased.

Utilization of Polymeric Micelles as a Lucrative Platform for Efficient Brain Deposition of Olanzapine as an Antischizophrenic Drug via Intranasal Delivery

Schizophrenia is a mental disorder characterized by alterations in cognition, behavior and emotions. Oral olanzapine (OZ) administration is extensively metabolized (~up to 40% of the administrated dose). In addition, OZ is a P-glycoproteins substrate that impairs the blood–brain barrier (BBB) permeability. To direct OZ to the brain and to minimize its systemic side effects, the nasal pathway is recommended. OZ-loaded polymeric micelles nano-carriers were developed using suitable biodegradable excipients. The developed micelles were physicochemically investigated to assess their appropriateness for intranasal delivery and the potential of these carriers for OZ brain targeting. The selected formula will be examined in vivo for improving the anti-schizophrenic effects on a schizophrenia rat model. The binary mixture of P123/P407 has a low CMC (0.001326% w/v), which helps in maintaining the formed micelles’ stability upon dilution. The combination effect of P123, P407 and TPGS led to a decrease in micelle size, ranging between 37.5–47.55 nm and an increase in the EE% (ranging between 68.22–86.84%). The selected OZ–PM shows great stability expressed by a suitable negative charge zeta potential value (−15.11 ± 1.35 mV) and scattered non-aggregated spherical particles with a particle size range of 30–40 nm. OZ–PM maintains sustained drug release at the application site with no nasal cytotoxicity. In vivo administration of the selected OZ–PM formula reveals improved CNS targeting and anti-schizophrenia-related deficits after OZ nasal administration. Therefore, OZ–PM provided safe direct nose-to-brain transport of OZ after nasal administration with an efficient anti-schizophrenic effect.

Development, Characterization, and Evaluation of α-Mangostin-Loaded Polymeric Nanoparticle Gel for Topical Therapy in Skin Cancer

The aim of this study was to prepare and evaluate α-mangostin-loaded polymeric nanoparticle gel (α-MNG-PLGA) formulation to enhance α-mangostin delivery in an epidermal carcinoma. The poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) were developed using the emulsion-diffusion-evaporation technique with a 3-level 3-factor Box-Behnken design. The NPs were characterized and evaluated for particle size distribution, zeta potential (mV), drug release, and skin permeation. The formulated PLGA NPs were converted into a preformed carbopol gel base and were further evaluated for texture analysis, the cytotoxic effect of PLGA NPs against B16-F10 melanoma cells, and in vitro radical scavenging activity. The nanoscale particles were spherical, consistent, and average in size (168.06 ± 17.02 nm), with an entrapment efficiency (EE) of 84.26 ± 8.23% and a zeta potential of -25.3 ± 7.1 mV. Their drug release percentages in phosphate-buffered solution (PBS) at pH 7.4 and pH 6.5 were 87.07 ± 6.95% and 89.50 ± 9.50%, respectively. The release of α-MNG from NPs in vitro demonstrated that the biphasic release system, namely, immediate release in the initial phase, was accompanied by sustained drug release. The texture study of the developed α-MNG-PLGA NPs gel revealed its characteristics, including viscosity, hardness, consistency, and cohesiveness. The drug flux from α-MNG-PLGA NPs gel and α-MNG gel was 79.32 ± 7.91 and 16.88 ± 7.18 µg/cm2/h in 24 h, respectively. The confocal study showed that α-MNG-PLGA NPs penetrated up to 230.02 µm deep into the skin layer compared to 15.21 µm by dye solution. MTT assay and radical scavenging potential indicated that α-MNG-PLGA NPs gel had a significant cytotoxic effect and antioxidant effect compared to α-MNG gel (p < 0.05). Thus, using the developed α-MNG-PLGA in treating skin cancer could be a promising approach.

Constant Voltage Iontophoresis Technique to Deliver Terbinafine via Transungual Delivery System: Formulation Optimization Using Box-Behnken Design and In Vitro Evaluation

Topical therapy of antifungals is primarily restricted due to the low innate transport of drugs through the thick multi-layered keratinized nail plate. The objective of this investigation was to develop a gel formulation, and to optimize and evaluate the transungual delivery of terbinafine using the constant voltage iontophoresis technique. Statistical analysis was performed using Box–Behnken design to optimize the transungual delivery of terbinafine by examining crucial variables namely concentration of polyethylene glycol, voltage, and duration of application (2–6 h). Optimization data in batches (F1–F17) demonstrated that chemical enhancer, applied voltage, and application time have influenced terbinafine nail delivery. Higher ex vivo permeation and drug accumulation into the nail tissue were noticed in the optimized batch (F8) when compared with other batches (F1–F17). A greater amount of terbinafine was released across the nails when the drug was accumulated by iontophoresis than the passive counterpart. A remarkably higher zone of inhibition was observed in nails with greater drug accumulation due to iontophoresis, as compared to the passive process. The results here demonstrate that the optimized formulation with low voltage iontophoresis could be a viable and alternative tool in the transungual delivery of terbinafine, which in turn could improve the success rate of topical nail therapy in onychomycosis.

Development and Optimization of Asenapine Sublingual Film Using QbD Approach

Asenapine, an atypical antipsychotic agent, has been approved for the acute and maintenance treatment of schizophrenia and manic episodes of bipolar disorder. However, the extensive hepatic metabolism limits its oral bioavailability. Therefore, the objective of the current investigation was to develop sublingual film containing asenapine to enhance the therapeutic efficacy. Sublingual films containing asenapine were fabricated using polyethylene oxide and hydroxypropyl methylcellulose by solvent casting method. Design of experiment was used as a statistical tool to optimize the proportion of the film-forming polymers in order to establish the critical quality attributes of the drug formulation. The process was studied in detail by assessing risk of each step as well as parameters and material attributes to reduce the risk to a minimum. A control strategy was defined to ensure manufacture of films according to the target product profile by evaluation of intermediate quality attributes at the end of each process step. Results of optimized formulations showed rapid disintegration, adequate folding endurance, good percentage elongation, tensile strength, and viscosity. Besides, the results from the in vitro dissolution/ex vivo permeation studies showed rapid dissolution (100% in 6 min) and higher asenapine permeation (~ 80% in 90 min) through the sublingual epithelium. In vivo study indicates greater asenapine absorption (31.18 ± 5.01% of administered dose) within 5 min and was comparable with marketed formulation. In summary, the designing plan to develop asenapine formulation was successfully achieved with desired characteristics of the delivery tool for sublingual administration.

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.

Nose-to-brain delivery of amisulpride-loaded lipid-based poloxamer-gellan gum nanoemulgel: In vitro and in vivo pharmacological studies

Unfavorable side effects of available antipsychotics limit the use of conventional delivery systems, where limited exposure of the drugs to the systemic circulation could reduce the associated risks. The potential of intranasal delivery is gaining interest to treat brain disorders by delivering the drugs directly to the brain circumventing the tight junctions of the blood-brain barrier with limited systemic exposure of the entrapped therapeutic. Therefore, the present research was aimed to fabricate, optimize and investigate the therapeutic efficacy of amisulpride (AMS)-loaded intranasal in situ nanoemulgel (AMS-NG) in the treatment of schizophrenia. In this context, AMS nanoemulsion (AMS-NE) was prepared by employing aqueous-titration method and optimized using Box-Behnken statistical design. The optimized nanoemulsion was subjected to evaluation of globule size, transmittance, zeta potential, and mucoadhesive strength, which were found to be 92.15 nm, 99.57%, -18.22 mV, and 8.90 g, respectively. The AMS-NE was converted to AMS-NG using poloxamer 407 and gellan gum. Following pharmacokinetic evaluation in Wistar rats, the brain C_max for intranasal AMS-NG was found to be 1.48-folds and 3.39-folds higher when compared to intranasal AMS-NE and intravenous AMS-NE, respectively. Moreover, behavioral investigations of developed formulations were devoid of any extrapyramidal side effects in the experimental model. Finally, outcomes of the in vivo hematological study confirmed that intranasal administration of formulation for 28 days did not alter leukocytes and agranulocytes count. In conclusion, the promising results of the developed and optimized intranasal AMS-NG could provide a novel platform for the effective and safe delivery of AMS in schizophrenic patients.

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.

Nanotechnologies for intranasal drug delivery: an update of literature

Scientific research has focused its attention on finding an alternative route to systemic oral and parenteral administration, to overcome their usual drawbacks, such as hepatic first-pass which decreases drug bioavailability after oral administration, off-target effects, low patient compliance and low speed of onset of the pharmacological action in first-aid cases. Innovative drug delivery systems (DDS), mainly based on polymer and lipid biocompatible materials, have given a great prompt in this direction in the last years. The intranasal (IN) route of administration is a valid non-invasive alternative. It is highly suitable for self-administration, the drug quickly reaches the bloodstream, largely avoiding the first pass effect, and can also reach directly the brain bypassing BBB. Association of IN route with DDS can thus become a winning strategy for the controlled delivery of drugs, especially when a very quick effect is desired or needed. This review aims at analyzing the scientific literature regarding IN-DDS and their different ways of administration (systemic, topical, pulmonary, nose-to-brain). In particular, attention was devoted to polymer- and lipid-based micro- and nanocarriers, being the topic of most published articles in the last decade, but the whole plethora of colloidal DDS investigated in recent years for IN administration was presented.

Determination of Asenapine Maleate in Pharmaceutical and Biological Matrices: A Critical Review of Analytical Techniques over the Past Decade

Asenapine maleate is a second-generation atypical antipsychotic agent used in the treatment of schizophrenia, a neuropsychiatric disorder. It is available as a fast-dissolving sublingual tablet to avoid extensive first-pass metabolism with higher bioavailability as compared to oral formulations. Although, the established therapeutic solutions do not sufficiently satisfy the patient's safety and efficacy needs. Thus, the core research emphasis is to investigate strategies to produce novel formulations with enhanced safety and efficacy. This necessitates the development of robust, precise, and accurate methods for quantification of asenapine maleate in different sample matrices. Given the foregoing information, the current analysis concentrates on the different analytical techniques used to assess asenapine maleate in bulk, pharmaceutical formulations, and biological specimens. Reverse-phase HPLC coupled with UV detection is a majorly (nearly 50% of papers investigated) used technique for the estimation of asenapine maleate in formulations. On the other hand, for its quantification in the biological matrix, hyphenated techniques using mass spectrometry are widely used. This critical review reveals different analytical methodologies, including spectrophotometric, chromatographic, capillary electrophoresis techniques reported from 2011 to 2020, for the measurement of asenapine maleate in various sample matrices. The information presented in this review would be useful in future research for robust analytical method development for asenapine maleate utilizing a more scientific and risk-based approach. Also, it would aid to minimize analytical failure as well as method fine-tuning throughout the product life cycle. Further, this review may also direct scientists toward the development of methodologies for green research.

Experimental design, formulation and in vivo evaluation of a novel topical in situ gel system to treat ocular infections

In situ gels have been extensively explored as ocular drug delivery system to enhance bioavailability and efficacy. The objective of present study was to design, formulate and evaluate ion-activated in situ gel to enhance the ocular penetration and therapeutic performance of moxifloxacin in ophthalmic delivery. A simplex lattice design was utilized to examine the effect of various factors on experimental outcomes of the in situ gel system. The influence of polymers (independent variables) such as gellan gum (X₁), sodium alginate (X₂), and HPMC (X₃) on gel strength, adhesive force, viscosity and drug release after 10 h (Q₁₀) were assessed. Selected formulation (MH7) was studied for ex vivo permeation, in vivo irritation and pharmacokinetics in rabbits. Data revealed that increase in concentration of polymers led to higher gel strength, adhesive force and viscosity, however, decreases the drug release. MH7 exhibited all physicochemical properties within acceptable limits and was stable for 6 months. Release profile of moxifloxacin from MH7 was comparable to the check point batches and followed Korsmeyer-Peppas matrix diffusion-controlled mechanism. Ocular irritation study signifies that selected formulation is safe and non-irritant for ophthalmic administration. In vivo pharmacokinetics data indicates significant improvement of moxifloxacin bioavailability (p < 0.0001) from MH7, as evidenced by higher C_max (727 ± 56 ng/ml) and greater AUC (2881 ± 108 ng h/ml), when compared with commercial eye drops (C_max; 503 ± 85 ng/ml and AUC; 978 ± 86 ng h/ml). In conclusion, developed in situ gel system (MH7) could offers a more effective and extended ophthalmic therapy of moxifloxacin in ocular infections when compared to conventional eye drops.

Critical Review of Lipid-Based Nanoparticles as Carriers of Neuroprotective Drugs and Extracts

The biggest obstacle to the treatment of diseases that affect the central nervous system (CNS) is the passage of drugs across the blood-brain barrier (BBB), a physical barrier that regulates the entry of substances into the brain and ensures the homeostasis of the CNS. This review summarizes current research on lipid-based nanoparticles for the nanoencapsulation of neuroprotective compounds. A survey of studies on nanoemulsions (NEs), nanoliposomes/nanophytosomes and solid lipid nanoparticles (SLNs)/nanostructured lipid carriers (NLCs) was carried out and is discussed herein, with particular emphasis upon their unique characteristics, the most important parameters influencing the formulation of each one, and examples of neuroprotective compounds/extracts nanoencapsulated using these nanoparticles. Gastrointestinal absorption is also discussed, as it may pose some obstacles for the absorption of free and nanoencapsulated neuroprotective compounds into the bloodstream, consequently hampering drug concentration in the brain. The transport mechanisms through which compounds or nanoparticles may cross BBB into the brain parenchyma, and the potential to increase drug bioavailability, are also discussed. Additionally, factors contributing to BBB disruption and neurodegeneration are described. Finally, the advantages of, and obstacles to, conventional and unconventional routes of administration to deliver nanoencapsulated neuroprotective drugs to the brain are also discussed, taking into account the avoidance of first-pass metabolism, onset of action, ability to bypass the BBB and concentration of the drug in the brain.

Antipsychotic Potential and Safety Profile of TPGS-Based Mucoadhesive Aripiprazole Nanoemulsion: Development and Optimization for Nose-To-Brain Delivery

Delivering therapeutics to the brain using conventional dosage forms is always a challenge, thus the present study was aimed to formulate mucoadhesive nanoemulsion (MNE) of aripiprazole (ARP) for intranasal delivery to transport the drug directly to the brain. Therefore, a TPGS based ARP-MNE was formulated and optimized using the Box-Behnken statistical design. The improved in vitro release profile of the formulation was in agreement to enhanced ex vivo permeation through sheep mucous membranes with a maximum rate of permeation co-efficient (62.87  cm h^-1 × 10³) and flux (31.43  μg cm^-2.h^-1). The pharmacokinetic profile following single-dose administration showed the maximum concentration of drug in the brain (C_max) of 15.19 ± 2.51  μg mL^-1 and T_max of 1 h in animals with ARP-MNE as compared to 10.57 ± 1.88  μg mL^-1 and 1 h, and 2.52 ± 0.38  μg mL^-1 and 3 h upon intranasal and intravenous administration of ARP-NE, respectively. Further, higher values of % drug targeting efficiency (96.9%) and % drug targeting potential (89.73%) of ARP-MNE through intranasal administration were investigated. The studies in Wistar rats showed no existence of extrapyramidal symptoms through the catalepsy test and forelimb retraction results. No ex vivo ciliotoxicity on nasal mucosa reflects the safety of the components and delivery tool. Further, findings on locomotor activity and hind-limb retraction test in ARP-MNE treated animals established its antipsychotic efficacy. Thus, it can be inferred that the developed ARP-MNE could effectively be explored as brain delivery cargo in the effective treatment of schizophrenia without producing any toxic manifestation.

Formulation development and characterization of lumefantrine nanosuspension for enhanced antimalarial activity

Variable and low oral bioavailability (4-11%) of lumefantrine (LUF), an anti-malarial agent, is characterized by very low solubility in aqueous vehicle. Thus, the present study was intended to formulate lyophilized nanosuspensions of LUF to resolve its solubility issues for the improvement of oral bioavailability. A three level 3² factorial design was applied to analyze the influence of independent variables, concentration of polysorbate 80 (X₁) and sonication time (X₂) on the responses for dependent variables, particle size (Y₁) and time to 90% release of LUF (t₉₀) (Y₂). Optimized formulation (F3) has shown to possess lowest particle size (95.34 nm) with minimum t₉₀ value (⁓3 mins), which was lyophilized to obtain the dry powder form of the nanosuspension. The characterization parameters confirmed the amorphous form of LUF with good stability and no chemical interactions of the drug with the incorporated components. Further, saturation solubility study revealed increased solubility of the LUF nanosuspension (1670 µg/mL) when compared to the pure drug (212.33 µg/mL). Further, rate of dissolution of LUF from the nanosuspension formulations were found to be significantly (p < 0.05) higher when compared to the pure drug. Fabricated lyophilized nanosuspension was found to be stable at 25 ± 2 °C/60 ± 5% RH and 40 ± 2 °C/75 ± 5% RH for the duration of three months. In conclusion, lyophilized nanosuspension showed ∼8-folds increase in drug release, which indicated a better way to offer higher release of LUF in controlling malaria.

Oral Gel Loaded by Fluconazole‒Sesame Oil Nanotransfersomes: Development, Optimization, and Assessment of Antifungal Activity

Candidiasis is one of the frequently encountered opportunistic infections in the oral cavity and can be found in acute and chronic presentations. The study aimed to develop fluconazole-loaded sesame oil containing nanotransfersomes (FS-NTF) by the thin-layer evaporation technique to improve the local treatment of oral candidiasis. Optimization of the formulation was performed using the Box‒Behnken statistical design to determine the variable parameters that influence the vesicle size, entrapment efficiency, zone of inhibition, and ulcer index. Finally, the formulated FS-NTF was embedded within the hyaluronic acid‒based hydrogel (HA-FS-NTF). The rheological behavior of the optimized HA-FS-NTF was assessed and the thixotropic behavior with the pseudoplastic flow was recorded; this is desirable for an oral application. An in vitro release study revealed the rapid release of fluconazole from the HA-FS-NTF. This was significantly higher when compared with the fluconazole suspension and hyaluronic acid hydrogel containing fluconazole. Correspondingly, the ex vivo permeation was also found to be higher in HA-FS-NTF in sheep buccal mucosa (400 μg/cm2) when compared with the fluconazole suspension (122 μg/cm2) and hyaluronic acid hydrogel (294 μg/cm2). The optimized formulation had an inhibition zone of 14.33 ± 0.76 mm and enhanced antifungal efficacy for the ulcer index (0.67 ± 0.29) in immunocompromised animals with Candida infection; these findings were superior to those of other tested formulations. Hence, it can be summarized that fluconazole can effectively be delivered for the treatment of oral candidiasis when it is entrapped in a nanotransfersome carrier and embedded into cross-linked hyaluronic acid hydrogel.

Development and Optimization of Naringenin-Loaded Chitosan-Coated Nanoemulsion for Topical Therapy in Wound Healing

The potential role of naringenin (NAR), a natural flavonoid, in the treatment of chronic wound has prompted the present research to deliver the drug in nanoemulsion (NE) form, where synergistic role of chitosan was achieved through development of chitosan-coated NAR NE (CNNE). The NE consisted of Capryol 90, Tween 20 and Transcutol P, which was fabricated by low-energy emulsification method to encapsulate NAR within the oil core. The optimization of the formulated NEs was performed using Box-Behnken statistical design to obtain crucial variable parameters that influence globule size, size distribution and surface charge. Finally, the optimized formulation was coated with different concentrations of chitosan and subsequently characterized in vitro. The size of the CNNE was found to be increased when the drug-loaded formulation was coated with chitosan. Controlled release characteristics depicted 67-81% release of NAR from the CNNE, compared to 89% from the NE formulation. Cytotoxicity study of the formulation was performed in vitro using fibroblast cell line (NIH-3T3), where no inhibition in proliferation of the cells was observed with CNNE. Finally, the wound healing potential of the CNNE was evaluated in an abrasion-created wound model in experimental animals where the animals were treated and compared histologically at 0 and 14 days. Significant improvement in construction of the abrasion wound was observed when the animals were treated with formulated CNNE, whereas stimulation of skin regeneration was depicted in the histological examination. Therefore, it could be summarized that the chitosan coating of the developed NAR NE is a potential platform to accelerate healing of wounds.