Formulation of intranasal surface engineered nanostructured lipid carriers of rotigotine: Full factorial design optimization, in vitro characterization, and pharmacokinetic evaluation

Design of experiment (DoE) of mucoadhesive valproic acid-loaded nanostructured lipid carriers (NLC) for potential nose-to-brain application

Epilepsy is a highly prevalent neurological disease and valproic acid (VPA) is used as a first-line chronic treatment. However, this drug has poor oral bioavailability, which requires the administration of high doses, resulting in adverse effects. Alternative routes of VPA administration have therefore been investigated, such as the nose-to-brain route, which allows the drug to be transported directly from the nasal cavity to the brain. Here, the use of nanostructured lipid carriers (NLC) to encapsulate drugs administered in the nasal cavity has proved advantageous. The aim of this work was to optimise a mucoadhesive formulation of VPA-loaded NLC for intranasal administration to improve the treatment of epilepsy. The Design of Experiment (DoE) was used to optimise the formulation, starting with component optimisation using Mixture Design (MD), followed by optimisation of the manufacturing process parameters using Central Composite Design (CCD). The optimised VPA-loaded NLC had a particle size of 76.1 ± 2.8 nm, a polydispersity index of 0.190 ± 0.027, a zeta potential of 28.1 ± 2.0 mV and an encapsulation efficiency of 85.4 ± 0.8%. The in vitro release study showed VPA release from the NLC of 50 % after 6 h and 100 % after 24 h. The in vitro biocompatibility experiments in various cell lines have shown that the optimised VPA-loaded NLC formulation is safe up to 75 µg/mL, in neuronal (SH-SY5Y), nasal (RPMI 2650) and hepatic (HepG2) cells. Finally, the interaction of the optimised VPA-loaded NLC formulation with nasal mucus was investigated and mucoadhesive properties were observed. The results of this study suggest that the use of intranasal VPA-loaded NLC may be a promising alternative to promote VPA targeting to the brain, thereby improving bioavailability and minimising adverse effects.

Development of Lipid Polymer Hybrid Nanoparticles of Abietic Acid: Optimization, In-Vitro and Preclinical Evaluation

The objective of the current research was to develop abietic acid (AA)-loaded hybrid polymeric nanoparticles (HNPs) for anti-inflammatory and antioxidant activity after oral administration. AAHNPs were developed by microinjection technique and optimized by 3-factor 3-level Box-Behnken design. The AAHNPs were evaluated for morphology, FTIR, X-ray diffraction, in-vitro release, ex-vivo permeation, in-vitro antioxidant, and in-vivo anti-inflammatory activity. The optimized AAHNPs (AAHNPsopt) displayed 384.5 ± 6.36nm of PS, 0.376 of PDI, 23.0 mV of ZP, and 80.01 ± 1.89% of EE. FTIR and X-ray diffraction study results revealed that AA was encapsulated into a HNPs matrix. The AAHNPsopt showed significant (P < 0.05) high and sustained release of AA (86.72 ± 4.92%) than pure AA (29.87 ± 3.11%) in 24h. AAHNPsopt showed an initial fast release of AA (20.12 ± 3.07% in 2h), which succeeded in reaching the therapeutic concentration. The AAHNPsopt showed 2.49-fold higher ex-vivo gut permeation flux than pure AA due to the presence of lipid and surfactant. The AAHNPsopt exhibited significantly (P < 0.05, P < 0.01, P < 0.001) higher antioxidant activity as compared to pure AA at each concentration. AAHNPsopt formulation displayed a significantly (P < 0.05) higher anti-inflammatory effect (21.51 ± 2.23% swelling) as compared to pure AA (46.51 ± 1.74% swelling). From the in-vitro and in-vivo finding, it was concluded that HNPs might be a suitable carrier for the improvement of the therapeutic efficacy of the drug.

Pharmacokinetics and Pharmacodynamics of a Nanostructured Lipid Carrier Co-Encapsulating Artemether and miRNA for Mitigating Cerebral Malaria

Cerebral malaria (CM), a severe neurological pathology caused by Plasmodium falciparum infection, poses a significant global health threat and has a high mortality rate. Conventional therapeutics cannot cross the blood-brain barrier (BBB) efficiently. Therefore, finding effective treatments remains challenging. The novelty of the treatment proposed in this study lies in the feasibility of intranasal (IN) delivery of the nanostructured lipid carrier system (NLC) combining microRNA (miRNA) and artemether (ARM) to enhance bioavailability and brain targeting. The rational use of NLCs and RNA-targeted therapeutics could revolutionize the treatment strategies for CM management. This study can potentially address the challenges in treating CM, allowing drugs to pass through the BBB. The NLC formulation was developed by a hot-melt homogenization process utilizing 3% (w/w) precirol and 1.5% (w/v) labrasol, resulting in particles with a size of 94.39 nm. This indicates an effective delivery to the brain via IN administration. The results further suggest the effective intracellular delivery of encapsulated miRNAs in the NLCs. Investigations with an experimental cerebral malaria mouse model showed a reduction in parasitaemia, preservation of BBB integrity, and reduced cerebral haemorrhages with the ARM+ miRNA-NLC treatment. Additionally, molecular discoveries revealed that nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) and Interleukin-6 (IL-6) levels were reduced in the treated groups in comparison to the CM group. These results support the use of nanocarriers for IN administration, offering a viable method for mitigating CM through the increased bioavailability of therapeutics. Our findings have far-reaching implications for future research and personalized therapy.

Syrupy herbal formulation of green bean pod extract of Phaseolus vulgaris L.: Formulation optimization by central composite design, and evaluation for anti-urolithiatic activity

The green bean pods of Phaseolus vulgaris L. are traditionally used as a folk remedy for treating calcium oxalate kidney stones. The current research aimed to develop a syrup formulation containing green bean pod extract for anti-urolithiatic activity. The syrup was prepared using a simple blending method and optimized through a central composite design (CCD) with two independent variables: the ratio of pod juice (PJ) to sugar solution (SS) ranging from 1:0.5 to 1:1.5, and the percentage of CMC from 0.2% to 0.4% w/v. These variables were analyzed for their impact on viscosity (CP) and sedimentation percentage, helping to identify the best formulation out of 13 variants. The finalized formulation (F-opt) underwent assessment for physicochemical characteristics such as organoleptic properties, viscosity, density, sedimentation rate, and stability. Additionally, a microbiological assessment was performed utilizing the spread plate method. Further, it was evaluated for in vitro, ex vivo, and in vivo anti-urolithiatic activity in rat models for 28 days and compared with that of the reference standard (Cystone syrup). Additionally, acute toxicity was assessed in albino Swiss mice. Histopathological evaluations were then conducted on the kidneys of the Wistar rats that had been used for the in vivo studies, providing insight into the treatment effects on kidney tissue structure. The optimized formulation (F-opt) was a green, viscous, clear syrup with a pH of 5.8, a viscosity of 256.38 CP, a density of 1.31 g/ml, and a sedimentation rate of 0.69%. The optimized formulation was found to be stable, showing no significant changes in physicochemical and microbiological properties. The results of the in vitro, ex vivo, and in vivo anti-urolithiatic studies indicated that the optimized formulation effectively inhibited the aggregation of calcium oxalate. The acute toxicity studies revealed no mortality or adverse effects for both the optimized formulation and pure bean pod juice at a dose of 2000 mg/kg body weight. Histopathological examination revealed that rats treated with the optimized formulation exhibited a significant reduction in both the number and size of calcium oxalate deposits within various parts of the renal tubules. It can be concluded that the syrupy formulation of Phaseolus vulgaris L. green bean pod extract demonstrated significant anti-urolithiatic activity. This activity could be due to its diuretic properties and its ability to inhibit the formation of calcium oxalate crystals. However, limitations of the study included a lack of elucidation of the mechanism and limited generalizability of the findings.

Nanotechnology for enhanced nose-to-brain drug delivery in treating neurological diseases

Despite the increasing global incidence of brain disorders, achieving sufficient delivery towards the central nervous system (CNS) remains a formidable challenge in terms of translating into improved clinical outcomes. The brain is highly safeguarded by physiological barriers, primarily the blood-brain barrier (BBB), which routinely excludes most therapeutics from entering the brain following systemic administration. Among various strategies investigated to circumvent this challenge, intranasal administration, a noninvasive method that bypasses the BBB to allow direct access of drugs to the CNS, has been showing promising results. Nanotechnology-based drug delivery systems, in particular, have demonstrated remarkable capacities in overcoming the challenges posed by nose-to-brain drug delivery and facilitating targeted drug accumulation within the brain while minimizing side effects of systemic distribution. This review comprehensively summarizes the barriers of nose-to-brain drug delivery, aiming to enhance our understanding of potential physiological obstacles and improve the efficacy of nasal delivery in future trials. We then highlight cutting-edge nanotechnology-based studies that enhance nose-to-brain drug delivery in three key aspects, demonstrating substantial potential for improved treatment of brain diseases. Furthermore, the attention towards clinical studies will ease the regulatory approval process for nasal administration of nanomedicines targeting brain disease.

Niosomes gel of apigenin to improve the topical delivery: development, optimization, ex vivo permeation, antioxidant study, and in vivo evaluation

Niosomes (NS) are the promising and novel carrier of the drug for effective transdermal delivery. Apigenin (AN) is a natural bioactive compound and has various pharmacological activities. AN is poorly water soluble which directly affects therapeutic efficacy. The aim of this research work was to develop the AN-NS gel to improve transdermal delivery. The thin-film hydration method was used for the development of AN-NS. The optimized AN-NS (AN-NS2) has a vesicle size of 272.56 ± 12.49 nm, PDI is 0.249, zeta potential is -38.7 mV, and entrapment efficiency of 86.19 ± 1.51%. The FTIR spectra of the AN-NS2 depicted that AN encapsulated in the NS matrix. AN-NS2 formulation was successfully incorporated into chitosan gel and evaluated. The optimized AN-NS2 gel (AN-NS2G4) has 2110 ± 14cps of viscosity, 10.40 ± 0.21g.cm/sec of spreadability, and 99.65 ± 0.53% of drug content. AN-NS2G4 displayed significantly (p < 0.05) higher AN released (67.64 ± 3.03%) than pure AN-gel (37.31 ± 2.87%). AN-NS2G4 showed the Korsmeyer Peppas release model. AN-NS2G4 displayed significantly (p < 0.05) higher antioxidant activity (90.72%) than pure AN (64.53%) at 300 µg/ml. AN-NS2G4 displayed significantly (p < 0.05) higher % inhibition of swelling than pane AN-gel in carrageenin-induced paw oedema in rats. The finding concluded that niosomes-laden gel is a good carrier of drugs to improve transdermal delivery and therapeutic efficacy.

Development of Atomoxetine-Loaded NLC In Situ Gel for Nose-to-Brain Delivery: Optimization, In Vitro, and Preclinical Evaluation

The present study investigates the brain-targeted efficiency of atomoxetine (AXT)-loaded nanostructured lipid carrier (NLC)-laden thermosensitive in situ gel after intranasal administration. AXT-NLC was prepared by the melt emulsification ultrasonication method and optimized using the Box-Behnken design (BBD). The optimized formulation (AXT-NLC) exhibited particle size PDI, zeta potential, and entrapment efficiency (EE) of 108 nm, 0.271, -42.3 mV, and 84.12%, respectively. The morphology of AXT-NLC was found to be spherical, as confirmed by SEM analysis. DSC results displayed that the AXT was encapsulated within the NLC matrix. Further, optimized NLC (AXT-NLC13) was incorporated into a thermosensitive in situ gel using poloxamer 407 and carbopol gelling agent and evaluated for different parameters. The optimized in situ gel (AXT-NLC13G4) formulation showed excellent viscosity (2532 ± 18 Cps) at 37 °C and formed the gel at 28-34 °C. AXT-NLC13-G4 showed a sustained release of AXT (92.89 ± 3.98% in 12 h) compared to pure AXT (95.47 ± 2.76% in 4 h). The permeation flux through goat nasal mucosa of AXT from pure AXT and AXT-NLC13-G4 was 504.37 µg/cm²·h and 232.41 µg/cm²·h, respectively. AXT-NLC13-G4 intranasally displayed significantly higher absolute bioavailability of AXT (1.59-fold higher) than intravenous administration. AXT-NLC13-G4 intranasally showed 51.91% higher BTP than pure AXT (28.64%) when administered via the same route (intranasally). AXT-NLC13-G4 showed significantly higher BTE (207.92%) than pure AXT (140.14%) when administered intranasally, confirming that a high amount of the AXT reached the brain. With the disrupted performance induced by L-methionine, the AXT-NLC13-G4 showed significantly (p < 0.05) better activity than pure AXT as well as donepezil (standard). The finding concluded that NLC in situ gel is a novel carrier of AXT for improvement of brain delivery by the intranasal route and requires further investigation for more justification.

Design of experiment (DoE) as a quality by design (QbD) tool to optimise formulations of lipid nanoparticles for nose-to-brain drug delivery

INTRODUCTION

The nose-to-brain route has been widely investigated to improve drug targeting to the central nervous system (CNS), where lipid nanoparticles (solid lipid nanoparticles - SLN and nanostructured lipid carriers - NLC) seem promising, although they should meet specific criteria of particle size (PS) <200 nm, polydispersity index (PDI) <0.3, zeta potential (ZP) ~|20| mV and encapsulation efficiency (EE) >80%. To optimize SLN and NLC formulations, design of experiment (DoE) has been recommended as a quality by design (QbD) tool.

AREAS COVERED

This review presents recently published work on the optimization of SLN and NLC formulations for nose-to-brain drug delivery. The impact of different factors (or independent variables) on responses (or dependent variables) is critically analyzed.

EXPERT OPINION

Different DoEs have been used to optimize SLN and NLC formulations for nose-brain drug delivery, and the independent variables lipid and surfactant concentration and sonication time had the greatest impact on the dependent variables PS, EE, and PDI. Exploring different DoE approaches is important to gain a deeper understanding of the factors that affect successful optimization of SLN and NLC and to facilitate future work improving machine learning techniques.

A Dual Therapy of Nanostructured Lipid Carrier Loaded with Teriflunomide-A Dihydro-Orotate Dehydrogenase Inhibitor and an miR-155-Antagomir in Cuprizone-Induced C57BL/6J Mouse

The effective treatment of central nervous system (CNS) disorders such as multiple sclerosis (MS) has been challenging due to the limited ability of therapeutic agents to cross the blood-brain barrier (BBB). In this study, we investigated the potential of nanocarrier systems to deliver miR-155-antagomir-teriflunomide (TEF) dual therapy to the brain via intranasal (IN) administration to manage MS-associated neurodegeneration and demyelination. Our results showed that the combinatorial therapy of miR-155-antagomir and TEF loaded in nanostructured lipid carriers (NLCs) significantly increased brain concentration and improved targeting potential. The novelty of this study lies in the use of a combinatorial therapy approach of miR-155-antagomir and TEF loaded in NLCs. This is a significant finding, as the effective delivery of therapeutic molecules to the CNS has been a challenge in treating neurodegenerative disorders. Additionally, this study sheds light on the potential use of RNA-targeting therapies in personalized medicine, which could revolutionize the way CNS disorders are managed. Furthermore, our findings suggest that nanocarrier-loaded therapeutic agents have great potential for safe and economical delivery in treating CNS disorders. Our study provides novel insights into the effective delivery of therapeutic molecules via the IN route for managing neurodegenerative disorders. In particular, our results demonstrate the potential of delivering miRNA and TEF via the intranasal route using the NLC system. We also demonstrate that the long-term use of RNA-targeting therapies could be a promising tool in personalized medicine. Importantly, using a cuprizone-induced animal model, our study also investigated the effects of TEF-miR155-antagomir-loaded NLCs on demyelination and axonal damage. Following six weeks of treatment, the TEF-miR155-antagomir-loaded NLCs potentially lowered the demyelination and enhanced the bioavailability of the loaded therapeutic molecules. Our study is a paradigm shift in delivering miRNAs and TEF via the intranasal route and highlights the potential of this approach for managing neurodegenerative disorders. In conclusion, our study provides critical insights into the effective delivery of therapeutic molecules via the IN route for managing CNS disorders, and especially MS. Our findings have significant implications for the future development of nanocarrier-based therapies and personalized medicine. Our results provide a strong foundation for further studies and the potential to develop safe and economic therapeutics for CNS disorders.

Recent Advances in Intranasal Liposomes for Drug, Gene, and Vaccine Delivery

Liposomes are safe, biocompatible, and biodegradable spherical nanosized vesicles produced from cholesterol and phospholipids. Recently, liposomes have been widely administered intranasally for systemic and brain delivery. From the nasal cavity, liposome-encapsulated drugs and genes enter the systemic circulation primarily via absorption in the respiratory region, whereas they can be directly transported to the brain via the olfactory pathway. Liposomes can protect drugs and genes from enzymatic degradation, increase drug absorption across the nasal epithelium, and prolong the residence time in the nasal cavity. Intranasal liposomes are also a potential approach for vaccine delivery. Liposomes can be used as a platform to load antigens and as vaccine adjuvants to induce a robust immune response. With the recent interest in intranasal liposome formulations, this review discusses various aspects of liposomes that make them suitable for intranasal administration. We have summarized the latest advancements and applications of liposomes and evaluated their performance in the systemic and brain delivery of drugs and genes administered intranasally. We have also reviewed recent advances in intranasal liposome vaccine development and proposed perspectives on the future of intranasal liposomes.