Ropinirole-dextran sulfate nanoplex for nasal administration against Parkinson's disease: in silico molecular modeling and in vitro-ex vivo evaluation

Fabricating Polymer/Surfactant/Cyclodextrin Hybrid Particles for Possible Nose-to-Brain Delivery of Ropinirole Hydrochloride: In Vitro and Ex Vivo Evaluation

Ropinirole is a non-ergolinic dopamine agonist used to manage Parkinson's disease and it is characterized by poor oral bioavailability. This study aimed to design and develop advanced drug delivery systems composed of poloxamer 407, a non-ionic surfactant (Tween 80), and cyclodextrins (methyl-β-CD or hydroxy-propyl-β-CD) for possible brain targeting of ropinirole after nasal administration for the treatment of Parkinson's disease. The hybrid systems were formed by the thin-film hydration method, followed by an extensive physicochemical and morphological characterization. The in vitro cytotoxicity of the systems on HEK293 cell lines was also tested. In vitro release and ex vivo mucosal permeation of ropinirole were assessed using Franz cells at 34 °C and with phosphate buffer solution at pH 5.6 in the donor compartment, simulating the conditions of the nasal cavity. The results indicated that the diffusion-controlled drug release exhibited a progressive increase throughout the experiment, while a proof-of-concept experiment on ex vivo permeation through rabbit nasal mucosa revealed a better performance of the prepared hybrid systems in comparison to ropinirole solution. The encouraging results in drug release and mucosal permeation indicate that these hybrid systems can serve as attractive platforms for effective and targeted nose-to-brain delivery of ropinirole with a possible application in Parkinson's disease. Further ex vivo and in vivo studies to support the results of the present work are ongoing.

Benchmarking the Solubility Enhancement and Storage Stability of Amorphous Drug–Polyelectrolyte Nanoplex against Co-Amorphous Formulation of the Same Drug

Amorphization, typically in the form of amorphous solid dispersion (ASD), represents a well-established solubility enhancement strategy for poorly soluble drugs. Recently, two amorphous drug formulations, i.e., the amorphous drug–polyelectrolyte nanoparticle complex (nanoplex) and co-amorphous system, have emerged as promising alternatives to circumvent the issues faced by ASD (i.e., large dosage requirement, high hygroscopicity). In the present work, the nanoplex was benchmarked against the co-amorphous system in terms of the preparation efficiency, drug payload, thermal stability, dissolution rate, supersaturation generation, and accelerated storage stability. Weakly acidic curcumin (CUR) and weakly basic ciprofloxacin (CIP) were used as the model poorly soluble drugs. The CUR and CIP nanoplexes were prepared using chitosan and sodium dextran sulfate as the polyelectrolytes, respectively. The co-amorphous CUR and CIP were prepared using tannic acid and tryptophan as the co-formers, respectively. The benchmarking results showed that the amorphous drug nanoplex performed as well as, if not better than, the co-amorphous system depending on the drug in question and the aspects being compared. The present work successfully established the nanoplex as an equally viable amorphous drug formulation as the more widely studied co-amorphous system to potentially serve as an alternative to ASD.

Dextran sulfate-based MMP-2 enzyme-sensitive SR-A receptor targeting nanomicelles for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is an ordinarily occurring autoimmune disease with systemic inflammatory. Targeted drug delivery systems have many successful applications in the treatment of rheumatoid arthritis. In order to develop nanoparticles for targeted delivery of Celastrol (Cel) to rheumatoid arthritis and specific drug release, the dextran sulfate (DS) was modified as the targeting molecular by binding to the scavenger receptor of macrophage. The dextran-sulfate-PVGLIG-celastrol (DS-PVGLIG-Cel), named DPC, amphiphilic polymeric prodrug was synthesized and characterized. The resulting DPC@Cel micelles had the average size of 189.9 nm. Moreover, the micelles had ultrahigh entrapment efficiency (about 44.04%) and zeta potential of −11.91 mV. In the in vitro release study, due to the excessive production of matrix metalloproteinase-2 (MMP-2) at the inflammatory joint, the MMP-2 reactive peptide was used to crack in the inflammatory microenvironment to accelerate the release of Cel. The results have shown that the nanoparticles can effectively deliver Cel to activated macrophages and significantly improve the bioavailability. In vivo experiments showed that DPC@Cel have better anti-rheumatoid arthritis effects and lower systemic toxicity than free Cel. This study provided a new therapeutic strategy for the treatment of RA.

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.

Importance of Nanoparticles for the Delivery of Antiparkinsonian Drugs

Parkinson's disease (PD) affects around ten million people worldwide and is considered the second most prevalent neurodegenerative disease after Alzheimer's disease. In addition, there is a higher risk incidence in the elderly population. The main PD hallmarks include the loss of dopaminergic neurons and the development of Lewy bodies. Unfortunately, motor symptoms only start to appear when around 50-70% of dopaminergic neurons have already been lost. This particularly poses a huge challenge for early diagnosis and therapeutic effectiveness. Actually, pharmaceutical therapy is able to relief motor symptoms, but as the disease progresses motor complications and severe side-effects start to appear. In this review, we explore the research conducted so far in order to repurpose drugs for PD with the use of nanodelivery systems, alternative administration routes, and nanotheranostics. Overall, studies have demonstrated great potential for these nanosystems to target the brain, improve drug pharmacokinetic profile, and decrease side-effects.

Parkinson's Disease: A Review from Pathophysiology to Treatment

Parkinson's Disease (PD) is the second most common neurodegenerative disease in the elderly population, with a higher prevalence in men, independent of race and social class; it affects approximately 1.5 to 2.0% of the elderly population over 60 years and 4% for those over 80 years of age. PD is caused by the necrosis of dopaminergic neurons in the substantia nigra, which is the brain region responsible for the synthesis of the neurotransmitter dopamine (DA), resulting in its decrease in the synaptic cleft. The monoamine oxidase B (MAO-B) degrades dopamine, promoting the glutamate accumulation and oxidative stress with the release of free radicals, causing excitotoxicity. The PD symptoms are progressive physical limitations such as rigidity, bradykinesia, tremor, postural instability and disability in functional performance. Considering that there are no laboratory tests, biomarkers or imaging studies to confirm the disease, the diagnosis of PD is made by analyzing the motor features. There is no cure for PD, and the pharmacological treatment consists of a dopaminergic supplement with levodopa, COMT inhibitors, anticholinergics agents, dopaminergic agonists, and inhibitors of MAO-B, which basically aims to control the symptoms, enabling better functional mobility and increasing life expectancy of the treated PD patients. Due to the importance and increasing prevalence of PD in the world, this study reviews information on the pathophysiology, symptomatology as well as the most current and relevant treatments of PD patients.

Chitosan-coated PLGA nanoparticles for the nasal delivery of ropinirole hydrochloride: In vitro and ex vivo evaluation of efficacy and safety

Nose-to-brain delivery is an attractive route for direct drug delivery to the central nervous system (CNS), avoiding hepatic first-pass metabolism and solving blood-brain barrier passage issues. Therefore, the aim of the present study was the development of PLGA and PLGA/chitosan (chit) nanoparticles (NPs) with mucoadhesive properties, able to encapsulate ropinirole hydrochloride (RH), an anti-Parkinsonian dopaminergic agonist, and suitable to promote RH delivery across the nasal mucosa. NPs produced by nanoprecipitation showed spherical shape and a mean average size of 98.8 nm and 468.0 nm (PLGA and PLGA/chit, respectively). RH loaded PLGA/chit NPs showed a complete release of the drug in simulated nasal electrolyte solution (SNES) over the period of 24 h and increased the permeation of RH through sheep nasal mucosa by 3.22-fold in comparison to PLGA NPs. None of RH loaded NPs induced hemolysis in whole blood or the production of reactive oxygen species (ROS) in Raw 264.7 cells. On their turn, PLGA/chit NPs decreased cell viability of Raw 264.7 cells and Peripheral Blood Mononuclear Cells (PBMCs) in a concentration-dependent manner. These results revealed that, particularly PLGA/chit NPs, could be a valuable carrier for the delivery of RH to the CNS, opening a new path for Parkinson's disease therapy.

Role of sodium l-cysteine alginate conjugate and isopropyl myristate to enhance the permeation enhancing activity of BCS class III drug from TDDS; optimization by central composite design and in vivo pharmacokinetics study

OBJECTIVE

The objective of the present research was to study the effect and optimization of sodium alginate l-cysteine conjugate and permeation enhancer on permeation of high soluble low permeable ropinirole hydrochloride from the transdermal formulation.

METHODS

Sodium alginate l-cysteine conjugate was prepared and characterized and the same was added into a transdermal formulation along with IPM as a permeation enhancer. Twelve primary formulations were prepared by solvent casting method and evaluated. The results were fed into Design Expert® Software to obtain optimized formulation. The optimized formulation was evaluated for physicochemical, ex vivo permeation, stability, skin irritation, and pharmacokinetic studies.

RESULTS

The results of the characterization of prepared sodium alginate l-cysteine conjugate confirmed the thiolation process. Stability studies suggested that the drug was compatible with all the excipients. SEM images of the transdermal patch revealed that the amorphous drug was uniformly distributed. From the design space, the optimized formulation from the polymer's ratio (SA: SACC; 4:6) and IPM 9.5%w/w of polymers weight showed target steady state flux 9.004 µg/cm²/h with maximum drug permeation. The increased target flux and maximum drug permeation from an optimized patch suggested that there was an effect of SACC on ropinirole hydrochloride permeation in the presence of IPM as a permeation enhancer. Pharmacokinetic studies in rabbits showed that the optimized patch improved bioavailability as compared to marketed oral tablets.

CONCLUSIONS

The study was concluded that there was a positive effect of sodium alginate l-cysteine conjugate and IPM on ropinirole hydrochloride permeation from the transdermal formulation.

Neuroprotective Effect of Ropinirole Lipid Nanoparticles Enriched Hydrogel for Parkinson's Disease: In Vitro, Ex Vivo, Pharmacokinetic and Pharmacodynamic Evaluation

Parkinson’s disease (rp) is a progressive neurodegenerative disorder. Ropinirole (RP) is a newer generation dopamine agonist used for the treatment of PD. It is prescribed as oral dosage form. However, limited oral bioavailability and frequent dosing limits the RP usage. The objective of the current investigation was to develop, optimize, evaluate pharmacokinetic (PK) and pharmacodynamic (PCD) activity of RP loaded solid lipid nanoparticles (RP-SLNs) and nanostructured lipid carriers (RP-NLCs) and containing hydrogel (RP-SLN-C and RP-NLC-C) formulations for improved oral and topical delivery. RP loaded lipid nanoparticles were optimized and converted to hydrogel using carbopol 934 as the gelling polymer. PK and PCD studies in haloperidol-induced PD were conducted in male Wistar rats. In vitro and ex vivo permeation studies showed sustained release profile and enhanced permeation compared with control formulations. Differential scanning calorimeter and X-ray diffraction studies revealed amorphous transformation; scanning electron microscope showed the spherical shape of RP in lipid nanoparticles. PK studies showed 2.1 and 2.7-folds enhancement from RP-SLN and RP-NLC from oral administration, 3.0 and 3.3-folds enhancement from RP-SLN-C and RP-NLC-C topical administration, compared with control formulations, respectively. RP-SLN-C and RP-NLC-C showed 1.4 and 1.2-folds topical bioavailability enhancement compared with RP-SLN and RP-NLC oral administration, respectively. PCD studies showed enhanced dopamine, glutathione, catalase levels and reduced lipid peroxidation levels, compared with the haloperidol-induced PD model. Overall, the results demonstrated that lipid nanoparticles and corresponding hydrogel formulations can be considered as an alternative delivery approach for the improved oral and topical delivery of RP for the effective treatment of PD.

Enhancing the stability of amorphous drug-polyelectrolyte nanoparticle complex using a secondary small-molecule drug as the stabilizer: A case study of ibuprofen-stabilized curcumin-chitosan nanoplex

While the solubility enhancement capability of amorphous drug-polyelectrolyte nanoparticle complex (nanoplex) has been widely established, its amorphous form stability during long-term storage is often lacking for poorly-soluble drugs with high crystallization propensity, such as curcumin (CUR). Herein we presented a new stabilization strategy of amorphous CUR nanoplex using a secondary small-molecule drug - ibuprofen (IBU) - as the auxiliary stabilizer to the polyelectrolytes (i.e. chitosan). The results showed that, unlike the single-drug CUR nanoplex, the dual-drug CUR-IBU nanoplex with CUR/IBU payload ratio of 1.7 remained stable after 24-month storage. The CUR-IBU nanoplex also exhibited superior CUR solubility enhancement (4-fold higher) than the CUR nanoplex. These improvements, however, were not evident for the CUR-IBU nanoplex prepared at higher CUR/IBU payload ratio of 14 due to insufficient IBU presence. Compared to the CUR nanoplex, the CUR-IBU nanoplex exhibited smaller size with less spherical morphology (100 nm), higher zeta potential (42 versus 19 mV), lower total drug payload (73% versus 83%), and lower CUR utilization rate (53% versus 94%) due to the competition with IBU in the drug-PE complexation. These results successfully established the use of a secondary drug to not only stabilized, but also improved solubility enhancement of amorphous drug nanoplex systems.

Enhancing the physical stability and supersaturation generation of amorphous drug-polyelectrolyte nanoparticle complex via incorporation of crystallization inhibitor at the nanoparticle formation step: A case of HPMC versus PVP

Amorphous drug-polyelectrolyte nanoparticle complex (or nanoplex in short) has emerged as a highly attractive solubility enhancement strategy of poorly-soluble drugs attributed to its simple and highly efficient preparation. The existing nanoplex formulation, however, exhibits poor amorphous form stability during long-term storage for drugs with high crystallization propensity. Using ciprofloxacin (CIP) and sodium dextran sulfate (DXT) as the model drug-polyelectrolyte nanoplex, we investigated the feasibility of incorporating crystallization inhibiting agents, i.e. hydroxypropyl methylcellulose (HPMC) and polyvinylpyrrolidone (PVP), at the nanoplex formation step to improve the physical stability of the CIP nanoplex. The effects of the HPMC or PVP additions on the nanoplex's physical characteristics (i.e. size, zeta potential, CIP payload), CIP utilization rate, dissolution rate, and supersaturation generation were also examined. The results showed that the additions of HPMC or PVP increased the CIP nanoplex size (from 300 to 500 nm) and CIP utilization rate (from 65% to 90% w/w) with minimal impacts on the CIP payload (70-80% w/w). Their additions had opposite impacts on the nanoplex's colloidal stability due to surfactant nature of PVP. Significantly, unlike the CIP-DXT and CIP-DXT-PVP nanoplexes, the CIP-DXT-HPMC nanoplex remained amorphous after three-month accelerated storage, while also exhibited superior solubility enhancement (15-30% higher).

N,N,N‑trimethyl chitosan modified flaxseed oil based mucoadhesive neuronanoemulsions for direct nose to brain drug delivery

Here we fabricated flaxseed oil-based neuronanoemulsions (NNEs) which were further surface-modified with a mucoadhesive polymer, N,N,N‑trimethyl chitosan (TMC) to form mucoadhesive neuronanoemulsions (mNNEs). The NNEs were loaded with high partitioning ropinirole-dextran sulfate (ROPI-DS) nanoplex and fabricated using hot high-pressure homogenization (HPH) technique. NNEs were optimized using Central Composite experimental design. TMC modified mNNE have not been prepared yet for direct nose to brain drug delivery. Here, an objective to provide controlled drug release with prolonged residence on the nasal mucosa for the treatment of Parkinson's disease (PD) is at prime consideration. Enhanced brain targeting through BBB bypass drug delivery, improved therapeutic efficacy through enhanced retention of mNNE formulation over nasal mucosal membrane, reduced dose and frequency of administration, and safety were further expected outcomes of this experiment. The mNNE formulation was subjected to 6 month stability assessment. The mNNE formulation was administered to the Swiss albino mice model via intranasal route and both, the plasma and brain pharmacokinetics were estimated. The in vivo studies performed on mice exhibited high brain targeting efficiency of mNNE formulation through nose to brain delivery via olfactory pathway. The prepared intranasal mNNEs could be on the clinics, if investigated more for behavioral and neurotoxicity studies.

Nanocarrier for levodopa Parkinson therapeutic drug; comprehensive benserazide analysis

Loss of dopamine-secreting neurons in the midbrain causes Parkinson's disease. L-DOPA, the precursor to the neurotransmitters dopamine, crosses vast majority of physiological and biochemical barriers that dopamine cannot. But most levodopa is decarboxylated to dopamine before it reaches the brain. This causes to little therapeutic gain with strong peripheral side effects. Benserazide is an irreversible inhibitor of peripheral aromatic L-amino acid decarboxylase that prevents the breakdown of levodopa in the bloodstream. The challenges are to increase the therapeutic efficiency, the bioavailability and decreasing the unfavourable side effects of Levodopa drug. Biocompatible nano-sized drug carriers could address these challenges at molecular level. Thus calculations of drug loading ability of acid-functionalized CNT for the benserazide as a nanodug carrier complex for L-DOPA were performed. In this regard, evaluation of all adsorption features of the most stable conformer of benserazide molecule onto carboxylated carbon nanotube is critical. To determine the minimum energy conformer of benserazide, the molecular structure and conformational analysis of 512 possible conformers have been subjected to first principle quantum mechanical calculations. Our work established a novel and easy-to-make formulation of benserazide/carboxylated CNT conjugate with extremely high drug loading efficiency of Levodopa for Parkinson disease treatment.