Levodopa Response Research Articles

Tremor Is Highly Responsive to Levodopa in Advanced Parkinson's Disease.

Tremor in Parkinson's disease (PD) is commonly regarded as less responsive to levodopa than bradykinesia and rigidity, with levodopa-resistant PD tremor considered relatively common. The aim was to assess the levodopa responsiveness of tremor, bradykinesia, and rigidity in a population with advanced PD. We performed a retrospective study of 526 people with PD screened for deep brain stimulation. Levodopa's Cohen's d effect sizes were in the same order of magnitude for the 3 cardinal motor symptoms. Proportional improvement in tremor (86.8%) was higher than bradykinesia (45.7%) and rigidity (67.0%) (P < 0.0001). Full resolution was more frequent for tremor (67.9%) than for bradykinesia (0.4%) or rigidity (24.8%) (P < 0.0001). Levodopa-unresponsive tremor, defined as improvement less than 25%, was documented only in 4.0%, as opposed to 19.4% for bradykinesia and 9.8% for rigidity (P < 0.0001). In advanced PD, tremor was more responsive to levodopa than bradykinesia and rigidity, and levodopa-unresponsive tremor was relatively rare.

Acute Levodopa Challenge in Atypical Parkinsonism: Comprehensive Analysis of Individual Motor Responses.

The acute levodopa challenge is widely used to distinguish Parkinson's disease (PD) from atypical parkinsonian syndromes (APSs) such as multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). In APSs, very few patients present a clinically relevant response to levodopa. The aim of this study was to determine whether patients with atypical parkinsonism benefit from levodopa in any aspect of their multiple motor deficits despite the generally poor response. This retrospective study analyzed individual motor responses to the acute levodopa challenge using the MDS-UPDRS III in 47 PSP, 26 MSA, and 71 PD patients at Hannover Medical School. Despite the generally poor levodopa response in both PSP and MSA patients, bradykinesia and rigidity were the symptoms most notably affected by levodopa in PSP patients, while MSA patients experienced significant improvements in bradykinesia and action tremor. These findings underscore the variability in levodopa response among PSP and MSA patients and highlight the need for personalized treatment approaches in atypical parkinsonism.

Clinico-Genetic Profiles of Seven Patients With PINK1-Related Parkinson's Disease: A Case Series From a Tertiary Care Centre in India and a Review of the Literature.

Recessive variants in the PINK1 gene are known causes of early-onset Parkinson's disease (EOPD). To describe the clinical features and genetic profiles of patients with PINK1-related Parkinson's disease (PARK-PINK1) mutations. We conducted a retrospective chart review of the demographic, clinical and genetic details of patients from our database carrying biallelic PINK1 variants. A total of 7 patients whose median age at onset was 33 years (range: 20-49) were recruited. All had asymmetrical onset, tremors were present in 4 patients, abnormal posturing was present in 2 patients, and slowness was present in 1 patient. The parkinsonism phenotype was noted in 6 patients (with dystonia in four) and isolated dystonia in one. Among the 6 patients with parkinsonism, five had rest tremors, all had good levodopa responses, and four had motor fluctuations with choreiform dyskinesia. Exome sequencing revealed biallelic pathogenic/likely pathogenic variants, five of which were novel. PARK-PINK1 presents as an EOPD with tremor-predominant phenotype, good levodopa-responsiveness, early motor fluctuation and dyskinesia. We describe five novel variants in PINK1 gene.

Instrumented timed up and go test and machine learning-based levodopa response evaluation: a pilot study

BackgroundThe acute levodopa challenge test (ALCT) is a universal method for evaluating levodopa response (LR). Assessment of Movement Disorder Society’s Unified Parkinson’s Disease Rating Scale part III (MDS-UPDRS III) is a key step in ALCT, which is some extent subjective and inconvenience.MethodsThis study developed a machine learning method based on instrumented Timed Up and Go (iTUG) test to evaluate the patients’ response to levodopa and compared it with classic ALCT. Forty-two patients with parkinsonism were recruited and administered with levodopa. MDS-UPDRS III and the iTUG were conducted in both OFF-and ON-medication state. Kinematic parameters, signal time and frequency domain features were extracted from sensor data. Two XGBoost models, levodopa response regression (LRR) model and motor symptom evaluation (MSE) model, were trained to predict the levodopa response (LR) of the patients using leave-one-subject-out cross-validation.ResultsThe LR predicted by the LRR model agreed with that calculated by the classic ALCT (ICC = 0.95). When the LRR model was used to detect patients with a positive LR, the positive predictive value was 0.94.ConclusionsMachine learning based on wearable sensor data and the iTUG test may be effective and comprehensive for evaluating LR and predicting the benefit of dopaminergic therapy.

A Silent Threat: Deep Vein Thrombosis in Early-Stage Parkinson's Disease.

The primary clinical manifestation of venous thrombosis is discomfort in the lower extremities. Some early Parkinson's disease (PD) patients feel discomfort in the lower limbs. Venous thrombosis can risk lives by causing pulmonary embolism. This study examines the incidence of DVT in early PD patients and its correlation with different clinical and lab features. A cross-sectional study was conducted on 117 patients with early-stage PD. Ultrasonography was employed to detect the presence of DVT. Factors such as age, gender, body mass index, lifestyle habits (smoking and drinking), medical history (hypertension, diabetes, atrial fibrillation, and tumor), and other lab tests linked to thrombosis were analyzed. In 117 patients, 11 (9.4%) had DVT, while 106 (90.6%) did not. There were no significant differences in gender, BMI, habits, medical history, or other thrombosis-related tests between both groups. However, DVT patients were older with higher d-dimer levels. They also showed an increased right substantia nigra ultrasound echo area, higher HY grades, higher UPDRS 3 scores, less improvement in UPDRS 3 scores and levodopa response. The primary risk factors for lower extremity venous thrombosis were found to be age, d-dimer levels, and low-dose levodopa. Therefore, for elderly patients with early-stage PD, it is crucial to conduct d-dimer and lower extremity vascular ultrasound tests. The prevention of venous thrombosis in the lower extremities of early PD patients is of utmost importance.

Long-standing preservation of levodopa response in progressive supranuclear palsy

The clinical and neuropathological characteristics of progressive supranuclear palsy (PSP) with preservation of levodopa (L-dopa) response are described in this report. We present the case of a 73-year-old Japanese man with a 13-year history of dopa-responsive Parkinsonism and abnormalities observed in metaiodobenzylguanidine (MIBG) myocardial scintigraphy, suggesting Parkinson's disease. However, autopsy results revealed PSP pathology, including tuft-shaped astrocytes and globose-type neurofibrillary tangles, without Lewy body pathology. The degeneration was moderately to severely distributed in the globus pallidus, subthalamic nucleus, and substantia nigra, whereas striatal degeneration was mild. These findings suggest an intact response to L-dopa therapy throughout the patient's lifetime. Pathological examination of cardiac sympathetic nerves revealed intact nerves, suggesting functional involvement in the MIBG abnormality. This study provides further evidence of the clinical and pathological heterogeneity of PSP. Homozygosity for both the rs564309-C allele at TRIM11 and the rs2242367-G allele at SLC2A13 might have played a protective role. This case indicates a protracted course-PSP, which may hold promise for future treatments.

Remote levodopa challenge test in Parkinson's disease: Feasibility, reliability, validity and economic value.

The aim was to demonstrate the feasibility, reliability and validity of an in-home remote levodopa challenge test (LCT), as delivered through an online platform, for patients with Parkinson's disease (PwPD). Patients with Parkinson's disease eligible for deep brain stimulation surgery screening were enrolled. Participants sequentially received an in-home remote LCT and an in-hospital standard LCT (separated by 2.71 weeks). A modified Movement Disorder Society Unified Parkinson's Disease Rating Scale Part III omitting rigidity and postural stability items was used in the remote LCT. The reliability of the remote LCT was evaluated using the intraclass correlation coefficient and the concurrent validity was evaluated using the Pearson's correlation coefficient r between the levodopa responsiveness of the remote and standard LCT. Out of 106 PwPD screened, 80 (75.5%) completed both the remote and standard LCT. There was a good reliability (intraclass correlation coefficient 0.81, 95% confidence interval 0.69-0.88) and a strong correlation (r = 0.84, 95% confidence interval 0.77-0.90) between the levodopa responsiveness of the remote and standard LCT. The mean cost for PwPD was estimated to be reduced by 91% by using the remote LCT. The remote LCT is feasible, reliable and valid and may reduce healthcare-related costs for PwPD and their caregivers.

Association between Fecal Bile Acids and Levodopa Response in Patients with Parkinson's Disease.

Levodopa is the mainstay of treatments for Parkinson's disease (PD), but large heterogeneity exists in patient response. Increasing evidence implicates bile acids (BAs) involved in the pathogenesis of PD. Furthermore, BAs have also participated in drug bioavailability. However, the impact of BAs on levodopa response (LR) has not been investigated. This study evaluated the association between fecal BAs and LR. Levodopa challenge test (LCT) was conducted in 92 PD patients to assess LR. A total of 36 fecal BAs and plasma levodopa concentrations were detected using LC-MS/MS. The difference of BAs between subgroups with bottom and top 30% LR were analyzed and fecal samples from the two groups were collected for metagenomic shotgun analysis. No fecal BAs were significantly correlated with LR, except for chenodeoxycholic acid-3-β-D-glucuronide (CDCA-3-β-glucuronide, R = -0.228, p-value = 0.039). We found no significant difference in BAs between subgroups with bottom and top 30% LR. What is more, no significant changes in bacterial species composition related to bile acids metabolism or in the proportional representation of genes encoding known bile acids enzymes were observed between the groups. Overall, our data do not support an association between fecal BAs and levodopa response in PD patients. More precise macro-metabolomic approaches are needed to reveal the potential association between gut microbial interactions and the treatment effect of levodopa.

Stratifying quality of life outcome in subthalamic stimulation for Parkinson’s disease

BackgroundSubthalamic nucleus deep brain stimulation (STN-DBS) for Parkinson’s disease (PD) improves quality of life (QoL), motor and non-motor symptoms (NMS). However, in previous studies, 43%–49% of patients did not experience...

Unlocking the potential: T1-weighed MRI as a powerful predictor of levodopa response in Parkinson’s disease

BackgroundThe efficacy of levodopa, the most crucial metric for Parkinson’s disease diagnosis and treatment, is traditionally gauged through the levodopa challenge test, which lacks a predictive model. This study aims to probe the predictive power of T1-weighted MRI, the most accessible modality for levodopa response.MethodsThis retrospective study used two datasets: from the Parkinson’s Progression Markers Initiative (219 records) and the external clinical dataset from Ruijin Hospital (217 records). A novel feature extraction method using MedicalNet, a pre-trained deep learning network, along with three previous approaches was applied. Three machine learning models were trained and tested on the PPMI dataset and included clinical features, imaging features, and their union set, using the area under the curve (AUC) as the metric. The most significant brain regions were visualized. The external clinical dataset was further evaluated using trained models. A paired one-tailed t-test was performed between the two sets; statistical significance was set at p < 0.001.ResultsFor 46 test set records (mean age, 62 ± 9 years, 28 men), MedicalNet-extracted features demonstrated a consistent improvement in all three machine learning models (SVM 0.83 ± 0.01 versus 0.73 ± 0.01, XgBoost 0.80 ± 0.04 versus 0.74 ± 0.02, MLP 0.80 ± 0.03 versus 0.70 ± 0.07, p < 0.001). Both feature sets were validated on the clinical dataset using SVM, where MedicalNet features alone achieved an AUC of 0.64 ± 0.03. Key responsible brain regions were visualized.ConclusionThe T1-weighed MRI features were more robust and generalizable than the clinical features in prediction; their combination provided the best results. T1-weighed MRI provided insights on specific regions responsible for levodopa response prediction.Critical relevance statementThis study demonstrated that T1w MRI features extracted by a deep learning model have the potential to predict the levodopa response of PD patients and are more robust than widely used clinical information, which might help in determining treatment strategy.Key PointsThis study investigated the predictive value of T1w features for levodopa response.MedicalNet extractor outperformed all other previously published methods with key region visualization.T1w features are more effective than clinical information in levodopa response prediction.Graphical

A covalent organic framework nanosheet-nanochannel composite with signal amplification strategy for electrochemical enantioselective recognition

Recognition and separation of chiral isomers are of great importance in both industrial and biological applications. However, owing to identical molecular formulas and chemical properties of enantiomers, signal transduction and amplification are still two major challenges in chiral sensing. In this study, we developed an enantioselective device by integrating chiral covalent organic framework nanosheets (CONs) with nanochannels for sensitive identification and quantification of enantiomers. Using 3,4-dihydroxyphenylalanine (DOPA) as the model analyte, the as-prepared chiral nanofluidic device exhibits a remarkable chiral recognition ability to l-DOPA than d-DOPA. More importantly, due to the chelation of DOPA with Fe3+ ions, it can efficiently block the ion transport through channel and shield the channel surface charge, which will amplify the difference in the electrochemical response of l-DOPA and d-DOPA. Therefore, a sensitive chiral recognition can be achieved using the present nanofluidic device coupled using electrochemical amplification strategy. Notably, using this method, an ultra-low concentration of l-DOPA (as low as 0.21 pM) can be facilely and successfully detected with a linear range of 1 pM–10 μM. This study provides a reliable and sensitive approach for achieving highly selective detection of chiral molecules.

Parkinson's Disease Associated with G2019S LRRK2 Mutations without Lewy Body Pathology.

The G2019S leucine-rich repeat kinase 2 (LRRK2) gene mutation is an important and commonly found genetic determinant of Parkinson's disease (PD). The neuropathological findings associated with this mutation have thus far been varied but are most often associated with Lewy body (LB) pathology. Describe a case of clinical Parkinson's disease with levodopa responsiveness found to have LRRK2 mutations and the absence of Lewy bodies. We present an 89-year-old man with a 10-year history of slowly progressive parkinsonism suspected to be secondary to Parkinson's disease. Neuropathological evaluation revealed nigral degeneration without Lewy bodies or Lewy neurites, but there were frequent tau-immunopositive neurites and astrocytes in the putamen and substantia nigra, neocortical glial tau positive astrocytes associated with aging-related tau astrogliopathy (ARTAG), as well as neurofibrillary tangles, beta amyloid plaques, and amyloid angiopathy typical of advanced Alzheimer's disease. G2019S LRRK2 homozygous mutations were found. This case illustrates that levodopa-responsive clinical PD caused by G2019S LRRK2 mutations can occur without Lewy bodies.

Improvement by Medication Less than Expected in Parkinson's Disease: Blinded Evaluation of Levodopa Response.

The latest Movement Disorder Society (MDS) diagnostic criteria require a good and sustained response to medication to get a diagnosis of Parkinson's disease, PD. The aim of this study was to evaluate levodopa response in a group of patients with probable PD, diagnosed by movement disorder specialists. An acute levodopa challenge test (LDCT) was performed after pausing the dopaminergic medication for 6 half-times. The motor part of the Unified Parkinson's Disease Rating Scale was performed in the OFF-state and after LDCT (ON). A good effect was defined as >30% improvement. A video-protocol was used to secure standardized motor examination with blinded assessments of the UPDRS-III OFF and ON. An age-matched group of control subjects (CS) was included but did not go through LDCT. All participants were evaluated with Montreal Cognitive Assessment (MoCA) and Beck's Depression Inventory (BDI). In the statistical analysis, 37 patients were included. Twenty-one patients showed an improvement ≤30%, while 16 patients showed an improvement >30%. LDCT showed an overall mean improvement of 27.3% of motor UPDRS. In 43.2%, there was a discrepancy between the effect seen with the LDCT and the patients' self-perceived medicine evaluation. Patients with PD had a significantly lower MoCA score and more depressive symptoms compared to CS. We showed an acute effect of levodopa using LDCT that was around 30% improvement. While it lends support to the use of this limit in the MDS diagnostic criteria, an acute effect of less than 30% should be considered acceptable in some patients. Our study highlights a discrepancy in the objective measure of medicine effect on motor symptoms and the patient's subjective evaluation.

The clinical and neuroimaging differences between vascular parkinsonism and Parkinson's disease: a case-control study.

Parkinson's disease (PD) and vascular parkinsonism (VaP) have highly overlapping phenotypes, and different prognosis. This study comprehensively investigated the clinical, brain MRI and transcranial sonography differences between VaP and PD. Forty-eight patients with PD, 27 patients with VaP, and 29 healthy controls were compared. All patients were assessed using the MDS-UPDRS, Berg Balance Scale (BBS), Ten-Meter Walking Test (10-MWT), Time Up and Go Test, and Non-Motor Symptoms Scale. Beck Depression Inventory, PD questionnaire- 39, international urine incontinence scale, cognitive assessment scales, MRI brain and transcranial colour-coded doppler. The study was registered on clinical-Trial.gov (NCT04308135) on 03/12/2020. VaP patients showed significantly older age of onset, shorter disease duration, lower drug doses and levodopa responsiveness, higher On and Off axial scores, On and Off BBS, higher On scores for PIGD, rigidity, bradykinesia and total motor MDS-UPDRS, lower On and Off tremor, lower-half predominance, lower asymmetrical presentation and symmetric index than PD patients. VaP patients had worse non-motor symptoms Scale (NMSS) than controls except for perceptual problems/hallucinations but better symptoms than PD patients except for urinary dysfunction. Quality of life (QoL) was impaired in VaP patients and was correlated with motor function and NMSs. The VaP group had significantly higher white matter lesions and brain atrophy, with lower hyperechogenicity of the substantia nigra and more impaired cerebral vascular resistance and vasoreactivity than the PD group. VaP has a characteristic motor and non-motor profile, with impaired QoL, white matter, and transcranial sonography abnormalities that differentiate it from PD. Further studies are warranted to explore the role of vascular lesions in the pathogenesis of VaP. The registered identifier NCT04308135 on clinical-Trial.gov. Registered on 03/12/2020.

Motor and Non-motor Outcomes of Deep Brain Stimulation across the Genetic Panorama of Parkinson's Disease: A Multi-Scale Meta-Analysis.

In the era of modern medicine, where high-throughput sequencing techniques are readily available, it is desirable to elucidate the role of genetic background in patients with Parkinson's Disease (PD) undergoing Deep Brain Stimulation (DBS). Genetic stratification of PD patients undergoing DBS may assist in patient selection and prediction of clinical outcomes and complement existing selection procedures such as levodopa challenge testing. To capture a broad spectrum of motor and non-motor DBS outcomes in genetic PD patients with data from the recently updated literature. A multi-scale meta-analysis with 380 genetic PD cases was conducted using the Cochrane Review Manager, JASP software and R. This meta-analysis revealed that overall, patients with genetic PD are good candidates for DBS but the outcomes might differ depending on the presence of specific mutations. PRKN carriers benefited the most regarding motor function, daily dose medication and motor complications. However, GBA carriers appeared to be more prone to cognitive decline after subthalamic nucleus DBS accompanied by a low quality of life with variable severity depending on genetic variants and concomitant alterations in other genes. Apart from GBA, cognitive worsening was also observed in SNCA carriers. Pre-operative levodopa responsiveness and a younger age of onset are associated with a favorable motor outcome. A personalized approach with a variant-based risk stratification within the emerging field of surgicogenomics is needed. Integration of polygenic risk scores in clinical-decision making should be encouraged.

The Clinical, Radiological and Genetic Spectrum of PLA2G6-Associated Neurodegeneration: An Experience From a Tertiary Center.

Despite being the second most common type of neurodegeneration with brain iron accumulation, there is limited literature on PLA2G6-associated neurodegeneration (PLAN) within the Asian ethnicity, particularly in the Indian context. We conducted a retrospective observational study on patients with pathogenic/likely pathogenic PLA2G6 variants based on exome sequencing. We identified 26 patients (22 families, 15 males) of genetically-confirmed PLAN with a median age of 22.5 years and age at onset of 13.0 years, encompassing various subtypes: infantile neuroaxonal dystrophy (5/26;19.2%), atypical neuroaxonal dystrophy (3/26;11.5%), dystonia-parkinsonism (5/26;19.2%), dystonia-parkinsonism-myoclonus (n = 4, 15.38%), early-onset Parkinson's disease (2/26;7.7%), complex dystonia (2/26;7.7%), and complicated hereditary spastic paraparesis (cHSP; 5/26;19.2%). The common initial symptoms included walking difficulty (7/26;26.9%), developmental regression (6/26;23.1%), and slowness (4/26;15.4%). Dystonia (14/26;53.8%), followed by parkinsonism (11/26; 42.3%), was the most common motor symptom. Non-motor symptoms included cognitive decline (12/26;46.2%) and behavioral changes (6/26;23.1%). Neuroimaging revealed cerebellar atrophy in 23/26 (88.5%) patients and claval hypertrophy in 80% (4/5) of INAD patients. Levodopa responsiveness was noted in 12 of 14 patients with parkinsonism/dystonia who received levodopa, and dyskinesia was noted in 10/11 patients. Genetic analysis revealed a total of 19 unique variants in PLA2G6 gene, of which 11 were novel. Twelve patients harbored the c.2222G>A variant, which is predominantly seen in Asian subpopulations. The study introduces 26 new patients of PLAN and 12 patients associated with the c.2222G>A variant, potentially forming the most extensive single center series to date. It also expands the phenotypic, neuroimaging, and genotypic spectrum of PLAN.

The connection of motor improvement after deep brain stimulation in Parkinson’s disease and microstructural integrity of the substantia nigra and subthalamic nucleus

BackgroundNigrostriatal microstructural integrity has been suggested as a biomarker for levodopa response in Parkinson’s disease (PD), which is a strong predictor for motor response to deep brain stimulation (DBS) of the subthalamic nucleus (STN). This study aimed to explore the impact of microstructural integrity of the substantia nigra (SN), STN, and putamen on motor response to STN-DBS using diffusion microstructure imaging. MethodsData was collected from 23 PD patients (mean age 63 ± 7, 6 females) who underwent STN-DBS, had preoperative 3 T diffusion magnetic resonance imaging including multishell diffusion-weighted MRI with b-values of 1000 and 2000 s/mm2 and records of motor improvement available. ResultsThe association between a poorer DBS-response and increased free interstitial fluid showed notable effect sizes (rho > |0.4|) in SN and STN, but not in putamen. However, this did not reach significance after Bonferroni correction and controlling for sex and age. ConclusionMicrostructural integrity of SN and STN are potential biomarkers for the prediction of therapy efficacy following STN-DBS, but further studies are required to confirm these associations.

Nature of Parkinsonian features in multiple system atrophy.

For this observational study, we evaluated the clinical profile of Parkinsonian features in multiple system atrophy (MSA), as there is no clarity about the specifics of these features in this disease compared to progressive supranuclear palsy (PSP) and Parkinson's disease (PD). Here, we selected 57 patients with MSA based on standard criteria and grouped them into two categories - Parkinsonian variant of MSA (MSA-P) and cerebellar variant of MSA (MSA-C). However, researchers did not distinguish among patients based on the nature of extrapyramidal syndrome or levodopa responsiveness. Then, we examined the patients at the time of their first visit to outpatient clinics or indoor wards and recorded and analyzed the specific extrapyramidal features or their variations. The extrapyramidal features including levodopa responsiveness were highly variable among MSA-C as well as MSA-P patients. A subset of patients presented with features resembling PSP (symmetry [56.1%], axial rigidity [52.6%], backward falls [28.1%], and down-gaze restriction [17.5%]), while others presented with features resembling PD (asymmetry [43.9%], tremors [71.9%], and peripheral rigidity [40.4%]). After grouping patients based on predominant extrapyramidal features, 36.8% of patients had PD-like, 19.3% had PSP-like, and 43.9 % had mixed presentation. Moreover, 86% of patients had a perceptible levodopa response, including a sustained response for more than six months in 64% of patients. Extrapyramidal features in MSA patients may be PD-like, PSP-like, or mixed. Moreover, an initial presentation resembling PSP or PD may be deceptive and one must follow it up for MSA.

Monitoring levodopa oxidation and reduction reactions using surface plasmon resonance on a nanohole array electrode

The traditional method of monitoring the oxidation and reduction of biomedical materials usually relies on electrochemical (EC) measurement techniques. Here, we demonstrate a surface plasmon resonance (SPR) method to monitor the oxidation process. Using levodopa L-dopa as the target analyte, a nanohole sensing plate is embedded in the EC electrode to enhance the oxidation signal and generate SPR. Cyclic voltammetry (CV) measurement was first conducted to understand the baseline of EC response of L-Dopa. Then, the redox reactions were simultaneously monitored through SPR measurements during the CV voltage scan. The results showed that the limit of detection using traditional CV reached 1.47 μM while using EC-SPR, the limit of detection improved to 1.23 μM. Most importantly, we found a strong correlation between CV current profiles and the SPR reflection spectra. Our results facilitate detecting electrochemical reactions using an optical probing method.

Bilosomes as Soft Nanovesicular Carriers for Ropinirole Hydrochloride: Preparation and In- vitro Characterization

Bilosomes are nanovesicular carriers that contain bile salts and non-ionic surfactants in a bilayer with cholesterol. These are more ultra-deformable, elastic, and flexible than other nanovesicular carrier.Ropinirole hydrochloride (RH) is a non-ergot dopamine D2-agonist. It is used to manage Parkinson's disease and to minimize "on-off" variations in levodopa responsiveness. The oral bioavailability is about 50% due to it being extensively metabolized in the liver, with an elimination half-life of about 6 h.The aim of this study was to enhance oral drug delivery and provide the sustained release of RH by preparing it as soft nanovesicular carriers (bilosomes).Eight formulas of RH bilosomes were prepared by a reverse-phase evaporation method using mixed surfactant (span®60: tween®60 at 1:2 ratio), cholesterol and sodium deoxycholate as bile salt.All formulas were evaluated for their drug content, entrapment efficiency, vesicle size, polydispersity index, zeta potential, drug release, transmission electron microscopy and fourier transform infrared spectroscopy.Results showed all prepared RH bilosomes were in nano-range with vesicle size ranging (from 124.40±10.60 to 294.60±11.50) nm, Zeta potential ranged (from -16.955±7.372 to -23.22±0.880) mV and with entrapment efficiency % ranged (from 57.30±6.48% to 77.77±3.78%).&#x0D; The best formula F5 showed vesicle size (160.60±15.82) nm, Zeta potential (-20.75±0.930) mV, and entrapment efficiency %(77.77±3.78%) with 84.39% in-vitro release of RH after 24 h.It is concluded that bilosomes are good nanovesicular carriers for enhancing oral drug delivery and providing the sustained release of RH and all that may enhance oral bioavailability for RH.