Rotigotine-loaded Microspheres Research Articles

Rotigotine-loaded microspheres exerts the antinociceptive effect via central dopaminergic system

Rotigotine-loaded microspheres (RoMS), a sustained-release formulation with a continuous release of rotigotine for more than 7 days in vivo, have been conducted a clinical trial for the treatment of Parkinson's disease (PD). Previous work from our laboratory showed that RoMS exerted an antinociceptive effect in rat models of inflammatory pain. The purpose of this study was to investigate the mechanisms of action underlying the antinociceptive effect of RoMS. A rat model of inflammatory pain was prepared by an intraplantar injection of carrageenan. The hot plate test and the Randall–Selitto test were used to evaluate the effect of domperidone (selective D2 receptor antagonist), D2D3 shRNA, and naloxone (nonselective opioid receptor antagonist) on RoMS-mediated antinociceptive efficacy. The expressions of D2 and D3 receptors in the striatum and periaqueductal gray were measured by Western blotting. Intracerebroventricular injection of domperidone abated the antinociceptive effect of RoMS. However, intraperitoneal injection of domperidone had no significant effect on the antinociceptive action of RoMS. Intracerebroventricular injection with D2D3 shRNA significantly attenuated the expressions of D2 and D3 receptors in the striatum and the periaqueductal gray. D2 and D3 receptors silence significantly weakened RoMS-mediated antinociceptive effect. Intracerebroventricular injection of naloxone also alleviated the antinociceptive effect of RoMS. The results suggest that RoMS-mediated antinociceptive efficacy is associated with activating central dopamine D2 and D3 receptors. Opioid receptors play a role in the antinociceptive effect of RoMS.

Lipopolysaccharide/D-galactosamine-induced acute liver injury could be attenuated by dopamine receptor agonist rotigotine via regulating NF-κB signaling pathway

The pathological of lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced acute liver injury is similar to what is seen clinically, and be mediated by the release of pro-inflammatory mediators. A growing body of studies have shown that dopamine (DA) and DA receptor agonist are associated with inflammation and immune response. Rotigotine, a non-ergoline dopamine receptor agonist, is a drug for the treatment of Parkinson’s disease. Rotigotine-loaded microspheres (RoMS) is an intramuscular extended-release agent, which can steadily release rotigotine for more than 7 days after a single administration. The present study aimed to investigate the effects of rotigotine and RoMS on inflammation and acute liver injury induced by LPS/D-Gal in mice. The LPS/D-Gal-induced liver injury was evidenced by increases of serum aminotransferases activities and liver histological lesions. Pretreatment with rotigotine or RoMS not only ameliorated the liver histologic lesions, but also reduced the activities of serum aminotransferases and the production of TNF-α. It also showed that rotigotine and RoMS increased DA receptor 2 (DRD2) expression in LPS/D-Gal-exposed mice. Rotigotine and RoMS activated β-arrestin 2, inhibited the phosphorylation of Akt, IκB and the transposition of NF-κB. In line with the above findings, the protective effects of rotigotine and RoMS were abrogated by haloperidol, a DA receptor antagonist. In conclusion, dopamine receptor agonist can regulate NF-κB inflammatory signaling pathway and exert protective effects in LPS/D-Gal-induced liver injury.

Dopamine receptor agonist rotigotine-loaded microspheres ameliorates sexual function deteriorated by fluoxetine in depression rats.

Low dopamine levels may cause depressive symptoms. Dopamine is also involved in sexual behavior. Rotigotine is a nonergolinic dopamine agonist. Fluoxetine, an antidepressant that acts as a selective serotonin (5-HT) reuptake inhibitor, may cause moderate or severe sexual dysfunction. This study aims to investigate the effects of rotigotine-loaded microspheres (RoMS) and rotigotine on fluoxetine-induced impairment of sexual function and their efficacy in depression-model rats. Rats with depressive-like behavior, induced by bilateral olfactory bulbectomy, were treated intragastrically with fluoxetine and co-administered RoMS or rotigotine subcutaneously. Then, copulatory behavior and open field tests were conducted. Serum luteinizing hormone and testosterone levels were assayed with enzyme-linked immunosorbent assay kits. The concentrations of 5-HT, dopamine, and norepinephrine were measured in the raphe nucleus and amygdala. The results showed that sexual function was decreased in olfactory bulbectomy rats and significantly deteriorated by fluoxetine. Co-administration of RoMS partly reversed the fluoxetine-induced impairment of sexual function, but rotigotine administration did not produce any improvement. Hyperactivity in olfactory bulbectomy rats was significantly attenuated by fluoxetine but was not influenced by co-administration of RoMS. Compared with the fluoxetine group, RoMS increased the testosterone, luteinizing hormone, dopamine, and norepinephrine levels. These findings indicated that RoMS improved the fluoxetine-induced impairment of sexual function and did not affect its antidepressant efficacy in depressive rats, which provides a potential treatment for patients with depression that can reduce the possibility of sexual dysfunction. Additionally, co-administration of fluoxetine with RoMS may be beneficial for Parkinson's disease patients with depression.

Antinociceptive effects of rotigotine-loaded microspheres and its synergistic interactions with analgesics in inflammatory pain in rats

Rotigotine-loaded microspheres (RoMS) are sustained-release formulations with prolonged anti-Parkinson's effects. Given that pain is a non-motor symptom of Parkinson's disease, this study investigated the antinociceptive effects of RoMS and their synergistic effects with analgesics on inflammatory pain. A model of inflammatory pain was prepared by intraplantarly injecting male Sprague-Dawley rats with carrageenan. The antinociceptive effects of RoMS, acetaminophen, and tramadol, both alone and in combination, were evaluated using the hind paw withdrawal latency in the hot plate test and Randall–Selitto test. The rotigotine concentrations in serum and tissues were assayed using ultra-performance liquid chromatography–tandem mass spectrometry. Isobolographic analysis was performed to evaluate the nature of the interactions of RoMS with acetaminophen or tramadol. The results showed that hind paw withdrawal latency to thermal and mechanical stimuli was significantly increased on day 3 and 7 after administered RoMS. Rotigotine could be detected in serum and tissues 3 and 7 days after an intramuscular injection of RoMS. However, the rotigotine concentration fell the detection limit of the assay on day 14 after administration. RoMS produced synergistic antinociceptive effects in the inflammatory pain model when RoMS is combined with acetaminophen or tramadol. These findings suggest that RoMS can relieve inflammatory pain in rats. Furthermore, the combination of RoMS with acetaminophen or tramadol produces synergistic antinociception, which may be clinically worthy because combination therapies may reduce the drug doses required for antinociception.

Effects of the rotigotine and venlafaxine on sexual dysfunction and depression in rats

Introduction: Rationale Venlafaxine is a serotonin-norepinephrine reuptake inhibitor (SNRI), differing from the selective serotonin reuptake inhibitors (SSRIs) in that it inhibits the reuptake of both serotonin and norepinephrine. Reportedly, the rates of sexual dysfunction with venlafaxine are lower or similar to those of the SSRIs. Dopamine plays a role in sexual behavior and is related to ejaculation. Objectives: To assess changes in the potential effects of dopamine receptor agonist rotigotine on venlafaxine -induced sexual dysfunction and depression in rats. Methods: The depressive-like rats models induced by olfactory bulbectomy (OB) were intragastrically administered with venlafaxine (40 mg/kg) and co-administered with rotigotine or rotigotine-loaded microspheres (RoMS) at dose of 20 mg/kg. The sex function and anti-depressive effects were observed by copulatory behavior test (CBT) and open field test (OFT) respectively. Result: The olfactory bulbectomy induced sexual dysfunction which significantly deteriorated by venlafaxine administration. Rotigotine could not attenuate the venlafaxine-induced sexual dysfunction, but RoMS could do it partly. The venlafaxine showed anti-depressive efficacy of OB, but the RoMS could not do better. Conclusion: RoMS partly reverses the venlafaxine-induced sexual dysfunction. It may be better that patients with depression are co-administered with venlafaxine and RoMS.

The direct analysis of drug distribution of rotigotine-loaded microspheres from tissue sections by LESA coupled with tandem mass spectrometry.

The direct analysis of drug distribution of rotigotine-loaded microspheres (RoMS) from tissue sections by liquid extraction surface analysis (LESA) coupled with tandem mass spectrometry (MS/MS) was demonstrated. The RoMS distribution in rat tissues assessed by the ambient LESA-MS/MS approach without extensive or tedious sample pretreatment was compared with that obtained by a conventional liquid chromatography tandem mass spectrometry (LC-MS/MS) method in which organ excision and subsequent solvent extraction were commonly employed before analysis. Results obtained from the two were well correlated for a majority of the organs, such as muscle, liver, stomach, and hippocampus. The distribution of RoMS in the brain, however, was found to be mainly focused in the hippocampus and striatum regions as shown by the LESA-imaged profiles. The LESA approach we developed is sensitive enough, with an estimated LLOQ at 0.05ng/mL of rotigotine in brain tissue, and information-rich with minimal sample preparation, suitable, and promising in assisting the development of new drug delivery systems for controlled drug release and protection. Graphical abstract Workflow for the LESA-MS/MS imaging of brain tissue section after intramuscular RoMS administration.

Effect of palmitic acid on the characteristics and release profiles of rotigotine-loaded microspheres

Background: The initial burst release is a major obstacle to the development of microsphere-formulated drug products.Purpose: To investigate the influence of palmitic acid on the characteristics and release profiles of rotigotine-loaded poly(d,l-lactide-co-glycolide) microspheres.Materials and methods: Rotigotine-loaded microspheres (RMS) were prepared using the oil-in-water emulsion solvent evaporation technique. The in vitro characteristics of the RMS were evaluated with scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and a particle size analyzer. The in vitro drug release and in vivo pharmacokinetics of the RMS were investigated.Results and discussion: The SEM results showed that the addition of palmitic acid changed the surface morphology of the microspheres from smooth to dimpled and then to non-smooth as the palmitic acid content increased. DSC revealed the existence of molecularly dispersed forms of palmitic acid in the microspheres. The in vitro and in vivo release profiles indicated that the addition of 5% and 8% palmitic acid significantly decreased the burst release of rotigotine from the microspheres, and the late-stage release was delayed as the palmitic acid content increased across the investigated range (5–15%).Conclusion: The addition of palmitic acid to the microspheres significantly affects the release profile of rotigotine from RMS.

Protection of MPTP-induced neuroinflammation and neurodegeneration by rotigotine-loaded microspheres

AimsThe aim of the study is to evaluate the neuroprotective effects of continuous dopaminergic stimulation (CDS) by rotigotine-loaded microspheres (RoMS) in a mouse model of MPTP-induced Parkinson's disease (PD) and to elucidate the potential mechanism underlying these effects. Main methodsMale C57BL/6 mice were treated either intramuscularly once with RoMS or twice daily for two weeks with rotigotine, and from the 9th day, MPTP (30mg/kg, i.p.) was injected for the last 5days. Following treatment, Parkinsonism scores were calculated and oxidative stress-related indicators in the striatum were performed. Neuroinflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were detected in the striatum. Expression of apoptosis-related proteins B-cell leukemia/lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (BAX) was measured in the striatum by Western blot. Nigral tyrosine hydroxylase (TH)-positive neurons and microglial cell markers, i.e., ionized calcium binding adaptor molecule-1 (Iba-1) and neuronal synaptosomes, were quantified to assess the neuroprotective efficacy of RoMS. Key findingsThe administration of rotigotine significantly improved the Parkinsonism score, protected dopaminergic neurons with antioxidants, reduced microglial cell activation and the release of neuroinflammatory cytokines, and balanced the expression of Bcl-2 and Bax in MPTP-treated mice. Interestingly, the neuroprotective properties of rotigotine were remarkably amplified by CDS treatment with RoMS. SignificanceThese results suggest that CDS therapy can play a neuroprotective role in an MPTP mouse model. Neuroprotective disease-modifying therapy may have the potential benefits of early treatment by normalizing compensatory mechanisms and may also help to delay dyskinesia in the later stages of PD.

Three-month subchronic intramuscular toxicity study of rotigotine-loaded microspheres in SD rats

Continuous dopaminergic stimulation (CDS) has been an important strategy of drug development for the treatment of Parkinson's disease (PD). Rotigotine is a non-ergoline D3/D2/D1 dopamine agonist for treating PD. As a new treatment option for CDS, rotigotine-loaded microspheres (RoMS), a long-acting sustained-release microspheres for injection with poly(lactide-co-glycolide) as drug carrier, are now being evaluated in clinical trial. In this study, subchronic toxicity of RoMS in SD rats has been characterized via intramuscular administration with RoMS (0-240 mg/kg/week) on a consecutive weekly dosing schedule for 3 months followed by 1-month recovery period. The No Observed Adverse Effect Level (NOAEL) was 45 mg/kg/week. One male at 240 mg/kg died from an extensive pulmonary embolism. The major toxicological effects were associated with the dopamine agonist-related pharmacodynamic properties of rotigotine (e.g. hyperactivity and stereotype, enlarged ovary, sporadic gastric mucous membrane lesions, decreased body weight, food consumption and prolactin, and increased mononuclear cell, neutrophil granulocyte, aspartate aminotransferase and alanine aminotransferase) and foreign body removal reaction induced by poly(lactide-co-glycolide) and carboxymethycellulose sodium. At the end of recovery period, all findings had recovered to a normal level or to a certain degree except foreign body reaction at injection sites. RoMS has exhibited high safety on SD rats.

Three-month subchronic intramuscular toxicity study of rotigotine-loaded microspheres in Cynomolgus monkeys

Continuous dopaminergic stimulation (CDS) is an important drug development strategy in the treatment of Parkinson’s disease (PD). Rotigotine is a non-ergoline D3/D2/D1 dopamine receptor agonist for treating PD. As a new treatment option for CDS, rotigotine-loaded microspheres (RoMS), long-acting sustained-release microspheres with poly(lactide-co-glycolide) as drug carrier, are now being evaluated in clinical trial. In the present study, the subchronic toxicity in Cynomolgus monkeys has been characterized via intramuscular administration with RoMS at 0, 10, 40 and 160mg/kg, weekly for 3months with a 1-month recovery period. The NOAEL was 10mg/kg/week. One male at 160mg/kg died from an extensive pulmonary embolism. The major toxicological effects were associated with dopamine agonist-related pharmacodynamic properties of rotigotine (e.g., hyperactivity and stereotype, decreased serum prolactin level) and foreign body removal reaction induced by poly(lactide-co-glycolide) and carboxymethycellulose sodium (e.g., increased mononuclear cells and neutrophils, thymus atrophy and vacuolar degeneration of adrenal cortex, foreign body granuloma with foam cells accumulation at injection sites and foam cells accumulation in spleen and multiple lymph sinuses). At the end of recovery period, above findings recovered to a normal level or to a certain degree except vacuolar degeneration of adrenal gland. RoMS has exhibited high safety on monkeys.

Preparation of Rotigotine-Loaded Microspheres and Their Combination Use with L-DOPA to Modify Dyskinesias in 6-OHDA-Lesioned Rats

To prepare rotigotine loaded microspheres (RoMS) to achieve continuous dopaminergic stimulation (CDS) for the treatment of Parkinson's disease (PD) and investigate both the therapeutic benefit and inducibility of AIMs of administration of RoMS combination with L-DOPA in 6-OHDA-leisioned rats. Rotigotine was encapsulated into poly(lactic-co-glycolic acid) (PLGA) microspheres by an oil-in-water emulsion solvent evaporation technique. In vitro characteristics and in vivo pharmacokinetics of RoMS either in rat blood or brain (by microdialysis) were investigated. Contraversive rotations and AIMs were observed to investigate the therapeutic benefit and the propensity to induce dyskinesia of RoMS or RoMS combination with L-DOPA in 6-OHDA-lesioned rats. RoMS displayed continuous-release characteristics of rotigotine in animals and exhibited a steady efficacy lasted for 2weeks in 6-OHDA-lesioned rats. No significant difference of the therapeutic benefit between the treatment of RoMS and pulsatile L-DOPA combination and mono L-DOPA was found. While the dyskinesia was significantly decreased with the treatment of RoMS and pulsatile L-DOPA combination compared to mono L-DOPA. RoMS could supply an alternative of CDS for the treatment of PD and the study indicates a potential advantage of RoMS for the treatment of mild and advanced PD patient in combination with L-DOPA.