罗替戈汀透皮贴剂的研究进展

罗替戈汀为选择性多巴胺D1/D2/D3受体激动剂,其透皮贴剂是第一个非麦角类多巴胺受体激动剂贴剂。罗替戈汀贴剂24h有效,能对帕金森病人持续提供多巴胺能刺激,目前获得FDA和EMA批准上市。对罗替戈汀贴剂研究情况进行简要综述。     

Safinamide for the treatment of Parkinson’s disease

Parkinson’s disease (PD) is a neurodegenerative disease caused by a complex interaction of loss of dopaminergic and non-dopaminergic neurotransmitter systems. Drugs acting on the dopaminergic pathways are the mainstay of treatment for motor symptoms today. Safinamide (NW-1015) is a novel drug with multiple actions. It is a monoamine oxidase B inhibitor and improves dopaminergic transmission. In addition, it has antiglutamatergic effects and can thus reduce dyskinesias, which is a side effect limiting most dopaminergic therapy. In Phase III trials, safinamide has been found to be a useful adjunctive to dopamine agonists in early PD and has been shown to increase time without increasing troublesome dyskinesias when used as an adjunct to levodopa in patients with advanced PD. A possible neuroprotective role in inhibiting PD disease progression is envisaged and warrants future studies.     

Recent trends in the transdermal delivery of therapeutic agents used for the management of neurodegenerative diseases

With the increasing proportion of the global geriatric population, it becomes obvious that neurodegenerative diseases will become more widespread. From an epidemiological standpoint, it is necessary to develop new therapeutic agents for the management of Alzheimer’s disease, Parkinson’s disease, multiple sclerosis and other neurodegenerative disorders. An important approach in this regard involves the use of the transdermal route. With transdermal drug delivery systems (TDDS), it is possible to modulate the pharmacokinetic profiles of these medications and improve patient compliance. Transdermal drug delivery has also been shown to be useful for drugs with short half-life and low or unpredictable bioavailability. In this review, several transdermal drug delivery enhancement technologies are being discussed in relation to the delivery of medications used for the management of neurodegenerative disorders.     

Pharmacokinetics and safety of single and multiple doses of rasagiline in healthy Japanese and caucasian subjects

As of March 2018, rasagiline is approved for the treatment of Parkinson disease in 55 countries including Japan. The present study evaluated the pharmacokinetics (PK) and safety of rasagiline in healthy Japanese and Caucasian subjects following single and multiple administrations of three rasagiline doses. In this double‐blind, placebo‐controlled study, 64 healthy subjects (32 Japanese and 32 Caucasian) received either rasagiline (0.5, 1.0, or 2.0 mg) or placebo for 10 days with PK sampling for single‐dose administration on day 1 and for multiple administration on day 10. Regardless of administration schedule, rasagiline plasma concentrations and dose‐related increases in exposure parameters were similar between Japanese and Caucasians. Rasagiline accumulation (2‐fold for 0.5 mg and 3‐fold for 1.0 mg and 2.0 mg doses) following multiple administration was similar across the ethnic groups. Geometric mean ratios (GMR) comparing Japanese to Caucasians for AUC_0‐24, C_max and AUC_inf following single administration were 1.38, 1.17 and 1.38 for 0.5 mg; 1.22, 1.20 and 1.22 at 1.0 mg; and 1.02, 1.00 and 1.02 at for 2.0 mg. GMR for AUC_tau and C_max,ss following multiple administration were 1.43 and 1.06 at 0.5 mg, 1.06 and 1.00 at 1.0 mg, and 1.09 and 1.07 at 2.0 mg. Safety measures were unremarkable and similar between Caucasian and Japanese subjects. Comparable systemic exposure and safety parameters were demonstrated for rasagiline administered to healthy Japanese and Caucasian subjects.     

A validated chiral liquid chromatographic method for the enantiomeric separation of safinamide mesilate, a new anti-Parkinson drug

A enantioselective reversed-phase high performance liquid chromatographic method was developed for the enantiomeric resolution of safinamide mesilate, 2(S)-[4-(3-fluorobenzyloxy)benzylamino] propionamide methanesulfonate, a neuroprotectant with antiparkinsonian and anticonvulsant activity for the treatment of Parkinson disease. The enantiomers of safinamide mesilate were baseline resolved on a Chiralcel OD-RH (150mm×4.6mm, 5μm) column using a mobile phase system containing 300mM sodium di-hydrogen phosphate buffer (pH 3.0):methanol:acetonitrile (65:25:10, v/v/v). The resolution between the enantiomers was not less than 3.0. The pH value of buffer solution in the mobile phase has played a key role in enhancing chromatographic efficiency and resolution between the enantiomers. The developed method was validated and proved to be robust. The limit of detection and limit of quantification of (R)-enantiomer were found to be 15 and 50ng/mL, respectively, for 20μL injection volume. The percentage recovery of (R)-enantiomer was ranged from 94.2 to 103.7 in bulk drug samples of safinamide mesilate. The sample solution and mobile phase were found to be stable at least for 48h. The final optimized method was successfully applied to separate (R)-enantiomer from safinamide mesilate and was proven to be reproducible and accurate for the quantitative determination of (R)-enantiomer in bulk drugs.     

Comparative pharmacokinetics of a marker compound,baicalin in KOB extract after oral administration to normal and allergic-induced rats

Abstract

KOB extracts are a polyherbal medicine had been prescribed for the treatment of hyperhydrosis and allergic diseases such as allergic asthma and rhinitis in oriental clinics. Therefore, the pharmacokinetic studies of the KOB extract administered orally to normal rats and rhinitis-induced rats to understand the correlation of the efficacy and plasma concentration of KOB in patients of allergic rhinitis in future were performed. The study was conducted according to administration for pure baicalin in normal rats, baicalin in KOB extract in normal rats and rhinitis-induced rats. Baicalin in rat plasma was analyzed and validated by HPLC analysis. The interday precision based on the standard deviation of replicates of quality control samples ranged from 3.6% to 7.9% with accuracy ranging from 92.9% to 101.2% for baicalin. Based on validated analysis, pharmacokinetic study was carried out. Pure baicalin in normal rats and baicalin in KOB extract in normal rats showed bimodal curves due to direct absorption and glucuronidation. The T_max, C_max and AUC of pure baicalin in normal rats or baicalin in KOB extract in normal rats were 12?h, 0.68?µg/ml and 9.85?µg?h/ml, respectively, or 12?h, 0.46?µg/ml and 6.36?µg?h/ml, respectively. The analytical method showed excellent sensitivity, precision and accuracy, being successfully employed in a pharmacokinetic study of polyherbal medicine, KOB extract. Allergic-induced condition did not affect the pharmacokinetics of KOB extracts, suggesting KOB extracts did not require dosage adjustment in subjects with allergic-induced diseases.     

The pharmacokinetics of acebvutolol in man,following the oral administration of acebutolol hcl as a single dose (400 mg), and during and after repeated oral dosing (400 mg,b.d.)

The pharmacokinetics of acebutolol have been studied in eight healthy male volunteers following the oral administration of acebutolol hydrochloride (‘Sectral’, May & Baker) as a single dose (400 mg), and during and after repeated oral dosing (400 mg, b.d. for 56 days). Following single dose administration, considerable inter-subject variation in plasma levels of parent drug and the major metabolite, diacetolol. was evident. Acebutolol appeared to be eliminated from plasma in a bi-phasic manner, and this was confirmed from urinary excretion rate data. Mean initial and terminal half-lives of about 2 and 11 h, respectively, were determined. Plasma levels of diacetolol were greater than those of parent drug from 3 to 4 h following dose administration. Total urinary excretion of diacetolol was generally greater than that of acebutolol. During repeated dosing, steady-state plasma levels of acebutolol and diacetolol were achieved in 6 volunteers. Acebutolol did not appear to stimulate or inhibit its metabolism.     

Species differences between rats and primates (humans and monkeys) in complex cleavage pathways of DS-8500a characterized by 14C-ADME studies in humans and monkeys after administration of two radiolabeled compounds and in vitro studies

Our previous study in rats demonstrated that the metabolic pathways of DS-8500a, a novel GPR119 agonist, include cleavage pathways: reductive cleavage of the oxadiazole ring in the liver and hydrolysis of the amide side chain. In the present study, in vivo metabolic profiling in humans and monkeys after the oral administration of two ¹⁴C-labeled compounds was performed to investigate species differences of the cleavage pathways. In monkeys, the oxadiazole ring-cleaved metabolites were mainly detected in feces, but not observed in bile, unlike in rats, suggesting that the reductive ring-opening metabolism occurs in the gastrointestinal tract. In vitro incubation with enterobacterial culture media demonstrated that the reductive cleavage of the oxadiazole ring in humans and monkeys was considerably faster than that in rats. The other cleavage metabolite (M20), produced via hydrolysis of the amide side chain, was detected as the major plasma metabolite in humans and monkeys, and its subsequent metabolite (M21) was excreted in feces, whereas M21 was not a major component in rats, indicating a notable species difference in the amide hydrolysis. In conclusion, this study comprehensively revealed the pronounced species difference of the cleavage pathways: reductive ring-opening by intestinal microflora and liver, and amide hydrolysis.     

Prophylactic neuroprotective efficiency of co-administration of Ginkgo biloba and Trifolium pretense against sodium arsenite-induced neurotoxicity and dementia in different regions of brain and spinal cord of rats

The present study was carried out to evaluate the potential protective role of co-administration of Ginkgo biloba, Trifolium pretenseagainst sodium arsenite-induced neurotoxicity in different parts of brain (Cerebral cortex, Hippocampus, striatum and Hind brain) and in the spinal cord of rats. Sodium arsenite caused impairment in the acquisition and learning in all the behavioral tasks and caused significant increase in tumor necrosis factor-α,thiobarbituric acid-reactive substances andlipid profile, while caused significant decrease in glutathione, total thiol content, total antioxidant capacity, acetylcholinesterase, monoamine oxidase and ATPases activities. These results were confirmed by histopathological, fluorescence and scanning electron microscopy examination of different regions of brain. From these results sodium arsenite-induced neurodegenerative disorder in different regions of brain and spinal cord and this could be mediated through modifying the intracellular brain ions homeostasis, cholinergic dysfunction and oxidative damage. The presence of Ginkgo biloba and/orTrifolium pretense with sodium arsenite minimized its neurological damages. It was pronounced that using Ginkgo biloba and Trifolium pretense in combination was more effective as protective agents compared to use eachone of them alone.     

Targeting autophagy using small-molecule compounds to improve potential therapy of Parkinson's disease

Parkinson's disease (PD), known as one of the most universal neurodegenerative diseases, is a serious threat to the health of the elderly. The current treatment has been demonstrated to relieve symptoms, and the discovery of new small-molecule compounds has been regarded as a promising strategy. Of note, the homeostasis of the autolysosome pathway (ALP) is closely associated with PD, and impaired autophagy may cause the death of neurons and thereby accelerating the progress of PD. Thus, pharmacological targeting autophagy with small-molecule compounds has been drawn a rising attention so far. In this review, we focus on summarizing several autophagy-associated targets, such as AMPK, mTORC1, ULK1, IMPase, LRRK2, beclin-1, TFEB, GCase, ERRα, C-Abelson, and as well as their relevant small-molecule compounds in PD models, which will shed light on a clue on exploiting more potential targeted small-molecule drugs tracking PD treatment in the near future.