Potential of microemulsified entacapone drug delivery systems in the management of acute Parkinson's disease

Nanotechnology-driven Microemulsion Based Intranasal Delivery to Neurotechnology-driven Neuralink: Strategies to Improve Management of Neurodegenerative Disorders

Neurodegenerative disorder refers to malfunctioning of neurons their degradation leading to death of neurons. Among various neurodegenerative disorders APHD (Alzheimer's, Parkinson's, and Huntington's Disease) are particularly concerning due to their progressive and debilitating nature. The therapeutic agent used for treatment and management of APHD often show unsatisfactory clinical outcome owing to poor solubility and limited permeability across blood brain barrier (BBB). The nose-to brain delivery can overcome this BBB challenge as it can transport drug directly to brain though olfactory pathways bypassing BBB. Additionally, the nanotechnology has emerged as a cutting-edge methodology to address this issue and specifically mucoadhesive micro/nanoemulsion can improve the overall performance of the drug when administered intranasally. Beyond the therapy neurotechnology has emerged as are revolutionary AI-driven BCI (Brain computer interface) aimed to restore independence in patients with function loss due to neuron degeneration/death. A promising BCI Neuralink has been recently explored for clinical trials and results revealed that a quadriplegia bearing person with implanted Neuralink chip was able to perform few normal functions of daily routine such as playing online games, text messaging, reading, and learning foreign languages online through accessing the particular websites. This review will discuss the fundamental concepts of neurodegeneration, application of micro/nanoemulsion through intranasal route and integration of neurotechnology for the management and treatment of APHD.

Biomaterials in the treatment of Parkinson's disease

Parkinson's disease is a neurodegenerative disease, the treatment of which is mainly centred around supplementation of dopamine. Additional targets have been identified and newer chemotherapeutic agents have been introduced but their clinical efficacy is limited due to solubility, bioavailability issues and inability to cross the blood-brain barrier (BBB). A wide range of biomaterials ranging from biomolecules, polymers, inorganic metal and metal oxide nanoparticles have been employed to assist the delivery of these therapeutic agents into the brain. Additionally, strategies to deliver cells to restore the dopaminergic neurons also have shown promise due to the integration of biocompatible materials that aid neurogenesis through a combination of topographical, chemical and mechanical cues. Neuroprosthetics is an area that may become significant in treatment of motor deficits associated with Parkinson's disease, and involves development of highly conductive and robust electrode materials with excellent cytocompatibility. This review summarizes the major role played by biomaterials in design of novel strategies and in the improvement of existing therapeutic methods as well as the emerging trends in this domain.

Biopharmaceutical Potential of Selegiline Loaded Chitosan Nanoparticles in the Management of Parkinson's Disease

BACKGROUND

Selegiline hydrochloride, a hydrophilic anti-Parkinson' moiety, undergoes extensive first-pass metabolism and has low bioavailability. A process to obtain of selegiline (SH) loaded chitosan nanoparticles was attempted to circumvent the above problem, through intranasal delivery.

METHODS

SH loaded polymeric nanoparticles were prepared by ionic gelation of chitosan with tripolyphosphate, and stabilized by tween 80/ poloxamer 188. The resulting nanoparticles (NPs) were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, entrapment efficiency, particle size, zeta potential and surface morphology by scanning electron microscopy. Further, they were schematically evaluated for mucoadhesive strength, in-vitro drug release, release kinetics, pharmacokinetics, catalepsy, akinesia, in-vivo lipid peroxidation, nitrite levels, glutathione, catalase enzyme levels in brain and physicochemical stability parameters.

RESULTS

Selegiline nanoparticles (SP18) produced were in size of 63.1 nm, polydispersity index of 0.201, zeta potential of +35.2 mV, mucoadhesion of 65.4% and entrapment efficiency of 74.77%. Selegiline showed biphasic release from nanoparticles, over a period of 36 h, with Fickian diffusion controlled release profile. Maximum concentration of SH in plasma was recognized as 52.71 ng/ml at 2 h for SP18, 20.09 ng/ml at 1 h for marketed formulation, and 21.69 ng/ ml for drug solution. SH loaded NPs showed a reversive effect in catalepsy and akinesia behaviour. This effect was especially pronounced in rats receiving SH loaded CS-NPs. Significant decrease in lipid peroxidation and nitrite concentration; increase in reduced glutathione and catalase enzyme levels were obtained due to antioxidant characteristics of SH, which turned to be useful to treat Parkinson's disease.

CONCLUSION

Selegiline loaded chitosan nanoparticles form an effective non-invasive drug delivery system of direct nose to brain targeting in Parkinson's disease.

Brain targeting stealth lipomers of combined antiepileptic-anti-inflammatory drugs as alternative therapy for conventional anti-Parkinson's

This study presents an alternative therapy to conventional anti-Parkinson's treatment strategies; where motor and non-motor symptomatic complications are considered. Thus; providing sustainability, patient compliance, therapeutic safety and efficiency, based on triggering secretion of endogenous dopamine (DA). Exogenous DA has long been considered the best therapy, however, its poor blood brain barrier (BBB) permeability, fluctuated plasma levels, and non-motor complications negligence, decreased response to therapy with time. Consequently; brain targeting Tween®80-coated pegylated lipomers were tailored for intravenous administration (IV) of L-Dopa, and two drugs of reported neuroprotective effect: lamotrigine (LTG) and tenoxicam (TX). Single-step nanoprecipitation method was used; for its reproducibility and ease of scaling-up. Formulation targeting and anti-PD efficiency was evaluated against marketed standards and L-Dopa. In-vitro and in-vivo pharmacokinetic and dynamic studies were carried out for setting optimization standards upon varying inter-components ratio. Results revealed that lipomers are, generally, significantly efficient in brain targeting compared to oral tablets. LTG-lipomers (LF20) showed the maximum anti-PD compared to its TX and L-Dopa analogues. Combining LTG and TX had synergistic effect; highlighting a new prescription for both drugs. Thus; offering a safe, targeted, and therapeutically efficient sustained dosage form, capable of mitigating PD risk and treating it though weekly administration. Hence; presenting a novel promising anti-neurodegenerative strategy; on employing various mechanisms that were previously achieved through additional therapeutic supplements.

Metal Chelation Therapy and Parkinson's Disease: A Critical Review on the Thermodynamics of Complex Formation between Relevant Metal Ions and Promising or Established Drugs

The present review reports a list of approximately 800 compounds which have been used, tested or proposed for Parkinson's disease (PD) therapy in the year range 2014-2019 (April): name(s), chemical structure and references are given. Among these compounds, approximately 250 have possible or established metal-chelating properties towards Cu(II), Cu(I), Fe(III), Fe(II), Mn(II), and Zn(II), which are considered to be involved in metal dyshomeostasis during PD. Speciation information regarding the complexes formed by these ions and the 250 compounds has been collected or, if not experimentally available, has been estimated from similar molecules. Stoichiometries and stability constants of the complexes have been reported; values of the cologarithm of the concentration of free metal ion at equilibrium (pM), and of the dissociation constant Kd (both computed at pH = 7.4 and at total metal and ligand concentrations of 10-6 and 10-5 mol/L, respectively), charge and stoichiometry of the most abundant metal-ligand complexes existing at physiological conditions, have been obtained. A rigorous definition of the reported amounts is given, the possible usefulness of this data is described, and the need to characterize the metal-ligand speciation of PD drugs is underlined.

In vitro characterization studies of self-microemulsified bosentan systems

CONTEXT

Bosentan is a poorly soluble drug and pose challenges in designing of drug delivery systems.

OBJECTIVE

The objective of this study is to enhance the solubility, dissolution and shelf-life of bosentan by formulating it as S-SMEDDS capsules.

MATERIALS AND METHODS

Solubility of bosentan was tested in various liquid vehicles such as oils (rice bran and sunflower), surfactants (span 20 and tween 80) and co-surfactants (PEG 400 and propylene glycol) and microemulsions were developed. Bosentan was incorporated into appropriate microemulsion systems which were previously identified from pseudo ternary phase diagrams. Bosentan-loaded SMEDDS were evaluated for drug content, drug release, zeta potential, and droplet size. The selected liquid SMEDDS were converted into solid SMEDDS by employing adsorption and melt granulation. Solid SMEDDS were characterized for micromeritics and evaluated for drug content, drug release, and shelf-life.

RESULTS

Isotropic systems R5, R13, S5, and S13 with submicron droplet size had exhibited 85.45, 94.12, 81.67, and 96.64% drug release, respectively. Solid SMEDDS of MR13 and AS13 formulations with rapid reconstitution ability, exhibited 84.85 and 86.74% of on par drug release. The formulations were physicochemically intact for 1.02 and 1.56 years.

DISCUSSION

Liquid SMEDDS composed with PEG400 had displayed optimal characters. Solid SMEDDS had high-dissolution profiles than bosentan due to modification in the crystalline structure of drug upon microemulsification.

CONCLUSION

Thus, solid SMEDDS addressed the solubility, dissolution, and stability issues of bosentan and becomes an alternate for clinical convenience.