Sustained release of risperidone from biodegradable microspheres prepared by in-situ suspension-evaporation process

Innovative centrifugal microfluidic approach for risperidone-loaded PLGA microsphere production

This paper proposes a novel and efficient centrifugal microfluidic technology to prepare risperidone-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres (RIS-MS). The effects of key parameters, including PLGA concentration and type, microchannel inner diameter and centrifugal speed on particle size, morphology and drug release were evaluated and optimized. The in vivo pharmacokinetic study of RIS-MS was conducted in rabbits. The results demonstrated that RIS-MS could be produced from microchannels with inner diameters of 170-210 μm at a centrifugal speed of 400 revolutions per minute (rpm) when the PLGA content is 15 % or higher. The mean plasma concentration of RIS-MS was more stable and Cmax of RIS-MS was significantly lower than that of the suspension group, and the RIS-MS could maintain the release of RIS in rabbits for up to 42 days. This study provided pioneering ideas for developing microspheres using centrifugal microfluidic technology. The optimized RIS-MS can make excellent sustained release and have the potential for the long-acting therapy of schizophrenia.

A dataset on formulation parameters and characteristics of drug-loaded PLGA microparticles

Polymer microparticles (MPs) are widely used to create long-acting injectable formulations due to their ability to enable sustained drug release. This feature can significantly benefit chronic disease management by reducing dosing frequency and improving patient adherence. To support the design and development of polymer MPs, we have compiled a dataset on MPs formed from poly(lactide-co-glycolide) (PLGA), the most commonly used polymer in commercial MP drug products. This dataset, derived from the literature, covers 321 in vitro release studies involving 89 different drugs. It aims to streamline future MP development by providing a reference for the current PLGA MP design space and supporting data-driven approaches such as machine learning. Published with open access, this dataset encourages broad utilization and aims to expand the range of available MP formulations.

Quantification of Microsphere Drug Release by Fluorescence Imaging with the FRET System

Accurately measuring drug and its release kinetics in both in vitro and in vivo environments is crucial for enhancing therapeutic effectiveness while minimizing potential side effects. Nevertheless, the real-time visualization of drug release from microspheres to monitor potential overdoses remains a challenge. The primary objective of this investigation was to employ fluorescence imaging for the real-time monitoring of drug release from microspheres in vitro, thereby simplifying the laborious analysis associated with the detection of drug release. Two distinct varieties of microspheres were fabricated, each encapsulating different drugs within PLGA polymers. Cy5 was selected as the donor, and Cy7 was selected as the acceptor for visualization and quantification of the facilitated microsphere drug release through the application of the fluorescence resonance energy transfer (FRET) principle. The findings from the in vitro experiments indicate a correlation between the FRET fluorescence alterations and the drug release profiles of the microspheres.

Engineered PLGA microspheres for extended release of brexpiprazole: in vitro and in vivo studies

OBJECTIVE

To develop poly(d,l-lactide-co-glycolide) (PLGA) microspheres to achieve controlled and sustained release of brexpiprazole in vivo.

METHODS

Brexpiprazole microspheres were prepared by oil-in-water emulsion-solvent evaporation method and evaluated for morphology, particle size, encapsulation efficiency, drug loading, conformation and compatibility of drug and polymer, in vitro release, and in vivo pharmacokinetics. By establishing the relationship between in vitro and in vivo release, it helps identify the appropriate in vitro release conditions to explore release profiles of brexpiprazole microspheres.

RESULTS

Porous PLGA microspheres with near spherical morphology were obtained displaying an average diameter of 20.43 ± 0.06 μm, a drug loading capacity of 27.24 ± 0.33% and an encapsulation efficiency of 81.87 ± 1.07%. Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC) analysis showed that some drugs encapsulated in the microspheres remained in the amorphous state and some were in the crystalline state. Different release setups resulted in different release kinetics. The dialysis release setup displayed a cumulative release of about 65% within 60 days, while the sample-and-separate setup showed a cumulative release of about 77% within 35 days. Per pharmacokinetic studies in rats, a burst phase in the plasma concentration-time curve was observed after intramuscular injection in the first 2 h followed by a clear zero-order release phase. Overall, brexpiprazole achieved in vivo sustained release from PLGA microspheres for up to 40 days.

CONCLUSION

A PLGA microsphere loaded with brexpiprazole was successfully developed and demonstrated potential for extended-release of therapeutics for schizophrenia treatment.

Artesunate-loaded poly (lactic-co-glycolic acid)/polydopamine-manganese oxides nanoparticles as an oxidase mimic for tumor chemo-catalytic therapy

Conventional tumor chemotherapy is limited by its low therapeutic efficacy and side effects, which severely hold back its further application as a first-line agent in clinic. To improve the cure efficacy of cancer, nanozyme with enzyme-like activity has now been extensively investigated as a new strategy for tumor treatment. Herein, an anti-tumor platform based on manganese oxides (MnOx) modified poly (lactic-co-glycolic acid) (PLGA)@polydopamine (PDA) nanoparticles (PP-MnOx NPs) as an oxidase mimic was developed. PP-MnOx NPs could not only produce abundant reactive oxygen species to inhibit tumor growth taking advantage of their oxidase-like activity, but also encapsulate and release antitumor drug (artesunate) to function as chemotherapy, achieving remarkable synergistic chemo-catalytic therapeutic effects. As an oxidase mimics, PP-MnOx NPs induced the decrease of mitochondrial membrane potential, down-regulation of Bcl-2, as well as activation of Bax and Caspase-3, demonstrating that the apoptosis triggered by PP-MnOx NPs was mediated via mitochondrial pathways. Importantly, the artesunate in PP-MnOx NPs further promoted this apoptosis. In addition, Mn ions released from PP-MnOx NPs facilitated the tumor-microenvironment-specific T1-weighted magnetic resonance imaging. Taken together, this study well clarifies the antitumor mechanism of artesunate-loaded PP-MnOx NPs and offer a synergistic chemo-catalytic strategy for tumor theranostics.

An Update on the Routes for the Delivery of Donepezil

Dementia is a significant public health problem in the 21st century. Alzheimer's disease (AD) is an essential factor in dementia. Currently, the drugs used for the treatment of AD are mainly acetylcholine inhibitors (AChEIs). As an AChEI, donepezil (DP) can improve patients' cognitive ability with low side effects and has been accepted by most patients and doctors. For AD patients, the dosage regimen is also crucial due to aging and diseases. Although there are DP oral tablets on the market, there are still many problems to be solved. At present, more and more research is conducted to optimize the route of administration of DP to improve the self-administration of patients. The research fields of DP administration include oral administration, injection administration, intranasal administration, and transdermal administration. This Review is to present the development of different DP administrations and evaluates the advantages and limitations of those works, hoping to optimize the DP dosage regimen for AD patients.

Polymeric microparticle systems for modified release of glucagon-like-peptide-1 receptor agonists

Type 2 diabetes is a fast-growing worldwide epidemic. Despite the multiple therapies available to treat type 2 diabetes, the disease is not correctly managed in over half of patients, mainly due to non-compliance with prescribed treatment regimes. The development of analogues to the glucagon-like peptide 1 (GLP-1) has resulted in the extension of its half-life and associated benefits. Further benefits in the use of peptide-based GLP-1 receptor agonists have been achieved by the use of controlled-release systems based on polymeric microparticles. In this review, we focus on commercially available formulations and others that remain in development, discussing the preparation methods and the relationship between in vitro and in vivo kinetic release behaviours.

Clinically established biodegradable long acting injectables: An industry perspective

Long acting injectable formulations have been developed to sustain the action of drugs in the body over desired periods of time. These delivery platforms have been utilized for both systemic and local drug delivery applications. This review gives an overview of long acting injectable systems that are currently in clinical use. These products are categorized in three different groups: biodegradable polymeric systems, including microparticles and implants; micro and nanocrystal suspensions and oil-based formulations. Furthermore, the applications of these drug delivery platforms for the management of various chronic diseases are summarized. Finally, this review addresses industrial challenges regarding the development of long acting injectable formulations.

Phenomenology of the Initial Burst Release of Drugs from PLGA Microparticles

Poly(lactic-co-glycolic acid) (PLGA) is the most prevalent polymer drug delivery vehicle in use today. There are about 20 commercialized drug products in which PLGA is used as an excipient. In more than half of these formulations, PLGA is used in the form of microparticles (with sizes in the range between 60 nm and 100 μm). The primary role of PLGA is to control the kinetics of drug release toward achieving sustained release of the drug. Unfortunately, most drug-loaded PLGA microparticles exhibit a common drawback: an initial uncontrolled burst of the drug. After 30 years of utilization of PLGA in controlled drug delivery systems, this initial burst drug release still remains an unresolved challenge. In this Review, we present a summary of the proposed mechanisms responsible for this phenomenon and the known factors affecting the burst release process. Also, we discuss examples of recent efforts made to reduce the initial burst release of the drug from PLGA particles.

Schizophrenia; A Review on Promising Drug Delivery Systems

Background:

Schizophrenia belongs to mental illnesses affecting 1% of the worldwide population. Its therapy is still unmet; thus, researchers aimed to develop new pharmacological molecules which can improve its management.

Methods:

Moreover, the current typical and atypical antipsychotics should be formulated in more efficacious systems that can deliver the drug in the brain with as few side effects as possible. Further, the development of long-acting efficient drug delivery systems could be significant in minimizing frequent dosing which is nonpreferred to schizophrenics.

Results:

Herein, authors focused on current developments of antipsychotic medications used in schizophrenia management. Various studies, which include the use of first and second-generation antipsychotics, were analyzed according to their efficacy. In fact, in this review, oral, injectable, transdermal and intranasal formulations entrapped antipsychotics are presented to be valuable guidance for scientists to formulate more effective drug delivery systems for schizophrenic patients.

Conclusions:

This review aimed to assist researchers working on schizophrenia management by summarizing current medications and newly synthesized drug delivery systems recently found in the literature.

Quality by design thinking in the development of long-acting injectable PLGA/PLA-based microspheres for peptide and protein drug delivery

Adopting the Quality by Design (QbD) approach in the drug development process has transformed from "nice-to-do" into a crucial and required part of the development, ensuring the quality of pharmaceutical products throughout their whole life cycles. This review is discussing the implementation of the QbD thinking into the production of long-acting injectable (LAI) PLGA/PLA-based microspheres for the therapeutic peptide and protein drug delivery. Various key elements of the QbD approaches are initially elaborated using Bydureon®, a commercial product of LAI PLGA/PLA-based microspheres, as a classical example. Subsequently, the factors influencing the release patterns and the stability of the peptide and protein drugs are discussed. This is followed by a summary of the state-of-the-art of manufacturing LAI PLGA/PLA-based microspheres and the related critical process parameters (CPPs). Finally, a landscape of generic product development of LAI PLGA/PLA-based microspheres is reviewed including some major challenges in the field.