Injectable PLGA Adefovir microspheres; the way for long term therapy of chronic hepatitis-B

Ayoub, Margrit M.; Elantouny, Neveen G.; El-Nahas, Hanan M.; Ghazy, Fakhr El-Din S.

doi:10.1016/j.ejps.2018.03.016

Cited by 20 publications

(6 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The transformation of lutein from crystalline to amorphous form is important, as amorphous forms are characterized by higher solubilities and increased bioavailability [ 51 , 52 , 53 , 54 ]. Similar results (loss of characteristic peak) were observed in other studies where crystalline drugs such as SN-38, doxorubicin oxcarbazepine, prilocaine, and adefovir were encapsulated into PLGA-based micro- and nanoparticles [ 24 , 25 , 55 , 56 , 57 ].…”

Section: Resultssupporting

confidence: 87%

Lutein-Loaded, Biotin-Decorated Polymeric Nanoparticles Enhance Lutein Uptake in Retinal Cells

et al. 2020

View full text Add to dashboard Cite

Age related macular degeneration (AMD) is one of the leading causes of visual loss and is responsible for approximately 9% of global blindness. It is a progressive eye disorder seen in elderly people (>65 years) mainly affecting the macula. Lutein, a carotenoid, is an antioxidant, and has shown neuroprotective properties in the retina. However, lutein has poor bioavailability owing to poor aqueous solubility. Drug delivery to the posterior segment of the eye is challenging due to the blood–retina barrier. Retinal pigment epithelium (RPE) expresses the sodium-dependent multivitamin transporter (SMVT) transport system which selectively uptakes biotin by active transport. In this study, we aimed to enhance lutein uptake into retinal cells using PLGA–PEG–biotin nanoparticles. Lutein loaded polymeric nanoparticles were prepared using O/W solvent-evaporation method. Particle size and zeta potential (ZP) were determined using Malvern Zetasizer. Other characterizations included differential scanning calorimetry, FTIR, and in-vitro release studies. In-vitro uptake and cytotoxicity studies were conducted in ARPE-19 cells using flow cytometry and confocal microscopy. Lutein was successfully encapsulated into PLGA and PLGA–PEG–biotin nanoparticles (<250 nm) with uniform size distribution and high ZP. The entrapment efficiency of lutein was ≈56% and ≈75% for lutein-loaded PLGA and PLGA–PEG–biotin nanoparticles, respectively. FTIR and DSC confirmed encapsulation of lutein into nanoparticles. Cellular uptake studies in ARPE-19 cells confirmed a higher uptake of lutein with PLGA–PEG–biotin nanoparticles compared to PLGA nanoparticles and lutein alone. In vitro cytotoxicity results confirmed that the nanoparticles were safe, effective, and non-toxic. Findings from this study suggest that lutein-loaded PLGA–PEG–biotin nanoparticles can be potentially used for treatment of AMD for higher lutein uptake.

show abstract

Section: Resultssupporting

confidence: 87%

Lutein-Loaded, Biotin-Decorated Polymeric Nanoparticles Enhance Lutein Uptake in Retinal Cells

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Therefore, characteristics like surface modifications or adjustment of physicochemical properties, and the biodegradation rate of the material are crucial. Several protocols for the preparation and modification of micro- and nano-scale PLGA systems have been established [6], [7], [8], [9], [10]. Depending on the manufacturing method and the operating parameters, the yield of the method and the loading efficiency of nano- and microparticles can vary drastically, influencing the therapeutic use [11], [12].…”

Section: Introductionmentioning

confidence: 99%

Development of a fast and precise method for simultaneous quantification of the PLGA monomers lactic and glycolic acid by HPLC

Pourasghar

Koenneke

Meiers

et al. 2019

Journal of Pharmaceutical Analysis

View full text Add to dashboard Cite

Poly(lactide- co -glycolide acid) (PLGA) is an extraordinary well-described polymer and has excellent pharmaceutical properties like high biocompatibility and good biodegradability. Hence, it is one of the most used materials for drug delivery and biomedical systems, also being present in several US Food and Drug Administration-approved carrier systems and therapeutic devices. For both applications, the quantification of the polymer is inalienable. During the development of a production process, parameters like yield or loading efficacy are essential to be determined. Although PLGA is a well-defined biomaterial, it still lacks a sensitive and convenient quantification approach for PLGA-based systems. Thus, we present a novel method for the fast and precise quantification of PLGA by RP-HPLC. The polymer is hydrolyzed into its monomers, glycolic acid and lactic acid. Afterwards, the monomers are derivatized with the absorption-enhancing molecule 2,4′-dibromoacetophenone. Furthermore, the wavelength of the derivatized monomers is shifted to higher wavelengths, where the used solvents show a lower absorption, increasing the sensitivity and detectability. The developed method has a detection limit of 0.1 µg/mL, enabling the quantification of low amounts of PLGA. By quantifying both monomers separately, information about the PLGA monomer ratio can be also directly obtained, being relevant for degradation behavior. Compared to existing approaches, like gravimetric or nuclear magnetic resonance measurements, which are tedious or expensive, the developed method is fast, ideal for routine screening, and it is selective since no stabilizer or excipient is interfering. Due to the high sensitivity and rapidity of the method, it is suitable for both laboratory and industrial uses.

show abstract

“…In order to relieve the pill burden and toxicity of current treatment methods for hepatitis B, PLGA microspheres were developed by Ayoub et al to release adefovir in a controlled manner for days to weeks. 102 Adefovir-loaded PLGA microspheres were prepared by single emulsion/solvent evaporation, and the effective half-lives of the drug alone and drug released from microspheres were determined to be 62.16 h and 359.10 days, respectively. Additionally, plasma concentration in rats of free drug peaked after the first hour (7.45 μg/mL) and remained constant for 8 h before being effectively reduced to zero after 24 h while the group receiving drug-loaded PLGA microspheres achieved a peak plasma concentration (7.4 μg/mL) after 6 h and then remained relatively steady near 6.5 μg/mL for 15 days.…”

Section: Infectious Diseases Treatmentsmentioning

confidence: 99%

Injectable controlled‐release systems for the prevention and treatment of infectious diseases

Kunkel,

McHugh

2023

J Biomedical Materials Res

View full text Add to dashboard Cite

Pharmaceutical drugs, including vaccines, pre‐ and post‐exposure prophylactics, and chronic drug therapies, are crucial tools in the prevention and treatment of infectious diseases. These drugs have the ability to increase survival and improve patient quality of life; however, infectious diseases still accounted for more than 10.2 million deaths in 2019 before the COVID‐19 pandemic. High mortality can be, in part, attributed to challenges in the availability of adequate drugs and vaccines, limited accessibility, poor drug bioavailability, the high cost of some treatments, and low patient adherence. A majority of these factors are logistical rather than technical challenges, providing an opportunity for existing drugs and vaccines to be improved through formulation. Injectable controlled‐release drug delivery systems are one class of formulations that have the potential to overcome many of these limitations by releasing their contents in a sustained manner to reduce the need for frequent re‐administration and improve clinical outcomes. This review provides an overview of injectable controlled drug delivery platforms, including microparticles, nanoparticles, and injectable gels, detailing recent developments using these systems for single‐injection vaccination, long‐acting prophylaxis, and sustained‐release treatments for infectious disease.

show abstract

Injectable PLGA Adefovir microspheres; the way for long term therapy of chronic hepatitis-B

Cited by 20 publications

References 26 publications

Lutein-Loaded, Biotin-Decorated Polymeric Nanoparticles Enhance Lutein Uptake in Retinal Cells

Lutein-Loaded, Biotin-Decorated Polymeric Nanoparticles Enhance Lutein Uptake in Retinal Cells

Development of a fast and precise method for simultaneous quantification of the PLGA monomers lactic and glycolic acid by HPLC

Injectable controlled‐release systems for the prevention and treatment of infectious diseases

Contact Info

Product

Resources

About