Polyacrylamide microbeads, a sustained release drug delivery system

El-Samaligy, Mohamed S.; Rohdewald, Peter

doi:10.1016/0378-5173(82)90139-9

Cited by 11 publications

(3 citation statements)

References 10 publications

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“…A major contributor to the presence of elastomers in the marine environment being tyre wear particles, with the majority of emission coming from road side run‐off (Wagner et al, ). Polyacrylamide microbeads described in our Pacific samples have been used in the past in drug delivery (El‐Samaligy & Rohdewald, ) and more recently for a number of biomedical applications such as encapsulation (Labriola, Mathiowitz, & Darling, ). Alternatively, these could originate from exfoliating agents in cosmetic products (Napper et al, ).…”

Section: Discussionmentioning

confidence: 99%

Microplastic ingestion ubiquitous in marine turtles

Duncan

Broderick

Fuller

et al. 2018

Global Change Biology

221

100

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Despite concerns regarding the environmental impacts of microplastics, knowledge of the incidence and levels of synthetic particles in large marine vertebrates is lacking. Here, we utilize an optimized enzymatic digestion methodology, previously developed for zooplankton, to explore whether synthetic particles could be isolated from marine turtle ingesta. We report the presence of synthetic particles in every turtle subjected to investigation (n = 102) which included individuals from all seven species of marine turtle, sampled from three ocean basins (Atlantic [ATL]: n = 30, four species; Mediterranean (MED): n = 56, two species; Pacific (PAC): n = 16, five species). Most particles (n = 811) were fibres (ATL: 77.1% MED: 85.3% PAC: 64.8%) with blue and black being the dominant colours. In lesser quantities were fragments (ATL: 22.9%: MED: 14.7% PAC: 20.2%) and microbeads (4.8%; PAC only; to our knowledge the first isolation of microbeads from marine megavertebrates). Fourier transform infrared spectroscopy (FT‐IR) of a subsample of particles (n = 169) showed a range of synthetic materials such as elastomers (MED: 61.2%; PAC: 3.4%), thermoplastics (ATL: 36.8%: MED: 20.7% PAC: 27.7%) and synthetic regenerated cellulosic fibres (SRCF; ATL: 63.2%: MED: 5.8% PAC: 68.9%). Synthetic particles being isolated from species occupying different trophic levels suggest the possibility of multiple ingestion pathways. These include exposure from polluted seawater and sediments and/or additional trophic transfer from contaminated prey/forage items. We assess the likelihood that microplastic ingestion presents a significant conservation problem at current levels compared to other anthropogenic threats.

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Section: Discussionmentioning

confidence: 99%

Microplastic ingestion ubiquitous in marine turtles

Duncan

Broderick

Fuller

et al. 2018

Global Change Biology

221

100

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“…It is also reported that polyacrylamides crosslinked with N,N′‐methylenbisacrylamide is a good copolymer for encapsulation of cancer drug 5‐fluorouracil . Similarly, tetracycline loaded polyacrylamide N,N′ ‐methylenebisacrylamide is also reported as promising candidate for designing controlled release formulations …”

Section: Introductionmentioning

confidence: 99%

Prospects use of hybrid layered double hydroxides‐polyacrylamide as controlled release media for antibiotic molecules

Allou

Bordoloi

Goswamee

2017

J of Applied Polymer Sci

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Some controlled‐release media containing two commercial antibiotic molecules, viz. Amoxicillin (AMX) and Ampicillin (AMP), were prepared using layered double hydroxides (LDH) intercalated and extended by polyacrylamide. The polycarylamide was prepared in situ by polymerization of acrylamide monomer intercalated in the interlayers of LDH. The LDH‐polyacrylamide‐antibiotic hybrid nanocomposites were characterized by various techniques like Fourier transform infrared (FT‐IR), powder X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and field emission scanning electron microscopy (FE‐SEM). The results from these characterizations have shown the successful incorporation of the antibiotics in the interlayers and provided important information regarding their interlayer structure. The nanocomposites showed increased thermal stability in TGA. The loading of antibiotic in the PAM/Mg‐Al nanocomposite was found to be 36.33% for AMX and 52.38% for AMP. The improved antibacterial activity of hybrid nanocomposite was evaluated against Escherichia coli using the wells diffusion technique. The aliquot samples in agar media drug release study were found to be highly effective against microorganisms. The sustained release of antibiotic drug from the hybrid nanocomposite was also verified. The release rate at pH 7.4 phosphate buffer was found slower than that at pH 4.6. It can be concluded that hybrid nanocomposites of LDH extended by in situ polymerized acrylamide are very suitable materials to host different antibiotics and their controlled release. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45442.

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“…In natural polydisperse microparticulate populations, including microcapsules, droplets, liposomes and cells, a first order behavioural pattern has proved to be the most common (Nixon & Walker 1971;Madan & Shanbhag 1978;Thies 1982;Benita & Donbrow 1982a,b;Benita et a1 1985a), probably as a result of the prevalence of distributions approximating to gamma or log normal density (Gross et al 1986). Nevertheless, matrix kinetics (Alpar & Walters 1981;Jun & Lai 1983;El Samaligy & Rohdewald 1983), dissolution kinetics and other types (Nixon & Walker 1971;Madan et a1 1976;Yalabik-Kas 1983) have been reported. Measurements were made using ensembles of generally undefined distribution character, heterogeneity not being considered a factor.…”

mentioning

confidence: 99%

Variation of Population Release Kinetics in Polydisperse Multiparticulate Systems (Microcapsules, Microspheres, Droplets, Cells) with Heterogeneity of One, Two or Three Parameters in the Population of Individuals

Donbrow

Hoffman

Benita

1988

Journal of Pharmacy and Pharmacology

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Release kinetics of active substances from ensembles of microparticles such as microcapsules, cells, droplets and liposomes constituted of individual entities releasing their contents at constant rates may follow zero order, first order, sigmoid or biphasic equations. The release equation observed depends upon the statistical distribution of release-determining parameters among the population. Typical cases are presented in terms of the distribution of two parameters, payload (m infinity) and time for complete payload release (t infinity) which also define the release rate constant (k). Heterogeneity of the two parameters generally leads to first order ensemble behaviour, whereas heterogeneity of one parameter only may lead to different ensemble release equations, viz. zero order (m infinity heterogeneous) or first order (t infinity heterogeneous). Biphasic distribution can lead to an apparent 'burst' effect, with apparent change of kinetics. The presence of a third heterogeneous parameter, lag time, yields a sigmoid ensemble release curve. These conclusions are demonstrated by simulations or experimentally, and are also valid for linearized curves of microparticles following matrix kinetics.

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Polyacrylamide microbeads, a sustained release drug delivery system

Cited by 11 publications

References 10 publications

Microplastic ingestion ubiquitous in marine turtles

Microplastic ingestion ubiquitous in marine turtles

Prospects use of hybrid layered double hydroxides‐polyacrylamide as controlled release media for antibiotic molecules

Variation of Population Release Kinetics in Polydisperse Multiparticulate Systems (Microcapsules, Microspheres, Droplets, Cells) with Heterogeneity of One, Two or Three Parameters in the Population of Individuals

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