Dependence of in vitro fatigue properties of PMMA bone cement on the polydispersity index of its powder

Lewis, Gladius; Li, Yuan

doi:10.1016/j.jmbbm.2009.05.003

Cited by 17 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The bounds on the daptomycin loading are consistent with the lowest and highest loadings reported in the literature on the influence of antibiotic loading on properties of PMMA bone cements [5,7,13,[19][20][21]25]. The bounds on the estimated mean fatigue limit represent the lowest and highest values of the 95% confidence limits on the fatigue limit of plain PMMA bone cements [22]. The bounds on the estimated elution rate are within the range of rates reported in the literature for the elution of gentamicin, tobramycin, and vancomycin from specimens fabricated hand-and vacuum-mixed laboratory-prepared ''low-dose'' ALBC formulations (herein defined as those with antibiotic loading \ 5 wt/wt%) [13,20,32].…”

supporting

confidence: 85%

An Approach for Determining Antibiotic Loading for a Physician-directed Antibiotic-loaded PMMA Bone Cement Formulation

Lewis

Brooks

Courtney

et al. 2010

Clinical Orthopaedics &Amp; Related Research

Self Cite

View full text Add to dashboard Cite

Background When a physician-directed antibiotic-loaded polymethylmethacrylate (PMMA) bone cement (ALBC) formulation is used in total hip arthroplasties (THAs) and total knee arthroplasties (TKAs), current practice in the United States involves arbitrary choice of the antibiotic loading (herein defined as the ratio of the mass of the antibiotic added to the mass of the cement powder). We suggest there is a need to develop a rational method for determining this loading. Questions/purposes We propose a new method for determining the antibiotic loading to use when preparing a physician-directed ALBC formulation and illustrate this method using three in vitro properties of an ALBC in which the antibiotic was daptomycin. Materials and MethodsDaptomycin was blended with the powder of the cement using a mechanical mixer. We performed fatigue, elution, and activity tests on three sets of specimens having daptomycin loadings of 2.25, 4.50, and 11.00 wt/wt%. Correlational analyses of the results of these tests were used in conjunction with stated constraints and a nonlinear optimization method to determine the daptomycin loading to use. Results With an increase in daptomycin loading, the estimated mean fatigue limit of the cement decreased, the estimated elution rate of the antibiotic increased, and the percentage inhibition of staphylococcal growth by the eluate remained unchanged at 100%. For a daptomycinloaded PMMA bone cement we computed the optimum amount of daptomycin to mechanically blend with 40 g of cement powder is 1.36 g. Conclusions We suggest an approach that may be used to determine the amount of antibiotic to blend with the powder of a PMMA bone cement when preparing a physician-directed ALBC formulation, and highlighted the attractions and limitations of this approach. Clinical Relevance When a physician-directed ALBC formulation is selected for use in a TKA or THA, the approach we detail may be employed to determine the antibiotic loading to use rather than the empirical approach that is taken in current clinical practice.

show abstract

supporting

confidence: 85%

An Approach for Determining Antibiotic Loading for a Physician-directed Antibiotic-loaded PMMA Bone Cement Formulation

Lewis

Brooks

Courtney

et al. 2010

Clinical Orthopaedics &Amp; Related Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…PDI (heterogeneity index or simply dispersity (Đ)) indicates the stability of the product since it denotes the particles distribution in colloidal solution. Smaller PDI suggest the homogeneity of the particle size in suspension, ideally the value of PDI should be ˂ 0.70 because they indicated a particle size distribution falls within a narrow range of sizes [27,[30][31][32][33]. In the present study all PDI were of acceptable range as recorded by DLS for all GKB spray, indicating the homogeneity of the particle size in the obtained suspension as showed in Figure 1.…”

Section: Spray Formulaesupporting

confidence: 60%

A Novel Topical Spray Formulation for Ginkgo Bioloba for Antifungal Activity

Aah¹

2016

J Nanomed Nanotechnol

View full text Add to dashboard Cite

The aim of this study is to prove the antifungal and antibacterial activity of Ginko biloba GKB from glycerin nanocapsules and nanoemulsions. GKB was formulated as spray formulation for topical application using ethyl alcohol 95%/glycerol/water based formulations. GKB spray was evaluated for their particle size distribution, pH, content uniformity, content per spray, in vitro release and antifungal activity. The antifungal activity was determined by Agar welldiffusion method. The formulae were tested for their skin permeation and the stability of the formulations. The results showed uniform formulae with nano-sized particles, pH compatible with the topical formulation and higher drug content. Diffusion studies of the optimized formulations through the abdominal rabbit skin showed higher penetrated drug over a period of 24 h. Stability studies indicated that formulations were stable. Skin irritation studies confirmed the compatibility of spray formulae with skin. Agar well-diffusion method showed that GKB was effective compared with fluconazole. The inhibition zones for all formulae were significant as compared with standard fluconazole. The results obtained showed that the topical spray formulation could be a promising and innovative therapeutic system as topical antifungal for the transdermal administration of GKB. The developed formulation can be used for delivery from spray formulation. This study proved the local activity of GKB as antifungal drugs.

show abstract

“…PDI is a measure of the distribution of molecular mass in a given polymer sample an also index that could indicate of the stability of the LOR-GNPs since it represents the particles distribution in colloidal solution. High PDI values indicates the heterogeneity of the particle size in suspension, while smaller PDI indicate the homogeneity of the particle size in suspension, ideally the value of PDI should be ˂0.7 because they indicate a particle size distribution falls within a narrow range of sizes [22,[25][26][27][28]. In the present study the PDI average value of ≈ 0.3 ± 0.02 was recorded for the formulated GNPs-LOR which revealed the homogeneity of the particle size in the obtained suspension.…”

Section: Resultsmentioning

confidence: 99%

Formulation of Novel Glycerin Nanoparticles for Enhancement the Solubility of Loratadine; Application to Transdermal Hydrogel Delivery System

Abou-Taleba¹,

Hamdb²,

Abdellatif³

2017

J Nanomed Nanotechnol

View full text Add to dashboard Cite

Owing to its slightly aqueous solubility, loratadine (LOR) is used in high doses in different marketed formulations to achieve its desirable bioavailability. The aim of this work is to formulate novel LOR-glycerin nanoparticles (LOR-GNPs) to increase LOR bioavailability. LOR-GNPs were prepared by a precipitation method and then evaluated for such size and morphology using dynamic scattering spectroscopy (DLS) and scanning electron microscopy (SEM), as well as the percentage entrapment efficiency (EE%) of free LOR from GNPs formulations was performed using titration method. Furthermore, the GNPs were formulated in hydrogel. The hydrogel viscosity, spreadability, homogeneity and abdominal rat skin permeation were studied and optimized DLS indicated a successful coating of LOR with glycerin surface that recorded an average size of 334 ± 30 nm with uniform particle size, while SEM showed LOR-NPs in different shapes. The EE% free LOR was found to be satisfactory with a mean content of 98.1 ± 0.3 and a relative standard deviation below 2.0% indicates the reproducibility of the LOR release. LOR-GNPs were formulated as a hydrogel to check their suitability for a dosage form usage. The hydrogel showed accepted viscosity, spreadability, and homogeneity. The results proved that the GNPs penetrated abdominal rat skin. The obtained results showed that LOR-GNPs are considered a new addition for improvement of LOR solubility when applied as a hydrogel. The developed method could be used for different insoluble candidates.

show abstract

Dependence of in vitro fatigue properties of PMMA bone cement on the polydispersity index of its powder

Cited by 17 publications

References 27 publications

An Approach for Determining Antibiotic Loading for a Physician-directed Antibiotic-loaded PMMA Bone Cement Formulation

An Approach for Determining Antibiotic Loading for a Physician-directed Antibiotic-loaded PMMA Bone Cement Formulation

A Novel Topical Spray Formulation for Ginkgo Bioloba for Antifungal Activity

Formulation of Novel Glycerin Nanoparticles for Enhancement the Solubility of Loratadine; Application to Transdermal Hydrogel Delivery System

Contact Info

Product

Resources

About