Association of ranibizumab (Lucentis®) or bevacizumab (Avastin®) with dexamethasone and triamcinolone acetonide: An in vitro stability assessment

Lead-212 is recognized as a promising radionuclide for targeted alpha therapy for tumors. Many studies of 212Pb-labeling of various biomolecules through bifunctional chelators have been conducted. Another approach to exploiting the cytotoxic effect is coupling the radionuclide to a microparticle acting as a carrier vehicle, which could be used for treating disseminated cancers in body cavities. Calcium carbonate may represent a suitable material, as it is biocompatible, biodegradable, and easy to synthesize. In this work, we explored 212Pb-labeling of various CaCO3 microparticles and developed a protocol that can be straightforwardly implemented by clinicians. Vaterite microparticles stabilized by pamidronate were effective as 212Pb carriers; labeling yields of ≥98% were achieved, and 212Pb was strongly retained by the particles in an in vitro stability assessment. Moreover, the amounts of 212Pb reaching the kidneys, liver, spleen, and skeleton of mice following intraperitoneal (i.p.) administration were very low compared to i.p. injection of unbound 212Pb2+, indicating that CaCO3-bound 212Pb exhibited stability when administered intraperitoneally. Therapeutic efficacy was observed in a model of i.p. ovarian cancer for all the tested doses, ranging from 63 to 430 kBq per mouse. Lead-212-labeled CaCO3 microparticles represent a promising candidate for treating intracavitary cancers.

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Chevron bunionectomy fixation: In vitro stability assessment of plate-and-screw system compared with kirschner wire

The Journal of Foot & Ankle Surgery ◽

10.1016/s1067-2516(09)80058-6 ◽

1995 ◽

Vol 34 (3) ◽

pp. 266-272 ◽

Cited By ~ 14

Author(s):

Robert K. Buckenberger ◽

Flair D. Goldman

Keyword(s):

Kirschner Wire ◽

Stability Assessment ◽

In Vitro Stability

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Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

Nuklearmedizin ◽

10.1055/s-0037-1620623 ◽

1977 ◽

Vol 16 (04) ◽

pp. 157-162 ◽

Cited By ~ 1

Author(s):

C. Schümichen ◽

B. Mackenbrock ◽

G. Hoffmann

Keyword(s):

Normal Saline ◽

Half Life ◽

Compound A ◽

Short Half Life ◽

Low Concentrations ◽

The Stability ◽

Kinetics Of ◽

In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

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Rhenium-188 Labeled Hydroxyapatite and Rhenium-188 Sulfur Colloid

Nuklearmedizin ◽

10.1055/s-0038-1629737 ◽

1997 ◽

Vol 36 (02) ◽

pp. 71-75 ◽

Cited By ~ 6

Author(s):

S. Glatz ◽

S. N. Reske ◽

K. G. Grillenberger

Keyword(s):

Synovial Fluid ◽

Ph Value ◽

Surgical Removal ◽

Radiation Synovectomy ◽

Sulfur Colloid ◽

Target Organs ◽

Aseptic Conditions ◽

In Vitro Stability ◽

Potential Use

Summary Aim: One therapeutic approach to rheumatoid arthritis and other inflammatory arthropathies besides surgical removal of inflamed synovium is radiation synovectomy using beta-emitting radionuclides to destroy the affected synovial tissue. Up to now the major problem associated with the use of labeled particles or colloids has been considerable leakage of radionuclides from the injected joint coupled with high radiation doses to liver and other non target organs. In this study we compared 188Re labeled hydroxyapatite particles and 188Re rhenium sulfur colloid for their potential use in radiation synovectomy. Methods: To this end we varied the labeling conditions (concentrations, pH-value, heating procedure) and analyzed the labeling yield, radiochemical purity, and in vitro stability of the resulting radiopharmaceutical. Results: After optimizing labeling conditions we achieved a labeling yield of more than 80% for 188Re hydroxyapatite and more than 90% for the rhenium sulfur colloid. Both of the radiopharmaceuticals can be prepared under aseptic conditions using an autoclav for heating without loss of activity. In vitro stability studies using various challenge solutions (water, normal saline, diluted synovial fluid) showed that 188Re labeled hydroxyapatite particles lost about 80% of their activity within 5 d in synovial fluid. Rhenium sulfur colloid on the other hand proved to be very stable with a remaining activity of more than 93% after 5 d in diluted synovial fluid. Conclusion: These in vitro results suggest that 188Re labeled rhenium sulfur colloid expects to be more suitable for therapeutic use in radiation synovectomy than the labeled hydroxyapatite particles.

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Development of Triamcinolone Acetonide-Loaded Microemulsion as a Prospective Ophthalmic Delivery System for Treatment of Uveitis: In Vitro and In Vivo Evaluation

Pharmaceutics ◽

10.3390/pharmaceutics13040444 ◽

2021 ◽

Vol 13 (4) ◽

pp. 444

Author(s):

Alaa Mahran ◽

Sayed Ismail ◽

Ayat A. Allam

Keyword(s):

Triamcinolone Acetonide ◽

Delivery System ◽

Histopathological Examination ◽

Rabbit Model ◽

Subconjunctival Injection ◽

In Vivo Evaluation ◽

Ternary Phase Diagrams ◽

Ophthalmic Delivery

Treatment of uveitis (i.e., inflammation of the uvea) is challenging due to lack of convenient ophthalmic dosage forms. This work is aimed to determine the efficiency of triamcinolone acetonide (TA)-loaded microemulsion as an ophthalmic delivery system for the treatment of uveitis. Water titration method was used to construct different pseudo-ternary phase diagrams. Twelve microemulsion formulations were prepared using oleic acid, Cremophor EL, and propylene glycol. Among all tested formulations, Formulation F3, composed of oil: surfactant-co-surfactant (1:1): water (15:35:50% w/w, respectively), was found to be stable and showed acceptable pH, viscosity, conductivity, droplet size (211 ± 1.4 nm), and zeta potential (−25 ± 1.7 mV) and almost complete in vitro drug release within 24 h. The in vivo performance of the optimized formulation was evaluated in experimentally uveitis-induced rabbit model and compared with a commercial TA suspension (i.e., Kenacort®-A) either topically or by subconjunctival injection. Ocular inflammation was evaluated by clinical examination, white blood cell count, protein content measurement, and histopathological examination. The developed TA-loaded microemulsion showed superior therapeutic efficiency in the treatment of uveitis with high patient compliance compared to commercial suspension. Hence, it could be considered as a potential ocular treatment option in controlling of uveitis.

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Leukocyte labeling with 99mTc-HMPAO. The role of the in vitro stability of HMPAO on the labeling efficacy and image quality

Nuclear Medicine and Biology ◽

10.1016/0969-8051(94)90170-8 ◽

1994 ◽

Vol 21 (6) ◽

pp. 893-895 ◽

Cited By ~ 2

Author(s):

Miklós Papós ◽

Jenő Láng ◽

Mária Rajtár ◽

László Csernay

Keyword(s):

Image Quality ◽

Leukocyte Labeling ◽

In Vitro Stability ◽

99Mtc Hmpao

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Melt-Cast Films Significantly Enhance Triamcinolone Acetonide Delivery to the Deeper Ocular Tissues

Pharmaceutics ◽

10.3390/pharmaceutics11040158 ◽

2019 ◽

Vol 11 (4) ◽

pp. 158

Author(s):

Akshaya Tatke ◽

Narendar Dudhipala ◽

Karthik Janga ◽

Bhavik Soneta ◽

Bharathi Avula ◽

...

Keyword(s):

Triamcinolone Acetonide ◽

Polymer Matrix ◽

Rabbit Model ◽

In Vivo Studies ◽

Invasive Technique ◽

Content Uniformity ◽

Scanning Calorimetry ◽

Ocular Tissues

Delivering an effective drug load to the posterior section of the ocular tissues, while using a non-invasive technique, has always been a challenge. In this regard, the goal of the present study was to develop sustained release triamcinolone acetonide (TA) loaded polymeric matrix films for ocular delivery. The TA-films were prepared in two different polymer matrices, with drug loadings of 10% and 20% w/w, and they were evaluated for ocular distribution in vivo in a conscious rabbit model. A 4% w/v TA suspension (TA-C) was used as a control for in vitro and in vivo studies. The TA-films, prepared with melt-cast technology, used polyethylene oxide (PEO) and Soluplus® as the polymer matrix. The films were evaluated with respect to assay, content uniformity, excipient interaction, and permeability across isolated rabbit sclera. The distribution of TA in the ocular tissues, post topical administration, was determined in New Zealand male albino rabbits as a function of dose, and was compared against TA-C. The assay of the 10% and 20% w/w film was in the range from 70–79% and 92–94% for the Soluplus® and PEO films, respectively, and content uniformity was in the range of 95–103% for both the films. The assay of the TA from Soluplus® films was less compared with the PEO films and showed an interaction with TA, as revealed by Differential Scanning Calorimetry (DSC). Hence, Soluplus® films were not selected for further studies. No interaction was observed between the drug and PEO polymer matrix. The enhancement of trans-scleral flux and permeability of TA was about 1.16 and 1.33-folds, respectively, from the 10% w/w PEO and 3.5 and 2.12-folds, respectively, from the 20% w/w PEO films, as compared with TA-C formulations. The in vivo studies demonstrate that significantly higher TA levels were observed in the anterior and posterior segments of the eye at the end of 6h with the PEO films. Therefore, the PEO based polymeric films were able to deliver TA into the back of the eye efficiently and for prolonged periods.

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Studies of two temperature-sensitive mutants of Mengo virus

Canadian Journal of Biochemistry ◽

10.1139/o79-110 ◽

1979 ◽

Vol 57 (6) ◽

pp. 902-913 ◽

Cited By ~ 1

Author(s):

Patrick W. K. Lee ◽

John S. Colter

Keyword(s):

Rna Synthesis ◽

Viral Rna ◽

Temperature Sensitive ◽

Supporting Evidence ◽

Structural Polypeptide ◽

Infected Cells ◽

Mengo Virus ◽

In Vitro Stability

Studies of the synthesis of viral ribonucleates and polypeptides in cells infected with two RNA−ts mutants of Mengo virus (ts 135 and ts 520) have shown that when ts 135 infected cells are shifted from the permissive (33 °C) to the nonpermissive (39 °C) temperature: (i) the synthesis of all three species of viral RNA (single stranded, replicative form, and replicative intermediate) is inhibited to about the same extent, and (ii) the posttranslational cleavage of structural polypeptide precursors A and B is partially blocked. Investigations of the in vivo and in vitro stability of the viral RNA replicase suggest that the RNA− phentotype reflects a temperature-sensitive defect in the enzyme. The second defect does not appear to result from the inhibition of viral RNA synthesis at 39 °C, since normal cleavage of polypeptides A and B occurs in wt Mengo-infected cells in which viral RNA synthesis is blocked by cordycepin, and at the nonpermissive temperature in ts 520 infected cells. Considered in toto, the evidence suggests that ts 135 is a double mutant.Subviral (53 S) particles have been shown to accumulate in ts 520 (but not ts 135) infected cells when cultures are shifted from 33 to 39 °C. This observation provides supporting evidence for the proposal that this recently discovered particle is an intermediate in the assembly pathway of Mengo virions.

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