Purification of Amoxicillin Trihydrate in the Presence of Degradation Products by Washing Method

CrystEngComm ◽  
2021 ◽  
Author(s):  
M Fatih Ergin
Keyword(s):  
Degradation Products ◽  
Pure Crystal ◽  
Amoxicillin Trihydrate ◽  
Washing Method

Repeated crystallization or the use of different chemicals to obtain a pure crystal can cause yield/purity issues. Therefore, impurity penetrating the crystalline mesh should be removed as much as possible...

Crystallization of Amoxicillin Trihydrate in the Presence of Degradation Products

2006 ◽  
Vol 10 (6) ◽  
pp. 1212-1218 ◽  
Author(s):  
Shaohua Feng ◽  
Ning Shan ◽  
Keith J. Carpenter
Keyword(s):  
Degradation Products ◽  
Amoxicillin Trihydrate

Validated Stability−Indicating LC Method for Estimation of Amoxicillin Trihydrate in Pharmaceutical Dosage Forms and Time-Dependent Release Formulations

2011 ◽  
Vol 4 (2) ◽  
pp. 1423-1427 ◽  
Author(s):  
Sarwar Beg ◽  
S M Hasnain ◽  
S Swain ◽  
K Kohli
Keyword(s):  
Degradation Products ◽  
Degradation Kinetics ◽  
Pharmaceutical Formulations ◽  
Time Dependent ◽  
Pharmaceutical Dosage Forms ◽  
Stability Indicating ◽  
Specificity And Sensitivity ◽  
Stress Degradation ◽  
Amoxicillin Trihydrate ◽  
Bulk Drug

The objective of this study was to establish a validated stability-indicating LC method for routine analysis of amoxicillin trihydrate in bulk drug samples, different pharmaceutical formulations, and degradation kinetics of the drug under different ICH recommended stress conditions. Chromatographic separation was achieved by a Capacel Pak C18 column with 50:50% v/v methanol-0.02 M phosphate buffer as mobile phase having pH 3.5 and flow rate of 1.0 ml/min; with UV absorbance at 229 nm. The method was validated for system suitability, linearity, precision, accuracy, robustness, specificity and sensitivity. The drug was subjected to stress degradation by exposure to acid and alkaline hydrolysis, oxidation, and photodegradation. It was observed that peaks of all degradation products were well resolved from the pure drug with significantly different retention times, which indicated the specificity and stability-indicating properties of the method. When the utility of the method was verified by analysis of the drug in marketed formulations and in-house time-dependent release tablet formulations, the assay was found to be 99.6–100.4%. Statistical analysis proves that the method is repeatable, selective, and accurate for the estimation of amoxicillin trihydrate in bulk drug samples and also in pharmaceutical formulations. 

Collagen degradation products modulate matrix metalloproteinase expression in cultured articular chondrocytes

2005 ◽  
Vol 24 (1) ◽  
pp. 63-70 ◽  
Author(s):  
M. Fichter ◽  
U. Körner ◽  
J. Schömburg ◽  
L. Jennings ◽  
A. A. Cole ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Articular Chondrocytes ◽  
Degradation Products ◽  
Collagen Degradation ◽  
Collagen Degradation Products

Structural Studies of Fibrinolysis by Electron and Light Microscopy

1999 ◽  
Vol 82 (08) ◽  
pp. 277-282 ◽  
Author(s):  
Yuri Veklich ◽  
Jean-Philippe Collet ◽  
Charles Francis ◽  
John W. Weisel
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Plasminogen Activator ◽  
Structural Changes ◽  
Molecular Mechanisms ◽  
Degradation Products ◽  
Molecular Model ◽  
Three Dimensional ◽  
Tissue Type ◽  
Type Plasminogen Activator

IntroductionMuch is known about the fibrinolytic system that converts fibrin-bound plasminogen to the active protease, plasmin, using plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator. Plasmin then cleaves fibrin at specific sites and generates soluble fragments, many of which have been characterized, providing the basis for a molecular model of the polypeptide chain degradation.1-3 Soluble degradation products of fibrin have also been characterized by transmission electron microscopy, yielding a model for their structure.4 Moreover, high resolution, three-dimensional structures of certain fibrinogen fragments has provided a wealth of information that may be useful in understanding how various proteins bind to fibrin and the overall process of fibrinolysis (Doolittle, this volume).5,6 Both the rate of fibrinolysis and the structures of soluble derivatives are determined in part by the fibrin network structure itself. Furthermore, the activation of plasminogen by t-PA is accelerated by the conversion of fibrinogen to fibrin, and this reaction is also affected by the structure of the fibrin. For example, clots made of thin fibers have a decreased rate of conversion of plasminogen to plasmin by t-PA, and they generally are lysed more slowly than clots composed of thick fibers.7-9 Under other conditions, however, clots made of thin fibers may be lysed more rapidly.10 In addition, fibrin clots composed of abnormally thin fibers formed from certain dysfibrinogens display decreased plasminogen binding and a lower rate of fibrinolysis.11-13 Therefore, our increasing knowledge of various dysfibrinogenemias will aid our understanding of mechanisms of fibrinolysis (Matsuda, this volume).14,15 To account for these diverse observations and more fully understand the molecular basis of fibrinolysis, more knowledge of the physical changes in the fibrin matrix that precede solubilization is required. In this report, we summarize recent experiments utilizing transmission and scanning electron microscopy and confocal light microscopy to provide information about the structural changes occurring in polymerized fibrin during fibrinolysis. Many of the results of these experiments were unexpected and suggest some aspects of potential molecular mechanisms of fibrinolysis, which will also be described here.

Fibrinogen Bastia (γ 318 Asp → Tyr) a Novel Abnormal Fibrinogen Characterized by Defective Fibrin Polymerization

1999 ◽  
Vol 82 (12) ◽  
pp. 1639-1643 ◽  
Author(s):  
Karim Chabane Lounes ◽  
Claudine Soria ◽  
Antoine Valognes ◽  
Marie France Turchini ◽  
Jaap Koopman ◽  
...  
Keyword(s):  
Calcium Ions ◽  
Clinical Symptoms ◽  
Degradation Products ◽  
Base Substitution ◽  
Chain Gene ◽  
Fibrinogen Concentration ◽  
Clotting Time ◽  
Terminal Part ◽  
Fibrin Polymerization ◽  
Chain Sequence

SummaryA new congenital dysfibrinogen, Fibrinogen Bastia, was discovered in a 20-year-old woman with no clinical symptoms. The plasma thrombin-clotting time was severely prolonged. The functional plasma fibrinogen concentration was low (0.2 mg/ml), whereas the immunological concentration was normal (2.9 mg/ml). Purified fibrinogen Bastia displayed a markedly prolonged thrombin-clotting time related to a delayed thrombin-induced fibrin polymerization. Both the thrombin-clotting time and the fibrin polymerization were partially corrected by the addition of calcium ions. The anomaly of fibrinogen Bastia was found to be located in the γ-chain since by SDS-PAGE performed according to the method of Laemmli two γ-chains were detected, one normal and one with an apparently lower molecular weight. Furthermore, analysis of plasmin degradation products demonstrated that calcium ions only partially protect fibrinogen Bastia γ-chain against plasmin digestion, suggesting that the anomaly is located in the C-terminal part of the γ-chain. Sequence analysis of PCR-amplified genomic DNA fragments of the propositus demonstrated a single base substitution (G → T) in the exon VIII of the γ chain gene, resulting in the amino acid substitution 318 Asp (GAC) → Tyr (TAC). The PCR clones were recloned and 50% of them contained the mutation, indicating that the patient was heterozygous. These data indicate that residue Asp 318 is important for normal fibrin polymerization and the protective effect of calcium ions against plasmin degradation of the C-terminal part of the γ-chain.

A Monoclonal Antibody-Based Enzyme Immunoassay for Fibrin Degradation Products in Plasma

1988 ◽  
Vol 59 (02) ◽  
pp. 310-315 ◽  
Author(s):  
P W Koppert ◽  
E Hoegee-de Nobel ◽  
W Nieuwenhuizen
Keyword(s):  
Enzyme Immunoassay ◽  
Degradation Products ◽  
Blood Clot ◽  
Tissue Type ◽  
Fibrin Degradation Products ◽  
Type Plasminogen Activator ◽  
Strong Positive Reaction ◽  
Sandwich Type ◽  
Capture Antibody

SummaryWe have developed a sandwich-type enzyme immunoassay (EIA) for the quantitation of fibrin degradation products (FbDP) in plasma with a time-to-result of only 45 minutes.* The assay is based on the combination of the specificities of two monoclonal antibodies (FDP-14 and DD-13), developed in our institute. FDP-14, the capture antibody, binds both fibrinogen degradation products (FbgDP) and FbDP, but does not react with the parent fibrin(ogen) molecules. It has its epitope in the E-domain of the fibrinogen molecule on the Bβ-chain between amino acids 54-118. Antibody DD-13 was raised using D-dimer as antigen and is used as a tagging antibody, conjugated with horse-radish peroxidase. A strong positive reaction is obtained with a whole blood clot lysate (lysis induced by tissue-type plasminogen activator) which is used as a standard. The EIA does virtually not detect FbgDP i. e. purified fragments X, Y, or FbgDP generated in vitro in plasma by streptokinase treatment. This indicates that the assay is specific for fibrin degradation products.We have successfully applied this assay to the plasma of patients with a variety of diseased states. In combination with the assay previously developed by us for FbgDP and for the total amount of FbgDP + FbDP (TDP) in plasma, we are now able to study the composition of TDP in patients plasma in terms of FbgDP and FbDP.

Enhanced Effective Fibrinolysis following the Neutralization of Heparin in Open Heart Surgery Increases the Risk of Post-Surgical Bleeding

1990 ◽  
Vol 63 (02) ◽  
pp. 241-245 ◽  
Author(s):  
Jørgen Gram ◽  
Thomas Janetzko ◽  
Jørgen Jespersen ◽  
Hans Dietrich Bruhn
Keyword(s):  
Blood Loss ◽  
Plasminogen Activator ◽  
Heart Surgery ◽  
Degradation Products ◽  
Open Heart Surgery ◽  
Tissue Type ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Chest Tube Drain ◽  
Median Blood Loss

SummaryThe tissue-type plasminogen activator related fibrinolytic system was studied in 24 patients undergoing cardiopulmonary bypass surgery. The degradation of fibrinogen and fibrin was followed during and after surgery by means of new sensitive and specific assays and the changes were related to the blood loss measured in the chest tube drain during the first 24 postoperative hours. Although tissue-type plasminogen activator was significantly released into the circulation during the period of extracor-poreal circulation (p <0.01), constantly low levels of fibrinogen degradation products indicated that a systemic generation of plasmin could be controlled by the naturally occurring inhibitors. Following extracorporeal circulation heparin was neutralized by protamine chloride, and in relation to the subsequent generation of fibrin, there was a short period with increased concentrations of fibrinogen degradation products (p <0.01) and a prolonged period of degradation of cross-linked fibrin, as detected by increased concentrations of D-Dimer until 24 h after surgery (p <0.01). Patients with a higher than the median blood loss (520 ml) in the chest tube drain had a significantly higher increase of D-Dimer than patients with a lower than the median blood loss (p <0.05).We conclude that the incorporation of tissue-type plasminogen activator into fibrin and the in situ activation of plasminogen enhance local fibrinolysis, thereby increasing the risk of bleeding in patients undergoing open heart surgery

Plasma Thrombospondin as an Indicator of Intravascular Platelet Activation in Patients with Vasculitis

1987 ◽  
Vol 58 (03) ◽  
pp. 850-852 ◽  
Author(s):  
M B McCrohan ◽  
S W Huang ◽  
J W Sleasman ◽  
P A Klein ◽  
K J Kao
Keyword(s):  
Platelet Activation ◽  
Plasma Levels ◽  
Half Life ◽  
Degradation Products ◽  
Plasma Concentrations ◽  
Primary Source ◽  
Positive Correlation ◽  
Activation Marker ◽  
Fibrin Degradation Products ◽  
The Mean

SummaryThe use of plasma thrombospondin (TSP) concentration was investigated as an indicator of intravascular platelet activation. Patients (n = 20) with diseases that have known vasculitis were included in the study. The range and the mean of plasma TSP concentrations of patients with vasculitis were 117 ng/ml to 6500 ng/ml and 791±1412 ng/ml (mean ± SD); the range and the mean of plasma TSP concentrations of control individuals (n = 33) were 13 ng/ml to 137 ng/ml and 59±29 ng/ml. When plasma TSP concentrations were correlated with plasma concentrations of another platelet activation marker, β-thromboglobulin (P-TG), it was found that the TSP concentration inei eased exponentially as the plasma β-TG level rose. A positive correlation between plasma levels of plasma TSP and serum fibrin degradation products was also observed. The results suggest that platelets are the primary source of plasma TSP in patients with various vasculitis and that plasma TSP can be a better indicator than β-TG to assess intravascular platelet activation due to its longer circulation half life.

The Inhibition of Platelet Aggregation by an Aorta Intima Extract

1974 ◽  
Vol 32 (02/03) ◽  
pp. 417-431 ◽  
Author(s):  
A. du P Heyns ◽  
D. J van den Berg ◽  
G. M Potgieter ◽  
F. P Retief
Keyword(s):  
Platelet Aggregation ◽  
Degradation Products ◽  
Adenosine Diphosphate ◽  
Inhibitory Effect ◽  
Protective Role ◽  
Vascular Trauma ◽  
Wear And Tear ◽  
Sequential Addition ◽  
Aggregation Activity

SummaryThe platelet aggregating activity of extracts of different layers of the arterial wall was compared to that of Achilles tendon. Arterial media and tendon extracts, adjusted to equivalent protein content as an index of concentration, aggregated platelets to the same extent but an arterial intima extract did not aggregate platelets. Platelet aggregation induced by collagen could be inhibited by mixing with intima extract, but only to a maximum of about 80%. Pre-mixing adenosine diphosphate (ADP) with intima extracts diminished the platelet aggregation activity of the ADP. Depending on the relationship between ADP and intima extract concentrations aggregating activity could either be completely inhibited or inhibition abolished. Incubation of ADP with intima extract and subsequent separation of degradation products by paper chromatography, demonstrated a time-dependent breakdown of ADP with AMP, adenosine, inosine and hypoxanthine as metabolic products; ADP removal was complete. Collagen, thrombin and adrenaline aggregate platelets mainly by endogenous ADP of the release reaction. Results of experiments comparing inhibition of aggregation caused by premixing aggregating agent with intima extract, before exposure to platelets, and the sequential addition of first the intima extract and then aggregating agent to platelets, suggest that the inhibitory effect of intima extract results from ADP breakdown. It is suggested that this ADP degradation by intima extract may play a protective role in vivo by limiting the size of platelet aggregates forming at the site of minimal “wear and tear” vascular trauma.

Plasma Thrombin Assay using a Chromogenic Substrate in Disseminated Intravascular Coagulation due to Snake Bite Envenomation

1979 ◽  
Vol 41 (03) ◽  
pp. 544-552 ◽  
Author(s):  
R P Herrmann ◽  
P E Bailey
Keyword(s):  
Disseminated Intravascular Coagulation ◽  
Degradation Products ◽  
Snake Bite ◽  
Chromogenic Substrate ◽  
Coagulation Parameters ◽  
Fibrinogen Degradation Products ◽  
Intravascular Coagulation

SummaryUsing the chromogenic substrate, Tos-Gly-Pro-Arg-pNA-HCL (Chromozym TH, Boehringer Mannheim) plasma thrombin was estimated in six cases of envenomation by Australian elapid snakes. All patients manifested findings chracteristic of defibrination due to envenomation by these snakes. Fibrin-fibrinogen degradation products were grossly elevated, as was plasma thrombin in all cases.Following treatment with antivenene, all abnormal coagulation parameters returned rapidly towards normal by 24 hours and plasma thrombin disappeared.

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