scholarly journals Stability and Beyond-Use Date of a Compounded Thioguanine Suspension

2020 ◽  
pp. 875512252095243
Author(s):  
Sagar S. Gilda ◽  
William M. Kolling ◽  
Marcelo Nieto ◽  
Timothy McPherson
Keyword(s):  
United States ◽  
High Performance ◽  
Room Temperature ◽  
Physical Stability ◽  
The United States ◽  
Chromatography Method ◽  
Priority List ◽  
Significant Difference ◽  
Stability Data ◽  
Liquid Chromatography Method

Background: Thioguanine (TG) is available only in the form of 40 mg tablets in the United States, and the patient population in which TG is used comprises mostly children. Recognizing its importance as a therapeutic agent and limited stability data for its compounded preparation, the United States Pharmacopoeia has listed TG in its priority list of compounded preparations monographs. Objective: The goal of the present study was to generate stability data and establish a beyond-use date for compounded TG suspension. Methods: Suspensions were compounded using TG tablets and ORA-Plus and ORA-Sweet as vehicles. A robust high-performance liquid chromatography method was developed and validated. TG and guanine (G) in suspensions were quantified immediately after compounding and at regular intervals for 90 days. Physical stability of suspensions was evaluated by observation of organoleptic properties. Results: Results from the study indicate that average TG levels in suspensions remained above 90% of the starting concentration and G formation was less than 2.5% for 90 days. There was no statistically significant difference in the amount of TG degraded over 90 days between suspensions stored at room temperature and in refrigerated conditions. There was also no statistically significant difference in G concentration of suspensions between day 0 and day 90. Conclusion: TG suspensions are stable for 90 days when stored at room temperature or refrigerated conditions and the beyond-use date can be set to 90 days.

Stability of Olmesartan Medoxomil Extemporaneous Suspensions

2021 ◽  
pp. 875512252110517
Author(s):  
Prapanna Bhattarai ◽  
Timothy McPherson ◽  
Marcelo Nieto ◽  
William M. Kolling
Keyword(s):  
United States ◽  
High Performance ◽  
Room Temperature ◽  
Physical Stability ◽  
Olmesartan Medoxomil ◽  
Storage Condition ◽  
The United States ◽  
Priority List ◽  
Study Results ◽  
Stability Data

Background: Olmesartan medoxomil (OLM) is only available in the United States as tablets. The United States Pharmacopoeia (USP) has placed OLM on its priority list of preparations that require stability data to support practitioner compounding. Objective: The purpose of the study was to develop a stability-indicating assay and then determine the beyond-use date (BUD) for an extemporaneous OLM suspension. Methods: A reverse-phase high-performance liquid chromatography (HPLC) assay was developed and validated according to guidelines for USP official compounded monographs. OLM 2 mg/mL suspensions were compounded with Ora-Sweet and Ora-Plus and stored at room temperature or in a refrigerator. Suspensions were assayed periodically over 90 days for OLM concentration and observed for physical stability. The pH was measured at the beginning and end of the study. Results: The OLM concentration remained above 97% of the starting concentration for 90 days when stored in the refrigerator and above 94% of the starting concentration for 90 days when stored at room temperature. The suspension pH did not change and indicators of physical stability were unchanged for 90 days. Conclusion: OLM 2 mg/mL suspensions were chemically and physically stable at room temperature and in the refrigerator for 90 days. The BUD may be set at 90 days under either storage condition.

scholarly journals Stability-Indicating Photochemical Method for the Assay of Thiamine by Spectrophotometry

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Iqbal Ahmad ◽  
Syed Haider Abbas ◽  
Zubair Anwar ◽  
Muhammad Ali Sheraz ◽  
Sofia Ahmed ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
The United States ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Stability Indicating ◽  
Low Concentrations ◽  
Photochemical Method ◽  
Significant Difference ◽  
Liquid Chromatography Method ◽  
States Pharmacopeia

A stability-indicating photochemical method has been developed for the assay of thiamine (TH) salts in aqueous solution and in fresh and aged vitamin preparations. It is based on the photooxidation of TH by UV irradiation to form thiochrome (TC) in alkaline solution. The TC : TH ratio under controlled conditions of light intensity, temperature, pH, exposure time, and irradiation distance is constant and can be used to determine the concentration of UV irradiated TH solutions. TC, on extraction with isobutanol from the photodegraded solution of TH, has been determined by the UV spectrophotometric method at 370 nm. It exhibits a high intensity of absorption in the UV region that can be used for the assay of even low concentrations of TH. Under optimum conditions, Beer’s law is obeyed in the concentration range of 0.20–2.00 mg/100 ml (R2 = 09998). The limit of detection (LOD) and limit of quantification (LOQ) are 0.0076 and 0.0231 mg/100 ml, respectively. The method has been validated and applied to aqueous solutions and vitamin preparations. The results have statistically been compared with the United States Pharmacopeia liquid chromatography method. It has been found that there is no significant difference between the two methods at 95% confidence level.

scholarly journals Product Quality of Parenteral Vancomycin Products in the United States

2012 ◽  
Vol 56 (6) ◽  
pp. 2819-2823 ◽  
Author(s):  
S. Nambiar ◽  
R. D. Madurawe ◽  
S. M. Zuk ◽  
S. R. Khan ◽  
C. D. Ellison ◽  
...  
Keyword(s):  
United States ◽  
Liquid Chromatography ◽  
Product Quality ◽  
High Performance ◽  
The United States ◽  
Hplc Method ◽  
Ultrahigh Pressure ◽  
Chromatography Method

ABSTRACTIn response to concerns raised about the quality of parenteral vancomycin products, the U.S. Food and Drug Administration (FDA) is investigating the product quality of all FDA-approved parenteral vancomycin products available in the United States. Product quality was evaluated independently at two FDA Office of Testing and Research (FDA-OTR) sites. In the next phase of the investigation, being done in collaboration with the National Institute of Allergy and Infectious Diseases, thein vivoactivity of these products will be evaluated in an appropriate animal model. This paper summarizes results of the FDA investigation completed thus far. One site used a validated ultrahigh-pressure liquid chromatography method (OTR-UPLC), and the second site used the high-performance liquid chromatography (HPLC) method for related substances provided in the British Pharmacopeia (BP) monograph for vancomycin intravenous infusion. Similar results were obtained by the two FDA-OTR laboratories using two different analytical methods. The products tested had 90 to 95% vancomycin B (active component of vancomycin) by the BP-HPLC method and 89 to 94% vancomycin by OTR-UPLC methods. Total impurities were 5 to 10% by BP-HPLC and 6 to 11% by OTR-UPLC methods. No single impurity was >2.0%, and the CDP-1 level was ≤2.0% across all products. Some variability in impurity profiles of the various products was observed. No adverse product quality issues were identified with the six U.S. vancomycin parenteral products. The quality parameters of all parenteral vancomycin products tested surpassed the United States Pharmacopeia acceptance criteria. Additional testing will characterizein vivoperformance characteristics of these products.

Plasma Levels of Neopterin and Biopterin in the Umbilical Vessels and the Maternal Vein

Pteridines ◽  
2003 ◽  
Vol 14 (1) ◽  
pp. 1-4
Author(s):  
Naoko Iwanaga ◽  
Seiichi Yamamasu ◽  
Daisuke Tachibana ◽  
Junko Nishio ◽  
Yuichiro Nakai ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
High Performance ◽  
Umbilical Artery ◽  
Umbilical Vein ◽  
Aromatic Amino Acids ◽  
Maternal Plasma ◽  
Chromatography Method ◽  
Fetal Plasma ◽  
Significant Difference ◽  
Liquid Chromatography Method

Abstract Tetrahydrobiopterin (BH4) is a highly bioactive pterin required for nitric oxide synthase and monooxygenases of aromatic amino acids, and is involved in the synthesis of nitric oxide, catecholamines and Serotonin. Although these functions imply that pterin metabolism plays critical roles in human development, the intrauterine metabolism is unclear. To elucidate the pterin metabolism in the human feto-placental unit, blood was obtained from the umbilical artery and vein, and the maternal vein, and plasma biopterin and neopterin concentrations were analyzed by the high-performance liquid chromatography method. To clarify the effect of labor, data was also compared between the transvaginal delivery (TV) and the caesarean delivery (CS). The levels of biopterin and the neopterin, and neopterin/biopterin ratio were higher in the fetal plasma than in the maternal plasma. Biopterin levels in the umbilical artery were higher than those in the umbilical vein. There were significant correlations in either biopterin or neopterin between the fetal plasma and the maternal plasma. There was no significant difference in the fetal pterin levels between TV and CS. The results suggest the stimulated BH4 synthesis in the fetoplacental unit, the independent homeostasis of the fetal pterin metabolism, and the possibility of dynamic movements of pterins among the fetus, the placenta and the mother.

scholarly journals Protective Effectiveness of Long-Lasting Permethrin Impregnated Clothing Against Tick Bites in an Endemic Lyme Disease Setting: A Randomized Control Trial Among Outdoor Workers

2020 ◽  
Vol 57 (5) ◽  
pp. 1532-1538
Author(s):  
Cedar Mitchell ◽  
Megan Dyer ◽  
Feng-Chang Lin ◽  
Natalie Bowman ◽  
Thomas Mather ◽  
...  
Keyword(s):  
United States ◽  
Rhode Island ◽  
The United States ◽  
Amblyomma Americanum ◽  
Adverse Outcomes ◽  
Control Group ◽  
Tick Bites ◽  
Outdoor Workers ◽  
Significant Difference ◽  
Protective Effectiveness

Abstract Tick-borne diseases are a growing threat to public health in the United States, especially among outdoor workers who experience high occupational exposure to ticks. Long-lasting permethrin-impregnated clothing has demonstrated high initial protection against bites from blacklegged ticks, Ixodes scapularis Say (Acari: Ixodidae), in laboratory settings, and sustained protection against bites from the lone star tick, Amblyomma americanum (L.) (Acari: Ixodidae), in field tests. However, long-lasting permethrin impregnation of clothing has not been field tested among outdoor workers who are frequently exposed to blacklegged ticks. We conducted a 2-yr randomized, placebo-controlled, double-blinded trial among 82 outdoor workers in Rhode Island and southern Massachusetts. Participants in the treatment arm wore factory-impregnated permethrin clothing, and the control group wore sham-treated clothing. Outdoor working hours, tick encounters, and bites were recorded weekly to assess protective effectiveness of long-lasting permethrin-impregnated garments. Factory-impregnated clothing significantly reduced tick bites by 65% in the first study year and by 50% in the second year for a 2-yr protective effect of 58%. No significant difference in other tick bite prevention method utilization occurred between treatment and control groups, and no treatment-related adverse outcomes were reported. Factory permethrin impregnation of clothing is safe and effective for the prevention of tick bites among outdoor workers whose primary exposure is to blacklegged ticks in the northeastern United States.

scholarly journals HPLC Quantification of Cytotoxic Compounds fromAspergillus niger

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Paula Karina S. Uchoa ◽  
Leandro Bezerra de Lima ◽  
Antonia T. A. Pimenta ◽  
Maria da Conceição F. de Oliveira ◽  
Jair Mafezoli ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Standard Deviation ◽  
High Performance ◽  
Chromatography Method ◽  
Relative Standard ◽  
Validation Parameters ◽  
Cytotoxic Compounds ◽  
Liquid Chromatography Method ◽  
Marine Strain

A high-performance liquid chromatography method was developed and validated for the quantification of the cytotoxic compounds produced by a marine strain ofAspergillus niger. The fungus was grown in malt peptone dextrose (MPD), potato dextrose yeast (PDY), and mannitol peptone yeast (MnPY) media during 7, 14, 21, and 28 days, and the natural products were identified by standard compounds. The validation parameters obtained were selectivity, linearity (coefficient of correlation > 0.99), precision (relative standard deviation below 5%), and accuracy (recovery > 96).

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