Stability of fentanyl 5 microg/mL diluted with 0.9% sodium chloride injection and stored in polypropylene syringes.

PURPOSE: The stability of fentanyl 5 microg/mL in 0.9% sodium chloride solution packaged in polypropylene syringes was studied. METHODS: Samples of fentanyl 5 microg (as the citrate) per milliliter in 0.9% sodium chloride injection were prepared and assessed for chemical stability using a validated, stability-indicating high- performance liquid chromatographic (HPLC) assay. A total of 12 syringe samples were submitted for chemical stability testing by HPLC. The syringes were protected from light and stored in controlled ambient conditions (23-27 degrees C and 55-65% relative humidity) in an environmental chamber. Three samples were tested initially and at each 30-day interval. Each syringe sample was tested with two determinations, using the average of the determinations for the assay result. Samples were assessed for pH and inspected for color and visible particulate matter. Stability was defined as the retention of 90-110% of the initial drug concentration at 30, 60, and 90 days. RESULTS: Fentanyl citrate injection maintained the appearance of a clear, colorless solution, with mean +/- S.D. pH values ranging from 4.13 +/- 0.01 to 4.52 +/- 0.02 throughout the study period. Recovery of fentanyl ranged from 99.86% +/- 0.29% to 102.74% +/- 1.60% of the initial concentration, with no detectable changes in the chromatographic profiles of all tested samples. CONCLUSION: Fentanyl 5 microg (as the citrate) per milliliter in 0.9% sodium chloride injection, packaged in polypropylene syringes and stored protected from light, was stable for at least 90 days in controlled ambient conditions.

Drug Compatibility with a New Generation of VISIV Polyolefin Infusion Solution Containers.

A new generation of VISIV polyolefin intravenous solution containers, made of a new and different proprietary polymer, were evaluated for sorption and leaching potential with a cadre of drugs known to exhibit those phenomena with polyvinylchloride containers. Sorption potential was evaluated for amiodarone hydrochloride, carmustine, regular human insulin, lorazepam, nitroglycerin, sufentanil citrate, and thiopental sodium. Leaching potential was evaluated for tacrolimus and teniposide as well as the vehicles of docetaxel and paclitaxel. Representative concentrations of the drugs in infusion solutions or undiluted were placed into the new generation of VISIV containers and left in contact for up to 24 hours at room temperature. High performance liquid chromatography was used to determine drug concentrations and the presence of plasticizer or other plastic components, if any. Only regular human insulin exhibited any substantial loss of concentration in the polyolefin containers that could be attirbuted to sorption. Other drugs' concentrations were consistent with their stabilities over the test periods. No evidence of leaching of plasiticizer or other plastic components was observed.

Physical and chemical stability of esomeprazole sodium solutions.

BACKGROUND: Esomeprazole sodium (Nexium IV, AstraZeneca) is the S-isomer of omeprazole and acts as a proton pump inhibitor gastric antisecretory agent indicated for the short-term treatment of gastroesophageal reflux disease in patients with a history of erosive esophagitis. Currently, there is no information on the long-term stability of esomeprazole sodium in infusion solutions beyond 12 hours. OBJECTIVE: To evaluate the stability of esomeprazole sodium in 5% dextrose, 0.9% sodium chloride, and lactated Ringer's injection, at 2 concentrations, at room temperature and when refrigerated. METHODS: Triplicate samples of esomeprazole 0.4 and 0.8 mg/mL as the sodium salt were prepared in the solutions required. Stability evaluations were performed initially, over 2 days stored at 23 degrees C, and over 5 days stored at 4 degrees C. Physical stability was assessed using turbidimetric and particulate measurement, as well as visual observation. Chemical stability was evaluated by stability-indicating high-performance liquid chromatography. RESULTS: The samples in all 3 infusion solutions were physically stable throughout the study. None of the samples had evidence of visible haze or particulates. Most samples developed a slight yellow discoloration within 24 hours, but this discoloration was not accompanied by an excessive loss of drug content. The esomeprazole sodium samples in all 3 infusion solutions exhibited less than 7% loss over 2 days at 23 degrees C and over 5 days at 4 degrees C. CONCLUSIONS: Esomeprazole 0.4 and 0.8 mg/mL as the sodium salt in the infusion solutions tested is chemically and physically stable for at least 2 days at room temperature and 5 days under refrigeration.

Stability of Metronidazole Benzoate in SyrSpend SF One-Step Suspension System.

The objective of this study was to determine the stability of metronidazole benzoate suspension in SyrSpend SF One-Step Suspension system. The studied samples were packaged in 60-mL amber plastic prescription bottles, which were stored protected from light under controlled environmental conditions for a period of 360 days. Stability of metronidazole benzoate suspension in SyrSpend SF was assessed based on retention of initial color or appearance, pH of suspension, and recovery of metronidazole benzoate from the packaged product. Duplicate samples were evaluated at each predefined time interval. An assay method by high performance liquid chromatography was validated for its specificity and stability-indicating characteristscs through a forced-degradation study, and was used in metronidazole benzoate assay. Metronidazole benzoate in SyrSpend SF retained its normal appearance of an opaque suspension, with acceptable pH values ranging from 4.43 to 4.53 (range 4.45 +/- 0.5). Recovery of metronidazole benzoate at subsequent time points was within 90% to 110% of inital concentration for samples stored at refrigerated temperature (2 deg C to 8 deg C), and ambient condition (25 deg C/60% relative humidity), with no detectable changes in chromatographic profile for most tested samples. The rates of change in potency for metronidazole benzoate were determined under the assumptions of first-order kinetics, and the time to reach 90% to 110% initial concentration was determined to be 366 days for samples in ambient storage, or 716 days for samples stored at refrigerated temperature. Metronidazole benzoate in SyrSpend SF, which was packaged in amber plastic prescription bottles, is stable for at least 1 year when stored protected from light at ambient condition (25 deg C/60% relative humidity). The shelf life for this product may be extended to 2 years when stored at refrigerated temperature.

Identification of CYP2D6 impaired functional alleles in Mexican Americans.

OBJECTIVES: To extend the genotyping analysis of the CYP2D6 gene and further explain variability of CYP2D6 activity in Mexican Americans by genetic factors. METHODS: CYP2D6 gene sequence variations associated with *6, *7, *8, *9, *11, *14, *29, *41, *45, and *46 alleles as well as the 2988G>A SNP were examined in 264 Mexican Americans; 236 had previously been phenotyped with dextromethorphan. All subjects were previously genotyped for CYP2D6*2, *3, *4, *5, *10, *17, and the presence of a gene duplication. Associations between genotype and CYP2D6 activity were determined. RESULTS: Mexican Americans revealed a high frequency of functional alleles (CYP2D6*1 and *2; 73.1%), followed by CYP2D6*4 (non-functional, 10.0%) and the reduced-function allele *41 (9.5%). The frequencies of CYP2D6*5, *6, *9, *10, duplication, and 2988A were 1.7%, 0.4%, 1.1%, 2.8%, 0.8%, and 5.7%, respectively. CYP2D6*3, *17, and *29 were found only in one individual (CYP2D6*2/*3, *1/*17, and *4/*29), while CYP2D6*7, *8, *11, *14, *45, and *46 were absent in this study population. Decreased CYP2D6 activity was more accurately predicted by the presence *41[-1584C] compared to *41[2988A]. One genotype/phenotype discordant subject was resolved by the presence of a CYP2D6*6 allele (*4/*6), while two other cases remained discordant (*41/*41 and *1/*1). CONCLUSIONS: The CYP2D6*4, *5, and *6 null alleles along the reduced function alleles *9, *10, and *41 are the major cause for diminished dextromethorphan oxidative capacity in Mexican Americans. These findings may have implications for the safety and efficacy of CYP2D6 substrates taken by Mexican Americans.

Polymorphisms of CYP2C19 and CYP2D6 in Israeli ethnic groups.

BACKGROUND: The cytochrome P450 isoenzymes CYP2C19 and CYP2D6 catalyze reactions involved in the metabolism of many widely used drugs. Their polymorphisms give rise to important interindividual and interethnic variability in the metabolism and disposition of several therapeutic agents and may cause differences in clinical response to some drugs. Individuals who carry two null alleles of either gene are known as poor metabolizers (PMs), while those who carry more than two copies of the functional CYP2D6 gene are ultrarapid metabolizers (UMs). AIM: The aim of the current study was to genotype Israelis from four different ethnic backgrounds with respect to CYP2C19 and CYP2D6. STUDY DESIGN: Polymorphisms of the CYP2C19 and CYP2D6 genes were determined by genotyping the four ethnic groups using PCR and/or restriction fragment length polymorphism (RFLP) analysis. The groups consisted of three Jewish communities, Yemenite Jews (n = 36), Sephardic Jews (n = 47), Ethiopian Jews (n = 28), and one Arabian population, Bedouins (n = 50). RESULTS: CYP2C19*2 allele frequencies ranged from 12.0 to 19.6% among the four ethnic groups. Within the study population, the CYP2C19*3 gene was only found in one Bedouin individual, in the heterozygous state (CYP2C19*1/*3). In each group, one individual was homozygous for CYP2C19*2, and were predicted to be PMs. The data revealed a high prevalence of CYP2D6*2, *4, *10, *41, and gene duplication, followed by *5 and *17, while *3 was very rare. The frequencies of the CYP2D6*4, *10, and *17 alleles and CYP2D6 gene duplication were significantly different among the four groups. However, the CYP2D6*2, *3, and *5 and *41 alleles showed similar frequencies in the four groups. Four (8.5%) Sephardic Jews and one (2.0%) Bedouin were found with the genotype CYP2D6*4/*4 (two null alleles), and were thus presumably PMs. A total of 15 individuals, distributed in all groups, were found with functional CYP2D6 gene duplications. The frequencies of predicted UMs (duplication of CYP2D6) were 17.8% (5/28) and 12.8% (6/47) in Ethiopian Jews and Sephardic Jews, respectively, which were higher than that of Yemenite Jews (5.6%, 2/36) and Bedouins (4.0%, 2/50). CONCLUSIONS: This is the first study of the CYP2D6 gene polymorphism in Israeli ethnic groups, either Jewish or Arab. Furthermore, this is also the first study of the CYP2C19 gene polymorphism in Jewish or Arab subgroups living in Israel. The frequencies of various alleles for the CYP2D6 gene are significantly different among the ethnic groups in Israel. These new findings may have important clinical implications in administrating drugs metabolized by CYP2D6 and for CYP2D6-related adverse drug reactions in the Israeli population.