RESUMEN
PURPOSE: To develop a strategy to control benzene, an ICH Q3C Class 1 impurity that may be present in spray solvents at ppm concentration, in amorphous polymer-stabilized spray-dried dispersion (SDD) products. METHODS: Risk assessments included determining the probability for benzene concentration in primary spray solvents, the physical properties of volatiles, and the potential enrichment of benzene from solution to solid. Mechanistic understanding of benzene removal was gained through a benzene-spiked fate and tolerance (F&T) study simulating worst-case spray-drying conditions and application of diffusion models for secondary drying. RESULTS: The mass ratio of spray solution to solid presented the highest risk of benzene enrichment. With slow spray-drying kinetics, benzene was reduced about 700-fold. Under standard secondary-drying conditions to remove residual solvents, residual benzene was further removed. Using diffusion models, the maximum benzene concentration was approximated for SDDs dried to the in-process control (IPC) limit of primary solvents. CONCLUSIONS: Two critical control points were established to eliminate any risk of residual benzene reaching patients: (1) upstream control of benzene in solvents (≤10 ppm) and (2) IPC of residual solvents in polymer-stabilized SDDs.
Asunto(s)
Benceno/análisis , Contaminación de Medicamentos/prevención & control , Excipientes/química , Metilcelulosa/análogos & derivados , Acetona , Cromatografía de Gases , Desecación , Difusión , Composición de Medicamentos , Metanol , Metilcelulosa/química , Modelos Estadísticos , Reproducibilidad de los Resultados , Medición de Riesgo , SolventesRESUMEN
PURPOSE: To understand the mechanisms of secondary drying of spray-dried dispersion (SDD) drug product and establish a model to describe the fate of organic solvents in such a product. METHODS: The experimental approach includes characterization of the SDD particles, drying studies of SDD using an integrated weighing balance and mass spectrometer, and the subsequent generation of the drying curve. The theoretical approach includes the establishment of a Fickian diffusion model. RESULTS: The kinetics of solvent removal during secondary drying from the lab scale to a bench scale follows Fickian diffusion model. Excellent agreement is obtained between the experimental data and the prediction from the modeling. CONCLUSIONS: The diffusion process is dependent upon temperature. The key to a successful scale up of the secondary drying is to control the drying temperature. The fate of primary solvents including methanol and acetone, and their potential impurity such as benzene can be described by the Fickian diffusion model. A mathematical relationship based upon the ratio of diffusion coefficient was established to predict the benzene concentration from the fate of the primary solvent during the secondary drying process.
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Acetona/aislamiento & purificación , Desecación/métodos , Metanol/aislamiento & purificación , Solventes/aislamiento & purificación , Difusión , Estabilidad de Medicamentos , Cinética , Modelos Químicos , TemperaturaRESUMEN
A reliable and reproducible high performance liquid chromatography method with coulometric detection was developed and validated for the quantitative determination of trace-levels of hydrogen peroxide in crospovidone, a pharmaceutical excipient, and a capsule pharmaceutical product. The method conditions included: a reproducible extraction procedure to provide a concentrated extract, aqueous extraction solvent; a simple HPLC mobile phase (aqueous 50 mM ammonium acetate) compatible with the coulometric detection; a reserve-phase HPLC column that did not collapse under 100% aqueous mobile phase conditions providing sufficient retention and separation of hydrogen peroxide from interferences; and a coulometric detector with a multi-electrode array providing sensitive and selective detection. The method validation results, including those for specificity, linearity, accuracy, precision, and recovery, were acceptable for the determination of trace levels of hydrogen peroxide. The method was shown to be linear over the range of 0.6-4.5 ppm (microg/g) and 6-90 ppm (microg/g) for the pharmaceutical product and crospovidone, respectively. The described method was applied to the determination of trace levels of hydrogen peroxide in different batches of crospovidone and the corresponding pharmaceutical product batches manufactured from these batches of this excipient.
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Cromatografía Líquida de Alta Presión/métodos , Peróxido de Hidrógeno/análisis , Povidona/análisis , Cápsulas , Contaminación de Medicamentos , Excipientes/análisis , Excipientes/química , Peróxido de Hidrógeno/química , Preparaciones Farmacéuticas/análisis , Preparaciones Farmacéuticas/química , Povidona/química , Reproducibilidad de los ResultadosRESUMEN
A sensitive, specific, and robust liquid chromatography/mass spectrometric (LC/MS) method was developed and validated that allows simultaneous analysis of arachidonic acid (AA) and its cyclooxygenase, cytochrome P450, and lipoxygenase pathway metabolites prostaglandins (PGs), dihydroxyeicosatrienoic acids (DiHETrEs), hydroxyeicosatetraenoic acids (HETEs) and epoxyeicosatrienoic acids (EETs), including PGF(2alpha), PGE(2), PGD(2), PGJ(2), 14,15-DiHETrE, 11,12-DiHETrE, 8,9-DiHETrE, 5,6-DiHETrE, 20-HETE, 15-HETE, 12-HETE, 9-HETE, 8-HETE, 5-HETE, 14,15-EET, 11,12-EET, 8,9-EET, and 5,6-EET in rat brain tissues. Deuterium labeled PGF(2alpha)-d(4), PGD(2)-d(4), 15(S)-HETE-d(8), 14,15-EET-d(8), 11,12-EET-d(8), 8,9-EET-d(8), and AA-d(8) were used as internal standards. Solid phase extraction was used for sample preparation. A gradient LC/MS method using a C18 column and electrospray ionization source under negative ion mode was optimized for the best sensitivity and separation within 35 min. The method validation, including LC/MS instrument qualification, specificity, calibration model, accuracy, precision (without brain matrix and with brain matrix), and extraction efficiency were performed. The linear ranges of the calibration curves were 2-1000 pg for PGs, DiHETrEs, HETEs, and EETs, 10-2400 pg for PGE(2) and PGD(2), and 20-2000 ng for AA, respectively.
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Ácido Araquidónico/análisis , Ácidos Araquidónicos/análisis , Química Encefálica/efectos de los fármacos , Eicosanoides/análisis , Ácidos Hidroxieicosatetraenoicos/análisis , Prostaglandinas/análisis , Animales , Calibración , Corteza Cerebral/química , Corteza Cerebral/metabolismo , Cromatografía Liquida , Sistema Enzimático del Citocromo P-450/metabolismo , Lipooxigenasa/metabolismo , Masculino , Espectrometría de Masas , Prostaglandina-Endoperóxido Sintasas/metabolismo , Control de Calidad , Ratas , Ratas Sprague-Dawley , Estándares de Referencia , Reproducibilidad de los ResultadosRESUMEN
INTRODUCTION: A specific, accurate, and reproducible liquid chromatography-mass spectrometric (LC/MS) method was developed and validated that allows simultaneous measurement of the centrally acting analgesic buprenorphine and its major metabolite, norbuprenorphine, in rat brain and plasma samples. METHODS: A 96-well plate solid phase extraction (SPE) procedure was developed for buprenorphine and norbuprenorphine using mixed-mode cation-exchange reversed-phase sorbent. An LC method using a C8 column with isocratic mobile phase (80:20 water/acetonitrile with 20 mM ammonium acetate and 0.1% acetic acid) was developed for reproducible and selective separation. A quadrupole mass spectrometer with atmospheric electrospray ionization source under positive ion mode was used for detection. d4-Buprenorphine and d3-norbuprenorphine were used as internal standards. RESULTS: The calibration curves for buprenorphine and norbuprenorphine in plasma and brain tissue were linear within the range of 7 to 8333 ng/ml (plasma) and 5 to 5000 ng/g (brain). The lower limit of quantification for both buprenorphine and norbuprenorphine from brain tissue was 5 ng/g, and from plasma was 7 ng/ml. Assay accuracy and precision of back-calculated standards were within +/-15%. DISCUSSION: This method will be useful for investigation of buprenorphine's mechanism of action and clinical profile.
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Analgésicos Opioides/análisis , Química Encefálica , Buprenorfina/análogos & derivados , Buprenorfina/análisis , Cromatografía Liquida/métodos , Espectrometría de Masa por Ionización de Electrospray/métodos , Analgésicos Opioides/sangre , Animales , Buprenorfina/sangre , Técnicas In Vitro , Masculino , Ratas , Estándares de Referencia , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: Increases in brain cyclooxygenase-2 (COX2) are associated with the central inflammatory response and with delayed neuronal death, events that cause secondary insults after traumatic brain injury. A growing literature supports the benefit of COX2-specific inhibitors in treating brain injuries. METHODS: DFU [5,5-dimethyl-3(3-fluorophenyl)-4(4-methylsulfonyl)phenyl-2(5)H)-furanone] is a third-generation, highly specific COX2 enzyme inhibitor. DFU treatments (1 or 10 mg/kg intraperitoneally, twice daily for 3 d) were initiated either before or after traumatic brain injury in a lateral cortical contusion rat model. RESULTS: DFU treatments initiated 10 minutes before injury or up to 6 hours after injury enhanced functional recovery at 3 days compared with vehicle-treated controls. Significant improvements in neurological reflexes and memory were observed. DFU initiated 10 minutes before injury improved histopathology and altered eicosanoid profiles in the brain. DFU 1 mg/kg reduced the rise in prostaglandin E2 in the brain at 24 hours after injury. DFU 10 mg/kg attenuated injury-induced COX2 immunoreactivity in the cortex (24 and 72 h) and hippocampus (6 and 72 h). This treatment also decreased the total number of activated caspase-3-immunoreactive cells in the injured cortex and hippocampus, significantly reducing the number of activated caspase-3-immunoreactive neurons at 72 hours after injury. DFU 1 mg/kg amplified potentially anti-inflammatory epoxyeicosatrienoic acid levels by more than fourfold in the injured brain. DFU 10 mg/kg protected the levels of 2-arachidonoyl glycerol, a neuroprotective endocannabinoid, in the injured brain. CONCLUSION: These improvements, particularly when treatment began up to 6 hours after injury, suggest exciting neuroprotective potential for COX2 inhibitors in the treatment of traumatic brain injury and support the consideration of Phase I/II clinical trials.
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Antiinflamatorios no Esteroideos/uso terapéutico , Lesiones Encefálicas/tratamiento farmacológico , Inhibidores de la Ciclooxigenasa/uso terapéutico , Furanos/uso terapéutico , Fármacos Neuroprotectores/uso terapéutico , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/farmacología , Ácidos Araquidónicos/análisis , Ataxia/tratamiento farmacológico , Ataxia/etiología , Química Encefálica , Lesiones Encefálicas/complicaciones , Lesiones Encefálicas/psicología , Trastornos del Conocimiento/tratamiento farmacológico , Trastornos del Conocimiento/etiología , Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa/administración & dosificación , Inhibidores de la Ciclooxigenasa/farmacología , Dinoprostona/análisis , Esquema de Medicación , Evaluación Preclínica de Medicamentos , Eicosanoides/análisis , Endocannabinoides , Inducción Enzimática , Conducta Exploratoria/efectos de los fármacos , Furanos/administración & dosificación , Furanos/farmacología , Glicéridos/análisis , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Fármacos Neuroprotectores/administración & dosificación , Fármacos Neuroprotectores/farmacología , Premedicación , Prostaglandina-Endoperóxido Sintasas/biosíntesis , Ratas , Ratas Sprague-Dawley , Recuperación de la Función , Reflejo Anormal/efectos de los fármacosRESUMEN
Arachidonic acid (AA) is metabolized to prostaglandins (PGs) via cyclooxygenases (COX) catalysis, and to epoxyeicosatrienoic acids (EETs), dihydroxyeicosatrienoic acids (DiHETrEs), and hydroxyeicosatetraenoic acids (HETEs) via cytochrome P450 (CYP450) enzymes. A reliable and robust fluorescence based HPLC method for these eicosanoids was developed. A new selective reverse-phase solid phase extraction (SPE) procedure was developed for PG, DiHETrEs, HETE, and EETs of interest from rat cortical brain tissue. The eicosanoids were derivatized with 2-(2,3-naphthalimino)ethyl-trifluoromethanesulphonate (NE-OTf), followed by separation and quantification at high sensitivity using reverse-phase HPLC with fluorescent detection, and further identified via LC/MS. The derivatization was studied and optimized to obtain reproducible reactions. Various PGs, DiHETrEs, HETEs, EETs, and AA were sensitively detected and baseline resolved simultaneously. LC/MS under positive electrospray ionization selected ion monitoring (SIM) mode was developed to further identify the peaks of these eicosanoids in cortical brain tissue. The method was applied in the traumatic brain injured rat brain.