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Publications (3)9.02 Total impact

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    ABSTRACT: Several sample preparation techniques were evaluated for extracting active pharmaceutical ingredient (API) from immediate release (IR) and controlled release (CR) tablet formulations. These techniques utilized either elevated temperature [e.g., accelerated solvent extraction (ASE) and microwave assisted extraction (MAE)] or particle size reduction [e.g., ball mill and homogenizer/Tablet Processing Workstation II (TPWII)]. Results were compared for equivalence to those obtained with the existing standard method for each formulation. For the CR formulations, sample preparation times were significantly reduced when using these techniques compared to the standard method. Advantages and limitations associated with each technique are discussed.
    Journal of Pharmaceutical and Biomedical Analysis 07/2008; 47(2):268-78. · 2.95 Impact Factor
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    ABSTRACT: Significant degradation of the amine-based smoking cessation drug varenicline tartrate in an early development phase osmotic, controlled-release (CR) formulation yields predominantly two products: N-methylvarenicline (NMV) and N-formylvarenicline (NFV). NMV is produced by reaction of the amine moiety with both formaldehyde and formic acid in an Eschweiler-Clarke reaction, while NFV is formed by reaction of formic acid alone with varenicline. This represents the first report of these reactions occurring on storage of solid pharmaceutical formulations. Both formaldehyde and formic acid are formed from oxidative degradation of polyethylene glycol (PEG) used in an osmotic coating through a process heavily dependent on the physical state of the PEG. When the concentration of PEG in the coating is sufficiently low, the PEG remains phase compatible with the other component of the coating (cellulose acetate) such that its degradation (and the resulting drug reactivity) is effectively eliminated. Antioxidants in the coating and oxygen scavengers in the packaging also serve to prevent the PEG degradation, and consequently provide for drug stability.
    Journal of Pharmaceutical Sciences 05/2008; 97(4):1499-507. · 3.13 Impact Factor
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    ABSTRACT: Non-traditional sample preparation/extraction techniques that utilized the Caliper Life Sciences Tablet Processing Workstation II (TPW II), Microwave Assisted Extraction (MAE), and Accelerated Solvent Extraction (ASE) were evaluated for the extraction of Compound A from a 50 mgA, 15% Spray Dried Dispersion (SDD) immediate released (IR) tablet formulation. The TPW II consistently provided complete recoveries with very short preparation/extraction times (approximately 30 min). MAE also provided complete recovery of the API from the tablet formulation, but required approximately twice the extraction time, while ASE provided the lowest recovery of the three non-traditional techniques. The sample preparation/extraction efficiencies of the three non-traditional techniques were compared to that of the 5.5 h long manual method.
    Journal of Pharmaceutical and Biomedical Analysis 12/2007; 45(4):565-71. · 2.95 Impact Factor