The Experts below are selected from a list of 165 Experts worldwide ranked by ideXlab platform

Steven L. Nail - One of the best experts on this subject based on the ideXlab platform.

  • freeze drying of tert butanol water cosolvent systems a case report on formation of a friable freeze dried powder of Tobramycin Sulfate
    Journal of Pharmaceutical Sciences, 2002
    Co-Authors: Sakchai Wittayaareekul, Gregory F. Needham, Nathaniel Milton, Michael L. Roy, Steven L. Nail
    Abstract:

    A case study is presented in which a tert-butanol (TBA)/water cosolvent system was found to be a useful means of producing freeze-dried Tobramycin Sulfate that readily forms a loose powder upon agitation in a specialized application in which a critical quality attribute is the ability to pour the sterile powder from the vial. Both formulation and processing variables are important in achieving acceptable physical properties of the cake as well as minimizing residual TBA levels. Liquid/liquid phase separation was observed above critical concentrations of both drug and TBA, resulting in a two-layered lyophilized cake with unacceptable appearance, physical properties, and residual TBA levels. However, the choice of Tobramycin Sulfate and TBA concentrations in the single-phase region of the phase diagram resulted in a lyophilized solid that can readily be poured from vials. Crystallization of TBA before drying is critical to achieving adequately low residual TBA levels, and this is reflected in the effect of thermal history of freezing on residual TBA levels, where rapid freezing results in incomplete crystallization of TBA and relatively high levels of residual solvent. Annealing at a temperature above T′g of the system after an initial freezing step significantly reduces the level of residual TBA. Secondary drying, even at increased temperature and for extended times, is not an effective method of reducing residual TBA levels. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91: 1147–1155, 2002

  • Freeze-Drying of tert-Butanol/Water Cosolvent Systems: A Case Report on Formation of a Friable Freeze-Dried Powder of Tobramycin Sulfate
    Journal of pharmaceutical sciences, 2002
    Co-Authors: Sakchai Wittaya-areekul, Gregory F. Needham, Nathaniel Milton, Michael L. Roy, Steven L. Nail
    Abstract:

    A case study is presented in which a tert-butanol (TBA)/water cosolvent system was found to be a useful means of producing freeze-dried Tobramycin Sulfate that readily forms a loose powder upon agitation in a specialized application in which a critical quality attribute is the ability to pour the sterile powder from the vial. Both formulation and processing variables are important in achieving acceptable physical properties of the cake as well as minimizing residual TBA levels. Liquid/liquid phase separation was observed above critical concentrations of both drug and TBA, resulting in a two-layered lyophilized cake with unacceptable appearance, physical properties, and residual TBA levels. However, the choice of Tobramycin Sulfate and TBA concentrations in the single-phase region of the phase diagram resulted in a lyophilized solid that can readily be poured from vials. Crystallization of TBA before drying is critical to achieving adequately low residual TBA levels, and this is reflected in the effect of thermal history of freezing on residual TBA levels, where rapid freezing results in incomplete crystallization of TBA and relatively high levels of residual solvent. Annealing at a temperature above T′g of the system after an initial freezing step significantly reduces the level of residual TBA. Secondary drying, even at increased temperature and for extended times, is not an effective method of reducing residual TBA levels. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91: 1147–1155, 2002

Jeffry G. Weers - One of the best experts on this subject based on the ideXlab platform.

  • Physical Characterization of Tobramycin Inhalation Powder: II. State Diagram of an Amorphous Engineered Particle Formulation
    Molecular pharmaceutics, 2017
    Co-Authors: Danforth Miller, Trixie Tan, John Nakamura, Richard Malcolmson, Thomas E. Tarara, Jeffry G. Weers
    Abstract:

    Tobramycin Inhalation Powder (TIP) is a spray-dried engineered particle formulation used in TOBI Podhaler, a drug-device combination for treatment of cystic fibrosis (CF). A TIP particle consists of two phases: amorphous, glassy Tobramycin Sulfate and a gel-phase phospholipid (DSPC). The objective of this work was to characterize both the amorphous and gel phases following exposure of TIP to a broad range of RH and temperature. Because, in principle, changes in either particle morphology or the solid-state form of the drug could affect drug delivery or biopharmaceutical properties, understanding physical stability was critical to development and registration of this product. Studies included morphological assessments of particles, thermal analysis to measure the gel-to-liquid crystalline phase transition (Tm) of the phospholipid and the glass transition temperature (Tg) of Tobramycin Sulfate, enthalpy relaxation measurements to estimate structural relaxation times, and gravimetric vapor sorption to measur...

  • Physical Characterization of Tobramycin Inhalation Powder: I. Rational Design of a Stable Engineered-Particle Formulation for Delivery to the Lungs
    Molecular pharmaceutics, 2015
    Co-Authors: Danforth Miller, Trixie Tan, John Nakamura, Richard Malcolmson, Thomas E. Tarara, Jeffry G. Weers
    Abstract:

    A spray-dried engineered particle formulation, Tobramycin Inhalation Powder (TIP), was designed through rational selection of formulation composition and process parameters. This PulmoSphere powder comprises small, porous particles with a high drug load. As a drug/device combination, TOBI Podhaler enables delivery of high doses of drug per inhalation, a feature critical for dry powder delivery of anti-infectives for treatment of cystic fibrosis. The objective of this work was to characterize TIP on both the particle and molecular levels using multiple orthogonal physical characterization techniques. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), electron spectroscopy for chemical analysis (ESCA), and Raman measurements show that a TIP particle consists of two phases: amorphous, glassy Tobramycin Sulfate with a glass transition temperature of about 100 °C and a gel-phase phospholipid (DSPC) with a gel-to-liquid-crystal transition temperature of about 80 °C. This was by design and...

Nathaniel Milton - One of the best experts on this subject based on the ideXlab platform.

  • freeze drying of tert butanol water cosolvent systems a case report on formation of a friable freeze dried powder of Tobramycin Sulfate
    Journal of Pharmaceutical Sciences, 2002
    Co-Authors: Sakchai Wittayaareekul, Gregory F. Needham, Nathaniel Milton, Michael L. Roy, Steven L. Nail
    Abstract:

    A case study is presented in which a tert-butanol (TBA)/water cosolvent system was found to be a useful means of producing freeze-dried Tobramycin Sulfate that readily forms a loose powder upon agitation in a specialized application in which a critical quality attribute is the ability to pour the sterile powder from the vial. Both formulation and processing variables are important in achieving acceptable physical properties of the cake as well as minimizing residual TBA levels. Liquid/liquid phase separation was observed above critical concentrations of both drug and TBA, resulting in a two-layered lyophilized cake with unacceptable appearance, physical properties, and residual TBA levels. However, the choice of Tobramycin Sulfate and TBA concentrations in the single-phase region of the phase diagram resulted in a lyophilized solid that can readily be poured from vials. Crystallization of TBA before drying is critical to achieving adequately low residual TBA levels, and this is reflected in the effect of thermal history of freezing on residual TBA levels, where rapid freezing results in incomplete crystallization of TBA and relatively high levels of residual solvent. Annealing at a temperature above T′g of the system after an initial freezing step significantly reduces the level of residual TBA. Secondary drying, even at increased temperature and for extended times, is not an effective method of reducing residual TBA levels. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91: 1147–1155, 2002

  • Freeze-Drying of tert-Butanol/Water Cosolvent Systems: A Case Report on Formation of a Friable Freeze-Dried Powder of Tobramycin Sulfate
    Journal of pharmaceutical sciences, 2002
    Co-Authors: Sakchai Wittaya-areekul, Gregory F. Needham, Nathaniel Milton, Michael L. Roy, Steven L. Nail
    Abstract:

    A case study is presented in which a tert-butanol (TBA)/water cosolvent system was found to be a useful means of producing freeze-dried Tobramycin Sulfate that readily forms a loose powder upon agitation in a specialized application in which a critical quality attribute is the ability to pour the sterile powder from the vial. Both formulation and processing variables are important in achieving acceptable physical properties of the cake as well as minimizing residual TBA levels. Liquid/liquid phase separation was observed above critical concentrations of both drug and TBA, resulting in a two-layered lyophilized cake with unacceptable appearance, physical properties, and residual TBA levels. However, the choice of Tobramycin Sulfate and TBA concentrations in the single-phase region of the phase diagram resulted in a lyophilized solid that can readily be poured from vials. Crystallization of TBA before drying is critical to achieving adequately low residual TBA levels, and this is reflected in the effect of thermal history of freezing on residual TBA levels, where rapid freezing results in incomplete crystallization of TBA and relatively high levels of residual solvent. Annealing at a temperature above T′g of the system after an initial freezing step significantly reduces the level of residual TBA. Secondary drying, even at increased temperature and for extended times, is not an effective method of reducing residual TBA levels. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91: 1147–1155, 2002

Gregory F. Needham - One of the best experts on this subject based on the ideXlab platform.

  • freeze drying of tert butanol water cosolvent systems a case report on formation of a friable freeze dried powder of Tobramycin Sulfate
    Journal of Pharmaceutical Sciences, 2002
    Co-Authors: Sakchai Wittayaareekul, Gregory F. Needham, Nathaniel Milton, Michael L. Roy, Steven L. Nail
    Abstract:

    A case study is presented in which a tert-butanol (TBA)/water cosolvent system was found to be a useful means of producing freeze-dried Tobramycin Sulfate that readily forms a loose powder upon agitation in a specialized application in which a critical quality attribute is the ability to pour the sterile powder from the vial. Both formulation and processing variables are important in achieving acceptable physical properties of the cake as well as minimizing residual TBA levels. Liquid/liquid phase separation was observed above critical concentrations of both drug and TBA, resulting in a two-layered lyophilized cake with unacceptable appearance, physical properties, and residual TBA levels. However, the choice of Tobramycin Sulfate and TBA concentrations in the single-phase region of the phase diagram resulted in a lyophilized solid that can readily be poured from vials. Crystallization of TBA before drying is critical to achieving adequately low residual TBA levels, and this is reflected in the effect of thermal history of freezing on residual TBA levels, where rapid freezing results in incomplete crystallization of TBA and relatively high levels of residual solvent. Annealing at a temperature above T′g of the system after an initial freezing step significantly reduces the level of residual TBA. Secondary drying, even at increased temperature and for extended times, is not an effective method of reducing residual TBA levels. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91: 1147–1155, 2002

  • Freeze-Drying of tert-Butanol/Water Cosolvent Systems: A Case Report on Formation of a Friable Freeze-Dried Powder of Tobramycin Sulfate
    Journal of pharmaceutical sciences, 2002
    Co-Authors: Sakchai Wittaya-areekul, Gregory F. Needham, Nathaniel Milton, Michael L. Roy, Steven L. Nail
    Abstract:

    A case study is presented in which a tert-butanol (TBA)/water cosolvent system was found to be a useful means of producing freeze-dried Tobramycin Sulfate that readily forms a loose powder upon agitation in a specialized application in which a critical quality attribute is the ability to pour the sterile powder from the vial. Both formulation and processing variables are important in achieving acceptable physical properties of the cake as well as minimizing residual TBA levels. Liquid/liquid phase separation was observed above critical concentrations of both drug and TBA, resulting in a two-layered lyophilized cake with unacceptable appearance, physical properties, and residual TBA levels. However, the choice of Tobramycin Sulfate and TBA concentrations in the single-phase region of the phase diagram resulted in a lyophilized solid that can readily be poured from vials. Crystallization of TBA before drying is critical to achieving adequately low residual TBA levels, and this is reflected in the effect of thermal history of freezing on residual TBA levels, where rapid freezing results in incomplete crystallization of TBA and relatively high levels of residual solvent. Annealing at a temperature above T′g of the system after an initial freezing step significantly reduces the level of residual TBA. Secondary drying, even at increased temperature and for extended times, is not an effective method of reducing residual TBA levels. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91: 1147–1155, 2002

Michael L. Roy - One of the best experts on this subject based on the ideXlab platform.

  • freeze drying of tert butanol water cosolvent systems a case report on formation of a friable freeze dried powder of Tobramycin Sulfate
    Journal of Pharmaceutical Sciences, 2002
    Co-Authors: Sakchai Wittayaareekul, Gregory F. Needham, Nathaniel Milton, Michael L. Roy, Steven L. Nail
    Abstract:

    A case study is presented in which a tert-butanol (TBA)/water cosolvent system was found to be a useful means of producing freeze-dried Tobramycin Sulfate that readily forms a loose powder upon agitation in a specialized application in which a critical quality attribute is the ability to pour the sterile powder from the vial. Both formulation and processing variables are important in achieving acceptable physical properties of the cake as well as minimizing residual TBA levels. Liquid/liquid phase separation was observed above critical concentrations of both drug and TBA, resulting in a two-layered lyophilized cake with unacceptable appearance, physical properties, and residual TBA levels. However, the choice of Tobramycin Sulfate and TBA concentrations in the single-phase region of the phase diagram resulted in a lyophilized solid that can readily be poured from vials. Crystallization of TBA before drying is critical to achieving adequately low residual TBA levels, and this is reflected in the effect of thermal history of freezing on residual TBA levels, where rapid freezing results in incomplete crystallization of TBA and relatively high levels of residual solvent. Annealing at a temperature above T′g of the system after an initial freezing step significantly reduces the level of residual TBA. Secondary drying, even at increased temperature and for extended times, is not an effective method of reducing residual TBA levels. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91: 1147–1155, 2002

  • Freeze-Drying of tert-Butanol/Water Cosolvent Systems: A Case Report on Formation of a Friable Freeze-Dried Powder of Tobramycin Sulfate
    Journal of pharmaceutical sciences, 2002
    Co-Authors: Sakchai Wittaya-areekul, Gregory F. Needham, Nathaniel Milton, Michael L. Roy, Steven L. Nail
    Abstract:

    A case study is presented in which a tert-butanol (TBA)/water cosolvent system was found to be a useful means of producing freeze-dried Tobramycin Sulfate that readily forms a loose powder upon agitation in a specialized application in which a critical quality attribute is the ability to pour the sterile powder from the vial. Both formulation and processing variables are important in achieving acceptable physical properties of the cake as well as minimizing residual TBA levels. Liquid/liquid phase separation was observed above critical concentrations of both drug and TBA, resulting in a two-layered lyophilized cake with unacceptable appearance, physical properties, and residual TBA levels. However, the choice of Tobramycin Sulfate and TBA concentrations in the single-phase region of the phase diagram resulted in a lyophilized solid that can readily be poured from vials. Crystallization of TBA before drying is critical to achieving adequately low residual TBA levels, and this is reflected in the effect of thermal history of freezing on residual TBA levels, where rapid freezing results in incomplete crystallization of TBA and relatively high levels of residual solvent. Annealing at a temperature above T′g of the system after an initial freezing step significantly reduces the level of residual TBA. Secondary drying, even at increased temperature and for extended times, is not an effective method of reducing residual TBA levels. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91: 1147–1155, 2002