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V J Stella - One of the best experts on this subject based on the ideXlab platform.

  • Release mechanisms of a sparingly water-soluble drug from controlled porosity-Osmotic pump pellets using sulfobutylether-β-cyclodextrin as both a solubilizing and Osmotic Agent
    Journal of pharmaceutical sciences, 2009
    Co-Authors: Sutthilug Sotthivirat, John L. Haslam, Ping I. Lee, Venkatramana M. Rao, V J Stella
    Abstract:

    ABSTRACT: The purpose of this work is to delineate the release mechanisms of a sparingly water-soluble drug, prednisolone (PDL), from a microporous or controlled porosity–Osmotic pump pellet (CP–OPP) using sulfobutylether-β-cyclodextrin (CD) as both a solubilizing and Osmotic Agent. All factors, Osmotic and diffusional, influencing drug release as described by the Theeuwes and Zentner equation were partially demonstrated in an earlier paper 1 and are further quantitatively evaluated here to determine whether the equation may be applied to CP–OPPs. The PDL release rate from the CP–OPPs containing precomplexed PDL follows the zero-order kinetics for up to 30–40% of drug release during the first 1–2 h and subsequently nonzero order kinetics. The zero-order drug release phase reveals the main contribution is from Osmotic pumping with a negligible diffusion component, resulting from the nearly constant driving forces in the system. The nonzero order drug release phase is associated with the dynamic changes in the system (e.g., declining Osmotic driving force and greater diffusion component with time). In addition, the parameters related to membrane characteristics were determined, and the effect of viscosity was evaluated for the pellet system. The membranes coated on the CP–OPPs are less permeable to water or solutes than the membranes coated on the previously reported tablets. The viscosity due to the CD decreases as a function of CD concentration, which partly affects the observed drug release profiles. The viscosity effect of CD is significant and captured in a hydraulic permeability term. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:1992–2000, 2009

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)(7m)-beta-CD as both a solubilizer and Osmotic Agent.
    Journal of controlled release : official journal of the Controlled Release Society, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-beta-cyclodextrin, (SBE)(7m)-beta-CD, as both a solubilizing and Osmotic Agent. The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. The release rate of CLP from OPTs containing (SBE)(7m)-beta-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)7m-β-CD as both a solubilizer and Osmotic Agent
    Journal of Controlled Release, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    Abstract Purpose: The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-β-cyclodextrin, (SBE)7m-β-CD, as both a solubilizing and Osmotic Agent. Method: The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. Results: The release rate of CLP from OPTs containing (SBE)7m-β-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. Conclusion: The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.

  • release of testosterone from an Osmotic pump tablet utilizing sbe 7m β cyclodextrin as both a solubilizing and an Osmotic pump Agent
    Journal of Controlled Release, 1999
    Co-Authors: K Okimoto, R A Rajewski, V J Stella
    Abstract:

    A controlled porosity Osmotic pump system for poorly water soluble drugs has been developed using sulfobutyl ether-beta-cyclodextrin sodium salt, (SBE)7m-beta-CD, which can act as both a solubilizing and an Osmotic Agent. The release of testosterone, a poorly water soluble drug (0.039 mg/ml at 37 degrees C), was evaluated using a new model device. The effect of (SBE)7m-beta-CD as the solubilizing and Osmotic pump Agent was compared with hydroxypropyl-beta-cyclodextrin (HP-beta-CD), a neutral cyclodextrin, and a sugar mixture (Osmotic Agent only). Testosterone release from the device was significantly faster with (SBE)7m-beta-CD than with HP-beta-CD or the sugar mixture. The solubility of testosterone in the device increased to 76.7 mg/ml through complexation with (SBE)7m-beta-CD in the imbibed water. It appears that testosterone release from the device in the presence of (SBE)7m-beta-CD was mainly due to Osmotic pumping while for HP-beta-CD the major contribution appears to be due to diffusion. In the case of the sugar mixture, testosterone was poorly released, presumably due to the absence of a solubilizer. Therefore, it was concluded that (SBE)7m-beta-CD provides novel properties for the development of controlled- porosity Osmotic pump tablets for poor solubility drugs.

K Okimoto - One of the best experts on this subject based on the ideXlab platform.

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)(7m)-beta-CD as both a solubilizer and Osmotic Agent.
    Journal of controlled release : official journal of the Controlled Release Society, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-beta-cyclodextrin, (SBE)(7m)-beta-CD, as both a solubilizing and Osmotic Agent. The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. The release rate of CLP from OPTs containing (SBE)(7m)-beta-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)7m-β-CD as both a solubilizer and Osmotic Agent
    Journal of Controlled Release, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    Abstract Purpose: The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-β-cyclodextrin, (SBE)7m-β-CD, as both a solubilizing and Osmotic Agent. Method: The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. Results: The release rate of CLP from OPTs containing (SBE)7m-β-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. Conclusion: The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.

  • release of testosterone from an Osmotic pump tablet utilizing sbe 7m β cyclodextrin as both a solubilizing and an Osmotic pump Agent
    Journal of Controlled Release, 1999
    Co-Authors: K Okimoto, R A Rajewski, V J Stella
    Abstract:

    A controlled porosity Osmotic pump system for poorly water soluble drugs has been developed using sulfobutyl ether-beta-cyclodextrin sodium salt, (SBE)7m-beta-CD, which can act as both a solubilizing and an Osmotic Agent. The release of testosterone, a poorly water soluble drug (0.039 mg/ml at 37 degrees C), was evaluated using a new model device. The effect of (SBE)7m-beta-CD as the solubilizing and Osmotic pump Agent was compared with hydroxypropyl-beta-cyclodextrin (HP-beta-CD), a neutral cyclodextrin, and a sugar mixture (Osmotic Agent only). Testosterone release from the device was significantly faster with (SBE)7m-beta-CD than with HP-beta-CD or the sugar mixture. The solubility of testosterone in the device increased to 76.7 mg/ml through complexation with (SBE)7m-beta-CD in the imbibed water. It appears that testosterone release from the device in the presence of (SBE)7m-beta-CD was mainly due to Osmotic pumping while for HP-beta-CD the major contribution appears to be due to diffusion. In the case of the sugar mixture, testosterone was poorly released, presumably due to the absence of a solubilizer. Therefore, it was concluded that (SBE)7m-beta-CD provides novel properties for the development of controlled- porosity Osmotic pump tablets for poor solubility drugs.

K Uekama - One of the best experts on this subject based on the ideXlab platform.

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)(7m)-beta-CD as both a solubilizer and Osmotic Agent.
    Journal of controlled release : official journal of the Controlled Release Society, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-beta-cyclodextrin, (SBE)(7m)-beta-CD, as both a solubilizing and Osmotic Agent. The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. The release rate of CLP from OPTs containing (SBE)(7m)-beta-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)7m-β-CD as both a solubilizer and Osmotic Agent
    Journal of Controlled Release, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    Abstract Purpose: The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-β-cyclodextrin, (SBE)7m-β-CD, as both a solubilizing and Osmotic Agent. Method: The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. Results: The release rate of CLP from OPTs containing (SBE)7m-β-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. Conclusion: The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.

R A Rajewski - One of the best experts on this subject based on the ideXlab platform.

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)(7m)-beta-CD as both a solubilizer and Osmotic Agent.
    Journal of controlled release : official journal of the Controlled Release Society, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-beta-cyclodextrin, (SBE)(7m)-beta-CD, as both a solubilizing and Osmotic Agent. The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. The release rate of CLP from OPTs containing (SBE)(7m)-beta-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)7m-β-CD as both a solubilizer and Osmotic Agent
    Journal of Controlled Release, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    Abstract Purpose: The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-β-cyclodextrin, (SBE)7m-β-CD, as both a solubilizing and Osmotic Agent. Method: The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. Results: The release rate of CLP from OPTs containing (SBE)7m-β-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. Conclusion: The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.

  • release of testosterone from an Osmotic pump tablet utilizing sbe 7m β cyclodextrin as both a solubilizing and an Osmotic pump Agent
    Journal of Controlled Release, 1999
    Co-Authors: K Okimoto, R A Rajewski, V J Stella
    Abstract:

    A controlled porosity Osmotic pump system for poorly water soluble drugs has been developed using sulfobutyl ether-beta-cyclodextrin sodium salt, (SBE)7m-beta-CD, which can act as both a solubilizing and an Osmotic Agent. The release of testosterone, a poorly water soluble drug (0.039 mg/ml at 37 degrees C), was evaluated using a new model device. The effect of (SBE)7m-beta-CD as the solubilizing and Osmotic pump Agent was compared with hydroxypropyl-beta-cyclodextrin (HP-beta-CD), a neutral cyclodextrin, and a sugar mixture (Osmotic Agent only). Testosterone release from the device was significantly faster with (SBE)7m-beta-CD than with HP-beta-CD or the sugar mixture. The solubility of testosterone in the device increased to 76.7 mg/ml through complexation with (SBE)7m-beta-CD in the imbibed water. It appears that testosterone release from the device in the presence of (SBE)7m-beta-CD was mainly due to Osmotic pumping while for HP-beta-CD the major contribution appears to be due to diffusion. In the case of the sugar mixture, testosterone was poorly released, presumably due to the absence of a solubilizer. Therefore, it was concluded that (SBE)7m-beta-CD provides novel properties for the development of controlled- porosity Osmotic pump tablets for poor solubility drugs.

T Irie - One of the best experts on this subject based on the ideXlab platform.

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)(7m)-beta-CD as both a solubilizer and Osmotic Agent.
    Journal of controlled release : official journal of the Controlled Release Society, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-beta-cyclodextrin, (SBE)(7m)-beta-CD, as both a solubilizing and Osmotic Agent. The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. The release rate of CLP from OPTs containing (SBE)(7m)-beta-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.

  • Factors affecting membrane-controlled drug release for an Osmotic pump tablet (OPT) utilizing (SBE)7m-β-CD as both a solubilizer and Osmotic Agent
    Journal of Controlled Release, 1999
    Co-Authors: K Okimoto, A Ohike, R Ibuki, O Aoki, N Ohnishi, R A Rajewski, V J Stella, T Irie, K Uekama
    Abstract:

    Abstract Purpose: The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity Osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-β-cyclodextrin, (SBE)7m-β-CD, as both a solubilizing and Osmotic Agent. Method: The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. Results: The release rate of CLP from OPTs containing (SBE)7m-β-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. Conclusion: The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.