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Parviz Mojaverian - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of gastrointestinal ph and Gastric Residence Time via the heidelberg radiotelemetry capsule pharmaceutical application
    Drug Development Research, 1996
    Co-Authors: Parviz Mojaverian
    Abstract:

    The Heidelberg Radiotelemetry Capsule (7 mm diameter x 20 mm length) represents a noninvasive device to monitor gastrointestinal (GI) pH and to evaluate Gastric Residence Time (GRT) in both animals and humans. Due to its large size and indigestible nature, Gastric emptying of the Heidelberg capsule occurs during the 5–15 min of Phase III migrating motor complex (MMC), which is responsible for emptying of indigestible debris leftover from a meal, the so-called housekeeper wave of the GI tract. Following initial in vitro accuracy and in vivo reproducibility studies, the Heidelberg capsule was used in young beagle dogs and normal healthy subjects. In the fasting state, Gastric pH was comparable in dogs and humans (1.5 ± 0.04 vs. 1.1 ± 0.15, mean ± SEM), where postprandially a more acidic pH was reported in beagle dogs (2.1 ± 0.04 vs. 3.6 ± 0.4). Both duodenal and fasting intestinal pHs were consistently higher in dogs than humans. Although fasting GRT of the Heidelberg capsule was similar between the two species (1.2 ± 0.33 vs. 1.2 ± 0.45 h), high intersubject variability in the GRT estimation was observed in both dogs and humans. The Heidelberg radiotelemetry technique was utilized in several clinical studies to evaluate the influence of physical and physiological parameters which alter the normal GI motility (i.e., food with varying composition and energy density, posture, gender, age, and Gastric alkalinization). The results of pH and GRT measurements via the Heidelberg capsule were found to be sensitive and responsive toward factors which alter the GI motility, and therefore, the Heidelberg capsule may be used in the clinical studies as a model for a large, nondisintegrating solid dosage form (i.e., enteric-coated formulations). Subsequently, the Heidelberg capsule was administered together with the enteric-coated aspirin (which is known for high inter- and intra-subject absorption variability) and with a more challenging enteric-coated formulation, diclofenac sodium. The results demonstrated that by reasonable estimation of the GRT, the Heidelberg capsule is capable of explaining and minimizing the traditional absorption variabilities observed with these formulations. In summary, the Heidelberg radiotelemetry device can be used as a noninvasive means of GI pH and transit Time. This accurate and reproducible telemetry system mimics the GI transit of a large indigestible solid dosage form and may be used in both animal research and human oral bioavailability/bioequivalency studies. © 1996 Wiley-Liss, Inc.

  • Influence of single and multiple doses of oral ranitidine on the Gastric transit of an indigestible capsule in humans
    Clinical Pharmacology & Therapeutics, 1990
    Co-Authors: Parviz Mojaverian, Peter H Vlasses, Susan Parker, Christopher W. Warner
    Abstract:

    The effect of single and multiple doses of ranitidine on the Gastric Residence Time of an indigestible pH-sensitive radiotelemetric device, the Heidelberg capsule, was evaluated in 12 healthy men (mean age, 29 ± 8 years) in a placebo-controlled, randomized, crossover study. Each subject received 150 mg ranitidine or placebo orally 2 hours before administration of the Heidelberg capsule. A 500 kcal standardized breakfast was served ½ hour before the capsule was administered. Gastric pH was monitored at 15-minute intervals, until pyloric passage (pH increase ≥3 U) of the Heidelberg capsule was observed. Blood samples (n = 12) were collected 0 to 8 hours after administration of drug or placebo. The subjects continued to receive ranitidine or placebo b.i.d. for 7 days and returned on day 8 for a similar evaluation. After a 1-week washout period, the subjects received the alternative treatment. The mean (±SD) Gastric Residence Time of the Heidelberg capsule was significantly decreased after both single and multiple doses of ranitidine compared to placebo (3.1 ± 0.9 versus 3.8 ±1.1 hours, p < 0.02; and 2.9 ± 0.74 versus 3.9 ± 0.9 hours, p < 0.005, n = 9). Gastric Residence Time was not determined in three subjects who showed unusually slow gastrointestinal motility after both placebo and ranitidine. Mean AUC(0–8 hr) and AUC(0–∞) were significantly increased, whereas Cmax, tmax, and t½ remained unchanged after 7 days of ranitidine b.i.d. treatment. No ranitidine double-peak profile or linear pharmacokinetic-pharmacodynamic relationship was identified. In conclusion, the findings of this study indicate that ranitidine may accelerate the Gastric transit of indigestible solid dosage formulations by approximately 1 hour. Clinical Pharmacology and Therapeutics (1990) 47, 382–388; doi:10.1038/clpt.1990.43

Vasudha Bakshi - One of the best experts on this subject based on the ideXlab platform.

  • DEVELOPMENT OF A PROLONGD RELEASE GASTRORETENTIVE TABLET FORMULATION OF LEVOFLOXACIN Original Article
    2020
    Co-Authors: I. Ashwini, P. Ramya Deepthi, A. Madhu Babu, Vasudha Bakshi
    Abstract:

    Objective: The present investigation concerns the design and evaluation of floating tablets of Levofloxacin, which after oral administration prolong the Gastric Residence Time and increased drug bioavailability. Methods: Levofloxacin is a synthetic chemotherapeutic agent used to treat severe or life-threatening bacterial infections. The present work was designed to formulate floating tablet of Levofloxacin with various swelling agents. Formulations were prepared using various concentrations of Guar gum, Carbopol, hydroxy propyl methyl cellulose and Ethyl Cellulose by direct compression technique. The selected batches were evaluated for various parameters like weight variation, thickness, diameter, friability, floating lag Time, duration of floating, swelling index, content uniformity and in-vitro drug release. The data obtained from the in-vitro dissolution studies of optimized batch F7 were fitted in different models. Results: The optimized formulation F7 showed 99.25% drug content, floating lag Time of 10 min and swelling index of 40%. Drug release mechanism was found to be zero order along with higuchi release kinetics exhibiting diffusion along with dissolution of the drug from the tablet by non fickian mechanism. Conclusion: Levofloxacin floating tablets exhibited increased Gastric Residence Time, there by improved bioavailability and therapeutic effect of the drug.

  • DEVELOPMENT OF A PROLONGD RELEASE GASTRORETENTIVE TABLET FORMULATION OF LEVOFLOXACIN
    International Journal of Applied Pharmaceutics, 2020
    Co-Authors: I. Ashwini, P. Ramya Deepthi, A. Madhu Babu, Vasudha Bakshi
    Abstract:

    Objective: The present investigation concerns the design and evaluation of floating tablets of Levofloxacin, which after oral administration prolong the Gastric Residence Time and increased drug bioavailability. Methods: Levofloxacin is a synthetic chemotherapeutic agent used to treat severe or life-threatening bacterial infections. The present work was designed to formulate floating tablet of Levofloxacin with various swelling agents. Formulations were prepared using various concentrations of Guar gum, Carbopol, hydroxy propyl methyl cellulose and Ethyl Cellulose by direct compression technique. The selected batches were evaluated for various parameters like weight variation, thickness, diameter, friability, floating lag Time, duration of floating, swelling index, content uniformity and in-vitro drug release. The data obtained from the in-vitro dissolution studies of optimized batch F 7 were fitted in different models. Results: The optimized formulation F7 showed 99.25% drug content, floating lag Time of 10 min and swelling index of 40%. Drug release mechanism was found to be zero order along with higuchi release kinetics exhibiting diffusion along with dissolution of the drug from the tablet by non fickian mechanism. Conclusion: Levofloxacin floating tablets exhibited increased Gastric Residence Time, there by improved bioavailability and therapeutic effect of the drug. Keywords : Levofloxacin, Gastro retentive, Guar gum, Hydroxy propyl methyl cellulose, Ethyl Cellulose, Carbopol.

Emile P Chen - One of the best experts on this subject based on the ideXlab platform.

  • Gastric ph and Gastric Residence Time in fasted and fed conscious beagle dogs using the bravo ph system
    Journal of Pharmaceutical Sciences, 2012
    Co-Authors: Kelly M Mahar, Robert W Coatney, Samm T Portelli, Emile P Chen
    Abstract:

    Abstract: To further characterize the Time course of Gastric pH with respect to meals and Gastric Residence Times (GRTs) in dogs, continuous pH measurements were recorded with Bravo® capsules, which were attached to the dogs' stomach mucosa or administered as free capsules, respectively. Experiments took place in home or study cages, and meals were administered at designated Times. Up until 2 h prior to mealTime, the fasted Gastric pH remained constantly acidic (∼2.0) regardless whether the dogs were in the study or home cages. However, as feeding Time became imminent, the pH was typically elevated for dogs in home cages, whereas the pH remained acidic for dogs in study cages. For both monitoring locations, the Gastric pH remained acidic during meal consumption and for at least 10 h after meals. The GRT between fasted (25 ± 32 min) and fed (686 ± 352 min) conditions was significantly different with considerable inter- and intrasubject variability. Fasted Gastric pH was similar to that of literature monkey and human values but differed after meals as the dog Gastric pH remained acidic unlike monkey and human. In dogs, the fasted GRT was remarkably rapid and under fed conditions, longer than that observed in humans. © 2012 Wiley Periodicals, Inc. and the American Pharmacists Association

  • Gastric ph and Gastric Residence Time in fasted and fed conscious cynomolgus monkeys using the bravo ph system
    Pharmaceutical Research, 2008
    Co-Authors: Emile P Chen, Kelly Mahar M Doan, Samm T Portelli, Robert W Coatney, Vernal Vaden
    Abstract:

    Purpose To measure fasted and fed Gastric pH and Gastric Residence Time (GRT) in Cynomolgus monkeys using Bravo® radiotelemetry capsules.

I. Ashwini - One of the best experts on this subject based on the ideXlab platform.

  • DEVELOPMENT OF A PROLONGD RELEASE GASTRORETENTIVE TABLET FORMULATION OF LEVOFLOXACIN Original Article
    2020
    Co-Authors: I. Ashwini, P. Ramya Deepthi, A. Madhu Babu, Vasudha Bakshi
    Abstract:

    Objective: The present investigation concerns the design and evaluation of floating tablets of Levofloxacin, which after oral administration prolong the Gastric Residence Time and increased drug bioavailability. Methods: Levofloxacin is a synthetic chemotherapeutic agent used to treat severe or life-threatening bacterial infections. The present work was designed to formulate floating tablet of Levofloxacin with various swelling agents. Formulations were prepared using various concentrations of Guar gum, Carbopol, hydroxy propyl methyl cellulose and Ethyl Cellulose by direct compression technique. The selected batches were evaluated for various parameters like weight variation, thickness, diameter, friability, floating lag Time, duration of floating, swelling index, content uniformity and in-vitro drug release. The data obtained from the in-vitro dissolution studies of optimized batch F7 were fitted in different models. Results: The optimized formulation F7 showed 99.25% drug content, floating lag Time of 10 min and swelling index of 40%. Drug release mechanism was found to be zero order along with higuchi release kinetics exhibiting diffusion along with dissolution of the drug from the tablet by non fickian mechanism. Conclusion: Levofloxacin floating tablets exhibited increased Gastric Residence Time, there by improved bioavailability and therapeutic effect of the drug.

  • DEVELOPMENT OF A PROLONGD RELEASE GASTRORETENTIVE TABLET FORMULATION OF LEVOFLOXACIN
    International Journal of Applied Pharmaceutics, 2020
    Co-Authors: I. Ashwini, P. Ramya Deepthi, A. Madhu Babu, Vasudha Bakshi
    Abstract:

    Objective: The present investigation concerns the design and evaluation of floating tablets of Levofloxacin, which after oral administration prolong the Gastric Residence Time and increased drug bioavailability. Methods: Levofloxacin is a synthetic chemotherapeutic agent used to treat severe or life-threatening bacterial infections. The present work was designed to formulate floating tablet of Levofloxacin with various swelling agents. Formulations were prepared using various concentrations of Guar gum, Carbopol, hydroxy propyl methyl cellulose and Ethyl Cellulose by direct compression technique. The selected batches were evaluated for various parameters like weight variation, thickness, diameter, friability, floating lag Time, duration of floating, swelling index, content uniformity and in-vitro drug release. The data obtained from the in-vitro dissolution studies of optimized batch F 7 were fitted in different models. Results: The optimized formulation F7 showed 99.25% drug content, floating lag Time of 10 min and swelling index of 40%. Drug release mechanism was found to be zero order along with higuchi release kinetics exhibiting diffusion along with dissolution of the drug from the tablet by non fickian mechanism. Conclusion: Levofloxacin floating tablets exhibited increased Gastric Residence Time, there by improved bioavailability and therapeutic effect of the drug. Keywords : Levofloxacin, Gastro retentive, Guar gum, Hydroxy propyl methyl cellulose, Ethyl Cellulose, Carbopol.

Bojan Zorko - One of the best experts on this subject based on the ideXlab platform.

  • optimisation of floating matrix tablets and evaluation of their Gastric Residence Time
    International Journal of Pharmaceutics, 2000
    Co-Authors: Sasa Baumgartner, Julijana Kristl, Franc Vrecer, Polona Vodopivec, Bojan Zorko
    Abstract:

    The present investigation concerns the development of the floating matrix tablets, which after oral administration are designed to prolong the Gastric Residence Time, increase the drug bioavailability and diminish the side effects of irritating drugs. The importance of the composition optimisation, the technological process development for the preparation of the floating tablets with a high dose of freely soluble drug and characterisation of those tablets (crushing force, floating properties in vitro and in vivo, drug release) was examined. Tablets containing hydroxypropyl methylcellulose (HPMC), drug and different additives were compressed. The investigation shows that tablet composition and mechanical strength have the greatest influence on the floating properties and drug release. With the incorporation of a gas-generating agent together with microcrystalline cellulose, besides optimum floating (floating lag Time, 30 s; duration of floating, \8 h), the drug content was also increased. The drug release from those tablets was sufficiently sustained (more than 8 h) and non-Fickian transport of the drug from tablets was confirmed. Radiological evidence suggests that, that the formulated tablets did not adhere to the stomach mucus and that the mean Gastric Residence Time was prolonged (\4 h). © 2000 Elsevier Science B.V. All rights reserved.

  • Optimisation of floating matrix tablets and evaluation of their Gastric Residence Time.
    International journal of pharmaceutics, 2000
    Co-Authors: Sasa Baumgartner, Julijana Kristl, Franc Vrecer, Polona Vodopivec, Bojan Zorko
    Abstract:

    The present investigation concerns the development of the floating matrix tablets, which after oral administration are designed to prolong the Gastric Residence Time, increase the drug bioavailability and diminish the side effects of irritating drugs. The importance of the composition optimisation, the technological process development for the preparation of the floating tablets with a high dose of freely soluble drug and characterisation of those tablets (crushing force, floating properties in vitro and in vivo, drug release) was examined. Tablets containing hydroxypropyl methylcellulose (HPMC), drug and different additives were compressed. The investigation shows that tablet composition and mechanical strength have the greatest influence on the floating properties and drug release. With the incorporation of a gas-generating agent together with microcrystalline cellulose, besides optimum floating (floating lag Time, 30 s; duration of floating, >8 h), the drug content was also increased. The drug release from those tablets was sufficiently sustained (more than 8 h) and non-Fickian transport of the drug from tablets was confirmed. Radiological evidence suggests that, that the formulated tablets did not adhere to the stomach mucus and that the mean Gastric Residence Time was prolonged (>4 h).