ABSTRACT
The in vitro acid reactivity of three commercial brands of aluminum and magnesium hydroxide antacid tablets was determined by two methods. A pH-stat test was used to examine the rate and extent of acid neutralization at a constant pH of 3.0. A modified Rossett-Rice test was used to record the length of time during which the antacid products maintained the pH of a simulated gastric solution at between 3.0 and 5.0. Acid neutralization by product A was faster and more complete than that by product B or C. The percent of theoretical acid consuming capacity at 30 minutes of product A (86.8%) was significantly greater than that of product B (56.1%) and product C (57.0%) tablets. The 32-minute Rosett-Rice time A was significantly longer than the 16- and 12-minute times of products B and C, respectively. The differences observed may be attributed to different reactivities of the raw materials used in the products, or formulation and processing variables. It is not known how the data relate to in vivo performance.
Subject(s)
Antacids , Acids , Aluminum Hydroxide , Chemical Phenomena , Chemistry , Hydrogen-Ion Concentration , Kinetics , Magnesium HydroxideABSTRACT
The effect of selected tablet components on the volatility of nitroglycerin from compressed sublingual tablets was studied by thermogravimetric analysis. The results, confirmed by chemical analyses, showed that nitroglycerin volatility is significantly reduced by the use of povidone USP and microcrystalline cellulose NF in tablet formulations. In general, the stabilizing effect of these materials was dependent on the presence and the concentration of each other. These studies demonstrated the utility of thermogravimetric analysis as a rapid and reliable means of screening nitroglycerin formulations for stability purposes.
Subject(s)
Nitroglycerin , Cellulose , Drug Stability , Excipients , Methods , Nitroglycerin/analysis , Povidone , Tablets , Thermogravimetry , Time Factors , VolatilizationABSTRACT
A stabilized compressed nitroglycerin tablet, containing microocrystalline cellulose NF and providone NF as stabilizing agents, was formulated. Bioavailability and physical tests were conducted on the compressed tablet and two leading brands of molded tablets. There was no difference in the mean pulse rate between a molded tablet formulation and the compressed tablet in a crossover study using 10 human volunteers and three tablet strengths, 0.3, 0.4, and 0.6 mg. The compressed tablet was most uniform when tested according to the USP method for weight variation and content uniformity. Various tests for nitroglycerin loss due to volatility, i.e., open dish test, thermogravimetric analysis, and simulated in-use test, all indicated that the stabilized compressed tablet was substantially more stable than partially stabilized or unstabilized molded tablets.
Subject(s)
Nitroglycerin , Adult , Animals , Biological Availability , Chemistry, Pharmaceutical , Dogs , Drug Stability , Female , Hemodynamics/drug effects , Humans , Male , Middle Aged , Nitroglycerin/analysis , Nitroglycerin/pharmacology , Solubility , Tablets , Time Factors , VolatilizationSubject(s)
Pharmacy , Administration, Oral , Adsorption , Animals , Anti-Bacterial Agents , Biological Availability , Biopharmaceutics , Cell Membrane Permeability , Chemical Phenomena , Chemistry, Pharmaceutical , Chemistry, Physical , Drug Compounding , Drug Interactions , Humans , Kinetics , Methods , Micelles , Pharmaceutical Preparations/metabolism , Radioisotopes , Rheology , Solubility , Surface Properties , Surface-Active AgentsSubject(s)
Pharmaceutical Preparations , Aerosols , Capsules , Color , Cosmetics , Delayed-Action Preparations , Dentistry , Drug Packaging , Drug Stability , Emulsions , Gels , Odorants , Ophthalmic Solutions , Pharmacy/instrumentation , Preservatives, Pharmaceutical , Sterilization , Suppositories , Suspensions , Tablets , Taste , Technology, PharmaceuticalABSTRACT
A rapid, simplified method of checking the calibration of a new motorized pendulum type of tablet hardness tester and the accuracy and precision of three testers were determined. Two force gauges were calibrated, and both gauges were used by two operators to determine the accuracy of the new testers. The calibration method using the force gauge was reliable for checking the accuracy. The results show the various new testers to be in calibration and to give reproducible results.
