Biomedical subjects

R M Franz

Publications and source records attributed to R M Franz.

6 recordsLinked to original sources

PubMed1990

Characterization of a hot-melt fluid bed coating process for fine granules.

The equipment modifications and process changes necessary to perform hot-melt particle coating in a fluid bed granulator are reviewed. A specific case is presented in which partially hydrogenated cottonseed oil is coated onto fine granules (mean particle size, 77 microns; range, 10-150 microns; one standard deviation is 10 microns) composed of a hydrophobic drug and sucrose. The major variables were product bed temperature, temperature of the wax, spray rate, and atomization air pressure. The product bed temperature was selected to give the optimum congealing rate, and the latter three variables were varied in a statistically designed experiment. The physical properties of wax-coated granules fabricated using combinations of process variables were examined. Response surface analysis was used to determine the optimum process settings in terms of dissolution, particle size, and density of the coated product. This system proved quite adequate for the production of uniformly coated granules, with the best product being obtained at the optimized conditions using 120 degrees C atomization air and molten coating temperature, 30 g/min as the spray rate, and an atomization air pressure of 5 bar.

Capsules↗

PubMed1988

Investigation into substrate cracking of a film-coated bilayered tablet.

Substrate cracking occurred during film coating of a bilayered tablet. The cause was traced to differences in the expansion characteristics of the two layers upon exposure to heat. Thermal mechanical analysis was used to determine the coefficients of thermal expansion of the respective layers.

Hardness↗

PubMed1987

Correlation of ibuprofen bioavailability with gastrointestinal transit by scintigraphic monitoring of 171Er-labeled sustained-release tablets.

External gamma scintigraphy was used to monitor the gastrointestinal (GI) transit of radiolabeled sustained-release tablets containing 800 mg ibuprofen in eight fasted healthy volunteers. Ibuprofen serum concentrations were determined from blood samples drawn sequentially over a 24-hr period. Serum concentrations and related parameters were correlated to the position of the dosage form in the GI tract from the scintiphotos. The sustained-release tablets were radiolabeled intact utilizing a neutron activation procedure, by incorporating 0.18% of 170Er2O3 (enriched to greater than 96% 170Er) into the bulk formulation. After manufacture of the final dosage forms, the tablets were irradiated in a neutron flux (4.4 x 10(13) n/cm2.sec) for 2 min, converting the stable 170Er to radioactive 171Er (t1/2 = 7.5 hr). Each tablet contained 50 microCi of 171Er at the time of administration. The scintigraphy studies suggested that the greatest proportion of ibuprofen was absorbed from this dosage form while the tablet was in the large bowel. The dosage forms eroded slowly in the small bowel and appeared to lose their integrity in the large bowel. In vitro studies showed only minimal effects of the neutron irradiation procedure on the dosage form performance.

Biological Availability↗

PubMed1986

Body cooling as a method for reducing hyperthermia. An evaluation of techniques.

The most important objective in the treatment of heatstroke and related conditions is to reduce the body core temperature to safe levels. Subjects performed at an external work rate of 54 W in hot, humid conditions (dry-bulb 40 degrees C, wet-bulb 35 degrees C), and a recent innovation to achieve body cooling, i.e. strategically placing instant cold packs (ICPs) (Coldpak; Medac) over the large vessels of the neck, axillae and groin, was evaluated under controlled laboratory conditions. We found that this procedure was not significantly more effective (P greater than 0.5) than passive body cooling in bringing about a 2 degrees C reduction in rectal temperature. Moreover, covering the whole body with ICPs plus induced evaporative cooling produced higher cooling rates than those achieved by the strategic placement of ICPs (0.0340 degrees C/min and 0.0344 degrees C/min respectively) (P less than 0.01).

Adult↗

PubMed1982

In vitro adsorption-desorption of fluphenazine dihydrochloride and promethazine hydrochloride by microcrystalline cellulose.

Fluphenazine dihydrochloride and promethazine hydrochloride were adsorbed in vitro from suspensions of the tableting excipient, microcrystalline cellulose. Studies were undertaken to determine how this adsorption phenomenon was affected by the type of phenothiazine derivative, the type of microcrystalline cellulose, and pH and ionic strength adjustment. The smaller the microcrystalline cellulose particle size, the more drug was adsorbed. Changes in the pH, the ionic strength, and the valency of the cation used to adjust the ionic strength all had a major effect on the extent of adsorption. The adsorption process was rapidly and completely reversed in vitro at gastric pH and ionic strength values.

Adsorption↗

PubMed1980

Cost evaluation of alternative pharmaceutical tableting processes by simulation.

A simulation model and a subsequent computer program were developed as experimentation methods for evaluating tableting processes with respect to cost. These methods also allow estimation of the various times involved in a tableting operation (e.g., the processing time). The model was programmed in FORTRAN using the GASP IV simulation language. After verification of the program, experiments were run that involved comparing different levels of specific input variables to determine which variable had an effect on the cost-time relationships of a particular processing method. Among the possible input variables chosen for evaluation were the drying method, the type of tableting machine, the batch size, the labor rate, and the operation of the equipment in the process. An analysis of variance was made, and three separate regression equations were developed that described the relationship between the input variables and the dependent variables of processing cost and time. Graphs were developed from the regression equations by manipulating them through series of different independent variables. These graphs then were used in determining minimum costs and times, breakeven points, and rates of change, as well as in simple evaluation of processes through graphic representation. By using the simulation program to run experiments and then by analyzing them, results can be obtained to help in making intelligent decisions about the cost-time relationships of a particular tableting procedure before it is implemented.

Chemistry, Pharmaceutical↗