PubMed · 5980905
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
B F Putney. 1966. Problems in compounding liquid prescriptions.. https://doi.org/10.1016/s0003-0465(15)31736-5
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Roller compaction (RC) is an important dry granulation technique. Since pilot and commercial scale roller compactors, which operate continuously on a large scale, usually require kilograms of material per run, formulation and process development directly on such roller compactors is not practical. In contrast, a compaction simulator (CS) can produce ribblets, also known as "slugs", using only a few grams of material with sinusoidal displacement profile replicating the motion of a specific point on the roll surface. Thus, it is possible to develop RC formulation and process in laboratory using a CS-based material-sparing approach. However, because of the inherently different configurations for applying pressure between die compression and roll compression, translating uniaxial pressure from CS experiments to roll pressure during RC is often unreliable, leading to significant uncertainties in the critical quality attributes of ribbons, such as ribbon solid fraction (or porosity) and mechanical strength. The objective of this study was to identify a correction factor (Kp = uniaxial die compression pressure/roll pressure), by correlating the compressibility profiles from CS and a roller compactor of interest, to enable more reliable process translation from CS to roller compactor. In this study, a Kp value of 0.5 was determined for Alexanderwerk WP120 and validated for Gerteis Mini-Pactor and Bepex Pharmapactor. This value may serve as a starting point for translating the optimal compaction pressure identified based on CS investigation to common roller compactors, requiring only minor adjustments to attain optimal RC process parameters (i.e., roll force and roll gap) for a chosen roller compactor.
Emulsification-solvent removal methods have been widely used for encapsulating bioactive macromolecules like proteins and polypeptides in biodegradable polymers. We report, a (water-in-oil)-in-oil emulsion technique wherein proteins and polypeptides differing in molecular weight and shape were encapsulated in polymers of current biomedical interest. When an oil was used as the processing medium in combination with a carefully selected mixed solvent system such that a stable (w/o1/o2 emulsion is formed and solvents are removed by a combination of extraction and evaporation, the entrapment efficiency was high and the product nonporous. The entrapment efficiency of globular proteins exceeded 90% while that of fibrous proteins was around 70%. Fracture studies revealed that the polymer matrix was dense. The mechanism of entrapment involved solvent-induced precipitation of the protein as the microspheres were being formed. The principle of the method will find use in preparation of non-porous polymer microparticles with reduced burst effect.
The voltammetric behaviors of trazodone using a platinum electrode in stationary or rotating conditions and its determination in tablets by DP rotating electrodes are described in this study. The experiments were conducted in the supporting electrolyte consisting of 0.2 M KCl and 0.2 M acetate or phosphate buffer. No adsorption was observed at +300 mV. The factor affecting the voltammetric current was diffusional in the range of 200-2000 rpm for rotating, and 2-10 mV potential rate for stationary conditions; and the calibration dependence was linear between 1x10-5-5x10-5 M trazodone solutions. The detection limit was found to be 2.5x10-6 M (sb=5.03, n=5) for stationary and 1.7x10-6 M (sb=2.12, n=5) for rotating electode assuming a signal to noise ratio of 3. According to the statistical evaluations, acceptable results were obtained at the 95% probability level. Therefore, the proposed method is practicable, sensitive and accurate for the analysis of trazodone preparations in quality control laboratories.