Dispensing methods comparison

The Committee for Proprietary Medicinal Products [8] applied the BCS, with certain requirements, to dispense with bioequivalency tests if the active pharmaceutical ingredient is class I and the in vitro dissolution of the finished dosage form is fast [9], An active substance is considered highly soluble if the amount contained in the HDS of an IR product is dissolved in 250 ml of each of three buffers within the range of pH 1-8 at 37°C (e.g., pH 1.0, 4.6, and 6.8). There should be linear and complete absorption, which indicates HP to reduce the possibility of an IR dosage form influencing the bioavailability [8], The similarity of the dissolution profiles of the test and reference products is demonstrated in each of three buffers within the range of pH 1-8 at 37°C (e.g., pH 1.0,4.6, and 6.8). If there is rapid dissolution of the product, where at least 85% of the active substance is dissolved within 15 min, no further comparison of the test and reference is required. Further requirements include that excipients be well established and have no interaction with the pharmacokinetics of the active substance and that the method of manufacture of finished product... 

With the formulations described here (namely the laminate dispensers), we had previously determined that the same pattern of release was obtained by either of two methods of measurement collection of pheromone emitted under controlled conditions of temperature and air speed (9, 10) or determination of residual lure content by extraction and gas chromatographic (GC) analysis. Since the latter method is simple and rapid and provides reproducible data for the comparison of formulations, it was used to obtain the data presented in this paper. 

These data also demonstrate the superiority of the ALHS system in comparison to manual methods. Utilization of the ALHS resulted in the production of 25% more formulations while reducing the sample preparation time. In addition, the increased accuracy and precision of the ALHS at dispensing small volumes is evident. Although the general trend in both data sets is similar, the trend is more distinct for formulations prepared using the ALHS, compared with the formulations prepared by hand. 

Verification of measurements conducted by the photometric or titrimetric technique can be done easily by comparing the results with results from the gravimetric method if the volume dispensed is sufficiently large. However, for the measurement of small liquid volumes where the gravimetric method is no longer applicable, verification can be difficult. In that case, cross-validation between various measuring techniques and/or comparison with a calibrated dispenser is essential. 

Suh et al. also reported a direct method for molding of PEG polymers [40], which involves the placement of a patterned PDMS mold on top of a drop-dispensed or spin-coated PEG solution typically dissolved in water or ethanol, leaving behind a polymer replica after solvent evaporation followed by mold removal. In comparison with qCP, the technique generates features varying in height with precise control over cell migration and interconnection of cell arrays. 

The oxycyanide reaction on which the above method is based is not stoichiometric so an excess of reagent must be used. The 20 ml specified is sufficient for the titration of up to 12 mg of chloride but it should be increased to 30 ml if this quantity is exceeded. It should be noted that, at the end-point of the titration with sodium chloride solution, the volumes and temperatures of both the test and comparison solutions should be the same. For many practical purposes it may be sufficiently accurate to calculate the chlorine content of the sample from the volume of 0-02N sulphuric acid used, thus dispensing with the second titration. 

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