Solutions versus suspension

Profiles of pH versus solubility and pH versus stability are needed for solution and suspension formulations to help assure physical and chemical stability as well as to maximize or minimize solubility. This information is also valuable for predicting the compatibility of drugs with various infusion fluids. 

The decision to develop a solution versus syrup versus suspension can also be influenced by other factors. The desired release profile of the drug may lead to the... 

For each of the two calibration-solution-versus-sample-solution groups, calculate the deltamethrin content (mimg) in the retained one-tenth of the suspension from the equation ... 

Figure 5.5. A plot of the relative absorbance (AMorigin) versus the irradiation time for solutions or suspensions with different water contents. Source From Li et al., 2006a.

From a plot of the data in Figure 1.5a as parts per million in solution versus the logarithm of time (days), the more nearly linear curves permit a reasonable extrapolation to 100 days. As shown in Figure 1.5c the amount of silica in solution continues to drop, suggesting that in all cases it is approaching the solubility of quartz. It is therefore likely that if this quartz powder with multilayers of adsorbed silica on the surface were left to age for a year or so instead of 40 days, or if the suspension were heated to 100 C, for example, the adsorbed material would become further converted to the structure of quartz and its solubility decrease to that of quartz. 

The dissolving and dispersing behavior of complexly formulated particles has to be measured in laboratory devices either by optical particle analysis, or by chemical analysis of dissolved matter within the solution or suspension. For that purpose, the spray particles are positioned in baskets within stirred containers, and the light extinction is measured in the suspension or the concentration of dissolved chemical species is recorded versus time (Schubert, 1990 Hogekamp and Pohl, 2004). Similar systems are applied to assess the release functions of pharmaceuticals (Martin and Leuenberger, 2002 Schultz and Kleinebudde, 1997). 

The appropriate volume ratio of CTS solution versus the cell suspension solution was firstly tested. The test was carried in triplicate. 

Rheological methods of measuring the interphase thickness have become very popular in science [50, 62-71]. Usually they use the viscosity versus concentration relationships in the form proposed by Einstein for the purpose [62-66], The factor K0 in Einstein s equation typical of particles of a given shape is evaluated from measurements of dispersion of the filler in question in a low-molecular liquid [61, 62], e.g., in transformer oil [61], Then the viscosity of a suspension of the same filler in a polymer melt or solution is determined, the value of Keff is obtained, and the adsorbed layer thickness is calculated by this formula [61,63,64] ... 

Figure 14.12 Reduction of 4-chlo-ronitrobenzene (4-C1-NB) in aqueous solution in the presence of 17 m2 L-1 magnetite and an initial concentration of 2.3 mM Fe(II) at pH 7 and 25°C plot of In ([4-C1-NB]/[4-Cl-NB]0) versus time ( ). [4-Cl-NB]o and [4-C1-NB] are the concentrations at time zero and t, respectively. Adapted from Klaus-en et al. (1995). Note that experimental points deviate from pseudo-first-order behavior for long observation times. 4-C1-NB was not reduced in suspensions of magnetite without Fe(II) (v), or solutions of Fe(II) without magnetite ( a ).

Figure 4.1 Gold loading and yield of DP versus solution pH for Au/Ti02 (Degussa P-25) catalysts prepared by DP (NaOH added to the suspension, preparation at 343K, nominal Au loading 13wt.%).62...

Netland PA, Leahy C, Krenzer KL. Emedastine ophthalmic solution 0.05% versus levocabastine ophthalmic suspension 0.05% in the treatment of aUergic conjunctivitis using the conjunctival aUergen chaUenge model. Am J Ophthalmol 2000 130 717-723. 

Amphotericin and itraconazole have been compared in a multicenter, open, randomized study in 277 adults with cancer and neutropenia (54). Itraconazole oral solution (100 mg bd, n — 144) was compared with a combination of amphotericin capsules and nystatin oral suspension n — 133). Adverse events were reported in about 45% of patients in each group. The most frequent were vomiting (14 versus 12 patients), diarrhea (12 versus 9 patients), nausea (5 versus 12 patients), and rash (2 versus 13 patients). There were no differences in liver function... 

Myerson (2002), Mullin (2001), and Mersmann (2001) provide excellent descriptions of methods for crystal growth rate measurements. These methods involve measurements of either single crystals or suspensions. Much information can be gained from the traditional technique of measuring ( grab samples or in-line) solute concentration versus time in batch crystallization on a seed bed. Initial and later slopes on such a plot can provide multiple data points of growth rate versus supersaturation. 

Diphenyl Mercury Adsorption. Adsorption of DPM from seawater onto amorphous iron hydroxide, manganese oxide and bentonite clay was not detected in this study. A comparison of standard diphenyl mercury solutions in seawater with Identical solutions to which sediment phase had been added and shaken for 48 hours was routinely performed as part of the isotherm determination. There was no significant difference in the concentration of dissolved diphenyl mercury for standard. versus standard plus solid phase for any of the suspensions of amorphous, Fe(OH)-, MnO, or bentonite in seawater, implying no significant adsorption of DPM from seawater onto these phases under the concentrations studied. If lower concentrations of DPM could have been used (ppb or lower) it is possible that adsorption might have been detected. 

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