Solutions and Powders

The evaluation of inhalation solutions and solutions for inhalation should include appearance, color, assay, degradation products, pH, sterility, particulate matter, preservative and antioxidant content (if present), net contents (fill weight and volume), weight loss, and extractables or leachables from plastic, elastomeric, and other packaging components. 

The evaluation of inhalation powders should include appearance, color, assay, degradation products, aerodynamic particle size distribution of the emitted dose, microscopic 

Handbook of Pharmaceutical Manufacturing Formulations Semisolid Products 

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ENDOR experiments can be performed in liquid solution, in which only the isotropic hfc s (Ajso) are detected. They are proportional to the spin density at the respective nucleus. Erom the assigned isotropic hfc s a map of the spin density distribution over the molecule can be obtained. In frozen solutions and powders the anisotropic hf interactions can also be determined. Eurthermore, the method allows the detection of nuclear quadrupole couplings for nuclei with 1 1. For dominant g anisotropy as found in many metal complexes the external magnetic field can be set to several specific g values in the EPR, thereby selecting only those molecules that have their g tensor axis along the chosen field direction. In such orientation-selected spectra only those hf components are selected that correspond to this molecular orientation ( single crystal-like ENDOR ). 

Solutions and powders of several lithium salts are very toxic to the human nervous system, thus requiring close observation by a physician when used as antidepressant drugs. 

Group VI Donors. The thio-oxinato-complex Ag(C9HgNS)2 (54 M = Ag) has been prepared, and its N and S co-ordination confirmed from i.r. data. Solution and powder e.s.r. studies of the compound isolated from the reaction between Ag acetate and the NN-di-n-butyldiselenocarbamate anion confirm that it is a Ag" complex of structure (96). A subsequent single-crystal e.s.r. 

FIGURE 18 Morphine plasma concentration in human volunteers after intravenous administration of morphine and after nasal administration of morphine as chitosan solution and powder formulations Mor Chi Sol, morphine solution containing chitosan Mor Chi PWD, morphine-chitosan powder IN, intranasal. (Reproduced from ref. 105 with permission of the American Society for Pharmacology and Experimental Therapeutics.)... 

Resta, O., Barbaro, M., and Carnimeo, N. (1992), A comparison of sodium cromoglycate nasal solution and powder in the treatment of allergic rhinitis, Br. J. Clin. Practice, 46, 94-98. 

Figure 4 Typical cryostat design for solution and powder samples. This design features an expanded berylhiun dome, which allows detection of the transmitted beam as well as the emitted X-rays that contribute to the NRVS signal. The Be dome and a thin polyethylene window on the front face of the sample cell minimize the absorption at 6.4 and 14.4 kev. A sapphire plate provides excellent thermal contact between the sample cell and the cryostat cold head, as well as allowing optical access for off-line Raman measurements to monitor sample integrity. Sample temperatures in the 20 - 30 K range are typically achieved for both solutions and powders...

Another method that has been developed for the preparation of thicker layers involves the use of diol solvents, such as 1,3-propanediol. Phillips et al. and Tu et al. have explored this route most thoroughly, and it has also been utilized by manufacturers. While the method has not been as intensely investigated as the 2-methoxyethanol process, a number of spectroscopic investigations have been carried out to study the details of the reaction chemistry. Coating thickness per deposited layer is 0.5 pm, compared to 0.1 pm for layers prepared by sol-gel methods using more common solvents, or by chelate or MOD processes. The manufacture of 1 pm films is therefore significantly less labor intensive. Lastly, others have prepared suspensions from sol-gel precursor solutions and powders... 

Remedial treatments for log eabins and millwork are applied generally by drilling holes into the member and adding a diffusible borate preservative. Borates have been formulated as rods, pastes, thiekened solutions and powders for this type of application. 

In general, the preparation of such formulations as poultices and pastes is extemporaneous, and it is unlikely that the industrial pharmaceutical formulator will be required to develop stable, safe and efficacious products of this type. Solutions and powders lack staying power (retention time) on the skin and can only afford transient relief. In modern-day pharmaceutical practice, semi-solid formulations are preferred vehicles for dermatological therapy because they remain in situ and deliver their drug payload over extended periods. In the majority of cases, therefore, the developed formulation will be an ointment, emulsion or a gel. Typical constituents for these types of formulations are shown in Table 14.5. 

A new, solid, heat-reactive resin based on bisphenol A was introduced recently (10) that is usable after even a year in storage at ambient (70-80 °F) temperatures. This resin polymerizes well at common curing temperatures of 300-400 °F and may be formulated into both solution and powder coatings (11) as will be discussed. 

The main parameter for the application of tannins as adhesives for wood-based panels is the content of reactive polyphenols and the reactivity of these components towards formaldehyde. Tannins can be used as adhesives alone (with a formaldehyde component as crosslinker) or in combination with aminoplastic or phenolic resins. These resins can react chemically with the tannin component in a polycondensation reaction, form only two interpenetrating networks, or both. The simplest adhesive mix formulation consists of the tannin solution and powdered paraformaldehyde as crosslinker [283]. The addition of paraformaldehyde can cause in the short term a relatively high level of formaldehyde emission. Glue mixes using paraformaldehyde for the production of particleboards with low formaldehyde emission are described and used industrially [284]. In the literature a large number of papers describe the combinations of tannins with synthetic resins (Table 14). 

Ultimately, the cement hardens to form dahllite, a carbonated apatite similar to that found in the mineral phase of bone [27, 47]. The cement has a micro-porous structure with pores smaller than 1 //m [86]. Calcium phosphate cement is available from multiple manufactures, as an example Norian Skeletal Repair System (SRS, Synthes West Chester, PA) consists of a liquid sodium phosphate solution and powder monocalcium phosphate monohydrate, tricalcium phosphate, and calcium carbonate. After mixing, the cement has a working time of approximately five minutes and hardens in approximately ten minutes. The material has a compressive strength of approximately 10 MPa at 10 minutes and maximum compressive strength of approximately 50 MPa within 24 hours. 

Chelate solutions and powders, 5%-10% Ca Calcium nitrate, granular or solution Calcium nitrate plus ammonium nitrate solutions Calcium lignosulfonate solution... 

Magnesium in solutions Epsom salts, MgS04 7H2O Chelated solutions and powders, l%-6% Mg... 

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