Suitability - Examples

Several marketed polymers have been found to fulfill the afore mentioned requirements, and others have been purposely synthesized. Table 5.1 presents a list of polymers that have been successfully used in the HME process. 

The main classes of polymers suitable for HME, listed in Table 5.1, include polyvinyl-based polymers (homo- and co-polymers), polyethyleneglycoles (PEG) and poly-ethylenoxides (PEO), poloxamers, methacrylate copolymers and cellulose derivatives. The main advantage of the polyvinyl polymers and related copolymers is their high solubilizing ability, which can be attributed to the presence of lipophiUc groups in the 

Polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer Soluplus 70 - 

Polyvinyl alcohol-polyethylene glycol copolymer Kollicoat IR 45 208 

Poly( vinyl acetate-co-methacrylic acid) ClBA-1 - 84-145 

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The three types of test procedure discussed in this chapter may often be identified in testing of inhibitors or inhibited products. The testing of inhibited engine coolants provides a suitable example. 

In Sections 10.11-10.16 it is shown how the change in pH during acid-base titrations may be calculated, and how the titration curves thus obtained can be used (a) to ascertain the most suitable indicator to be used in a given titration, and (b) to determine the titration error. Similar procedures may be carried out for oxidation-reduction titrations. Consider first a simple case which involves only change in ionic charge, and is theoretically independent of the hydrogen-ion concentration. A suitable example, for purposes of illustration, is the titration of 100 mL of 0.1M iron(II) with 0.1M cerium(IV) in the presence of dilute sulphuric acid ... 

Aluminothermic reduction is one among the few pyrometallurgical processes where the actual process closely follows the route theoretically predicted from thermodynamic data. This characteristic, coupled with the simplicity associated with the whole process, makes it well suited for demonstration experiments. The reduction of magnetite by aluminum is a suitable example in this context. 

One of the suitable examples of sizable molecules may be ethane. The trans form belongs to the symmetry D3(l. The HO s are degenerate leg MO, which are largely localized at C—Hbondsand have bonding character on these bonds. The mode of extension is indicated below 89.00). The LU is also localized at C—H bonds and antibonding. It is understood that most of the ionic and radical reactions of aliphatic hydrocarbons have some concern with the C—H bond. 

In order to get an idea about the depth resolution of the system and about sputtering rates, electrochemically prepared Ta2Os serves as a very suitable example. The thickness of the oxide layer can be easily varied by choosing a proper oxidation potential (16A/V). Tantalum oxide is not reduced during sputtering according to [26],... 

An enormous variety of solvates associated with many different kinds of compounds is reported in the literature. In most cases this aspect of the structure deserved little attention as it had no effect on other properties of the compound under investigation. Suitable examples include a dihydrate of a diphosphabieyclo[3.3.1]nonane derivative 29), benzene and chloroform solvates of crown ether complexes with alkyl-ammonium ions 30 54>, and acetonitrile (Fig. 4) and toluene (Fig. 5) solvates of organo-metallic derivatives of cyclotetraphosphazene 31. In most of these structures the solvent entities are rather loosely held in the lattice (as is reflected in relatively high thermal parameters of the corresponding atoms), and are classified as solvent of crystallization or a space filler 31a). However, if the geometric definition set at the outset is used to describe clathrates as crystalline solids in which guest molecules... 

No suitable examples were found to present a comparative study of these systems. 

A suitable example is Cl Acid Blue 27 (6.37 X = NHCH3), which is made from 4-bromo-l-methylaminoanthraquinone by nucleophilic displacement followed by sulphonation. Some commercial acid dyes based on 1,4-diaminoanthraquinone contain substituents in both the 2- and the 3-positions. Thus, for example, Cl Acid Violet 41 (6.38) is produced by the condensation of l,4-diamino-2,3-dichloroanthraquinone with phenol in the presence of sodium sulphite and manganese dioxide. 

The incorporation of an indole ring system often leads to an improvement in the light fastness. A suitable example is Cl Acid Blue 123 (6.177), which is derived from 4,4 -dichlorobenzophenone. Condensation with l-methyl-2-phenylindole in the presence of phosphorus oxychloride produces the triarylmethane ring system. Replacement of the chlorine atoms with p-phenetidine, followed by sulphonation, gives the dye. 

The minimal basis calculation on the hydrogen molecule is a well-worn but eminently suitable example for our purposes. It has a convenient symmetry element and orbital basis calculations can be carried through which are quantitatively acceptable and yet not prohibitively unwiedly to report. We give below variational calculations on the H2 molecule using the familiar simplest AO basis in the one-electron-group (MO) model and the electron-pair (VB) model. These calculations have been performed explicitly to investigate the effect of symmetry constraints . 

Describe the primary process in photochemical reactions with help of suitable examples. 

What is the importance of Purity in pharmaceutical chemicals for manufacturing drugs Discuss with suitable examples. 

Give a detailed account on the Limit Tests Vs Quantitative Determinations by providing suitable examples. 

Give suitable examples in support of your answer. 

What are the two major types of errors invariably encountered in pharmaceutical analysis Explain with suitable examples. 

How would you differentiate between accuracy and precision Support your answer with suitable examples. 

Elaborate the following statistical methods with suitable examples ... 

Describe the various means and ways usually adopted for Sampling Statistics . Give suitable examples. 

A good number of pharmaceutical substances can be assayed gravimetrically. The gravimetric methods adopted vary according to the nature of the substance under determination. However, most of the substances being estimated gravimetrically fall into one or the other categories stated below, which would be discussed briefly with suitable examples ... 

What are the advantages of gravimetric analysis over titrimetric analysis Give suitable examples to expatiate your answer. 

Give at least ONE suitable example from each method in support of your answer. 

Why is bromine preferred to iodine in redox methods for the assay of pharmaceutical organic substances Explain with suitable examples. 

How would you determine the refractive index of pharmaceutical substances Give suitable examples. 

Give suitable examples whereve necessary to justify your plausible explanation. 

Provide suitable examples wherever possible to make your explanation more plausible and understandable. 

Enumerate the vital theoretical aspects of HPLC giving suitable examples. 

Elaborate the theoretical aspects of RIA with suitable examples/explanations. 

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