Pharmacy physical properties

NA Peppas, HJ Moynihan. Structure and physical properties of poly(2-hydroxy-ethyl methacrylate) hydrogels. In NA Peppas, ed. Hydrogels in Medicine and Pharmacy, Vol II Polymers. Boca Raton, EL CRC Press, 1987, pp 49-64. 

All drugs are chemicals, and pharmacy is a subject that deals with the study of various aspects of drugs. Therefore, it is needless to say that to become a good pharmacist the knowledge of the chemistry of drugs is essential. Before moving on to the other chapters, let us try to understand some of the fundamental chemical concepts in relation to the physical properties of drug molecules. 

R. Prankerd, Some physical factors and drug activity— Physical properties and biological activity in certain barbituric acid structures. University of Otago, Dunedin, NZ, Master of Pharmacy Thesis, 1977. 

PHAs have rapidly gained interest both in research and industry due to their structural versatility and characteristics such as biodegradability, insolubility in water, nontoxicity, biocompatibility, piezoelectric property, thermoplasticity and or elastomeric properties, which make them favourable to be used in the packaging industry, medicine, pharmacy, agriculture, food industry and in the paint industry. The chemical and physical properties of the polymer are dependent on the monomeric composition which is determined by the producing microorganism and their nutrition. So far scl-PHAs are being studied extensively due to their easier... 

Filter tests must be performed by the manufacturer before release to the market and by the individual user also, to ensure that the membrane filter complies with the specifications, is undamaged, and is eventually placed correctly in the filter case by the user. As described before in this chapter, such a test should in fact be performed with Brevundimonas diminuta. However, in daily practice this is not possible for the user in the pharmacy, and thus test methods have been derived, which are based on the physical properties of the membrane filter. Such test methods are called filter integrity tests. 

For pharmacy preparations, usage periods per dosage form are given in Table 22.7. These general suggestions are mostly based on microbiological factors, and sometimes on physical properties. Often they may also be used for licensed medicines. See Sect. 22.7. for details. 

Phadke, D.S., Keeney, M.P. And Norris, D.A., 1994, Evaluation of Batch-To-Batch and Manufacturer-To-Manufacturer VariabUity in the Physical Properties of Talc and Stearic Acid , Drug Development and Industrial Pharmacy, 20(5), pp 859-871 Ratafia, M., 1989, Big Business in Osteoporosis Prodncts , Medical Marketing and... 

The scope of this branch of chemistry encompasses both the fundamental understanding of how to measure properties and amounts of chemicals, and the practical understanding of how to implement such measurements, including the design of the necessary instruments. The need for analytical measurements arises in all research disciplines, industrial sectors, and human activities that entail the need to know not only the identities and amounts of chemical components in a mixture, but also how they are distributed in space and time. These sectors of need include research in specific disciplines (such as chemistry, physics, materials science, geology, archeology, medicine, pharmacy, and dentistry) and in interdisciplinary areas (such as forensic, atmospheric, and environmental sciences), as well as the needs of government policy, space exploration, and commerce. 

The stereochemistry deals with the study of spatial structure of molecules and its effect on the physical and chemical properties of the compound. Until recently stereochemistry was thought to be purely a theoretical area of study but since it not only affects the properties but also controls the rate of reaction, it has assumed great practical importance. Now stereochemistry is applied to study physiological properties, biochemistry, molecular biology, pharmacy and even in medicine. So the scope of the subject has become enormous. Stereoisomerism is classified into two types. 

It is certainly not by chance that Barriol s first research, in collaboration with Pierre Donzelot, dealt with the Raman effect. Lespieau had been one of the first who had studied, often with Maurice Bourguel, the Raman effect, [9] in relation to chemical constitution. [10] Donzelot did some research on the same subject with Charles Prevost, another student of Lespieau, when Prevost was a professor of chemistry at the Nancy Faculte de Pharmacie. At the very same time Barriol also was around. A note to the Academic, des Sciences, concerning the relation between Raman frequencies and interatomic distances, by Donzelot and Barriol, was presented by Lespieau and concluded It seems that the interatomic distance constitutes an essential characteristic of a molecule, around which one can group the properties, not only those related to the Raman effect, but also manyfold physical characteristics. [11]... 

David Attwood is Professor of Pharmacy at the University of Manchester he previously lectured at the University of Strathclyde. His research interests are in the physicochemical properties of dmgs and surfactants, and in polymeric dmg delivery systems. He has many years experience in the teaching of physical pharmacy. 

The relative importance of each of these properties for pharmaceutical and environmental sciences is then judged by the publication rate. Figure 9.1 shows the number of publications for each of these properties in subject categories pharmacology and pharmacy, medicinal chemistry, and environmental sciences as defined by ISI Web of Knowledge (http //www.isiknowledge.com). Notice that the same properties are much differently represented in other sciences for instance, in applied physics there are about 400 publications each year dealing with vapor pressure. 

Depending on the structure of the organization, the contents of the preformulation report may be included in several different reports. Typically, the analytical profile may be issued by the analytical development group, and specifications of the drug substance may be issued by the QC laboratory. Physicochemical property determination, stability, compactibility, and pharmaceutical properties may be reported by the basic pharmaceutics or physical pharmacy group. The biopharmaceutical group may issue the report with KADME and bioavailability data. 

Properties.—Physical.—A greenish-yellow gas, at the ordinary temperature and pressure it has a penetrating odor, and is, even when highly diluted, very irritating to the respiratory passages. Being soluble in HsO to the extent of one volume to three volumes of the solvent, it must be collected by displacement of air, as shown in Fig. 33. A saturated aqueous solution of Cl is known to chemists as chlorin water, and in pharmacy as aqua chlori (Z7. S.), Liquor chlori (2f .). It should bleach, but not redden, litmus paper. Under a jiressure of 6 atmospheres at 0° (33° F.), or 8 atmospheres at 13° (53°. 6 F.), Cl becomes an oily, yellow liquid, of sp. gr. 1.33 and boiling at —83.6° (—38°.5 P.). 

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