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Практика фармации в РоссииФармация-это наука медицины, касающиеся производства, обработки, хранения, анализа, подготовки и доставки
№16 Extraction of drugs The active constituents of drugs are separated from the inert tissue of the plant by the simple process of collecting and expressing the juice from the fresh plant material. Although more and more components of plants are being prepared synthetically now, one knows that isolating from natural sources remains the easiest and the cheapest method of preparation. Moreover it became very modern and actual one in contemporary medicine. It is generally accepted that sucrose is often obtained from the sugar beet. The first stage of extracting is a diffusion process. The beet is being cut into shreds and extracted by water at 78 to 80 C in a battery of diffusers for some hours. It is important to note that the diffusers are arranged so that the shredded beet passes from a liquid containing less sugar and finally to purified water as quick as possible. For some time the juice is being heated to higher temperature from 80 to 90 C and treated with lime. It is believed that under such conditions it coagulates and absorbs much more colloidal impurities and better neutralizes free acids. After passing carbon dioxide and filtering the treated juice is further purified by passing through sulphur dioxide and filtration. The concentration is now done at a much lower temperature. Then it is necessary to evaporate the filtrate under reduced pressure to a thicker juice. This one reaches the highest saturation or graining point. At this stage of extracting the semi – crystalline mass of sucrose crystals passes to a centrifuge where the mother liquid is separated and the obtained crystals are washed with a little water. The sugar is further cooled, dried and screened. 16 Извлечения наркотиков
№17 Preparation of tablets One knows that a tablet is the most common form of medication for the administering of drugs in a dry state. Its preparation constitutes an important part of modern “Pharmaceutical Technology”. The method of tablet making or tabletting is defined as a process of pressure of powdered medicine. It is generally observed that some tablets are made easier from certain drugs than from other ones. For example, sodium chloride is used without the addition of auxiliary substances. But for lactose the addition of such substances is necessary to overcome certain difficulties. It is interesting that in the process of tabletting some materials are continuously binding and sticking in the special machine. Sticking takes place when there is too much moisture in the granules because of insufficient drying, etc. The application of different pressure during tabletting plays a very great role. It is important that tablets which are being dissolved slowly by saliva in the mouth are more strongly compressed than other ones using for common internal administration. Another important effect of higher pressures is an increase of friction which causes the use of greater amount of lubricating and gliding substances, such as natural starch. The use of starch as an auxiliary component in tablet making is generally recognized. It was stated that starches possessed very good gliding properties and didn’t show any lubricating action. 17 Подготовка планшетов
№18 Shapes and sizes of tablets A great variety of shapes and sizes is available among medical tablets. One knows that the most common shape of the tablet is a circular body with flat or slightly convex sides. In the Scandinavian countries where the Pharmacopoeia provides official specification of formula, the method of tablet making, the size and shape are also specified officially. In selecting of particular shapes and sizes the primary consideration is ethical. It is generally recognized that prepared tablets must have a pleasing appearance. It is important that the tablet for making solutions is required to dissolve as quick as possible. This will require a larger diameter than average tablets of the same weight. A tablet for oral using should be flat and thick enough. While it is slowly dissolving in the mouth the patient will feel a pleasant lasting sense. The efficiency of the tablet depends on this effect. Similarly, coated tablets which have a more convex shape are harder than other ones. It is more convenient to have the thinnest edges because it is easier to cover a thin edge during the coating process. In addition, it was found that preparing of very convex tablets was more difficult. The density of compressing substance is also important factor. Thus a lighter and less dense material needs a bigger punch – press machine than a similar weight of more dense material. In the process of tablet making different pressures are used for the compressing of various shapes of tablets. The flat-faced tablets show a relatively greater strength than the convex-shaped ones. 18 Форм и размеров таблеток
№19 Antibiotics Since the end of the twentieth century modern medicine has been making an extensive use of various antibiotics. It should be noted that antibiotics are powerful agents in combating infections. The problem of discovering new antibiotics can be most successfully solved at special research institutes which may have a small experimental plant producing preparations of new antibiotics. Russia has several research institutes working in this field. Before new generation of antibiotics made its appearance Russian science had produced a series of new effective drugs, such as albomycin, etc. This practically non-toxic preparation has found wide application in the treatment of pneumonia in newborn and small children. It is also successfully used in obstetric and gynecological practice. Surgeons have to use it during the treatment of the septic processes caused by staphylococci which can resist other antibiotics. It has been established experimentally that the composition of its molecule includes iron and it has a peculiar mechanism of affecting the bacteria. Mention must also be made of tetracyclines, such as chlortetracycline. It was introduced after chlorphenol had been discovered. Therefore chlortetracycline was considered the second broad – spectrum antibiotic developed for therapeutic purposes. It was isolated in 1948 from biomycin. Because of its yellow colour it was marked as auremycin. Another antibiotic of this series is tetracycline. It has been found that it possesses great advantages over its sister compounds. It may produce less toxic effect and penetrate the cerebrospinal fluid to a much greater extent. It has been stated that in ordinary use the tetracyclines can be given orally in doses of 250 mg. 19 Антибиотики №20 What is pharmacy? The word «pharmacy» comes from Greek and in the modern language means «a drug». The civilization of the past contributed to our present knowledge by the collection of drugs and medicinal preparations. Pharmacy was an integral part of medicine when preparative pharmaceutical techniques were simple. It became an independent branch of medicine when an increasing variety of drugs and their complex compositions demanded specialists familiar with such technologies. However, only in the late eighteenth and nineteenth centuries chemical knowledge advanced to the point at which it became capable to contribute significantly to pharmacology. The first and the most important was the isolation in relatively pure chemical form of the active constituents of plants. For example, in 1806 Serturner isolated morphine from opium. It took man over five thousand years to make this very important step. The industrial revolution of the last century gave birth to synthetic organic chemistry and established a new branch of knowledge necessary for the synthesis of new drugs. At present pharmacy is defined as the art and science of recognition, identification, collection, preparation, storage, test, composition and distribution of all substances used in preventive or in curative medicine for people’s treatment. It includes different subjects, such as physics, chemistry, botany, pharmacognosy, pharmacology, etc. which pharmaceutical students master to become highly good qualified pharmaceutists. 20 Что такое аптека?
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