Routes of drug administration
The route of administration, absorption site, and bioavailability of the drug from the dosage form are important factors in the manufacturing of the drug product.
Drugs intended for local activity, such as topical antibiotics, anti-infectives, antifungal agents and local anesthetics are the formulations in dosage form that minimize systemic absorption. The concentration of these drugs at the application site affects their activity.
When systemic absorption is desired, bioavailability of the drug from the dosage form at the absorption site must be considered (e.g., a drug given intravenously is 100% bioavailable because all of the drug is administered directly into the systemic circulation). The amount of the dose depends on the drug absorption and the desired systemic drug concentration. The type of dosage form (e.g., immediate release or controlled release) affects the rate of drug absorption.
There are different forms of parenteral drug administration, including intravenous and intra-arterial injection, intravenous infusion, intramuscular injection, subcutaneous injection, intra-articular injection, intradermal injection, and intratechal injection. In intra-arterial injection the drug is injected into a particular artery to achieve a high drug concentration in a specific tissue before drug distribution throughout the body occurs. Intra-arterial injection is administered for diagnostic purposes, and occasionally in chemotherapy.
Enteral administration includes the buccal and sublingual routes, and oral and rectal administration. In buccal and sublingual administration, the drug is absorbed directly into the systemic circulation, bypassing the liver. When the drug is administered orally, it is swallowed, and undergoes absorption from the gastrointestinal tract through the mesenteric circulation into the liver and then to the systemic circulation. Oral route is the most common, as well a as the most convenient, and safest route of drug administration, though it has a number of disadvantages.
In rectal administration, the drug in the form of solution (enema) or in semisolid form (suppository) is placed into the rectum. It is absorbed through the mucosa in the lower two thirds of the rectum, and enters the systemic circulation directly, bypassing the liver.
Respiratory tract administration involves intranasal administration and pulmonary inhalation. Intranasal administration may be used for local, or systemic effects. The drug contained in a solution or suspension is administered to the nasal mucosa either as a spray or as drops. In pulmonary inhalation, the drug is inhaled from a nebulizer or an aerosol container into the respiratory tract.
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Transdermal (percutaneous) drug absorption is application of the drug (in the form of a lotion, cream, paste, or patch) on skin surface for systemic absorption. An occlusive dressing or film improves systemic drug absorption from the skin. Such drugs as antibacterial agents, and local anesthetics are applied topically onto the skin for a topical effect.
Other routes of drug administration include ophthalmic, otic, urethral, and vaginal administration. These routes are generally used for achieving a local therapeutic effect. However, some systemic drug absorption may also occur.
III. Послетекстовые упражнения.
III.1. Сгруппируйте названия органов и тканей человеческого тела по способу введения лекарств, по следующему образцу:
respiratory tract administration: the nose, airways (pharynx, larynx, trachea, bronchi), the lungs (bronchioles, alveoli).
Intradermal administration:
Parenteral administration:
Enteral administration:
Topical administration:
Other routes:
the skin, the blood, the intestines, the stomach, the mouth, the veins, the arteries, the capillaries: the epidermis, the derma, the muscles, the joints, the spinal fluid, the cheek, the tongue, the rectum, the eyes, the ears, the liver, the vagina, the urethra.
III.2. Выберите правильный вариант ответа:
1. Which statement best describes bioavailability?
(A) relation between the physical and chemical properties of a drug and its systemic absorption
(B) Measurement of the rate and amount of therapeutically active drug that reaches the systemic circulation
(C) Movement of drug into body tissues over time
(D) Dissolving of the drug in the gastrointestinal tract
2. The route of drug administration that provides the most rapid onset of the pharmacologic effect is
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(A) intramuscular injection
(B) intravenous injection
(C) oral administration
(D) subcutaneous administration
3. The route that provides complete (100%) bioavailability is
(A) intramuscular injection
(B) intravenous injection
(C) oral administration
(D) subcutaneous administration
4. After oral administration, drugs are generally best absorbed from the
(A) buccal cavity
(B) stomach
(C) duodenum
(D) rectum
III.3. Соедините в пары названия органов и тканей человеческого организма и прилагательные, образованные от них с помощью латинско-греческих терминоэлементов.
1. blood A. vascular
2. liver B. pulmonary
3. blood vessel C. hematic
4. stomach D. oral
5. lung E. hepatic
6. skin F. gastric
7. mouth G. otic
8. brain H. ophthalmic
9. joint I. cutaneous, dermal
10. eye J. arthral
11. cheek K. cardiac
12. tongue L. buccal
13. nose M. cervical
14. ear N. (sub-) lingual
15. neck O. nasal
16. heart P. cerebral
17. kidney Q. renal
III.4. Ознакомьтесь со списком из безрецептурных лекарств, пользующихся наибольшей популярностью у потребителей в США. Ниже приводится таблица с адресами источников фармацевтической информации в Интернете. Найдите в одном из источников следующую информацию о заинтересовавшем вас лекарстве. Задайте вопросы письменно по-английски:
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а) есть ли данное лекарство в наличии?
б) что это за лекарство: дженерик или фирменное лекарство?
в) какая фармацевтическая компания, и в какой стране производит
лекарство?
г) к какой из групп относится лекарство (рецептурным или
безрецептурным)?
д) сколько времени лекарство находится на рынке?
е) в каких дозированных формах продается лекарство?
| Site | Web URL |
| Agency for Healthcare Policy and Research | http://www.ahcpr.goy |
| American Association of Colleges of Pharmacy | http://www.aacp.org |
| American Cancer Society | http://www.cancer.org |
| American Diabetes Association | http://www.diabetes.org |
| American Heart Association | http://www.amhrt.org |
| American Society of Health-Systems Pharmacists | http://www.ashp.org |
| Avicenna Systems Corporation | http://www.avicenna.com |
| Centers for Disease Control | http://www.cdc.gov |
| Department of Health and Human Services | http://www.os.dhhs.gov |
| Drug InfoNet | http://www.druginfonet.com |
| Food and Drug Administration | http://www.fda.gov |
| Pharm Info | http://www.pharminfo.com |
| RxList | http://www.rxlist.com |
| RxMed | http://www.rxmed.com |
| Virtual Medical Center | http://www.mediconsut.com |
Top-Selling Prescription Drugs Listed by Trade Name
| Trade Name | Ceneric Name | Trade Name | Generic Name |
| Accupril | Quinapril HCI | Ceftin | Cefuroxime axetil |
| Adalat CC | Nifedipine | Cefzil | Cefprozil |
| Amoxil | Amoxicillin | Compazine | Prochlorperazine |
| Ansaid | Flurbiprofen | Corgard | Nadolol |
| Antivert | Hydroxyzine HCl | Cortisporin Otic HC | Polymyxin B / neomycin / hydrocortisone |
| Ativan | Lorazepam | Coumadin | Warfarin |
| Atrovent | Ipratropium bromide | Cozaar | Losartan potassium |
| Bactrim DS | Trimethoprim / sulfamethoxazole | Deltasone | Prednisone |
| Biaxin | Clarithromycin | Dilacor XR | Diltiazem HCl |
| Bleph-10 | Prednisone acetate / sodium sulfacetamide | Dilantin | Phenytoin |
| Capoten | Captopril | E-Mycin | Erythromycin |
| Carafate | Sucralfate | E.E.S. | Erythromycin ethyl succinate |
| Cardizem CD | Diltiazem HCl | ERYC | Erytromycin |
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III.5. Переведите следующие предложения с русского языка на английский.
1. Фармацевтические препараты — это химические вещества, используемые в лечении, диагностике и профилактике заболеваний.
2. Лекарственная субстанция и инертное вещество вместе составляют матрицу лекарственной формулы.
3. Лекарственный продукт — это дозированная лекарственная форма, которая содержит активно действующее начало в сочетании с другими инертными веществами.
4. Химическое название лекарства несёт информацию о его химической структуре, но оно часто бывает длинным и сложным.
5. Непатентованное название - достояние широкой общественности, и его может использовать любой (человек).
6. Патентованное название, известное также как коммерческое название, является интеллектуальной собственностью компании или индивида, включающей патенты, лицензии, и авторские права.
7. Лекарства местного действия — это дозированные лекарственные формы с составом, который минимизирует их всасывание в системное кровообращение.
8. Тип дозированной лекарственной формы (мгновенного действия или замедленного действия) влияет на скорость всасывания лекарства.
9. При пероральном применении, лекарство проглатывается и всасывается из желудочно-кишечного тракта через печень в большой круг кровообращения.
10. При легочной ингаляции, лекарство вдыхается из ингалятора или аэрозольного контейнера в респираторный тракт.
III.6. Расположите в правильном порядке следующие этапы разработки новых лекарств:
1. Clinical testing on a limited number of healthy volunteer.
2. Evaluation of animal pharmacology and assessing drug toxicity.
3. Submission of an IND application to the FDA.
4. Large - scale multicenter clinical trials.
5. Manufacturing scale - up activities.
6. Submission of a new NDA for review and approval.
7. Improvement of the drug product to meet the market demand
III.7. Перечислите все возможные способы и пути применения лекарств, которые вы знаете.
III.8. Представьте содержание текста В в виде краткой аннотации (письменно).
III.9. Назовите по-английски источники, из которых можно получить информацию о: - новых лекарствах; - лекарствах, разрешенных к продаже; - лекарствах, не разрешенных к продаже.
III.10. Прочтите определения разных видов клинических испытаний и заполните пропуски в таблице соответствующими названиями клинических испытаний лекарств.
A blind study means that the people observing the patients do not know who is a subject and who is a control.
A single-blind study means that the people observing the patients know who is the subject and who is a control.
A double-blind study means that neither the patients nor the people observing them know whether they received the substance being studied ar a placebo.
Types of Clinucal Studies
| Types of study | Patient Aware of Treatment | Physician Aware of Treatment |
| Open label (non-blind) | × | × |
| - | × | |
| - | - | |
| × | - |
Unit eight
Solid dosage forms
Грамматика: 1. Типы придаточных предложений. Бессоюзные придаточные предложения.
2. Предлоги.
3. Многофункциональные служебные слова.
I. Предтекстовые упражнения
I.1. Переведите эти предложения и определите тип придаточных предложений в каждом из них.
1. Today pills are rarely prescribed, though some popular types are manufactured by machine.
2. Despite the wide variety of the over-the-counter headache remedies, almost every product contains one of the three drugs: paracetamol, ibuprofen, or aspirin.
3. How a drug is labelled is determined by its classification.
4. If the drug has an established name, it must be displayed with the trade name.
5. Liquid dosage forms are useful for patients who have trouble swallowing solid dosage forms.
6. After the ingredients are weighed, comminited and mixed, the powders must be accurately divided into the prescribed number of doses.
7. Capsules are solid dosage forms in which one or more medicinal or inert substances are enclosed within a small gelatin shell.
8. When you are working with toxic substances, take all the necessary precautions.
9. The doctor wanted to know which medications were being taken by the patient for his asthma and allergic reactions.
10. When we entered the room, the presentation of the pharmaceuticals was on-going.
11. Although diabetics should not take fish oil supplements, they should consume the fish for its essential fatty acids.
12. All pharmacy personnel who handle toxic agents should receive special training.
I.2. Укажите номера предложений, в которых содержится придаточное причины. Переведите остальные предложения на русский язык.
1. Because of possible drug interactions patients should tell their physicians what other drugs they are taking.
2. Castor oil should not be used in pregnant women because it can induce premature labor.
3. Because these agents are administered orally, potential systemic effects are more likely.
4. People can become obese because they ingest more calories than their body is able to metabolize.
5. Because of its irritant properties, tretinoin can cause exessive irritation and peeling of the skin.
6. Because of the drug’s toxicity it is not safe for use except under the supervision of a doctor.
7. Because the herbal remedy contained steroids it was not approved by the Board of Pharmacy.
8. This drug is not for long-term treatment because it is habit-forming.
9. Drug-related problems may occur because of an undiagnosed condition.
10. Plastic containers have advantages over glass because of their durability, reduced weight and improved safety.
I.3. Соедините следующие простые предложения в сложноподчинен-ные, выбрав подходящие по смыслу союзы из списка под чертой.
1. You are examining and using textbooks as sources of drug information. Consider many factors, including the year of publication (copyright data), and the data concerning the author and the publisher.
2. You are taking analgesics more than twice a week. Tell your doctor. You could become dependent.
3. Each type of protein is composed from different amino acids. They are not interchangeable.
4. There are no major chemical differences between vitamins found in food, and those created in the laboratory. Natural supplements contain only natural ingredients.
5. Paracetamol does not cause irritation in the gastrointestinal tract or bleeding in the stomach. It is considered the safest of the analgesics.
6. Codein is used. The pain becomes severe.
7. The desired effect is not achieved in 20-30 minutes. A repeat dose of 10 ml will be administered.
8. The mineral enters the body. It must compete with other minerals for absorption. Minerals should always be taken in balanced amounts.
9. Some laxative medications may contain sugar. Diabetics should use sugar-free products.
10. A mineral is absorbed. It must be carried by the blood to the cells and then transported across the cell membrane.
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(since, as, because, once, if, when, therefore, that, although, after)
I.4. Заполните пропуски в этом тексте подходящими по смыслу предлогами.
Filling capsules
Capsules are usually filled ... the punch method. The powder is placed ... paper and flattened ... a spatula so that the layer ... powder is no more than approximately 1/3 the length ... the capsule. The paper is held ... the left hand. The body ... the capsule is held ... the right hand and repeatedly pressed ... the powder until the capsule is filled. The cap is replaced and the capsule is weighed. After they are filled, the capsules must be cleaned and polished. ... a small scale, capsules are cleaned individually or in small numbers ... rubbing them ... a clean gauze or cloth. ... a large scale, they are passed ... a vacuum cleaning device fitted ... the capsule-filling machine, which removes any extraneous material after the capsule leaves the machine. Powder capacity … capsules ranges … 60-130 mg … 650-2000 mg … capsule sizes … No. 5, which is the smallest … No. 000, which is the largest capsule size.
I.5. Прослушайте рекламу лекарственного средства и ответьте на следующие вопросы.
1. What dosage form is the drug offered in?
2. What is the name of the drug?
3. When is it indicated?
4. How should it be taken?
5. When is it contraindicated?
I.6. Прочтите следующие вопросы и отметьте номера тех вопросов, на которые вы затрудняетесь ответить. Вернитесь к этому упражнению после проработки второго рздела этого урока и дайте правильные ответы.
1. What solid dosage forms of the drugs do you know?
2. What are their advantages?
3. Why are some drugs enclosed in shells or capsules?
4. Which of the solid dosages is administered most commonly?
5. Why is the use of powders and pills restricted?
6. How are powders packaged and dispensed?
7. How are tablets manufactured?
8. What ingredients does a tablet contain.
9. Why are some tablets coated?
10. What kinds of coatings can a tablet have?
II. Работа с текстом.
II.1. Ознакомьтесь со словами к тексту А.
| advantages | [{dPva:ntIdZIz] | преимущества |
| bulk, bulky | [bölk] | объём, объемный |
| to be intended for | [InPtendId] | быть предназначенным для |
| homogeneous | [hOm@PdZi:nI@s] | гомогенный, однородный |
| ranules, to granulate | [Pgr{nju:lz] | гранулы, гранулировать |
| cachet | [Pk{SeI] | облатка, капсула |
| a shell | [Sel] | оболочка |
| starch | [sta:tS] | крахмал |
| to swallow | [swOlou] | глотать, проглатывать |
| hard/soft capsule | твёрдая/мягкая капсула | |
| machine-made | [m@PSi:n PmeId] | фабричного изготовления |
| a pill | пилюля | |
| a binding agent | [PbaIndIŋ] | связывающее вещество |
| acacia | [@PkeIS@] | смола акации |
| tragacanth | [,tr{g@Pk{nT] | трагакант, смола растений рода Astragalus |
| to incorporate | [InPkO:p@reIt] | присоединять, смешивать |
| to roll | [Proul] | скатать в шарик |
| to coat, a coating | [Pkout], [PkoutIŋ] | покрыть оболочкой, покрытие (таблетки) |
| compression | [k@mPpreS@n] | прессование |
| to dilute, diluent | [daIPlu:t], [daIPlu:@nt] | разбавлять, разбавитель |
| to disintegrate | [dIsPIntIgreIt] | распадаться, расщепляться |
| to stick, sticking | [stIk] | застревать, застревание |
| a lubricant | [Plu:brIk@nt] | смазка, лубрикант |
| to force through | [fO:s] | пропускать под давлением сквозь |
| a mold | [mould] | формочка |
| fragile | [Pfr{ddZaIl] | хрупкий |
| troches, lozengers, pastilles | [PtrouSIz], [lOzIndZ@z], [Pp{stIlz] | леденцы, лепёшки, таблетка для рассасывания во рту |
| to release | [rIlPi:s] | выделять, высвобождать |
| a gum | [Pgöm] | смола |
| fusion | [Pfju:Zn] | плавление |
| to deteriorate | [dIPtI@rI@reIt] | портиться, ухудшаться |
| a sieve, to sieve, to sift | [si:v] | сито; просеивать, посыпать через сито |
II.2. Прочтите текст А и составьте план к содержанию текста.
Text A
Solid dosages
Solid dosages, such as tablets, have many advantages over other types: greater stability, lesser risk of chemical interreaction between different medicaments, smaller bulk, accurate dosage, and ease of production.
Powders intended for internal use are usually mixtures of two or more ingredients. If two ingredients are present in unequal quantities, then the lesser ingredient (usually the drug substance) is mixed with an equal weight of the greater ingredient. Next, the resulting mixture is combined with an equal weight of the greater ingredient in steps until the mixture is homogeneous and complete. This process of geometric dilution is essential in order to produce a homogeneous powder. Cachets, occasionally used for administration of powdered drugs with unpleasant taste, consist of shells made of gelatinized starch paste. More common today is the hard capsule, in which the powder is enclosed in a shell of hard gelatin. Semi-liquid and liquid drugs are often enclosed in a soft capsule with a soft gelatin shell.
Before the machine-made compressed tablet, pills were a very popular solid dosage form. Today, pills are rarely prescribed, though some popular types are manufactured by machine. The powdered ingredients are mixed together with a binding agent, such as tragacanth or acacia, and are then made into a plastic mass by incorporation of an appropriate liquid drug and addition of an inert liquid. The resulting mass, known as the pill mass, is then rolled into spheres and coated with talk, gelatin, or sugar.
Tablets, by far the most common method of administration of drugs, are only rarely made by compression of the drug alone (e.g., potassium bromide tablets). Usually, the drug is mixed with suitable diluents, such as dextrin, lactose, salt, starch, or synthetic substances, designed to ensure disintegration of the tablet in the body. To prevent sticking in the machine, a lubricant such as liquid paraffin, stearic acid, talk, or a synthetic substance is usually added. It is essential that the tablet machines are fed with the drug mixture in a free-flowing form to ensure complete filling of the molds. To achieve that, the drug mixture is granulated by mechanically forcing pellets of the mixture through a sheet of perforated metal. The granulated mixture is then fed into the tablet machine which feeds the correct dose into the mold, and the mixture is compressed. Excessive compression may mean that the tablet will not disintegrate in the body, while insufficient compression results in fragile tablets that may break, causing inaccurate dosage. Coatings of various types may be applied onto the tablet in order to protect the ingredients from deterioration, to hide the taste of certain drugs, to control the release of the drug from the tablet, or to produce a more attractive tablet. In the manufacture of layered tablets, incorporating two or more drugs, a compressed tablet is fed into a second machine where another layer is compressed around it. In this way, drugs normally incompatible may be formulated in the same tablet.
Other solid dosages include troches and dry extracts. Troches, also known as lozengers or pastilles, disintegrate or dissolve in the mouth, slowly releasing the active drug. The base usually consists of a mixture of sugar and gum and gelatin. Lozengers are generally manufactured by compression techniques, while pastilles are fabricated by fusion and the use of molds. Dry extracts are usually granulated by being passed through a sieve and may be used for the preparation of tablets.
II.3. Найдите в тексте ответы на следующие вопросы.
1. What advantages do the solid dosage forms have?
2. What method is generally used in making powders if the drug is being mixed with a bulky ingredient?
3. Which solid dosage form is especially suitable for the preparation of solutions from the drugs unstable in the presence of water?
4. Which of the solid dosages is rarely used today and why?
5. Why are diluents added in the process of drug tabletting?
6. What is the function of lubricants in the process of tabletting?
7. Why is proper compression so important in tablet-making?
8. What is the purpose of applying different coatings onto the tablets?
9. How can incompatible drugs be formulated in the same tablet?
10. What are the drugs like lozengers designed for?
II.4. Найдите в тексте А эквиваленты следующим словам и словосочетаниям:
преимущества перед; точная дозировка; предназначенный для внутреннего применения; поэтапно; разбавление в геометрической прогрессии; однородный (гомогенный) порошок; порошковые лекарства с неприятным вкусом; оболочки, сделанные из желатинизированного крахмала; жёсткая (твёрдая) капсула; полужидкий; прессованная таблетка фабричного изготовления; пилюльная масса; подходящие разбавители; для предотвращения застревания в машине; смазка; подавать точную дозу в формочку; недостаточное / чрезмерное прессование; наносить оболочку на таблетку; плавление.
II.5. Найдите в правой колонке синонимы для слов и выражений из левой колонки слов.
cachet to hide
administration lozengers
rarely to be intended for
often capsule
to incorporate use
to be designed for seldom
to disintegrate commonly
to mask to add
troches to decompose
II.6. Найдите под чертой антонимы для следующих слов и выражений:
greater, solid, advantages, homogeneous, internal, rarely, inert, common, synthetic, correct, initial, ease, soft
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external, liquid, final, difficulty, lesser, disadvantages, often, hard, wrong, active, rare, heterogeneous, natural, commonly
II.7. Образуйте от этих слов слова с противоположным значением с помощью приставок un-, in-, dis-, im-, ir-
accurate, regular, common, advantage, miscible, soluble, pleasant, sufficient, compatible, equal, complete, stable, correct
II.8. Ознакомьтесь со словами к тексту B.
| intimately | [PIntImItI] | однородно (хим.) |
| fine, finely | [fain] | мелкий, мелко |
| insufflation | [Ins@fPleISn] | вдувание, порошок для вдувания |
| to mask | [ma:sk] | маскировать, скрывать |
| to restrict | [rIPstrIkt] | ограничивать |
| blending | [Pblendiŋ] | смешивание, купажирование |
| to accomplish | [@PkOmplIS] | осуществлять |
| to pulverize | [Ppölv@raIz] | измельчать в порошок |
| to sift, sifting | [sIft] | просеивать, просеивание |
| tumbling | [PtömblIŋ] | вращение, опрокидывание |
| to rotate | [routPeIt] | вращать |
| a bulk powder | порошок в объемных упаковках | |
| a powder paper | порошок в дозированных пакетиках | |
| a sifter can | банка с отверстиями | |
| to dust, dusting | [döst] | посыпать, присыпание |
| an aerosol container | [PE@r@sOl] | аэрозольный контейнер |
| to spray, spraying | [spreI] | распылять, распыление |
| douching | [Pdu:SIŋ] | спринцевание |
| hygroscopic | [,haIgrouPskOpIk] | гигроскопичный |
| effervescent | [@f@Pves@nt] | шипучий, пенистый |
| tight | [PtaIt] | герметичный |
| jar | [PdZa:] | банка |
| eutechtic | [ju:PtektIk] | эвтектический, плавящийся легко, даже при низкой температуре |
| to liquefy | [PlIkw@faI] | разжижаться |
| metal foil | [Pmet@lPfOIl] | фольга |
| sealed | [Psi:ld] | запаянный |
| deliquescent | [delIPkwes@nt] | разжижающийся |
| sachet | [söPSeI] | саше, пакетик; фильтр-пакет |
II.9. Просмотрите текст B и найдите в нём 10 предложений c разными типами придаточных предложений. Переведите их на русский язык.
II.10. Прочтите текст В и назовите 3 основных типа фармацевтических порошков и 4 способа их приготовления.
Text B
Powders
Pharmaceutical powders are complete mixtures of dry, finely divided drugs and/or chemicals that may be used internally or externally. The most common types are powder papers, bulk powders, and insufflations. Powdered dosage forms are used when drug stability or solubility is a concern. These dosage forms may also be used when the powders are too bulky to make into capsules and when the patient has difficulties in swallowing a capsule. Such disadvantages as the rapid deterioration and the inability to mask an unpleasant taste of some medications restrict the use of the powders.
Blending of powders may be accomplished by trituration in a mortar, stirring with a spatula or sifting. If two ingredients are present in unequal quantities, the technique of geometric dilution is used. When heavy powders are mixed with lighter ones, the heavier powder should be placed on top of the lighter one, and then blended. When mixing two or more powders, each powder should be pulverized separately to about the same particle size before blending together. Light powders are mixed best by using the sifting method. The sifting is repeated three to four times to ensure thorough mixing of the powders. In industry, a tumbling method is more commonly used. Tumbling is the process of mixing powders in a large container rotated by motorized process.
Depending on their intended use, powders are packaged and dispensed by pharmacists as bulk powders or divided powders. Bulk powders are dispensed in bulk containers. A perforated can, or sifter can, is used for external dusting, and an aerosol container is used for spraying onto the skin. A wide-mouthed glass jar permits easy removal of a spoonful of powder.
Powders dispensed in bulk form include antacids and laxative powders, douche powders for vaginal use, dental cleansing powders, and insufflation powders. After a bulk powder has been pulverized and blended, it should be dispensed in an appropriate container. Hygroscopic or effervescent powders (salts) should always be placed in tight wide-mouthed jars. Dusting powders should be placed in a container with a sifter top. Eutechtic mixtures of powders, can cause problems because they may liquefy. Therefore, some inert powder is commonly added, such as magnesium oxide, to separate the eutectic material.
Divided powders are dispensed in individual doses, usually in folded paper (chartulae) or sachets. They may also be dispensed in metal foil, small thermally sealed or resealable plastic bags, or other containers. Depending on the potency of the drug substance, the pharmacist decides whether to weigh each portion separately before packaging, or to approximate portions by the block-and-divide method. The basic types of powder paper include vegetable parchment (thin, semiopaque, moisture-resistant paper), white bond (opaque paper that has no moisture-resistant properties), glassine (a glazed, transparent, moisture-resistant paper), and waxed paper (transparent waterproof paper). Hygroscopic, deliquescent, and effervescent powders require the use of glassine paper as an inside lining. Plastic bags or envelopes with snap-and-seal closures are a convenient alternative to powder papers. The folded papers are dispensed in a powder box or other suitable container; however, these containers are not child-resistant.
II.11. Ознакомьтесь со словами к тексту С.
| manufacturing cost | [,m{njuPf{ktS@iŋ PkOsts] | производственные расходы |
| precise, precision | [prIPsaIs] | точный, точность |
| shipping | [PSIpiŋ] | доставка (потребителю) |
| space | [PspeIs] | место, пространство |
| tamperproof | [Pt{mp@pru:f] | защищённый от доступа посторонних лиц |
| ingestion, to ingest | [InPdZest] | поглощение, поглощать |
| fillers | [PfIl@z] | наполнители |
| cohesion | [kouPhi:Zn] | сила сцепления (молекул) |
| to interfere with | [Int@PfIP@] | мешать, препятствовать |
| adhesives | [{dPhi:sivz] | адгезивы, вещества, повышающие коэффициент слипания |
| starch: corn starch | [sta:tS] | крахмал: кукурузный крахмал |
| to crumble | [krömbl] | крошиться |
| to cause | [kO:z] | быть причиной, вызывать |
| to facilitate | [f@PsIlIteIt] | облегчать, способствовать |
| to be exposed to | [IksPpouzd] | подвергаться воздействию, контактировать с |
| to swell | [swell] | набухать |
| a lubricant | смазка, лубрикант | |
| to glide, glidant | [glaId] | скользить, вещество, улучшающее скольжение |
| overlapping | [ouv@Pl{piŋ] | частично совпадающий |
| friction | [PfrIkS@n] | трение |
| a dye | [daI] | краситель |
| a flavouring agent | [PfleIv@rIŋ PeIi@nt] | вкусовая добавка (эссенция) |
| a chewable tablet | [PtSu:@bl] | жевательная таблетка |
| enteric-coated | [Pent@rIkPkoutId] | с кишечнорастворимой оболочкой |
| irritation | [IrPteIS@n] | раздражение |
| sugar-coated | [PSug@PkoutId] | с сахарной оболочкой |
| film-coated | с плёночным покрытием | |
| durable | [Pdju@r@bl] | прочный |
| chipping | [PtSIpIŋ] | обшелушивание |
| output | [Pautput] | выход конечного продукта |
II.12. Прочтите и переведите текст С. Назовите компоненты таблетки, типы оболочек и их предназначение.
Text С
Tablets
Tablets are the most commonly used solid dosage forms. They are best suited to large-scale production because of their low manufacturing cost, precision of the unit dose, and ease of packaging and shipping. Besides, they are the most stable of all oral dosage forms, they need less shelf space than liquids, and they are simple to identify and are essentially tamperproof. They are also most appropriate for special-release forms.
The tablets are manufactrured by wet granulation, dry granulation, or direct compression. Regardless of the method of manufacture, tablets for oral ingestion usually contain excipients, which are components added to the active ingredients that have special functions.
Diluents are fillers designed to make up the required bulk of the tablet when the drug dosage amount is inadequate. Diluents may also improve cohesion, permit direct compression, or promote glidance. Common diluents include kaolin, lactose, mannitol, starch, microcrystalline cellulose, powdered sugar, and others. Selection of the diluent is based on the cost of the diluent and its compatibility with the other tablet ingredients. For example, calcium salts cannot be used as fillers for tetracycline products because calcium interferes with the absorption of tetracycline from the gastrointestinal tract.
Binders and adhesives are added in either dry or liquid form to promote granulation or cohesion of ingredients during direct compression. Common binding agents include a 10-20% aqueous preparation of corn-starch, a 25-50% solution of glucose, various natural gums (e.g., acacia), and others. The proper amount of binder or adhesive is very important, because overwetting usually produces granules that are too hard, while underwetting usually produces tablets that are too soft and tend to crumble.
Disintegrants are added to tablet formulations to facilitate disintegration when the tablet is exposed to gastrointestinal fluid. Disintegrants function by drawing water into the tablet, swelling, and causing the tablet to burst. Common disintegrants include corn starch, potato starch, and their derivatives.
Lubricants, glidants, and antiadherents have overlapping functions. Lubricants and glidants reduce the friction and promote ejection of the tablet from the mold, as well as the flow of the tablet along the esophagus. Antiadherents reduce the sticking of the tablet in the tablet-making machine Talc. magnesium stearate, and calcium stearate are commonly used as lubricants.
Colours and dyes provide product identification, and produce a more aesthetic appearance of the product. Food, drug, and cosmetic dyes are applied as solutions. Flavouring agents are usually limited to chewable tablets or tablets intended for dissolving in the mouth. Some sweeteners or flavour oils may be added in the process of granulation .
Compressed tablets are manufactured by compression and have no special coating. Tablets may be coated for a number of reasons: to mask the taste, colour, or odour of the drug, to control drug release, to protect the drug from the acid medium in the stomach, to incorporate another drug and provide sequential release or avoid incompatibility, or to improve appearance.
Delayed-action and enteric-coated tablets delay the release of a drug from a dosage form. This delay is intended to prevent destruction of the drug by gastric juices, to prevent irritation of the stomach lining by the drug, or to promote absorption, which is better in the intestine than in the stomach. However, not all delayed-action tablets are enteric or are intended to produce an enteric effect.
Sugar-coated tablets are compressed tablets that are coated with coloured or uncoloured sugar. The process involves seal coating (waterproofing), subcoating, syrup coating (for smoothing and coloring), and polishing. These steps take place in a series of mechanically operated coating pans. Disadvantages of sugar-coated tablets include the time and expertise required for the process and the increase in the tablet size and weight. Sugar-coated tablets may be 50% larger and heavier than the original compressed tablet.
Film-coated tablets are covered with a thin layer of water-insoluble or water-soluble polymer (e.g., povidone). The film is usually coloured, and is more durable, less bulky, and less time-consuming than sugar-coating. Although the film increases tablet weight by 2-3%, it increases formulation efficiency, resistance to chipping, and output.
II.13. Переведите письменно абзацы 8 и 9 текста С.
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