【正文】 in a low humidity environment → to avoid the absorption of moisture and a premature chemical reaction. The granules are dried at a temperature not exceeding 54℃ and immediately placed in containers and tightly sealed. 57 The preparation of effervescent granules—— wet method The binding agent is the water added to alcohol as the moistening agent——forming the pliable mass for granulation. All of the powders may be anhydrous as long as water is added to the moistening liquid. 。 b) left amount. 2)amount of medication actually received by the patient:a) hard to determine。 less propellant loss. 47 Testing of pharmaceutical aerosols A. Flammability(可燃性 ) and bustibility(燃燒性 ) 1. Flash point(閃點(diǎn) ) of limited value 2. Flame extension(火焰延長 ), including flashback(閃回 ) B. Physicochemical characteristics 1. vapor pressure: pressure gauge(壓力計(jì) ), water bath, pressure variation from container to container。 less danger of contamination of the product with moisture。 F。 not acceptable for the incorporation of potent drugs into a diluent powder 28 Blending powders The methods of blending —— 4. tumbling (翻轉(zhuǎn) ) Features: tumbling the powder enclosed in a rotating container (Vshape, cube, cylinder etc.)。 shear mixing。 不用停機(jī)即可控制產(chǎn)品的細(xì)度，且細(xì)粉能全部回收， 不污染環(huán)境 ； 不升溫 ，由于物料是在氣體膨脹狀態(tài)下粉碎，所以粉碎腔體溫度控制在常溫狀態(tài)，溫度不會升高； 對 易燃、易爆物料 可用惰性氣體作介質(zhì)粉碎。s ? ?212118??????????gddvD ?10 On micromeritics (微粒學(xué) ,粉粒學(xué) ) Micromeritics is the science of small particles。sec1 = 1 p = 100 cp =sec1 (poise) in cgs units Incidentally, the water at 20 ℃ has a viscosity of approximately one centipoises ( poise). 1 gsec2 η＝ the viscosity of the medium in poises, ., g 15 μm, deposition deep in the respiratory tract) ? Nongrittiness(無砂礫感 ) (dermal ointments, creams, and ophthalmic(眼科 ) preparations。 c. ointments and creams. Connotation 2, a type of pharmaceutical preparation a medicated powder intended for internal (., oral powder) or external (., topical powder) use The use of medicated powders per se in therapeutics is limited 3 Definition of granules Granules are prepared agglomerates of powdered materials, and may be used per se for the medicinal value of their content or they may be used for pharmaceutical purposes, as in tableting. 4 The chemical and physical features of solid materials used in the preparation of pharmaceutical products 1. morphology (形態(tài)學(xué) ) 2. purity (純度 ) 3. solubility (溶解度 ) 4. stability (穩(wěn)定性 ) 5. particle size (粒徑 ) 6. uniformity (均一性 ) 7. patibility (相容性 ) with any other formulation ponents chemical and pharmaceutical processing efficient production of a finished dosage form and optimum therapeutic efficacy The requirements for the material of solid dosage form ? Mixing thoroughly ? Flowability ? Filling property 5 Particle size and analysis The particle size gradation in USP ? Very coarse（最粗粉） ? Coarse（粗粉） ? Moderately coarse（中粉） ? Fine（細(xì)粉） ? Very fine（最細(xì)粉） This gradation system is based on sieving method（篩分法） , and is related to the proportion of powder that is capable of passing through the opening of standardized sieves of varying dimensions in a specified time period under shaking. 6 Particle size and analysis typical particle size of granules: 4 to 12 sieve Granules fall within the range of 12 to 20 sieve are sometimes used in tablet making. The purpose of particle size analysis in pharmacy is to obtain quantitative data on the size, size distribution, and shapes of drug and nondrug ponents to be used in pharmaceutical formulations 7 Particle size and analysis Particle size can influence a variety of important factors: ? Dissolution rate (particle size↓→ surface area↑) ? Suspendability(混懸性 ) (suspensions。1 Chapter 3 Powders and granules 2 Definition of powders Connotation(涵義 ) 1, the physical form of a material a dry substance posed of finely divided particles The use of powdered substances in the preparation of other dosage forms is extensive. For example, a. tablets and capsules。 b. liquid dosage forms (solutions or suspensions)。 μm) ? Uniform distribution to ensure dosetodose content uniformity (powders, granules and tablets) ? Perability (inhalers。 50100 μm) 8 Particle size and analysis The methods used for the determination of particle size ? Sieving 40 to 9500 μm ? Microscopy to 100 μm provide information of shape ? Sediment