18. Micromeritics - Physical Pharmacy Laboratory
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SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Chapter 22 (경구용 고형제) (pp. 563-577) 내용의 정리/요약 Hand writing할 것 Due date: Dec 7 (강의 시작 전) SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Particle Size and Size Distribution Methods for Determining Particle Size Particle Shape and Surface Area Methods for Determining Surface Area Derived Properties of Powder SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Science and technology of small particles SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Surface diameter(ds) The diameter of a sphere having the same surface area as the particle Volume diameter(dv) The diameter of a sphere having the same volume as the particle SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Projected diameter(dp) The diameter of a sphere having the same observed area as the particle Stokes’ diameter(dst) An equivalent sphere undergoing sedimentation at the same rate as the asymmetric particle SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Fig. 181 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Frequency distribution curve Fig. 18-2 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Cumulative percent curve Fig. 18-3 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Log-normal distribution curve Fig. 18-4 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Log-probability curve Fig. 18-5 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Number of particles per unit weight e.g. if particle = sphere d 3 vn 6g 1 particle N 1g N Example 18-2 6 d vn 3 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Based on number distribution of different particle size Range : 0.2 - 100m >200 counts (300-500 counts) SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 장점 particle의 shape을 알 수 있다 단점 번거롭다 operater간 오차가 심하다 only two dimensions (길이, 폭) SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 1 : Martin diameter 2 : Feret’s diameter 3 : Projected diameter Fig. 18-7 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 This method uses a series of standard sieves Range : 44 - 1000m 20 mesh 100 mesh No opening SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Mesh number number of openings per inch Sieve opening actual size of openings between wires Sieve opening SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 The diameter is obtained by gravity sedimentation Andreasen apparatus SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Stoke’s law h d st s 0 g v t 180 2 180 h d st s 0 gt v : rate of settling h : distance of fall in time t s : density of particle 0 : density of dispersion medium g : acceleration due to gravity 0 : viscosity of medium SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Reynolds number Re Re vd 0 0 Re > 0.2 Stoke’s law cannot be used SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 The surface area per unit volume (Sv) or per unit weight (Sw) s Sv vd 단위용량당의 표면적 6 d vs 단위중량당의 표면적 Sw SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 The volume in cubic centimeters of gas adsorbed per gram of adsorbent may be plotted against the pressure of the gas at constant temperature 𝑝 1 𝑏−1 𝑝 = + 𝑉(𝑝0 − 𝑝) 𝑉𝑚 𝑏 𝑉𝑚 𝑏𝑝0 𝐴𝑚 𝑁 𝑆𝑤 = × 𝑉𝑚 𝑐𝑚2 /𝑔 𝑀 𝜌 (18-18) BET EQ. (18-19) SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Fig. 18-10 Fig. 18-11 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 The principle resistance to the flow of a fluid, such as air, through a plug of compressed powder is the surface area of the powder The flow rate through the plug, or bed, is affected by the degree of compression of the particles the irregularity of the capillaries SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Fig. 18-12. The Fisher subsieve sizer SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Porosity (공극률) Packing arrangement (충전배열) Densities of particles (입자밀도) Bulkiness (분말용적) Flow properties (유동성) Compaction (압축성) SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Void volume (v) : the volume of space v Vb Vp Vb Vp Vb 1 Vp Vb Bulk volume (Vb) : occupied volume True volume (Vp) SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 26% 48% Fig. 18-16 SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 True density () Density of the actual solid material Granule density (g) (Particle density) The mass of particles devided by the volume as determined by the liquid(mercury) displace method Bulk density (b) (Apparent density) The mass of a powder divided by the bulk volume SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Bulk density Tap density Granule density True density SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Bulkiness(bulk) is specific bulk volume, the reciprocal of bulk density SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 Light(경질) : low bulk density or large bulk volume Heavy(중질) : high bulk density or small bulk volume Light powders Heavy powders SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실 A bulk powder is some what analogous to a nonNewtonian liquid(plastic flow, dilatancy) Flow property is affected by particle size, shape, porosity, density, surface texture Measurement : angle of repose() (= f(roughness)) tan = : coefficient of friction SKKU Physical Pharmacy Laboratory 성균관대학교 물리약학연구실
