SCformulationsSuspensionConcentrates論壇（第十屆山東省農(nóng)藥信息交流會(huì)）SC水懸浮劑描述：固體顆粒懸浮于水中

Description:Solidparticlessuspendedinwater常見問題Issues懸浮物質(zhì)與水之間存在密度差Densitydifferencebetweensuspendedmatterandwater如果原藥密度大于1克/毫升將形成沉淀

Willformsedimentifdensityis>1如果原藥密度大于1克/毫升將漂浮

Willfloatifdensityis<1根據(jù)斯托克斯定律：較小的粒徑是必須的Stokeslaw:smallparticlesarerequired怎樣獲得較小的粒徑Howtoobtainsmallparticles?怎樣保持粒子的懸浮穩(wěn)定性

Howtokeeptheparticlessuspended?結(jié)晶增長(zhǎng)CrystalgrowthFormulationbreakdownprocesses制劑被破壞的過程Reversible可逆的Irreversible不可逆的膏化沉淀絮凝相轉(zhuǎn)化聚結(jié)奧氏熟化HowtopreventOswaldripening怎樣預(yù)防奧氏熟化的發(fā)生較窄的粒徑分布范圍

Narrowparticlesizedistribution還有其他的訣竅

Thereareothertricks:Verylimitedamountofdilutedoilinaqueousphase將一定量的油稀釋到水相中

TomakeanSC水懸浮劑制備Preparationofsmallparticles小粒子的制備PreventingflocculationPreventingsedimentationTomakeanSC水懸浮劑制備Preparationofsmallparticles

小粒子的制備Smallsuspendedparticlesarepreparedbymillingprocess通過砂磨設(shè)備獲得較小粒徑Processingconditionsareimportant生產(chǎn)工藝條件很重要Milling砂磨Wetting->Dispersion->stabilization

潤(rùn)濕—分散—穩(wěn)定性Issueduringmillingprocess

砂磨過程中出現(xiàn)的問題Duringmillingprocessfreshsurfaceisgenerated>砂磨過程中新的粒子表面產(chǎn)生Freshsurfaceisgenerallyofnon-polarnatureenwillclustertogetherrapidly>新產(chǎn)生的非極性的表面通常是的自然對(duì)開很容易迅速聚集Thiscouldleadtoincreasedviscosityandevenmillblockage>這可能導(dǎo)致粘度增加甚至阻礙砂磨進(jìn)程Toovercomemillblockageawettingagentisneeded>為了克服這一問題所以潤(rùn)濕劑的加入是非常必要的TomakeanSC水懸浮劑制備PreparationofsmallparticlesPreventingflocculation絮凝的預(yù)防PreventingsedimentationElectrostaticStabilization

靜電排斥作用GhGmaxElectrostatic靜電學(xué)Electrosteric靜電空間GhGh

2dM

h

Ghd2dp

Monomer單體-Polymer高分子StericStabilization空間位阻作用空間位阻是由于非離子表里面活性劑和/或高分子表面活性劑提供的Stericbarriersareproducedbyadsorptionofnonionicsurfactantsand/orpolymericsurfactant由于鏈的不利交叉排斥和熵值作用對(duì)重大交疊的影響RepulsionisduetounfavourablemixingofthechainsandentropiceffectsonsignificantoverlapFunctionsofsurfactants

表面活性劑的功能Wet潤(rùn)濕Disperse分散Sizedoesmatter

分子大小關(guān)系DispersedPhase

分散內(nèi)相CONVENTIONALDISPERSANT

常規(guī)分散劑POLYMERICDISPERSANT

高分子分散劑DispersedPhase

分散內(nèi)相2dM

h

Ghd2dp

Monomer單體-Polymer高分子StericStabilization空間位阻作用空間位阻是由于非離子表里面活性劑和/或高分子表面活性劑提供的Stericbarriersareproducedbyadsorptionofnonionicsurfactantsand/orpolymericsurfactant由于鏈的不利混合排斥和熵值作用對(duì)重大交疊的影響RepulsionisduetounfavourablemixingofthechainsandentropiceffectsonsignificantoverlapRheologyproagentvs.polymericdispersant

潤(rùn)濕劑與高分子分散劑流變性特征對(duì)比Wettingagent

潤(rùn)濕劑

Polymericdispersant高分子分散劑

Nosheareffectpolymericdispersantflowcurve:suspensionisproperlystabilized高分子分散劑在剪切作用下的流變曲線無影響：懸浮液相對(duì)穩(wěn)定

Wettingagentflowcurveincreaseshugelyatlowshear:insufficientstabilisation潤(rùn)濕劑在低剪切作用下的流變曲線明顯增大：不夠穩(wěn)定

Ifwettingagentisrequired,useatlowpossibleconcentration!如果潤(rùn)濕劑是必須添加的，盡可能在最低添加量下使用Stokeslaw斯托克斯定律

Vs=velocityofsettling/creaming粒子沉降速度，cm/s;η=viscosity

水懸浮劑粘度，Pa.S;g=gravity

重力加速度，cm/s;r=radiusofsphere

分散介質(zhì)粒子直徑，cm;Δδ=densitydifferencesphere&continuousphase

分散粒子的密度與水的密度差Vs=--------------------9η2gr2ΔδStokeslaw斯托克斯定律

Vs=--------------------9η2gr2ΔδNosedimentationifdensityofsuspendedmatterandwaterphaseareequal如果懸浮介質(zhì)和水相之間沒有密度差，沉淀問題就不可能發(fā)生固相/液相密度差=0Stokeslaw斯托克斯定律

Vs=--------------------9η2gr2ΔδThesmallertheparticlesize,thelessersedimentation粒徑越小沉淀越慢Notethisasquarefunction值得注意的是稱將速度與粒徑的平方正相關(guān)10timestheparticlesizeis100timesfastersedimentation10倍的粒徑大小差異將導(dǎo)致100倍的沉降速度差別粒徑大小Rheologyprogum

黃原膠的流變學(xué)特征粘度轉(zhuǎn)速SC水懸浮劑Generalformula:一般配方組成

成份用量Suspendedphase 分散相

40%Dispersant分散劑

4%Wettingagent潤(rùn)濕劑

0.5%Glycerine

防凍劑

5.2%Antifoam消泡劑

0.1%Preservative防腐劑

0.1%Kelzangum增稠劑

0.1%Water水

50%Issue:longtermstabilityandemulsionstabilityupondilution問題：經(jīng)時(shí)穩(wěn)定性和乳液的稀釋穩(wěn)定性Withtraditionalwettingagent

傳統(tǒng)的潤(rùn)濕劑用量的確定Optimumapproach:最理想的途徑——三元復(fù)配組合12345678910111213

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171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667Dispersant分散劑Co-dispersant助分散劑Wettingagent潤(rùn)濕劑Performancecriteria:評(píng)估標(biāo)準(zhǔn)Millingefficiency砂磨的效率Storagestability儲(chǔ)存穩(wěn)定性Crystalgrowth;partII結(jié)晶增長(zhǎng)PolymericDispersant高分子分散劑PolymericplusmonomericDispersant高分子/單體分散劑Crystalgrowth;partII結(jié)晶增長(zhǎng)Effectofsurfactantmicelles表面活性