常用軟膏劑的制備

常用軟膏劑的制備

0542327仝贇

Preparationofointments

Ointmentsaresemi-solidpreparationsmadeofmedicamentsandsuitablebases,whichareintendedforexternalapplicationtotheskin.Ointmentbasesrecognizedforuseasvehiclesdistinguishedintothreegeneralclasses:theoleaginousbases,theemulsionbases,andthewater–solublebases.

Therearethreegeneralmethods:themethodofgrindingandmixing,themethodofmeltingandmixing,themethodofemulsification.

Ophthalmicointmentsareointmentsforapplicationtotheeyewhosebasesgeneralincludeliquidparaffin,Vaselineandwoolfat.Specialprecautionsmustbetakeninthepreparationofophthalmicointments.Theyaremanufacturedfromsterilizedingredientsunderrigidlyasepticconditions.Theointmentbasethatisselectedmustbewithoutanyirritationtoeye.

Equipments:evaporating,waterbath,electricfurnace,analyticalbalance,thermometer,microscopeetc.

Materials:Stearicacid,glycerolmonostearate,Vaseline,glycerol,liquidparaffin,triethanolamine,calciumhydroxide,CMC-Na,span80,nonoxynol-10,distilledwateretc.Procedures:

1.

O/Wemulsionbase

FormulationStearicacid

4.8gGlycerolmonostearate

1.4gLiquidparaffin

2.4gVaseline

0.4g

TokeepwaterWoolfat

2.0gTriethanolamine

0.16gDistilledwateraddupto

40.0g

Preparation:

Addstearicacid,glycerolmonostearate,liquidparaffin,Vaselineandwoolfatintoevaporatingdish,whichthemixtureisusedasoilphase.Addtriethanolamineanddistilledwaterintobeaker,whichthesolutionisusedasawaterphase.Thetwocontainersareheatedto80°Cinwaterbathandkeptuntilmeltingcompletely.Pouroilphaseintowaterphaseslowly,andstirthemfully.Coolatroomtemperature,thentheO/Wemulsionbasecanbegot.2.

W/Oemulsionbase

Formulation:Glycerolmonostearate

0.85gBeeswax

5.25gParaffin

3.75gStearicacid

0.625gLiquidparaffin

20.5gVaseline

3.35g

TokeepwaterSpan80

0.5gcalciumhydroxide

0.05gEthylparaben

0.1gDistilledwater

10.0gEssence

2drops

Preparation:

Addglycerolmonostearate,paraffinandstearicacidintotheevaporatingdishthatisabovewaterbath.Whenthemixtureismelted,addVaseline,liquidparaffinandaluminumdistearateintoit.Theabovemixtureisusedastheoilphase.Calciumhydroxideandethylparabenaredissolvedindistilledwater.Thedegreeofwaterisabout80°C.Thesolutionisusedasthewaterbase.Aclockwisestirringisneededwhenaddwaterphaseintooilphase.Coolthebasetotheroomtemperature,thentheW/Oemulsionbasecanbegot.

ResultsandDiscussion:

ThefirstO/Wisakindofthickwhiteointment,whilethesecondisabityellow,andtheformeristhinthanthelatter.Boththetwoproductshaveakindofsmell.

Inthepreparationofointments,weshouldkeepthetemperatureat80°Cforthereasonofgettingthereactionstarted.Andthetemperatureofthewaterphaseshouldbehigherthanthatoftheoilphase,underthiscondition,wecanmakesurethattheoilphaseandthewatergetintouchandhaveacompletereaction.

Theexperimentisconsideredtobeasuccessfulone.

References:

軟膏劑（Ointments）

軟膏劑（Ointments）指藥物與適宜基質(zhì)均勻混合制成的具有一定稠度的半固體外用制劑。常用基質(zhì)分為油脂性、水溶性和乳劑型基質(zhì)，其中用乳劑基質(zhì)制成的易于涂布的軟膏劑稱乳膏劑。

因藥物在基質(zhì)中分散狀態(tài)不同，用溶液型軟膏劑和混懸型軟膏劑之分。溶液型軟膏劑為藥物溶解或共熔于基質(zhì)或基質(zhì)組分中制成的軟膏劑，混懸型軟膏劑為藥物細(xì)粉均勻分散與基質(zhì)中制成的軟膏劑。

軟膏劑基質(zhì)可分為油脂性基質(zhì)和水溶性基質(zhì)。油脂性基質(zhì)常用的有凡士林、石蠟、液體石蠟、硅油、蜂蠟、硬脂酸、羊毛脂等，水溶性基質(zhì)主要有聚乙二醇。

乳膏劑：系指藥物溶解或分散于乳狀液型基質(zhì)中形成的均勻的半固體外用制劑。乳膏劑由于基質(zhì)不同，可分為水包油型乳膏劑和油包水型乳膏劑。

乳膏劑常用的乳化劑可分為水包油型和油包水型。水包油型乳化劑有鈉皂、三乙醇胺皂類、脂肪醇硫酸（酯）鈉類（十二烷基硫酸鈉）和聚山梨酯類；油包水型乳化劑有鈣皂、羊毛脂、單甘油酯、脂肪醇等。

軟膏劑和乳膏劑基質(zhì)應(yīng)均勻、細(xì)膩，涂于皮膚或黏膜上應(yīng)無刺激性，混懸型軟膏劑中不溶性固體藥物應(yīng)預(yù)先用適宜的方法磨成細(xì)粉，確保粒度符合規(guī)定。

軟膏劑和乳膏劑根據(jù)需要可加入保濕劑、防腐劑、增稠劑、抗氧劑及透皮促進(jìn)劑。

軟膏劑和乳膏劑應(yīng)具有適當(dāng)?shù)恼吵矶?，?yīng)易涂布于皮膚或粘膜上，不融化，粘稠度隨季節(jié)變化應(yīng)很小。

軟膏劑和乳膏劑應(yīng)無酸敗、異臭、變色、變硬，乳膏劑不得有油水分離及脹氣現(xiàn)象。

除另有規(guī)定外，軟膏劑應(yīng)遮光密閉保存，乳膏劑應(yīng)遮光保存，宜置25℃

Ointments

Ointmentsareusedtopicallyforseveralpurposes,e.g.,asprotectants,antiseptics,emollients,antipruritics,kerotolytics,andastringents.Thevehicleorbaseofanointmentisofprimeimportanceifthefinishedproductisexpectedtofunctionasanyoneoftheabovecategories.Inthecaseofaprotectiveointment,itservestoprotecttheskinagainstmoisture,air,sunraysandotherexternalfactors.Itisnecessarythattheointmentneitherpenetratesthehumanskinbarriersnorfacilitatestheabsorptionofsubstancesthroughthisbarrier.Anantisepticointmentisusedtodestroyorinhibitthegrowthofbacteria.Frequentlybacterialinfectionsaredeeplyseated;abasewhichhasthecapacitytoeitherpenetrateordissolveandreleasethemedicationeffectivelyisthereforedesired.Ointmentsusedfortheiremollienteffectshouldbeeasytoapply,benon-greasyandeffectivelypenetratetheskin.

Therearefive(5)classesortypesofointmentbaseswhicharedifferentiatedonthebasisoftheirphysicalcomposition.Theseare:oleaginousbasesabsorptionbaseswaterinoilemulsionbasesoilinwateremulsionbaseswatersolubleorwatermisciblebases

Eachointmentbasetypehasdifferentphysicalcharacteristicsandtherapeuticusesbaseduponthenatureofitscomponents.Thefollowingtablesummarizesthecomposition,properties,andcommonusesofeachofthefivetypes.FormoreinformationconsultRemington's.

Toincorporateaninsolubledrugintothesebases,pulverizethepowderonthepilltileorwithamortarandpestle(above/right).Usealevigatingagenttowetthepowderandthenincorporatethewettedpowderintotheointmentbase.Generally,theamountofdrugtobeincorporatedintotheointmentwillbemuchlessthantheamountofointment.Inotherwords,asmallamountofdrugwillbeincorporatedintoalargeamountofointment.Theprocessofgeometricdilutionwill"diluted"thedrugintotheointment.Geometricdilutioninvolvesaseriesofdilutionsteps.Itbeginsbyincorporatingthedrugintoanamountofointmentofapproximatelythesamesize.Thenasecondamountofointmentapproximatelyequaltothefirstmixtureisaddedandmixed.Thisstepwisedilutionprocessiscontinuedalloftheointmenthasbeenused.

Agoodlevigatingagentismineraloilsinceitiscompatiblewitholeaginousbases.Sometimesusingasmallquantityofthebaseitselfasthelevigatingagentissufficient.

Solubledrugscanbeincorporatedintooleaginousbasesbyfusion.Thebaseisliquefiedoverlowheat(nottoexceed70°C)andthenthedrugisaddedtothemoltenbase.Themixtureisthenallowedtocoolwithoccasionalstirring.

Showhowtoincorporatedadrugintoanointmentusinggeometricdilution&2spatulas

Incorporatinginsolubledrugsintothesebasescanbedonemechanicallyorbyfusion.Thefinaldestination(internalorexternalphaseoftheemulsion)ofthedrugmustbeconsideredwhenselectingalevigatingagent.Ifthedrugwillresideintheinternalphase(waterphase),thenthelevigatingagentshouldbewatersolubleormiscible.Water,glycerin,alcohol,orpropyleneglycolwouldbesuitablelevigatingagents.Ifthedrugwillresideintheexternalphase,thenmineraloilshouldbeused.

Watersolubleingredientscanbeaddedtothewaterphaseofthew/oemulsion.Ifthedrugwilldissolveinasmallamountofwater,theaqueoussolutioncanbeaddeddirectlytothebaseusingapilltileandspatula.Ifalargerquantityofwaterisneededtosolubilizethedrugorifanaqueoussolutionisbeingaddedtothebase,heatmaybeneededtocompoundtheformulation.Itmaybenecessarytoaddadditionalemulsifiertotheemulsiontoaccommodatetheaddedwater.Somecommercialemulsionsdohavethenecessaryexcessemulsifier.

W/OEmulsionBases

Oilsandinsolublepowderscanbedirectlyincorporatedintotheexternalphaseusingapilltileandspatula.Ifalevigatingagentistobeusedwiththeinsolublepowders,itshouldbemisciblewiththeoilphase;mineraloilwouldbeasuitableagent.Levigatingagentsmaybeneededwithlargerquantitiesofinsolublepowders.Iftheinsolublepowderhasadifferentsaltformthatisoilsoluble,considerationshouldbegiventousingthatsaltform.

Thesamecommentsthatapplytoincorporatingwatersolubleingredientsintoabsorptionbasesalsoapplytow/oemulsionbases.

O/WEmulsionBases

Watersolublepowderscanbedirectlyincorporatedintotheexternalphaseusingapilltileandspatula.Ifthepowderisinsoluble,thelevigatingagentshouldbewatermisciblesoglycerin,propyleneglycol,polyethyleneglycol(PEG)300or400,oralcoholwouldbeacceptable.Iftheinsolublesubstancehasadifferentsaltformthatisaqueoussoluble,considerationshouldbegivento