CHAP 14: DISPERSE SYSTEMS DISPERSE SYSTEM
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Types ypes of of liqui liquid d prepa prepara ratio tions ns cont contain aining ing undissolved or immiscible drug distributed throughout a vehicle
A. Dispersed Dispersed phase subs ubstan tance di distrib tribu uted ted - Usua Usuall lly y inso insolu lubl ble e mate materi rial als s Emulsions – dispersed phase is liquid o Emulsifcation – results in dispersion of liquid drug as ne droplets Aerosol – dispersed phase may be small air ules throughout solution or emulsion B. Dispersi Dispersing ng phase/Dis phase/Dispers persing ing medium – vehicle
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%uspension ensures chemical stability #hile permitting liquid therapy Ease of s#allo#ing liquids - advantageous for infants children and elderly $isagreeable taste is overcome Er)t*rom)cin estolate o - less #ater soluble ester of erythromycin -used to prepare a palatable liquid dosage form of erythromycin - Er)t*rom)cin Estolate (ral Sus!ension+ &SP
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Coarse dis!ersions Containing coarse !articles Ex: Ex: Emul Emulsi sion ons s sus suspe pens nsio ions ns "ine dis!ersions Containing particles of smaller si$e Ex: !agmas and gels Colloidal dis!ersions "articles in colloidal ran%e
Features Desired in a Pharmaceutical Suspension:
)* %hould settle slo,l) and should be readil) dis!ersed u!on %entle s*a-in% +* "artic "article le si,e si,e of suspe suspenso nsoid id should should remain .airl) constant throughout long periods of standing * %hould !our readil) and e/enl)
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S&SPE'SI('S
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Cont Contai ain n nel nely y divi divide ded d drug drug par parti ticl cles es or or suspensoid distributed distributed some#hat uniformly throughout a vehicle $rug $rug exhi exhibi bits ts a min minim imum um degr degree ee of of solubility
“For Oral Suspension”
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$rug $rugs s that that ar are unst unstab able le if if mai maint ntai aine ned d for long periods of time in presence of an aqueous vehicle %upp %uppli lied ed as as dry dry po#d po#der er mix mixtu turres for for reconstitution
Use of insoluble forms of drugs in suspension greatly reduces di'cult taste-mas(ing problems
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Sto-es equation Unifo Uniform rm perf perfect ectly ly spher spherica icall part particl icles es settle ,it*out !roducin% turulence+ turulence+ ,it*out collision+ ,it*out a0nit) to dis!ersin% medium .educ educin ing g part partic icle le si, si,e e – prod produc uces es slo#er rate of descent /deal /deal featur feature e – densit density y of of part partic icles les is greater than vehicle greater particle density greater rate of descent velocity of fall greater for larger particles
“Oral Suspension”
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&ott requi &o equiri ring ng recon econst stit itut utio ion n
Reasons for Suspensions:
Corte, 0*1 +2"3
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iscometer - determines viscosity of pharmaceutical prep*
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2roo-feld /iscometer - measures viscosity by force required to rotate a spindle in the 4uid
Phsical Features of the Dispersed Phase of a Suspension: •
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Dr) millin% 5enerally used for particle si,e reduction Micro!ul/eri$ation !ost rapid most convenient inexpensive method of producing ne drug po#ders o Micro!ul/eri$ers - high-speed attrition or impact mills "luid ener%) %rindin% 2or ner particles 6lso called !et milling or microni"ing %hearing action of high velocity compressed airstreams S!ra) dr)in% "roduce particles of extremely small dimensions o S!ra) dr)er - cone-shaped - solution of drug is sprayed and rapidly dried
2ine particles tend to form a ca(e upon settling - resists brea(up #ith sha(ing - !article s*a!e o. sus!ensoid – a7ects ca(ing S)mmetrical arrel#s*a!ed !articles o. calcium caronate - produce more stable suspensions As)mmetrical needle#s*a!ed !articles o. calcium caronate - form tenacious sediment ca(e
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/ntentional formation of less rigid or loose aggregation of particles 2orms a lattice that resists complete settling 8ess prone to compaction o Cla)s - commonly employed as 4occulating agent - help support the 4oc once formed -ex: diluted entonite ma%ma For parenteral suspensions: - 4oc can be produced by alteration in !H o. !re!aration o
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Electrol)tes - can also be used 4occulating agents - reduce electrical barrier bet* particles of suspensoid 'onionic sur.ace acti/e a%ents 5sur.actants6 - also induce 4occulation of particles
Dispersion #edium: # #
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Sus!endin% a%ents 6dded to dispersion medium to lend it structure Employed to thic(en the dispersion medium Caro7)met*)lcellulose Met*)lcellulose Microcr)stalline cellulose Pol)/in)l!)rrolidone 8ant*an %um 2entonite Pol)meric and *)dro!*ilic colloids Can bind certain medicinal agents 9hen used as suspending agents tests should be done R*eolo%) %tudy of 4o# characteristics
"actors t*at a9ect su!!ort o. sus!ensoid: •
"loc or 3occules
Corte, 0*1 +2"3
)* $ensity of the suspensoid +* 9hether it is 4occulated +
* 6mount of material requiring support
Preparation of Suspension: •
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ettin% a%ents 9hen drugs 4oat on top of vehicle Employed #hen aqueous vehicle is to be used 2unction by: displacing air in crevices of particles dispersing particles allo#ing penetration of dispersion medium Alco*ol ;l)cerin Pro!)lene ;l)col other hygroscopic liquid
=euco/orin calcium - most stable in mil( or antacid - unstable in acidic solutions International >ournal o. P*armaceutical Com!oundin% Contains hundreds of compounded liquid formulations o
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+ompounding suspensions for neonates
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Colloid mill 2or large-scale mixing of #etting agents Mortar and !estle 2or small-scale
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Hand#*omo%eni$er+ *omomi7er+ colloid mill %uspension is homogeni,ed
%hould not include !reser/ati/es+ colourin%s+ 3a/ourin%s+ alco*ol Alco*ol 6lter liver function Cause gastric irritation E7ect neurologic depression This is the same for elderly patients and patients #ho are ta(ing medications that depresses C&% metrodina$ole ?"la%)l@+ disulfram ?Antause@; Preser/ati/es 6dverse e7ects on infants 2en$)l alco*ol # cause %as!in% s)ndrome deterioration of multiple organ systems; Pro!)lene %l)col - sei,ures and stupors
Sustained$release suspensions: •
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Penn-inetic s)stem Combination of ion-exchange resin complex and particle coating /onic drugs are complexed #ith ion exchange resins and the drug-resin complex is coated #ith et*)lcellulose E7: *)drocodone !olistire7 %&ussione' Penn(inetic )'tended$ Release Suspension*
should be stored in airti%*t+ li%*t resistant ottle s*a-e ,ell
)'amples of Oral Suspensions:
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antacid and antibacterial suspensions aolin mi7ture ,< !ectin – treatment for diarrhea
Antacid Oral Suspensions )'temporaneous +ompounding of Suspensions: Di0cult)
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$rugs in liquid form have .aster decom!osition rates than solid form
Corte, 0*1 +2"3
Antacids - /ntended to counteract e7ects of %astric *)!eracidit) - Employed by persons #ho must reduce t*e le/el o. acidit) in stomac* peptic ulcer patients;
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3uoroquinone+ tetrac)cline antiiotics+ iron salts
Anti,iotic Oral Suspensions:
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Hearturn and %astric distress %ingle dose of sodium bicarbonate or magnesium hydroxide &lcerati/e conditions Combination of magnesium hydroxide > aluminum hydroxide ;astroeso!*a%eal re3u7 8iquid antacids – faster action
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2$6 requires that antacid tablets not intended to be che#ed must disinte%rate ,it*in 1B mins 6luminum and calcium containing products interfere #ith absorption of
Corte, 0*1 +2"3
2arium Sul.ate Sus!ension &SP 2or diagnostic visuali,ation of 5/ tract Mesalamine 5#aminosalic)lic acid6 !ar(eted as Ro,asa Treatment of Cro*n disease+ distal ulcerati/e colitis+ !roctosi%moiditis+ !roctitis &o longer commercially available Colocort 3ydrocortisone rectal suspension 6d?unctive therapy in treatment of ulcerati/e colitis
Dr Po-ders of Oral Suspension:
Contain:
Dr) !o,der .or reconstitution $ispersing phase is aqueous Usually colored s#eetened 4avoured – render liquid more appealing and palatable Palmitate .orm o. c*loram!*enicol - #ater insoluble and 4avourless
Rectal Suspensions:
Antiiotic sustances erythromycin and tetracycline; Sul.onamides sulfamethoxa,ole and sulsoxa,ole; Anti#in.ecti/e a%ents methenamine mandelate and nitrofurantoin; Cominations sulfamethoxa,ole > trimethoprim;
Antiiotic Colorants 2$@C dyes; "la/orants S,eeteners sucrose or sodium saccharin; Sus!endin% a%ents guar gum xanthan gum methylcellulose;
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Preser/in% a%ents methylparaben sodium ben,oate;
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"illmaster< "illmaster Plus 6id in reconstitution
Er)t*rom)cin et*)lsuccinate acet)l sulfso7a$ole Treatment of acute middle ear infection caused by Haemophilus infuenzae Proenecid am!icillin Treatment of uncomplicated infections caused by Neisseria gonorrhoea C*olest)ramine 5uestran6 !anagement of hyperlipidemia 2arium sul.ate 52aros!erse6 .adiopaque contrast medium 2arium sul.ate - contrast medium for roentgen ray examination - #ater insolubleB not absorbed in 5/ tract
EM&=SI('S
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$ispersed phase is composed of small globules of a liquid distributed throughout a vehicle in #hich it is immiscible A. Dispersed phase - internal phase B. Dispersion medium - external or continuous phase +. )mulsifing agent - third phaseB to prepare a stable emulsion Purpose of )mulsions and of )mulsication:
)* Enables ."h to prepare relatively stable and homogenous mixtures of + immiscible liq* +* "ermits administration of liquid drug in form of minute globules * "ermits palatable administration of distasteful oils
Corte, 0*1 +2"3
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&heories of )mulsication:
)* Sur.ace Tension t*eor) - Use of tension-lo#ering substances as emulsiers=stabili,ers lo#ers interfacial tension of + immiscible liquid Inter.acial tension - force causing each liquid to resist brea(ing up into smaller particles +* (riented ,ed%e t*eor) - !ono-molecular layers of emulsifying agents curved around the droplet - Certain emulsifying agents orient themselves about and #ithin a liquid in a manner re4ective of their solubility - Emulsifying agent #hich is F *)dro!*ilic #ill promote o<, emulsion FH)dro!*oic promotes a ,
!ust be compatible #= other ingredients !ust not interfere #ith stability or e'cacy %table and not deteroriate &on toxic "ossess little odor taste color
)* Caro*)drate materials a* &aturally-occuring Acacia - frequently employed Pectin Tra%acant* A%ar C*ondrus b* %ynthetic
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Microcr)stalline cellulose - viscosity regulator Protein Sustances 5elatin - disadvantage: too 4uid Egg yol( Casein "roduce o=# emulsions Hi%* molecular ,ei%*t alco*ols %tearyl alcohol Cetyl alcohol 5lyceryl monostearate Thic(ening agents and stabili,ers for o=# emulsions ettin% a%ents Anionic # lipophilic portion is negatively charged - p3 range greater than D Triet*anolamine oleate Sul.onates - %8% Cationic - positively charged - p3 range of - 2en$al-onium Cl 'onionic # p3 range of -)F Soritan esters Pol)o7)et*)lene deri/ati/es "inel) di/ided solids 2orm o=# emulsions 2entonite M% *)dro7ide Al *)dro7ide
In/ersion Change from o=#
#=o and vice versa
0B Sstem
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Emulsifying agents or surfactants categori,ed on basis of their chemical ma(eup as to their H=2 G hydrophiliclipophilic balance Hi%*l) !olar - higher number H=2 # - greatly lipophilic - produce #=o emulsions
Corte, 0*1 +2"3
H=2 J#1J - produce o=# emulsions
#ethods of )mulsion Preparation
)* Dr) ;um
oil then #ater - 4:K:1 met*od – A parts oil + parts #ater ) part gum +* et #ater then oil * 2ottle<"ores met*od - Golatile oils and lo# viscosities - &ot suited for viscous oils A* Au7iliar) met*ods - 3and homogeni,er * In Situ Soa! met*od - Calcium soaps and soft soaps Calcium soa!s - #=o emulsions that contain certain vegetable oils in combination #= lime#ater Ex: Calamine liniment H* Microemulsions - Thermodynamically stable - %urfactants 38I range )-)D polysorbate HF and polysorbate DF; 6dvantages: !ore rapid and e'cient oral absorption Enhanced transdermal drug delivery Unique potential in devt of articial .ICs Sta,ilit of )mulsions:
- Emulsions are generally unstable if: ); 2orm aggregates of globules upon standing +; 5lobules rise to the top or fall to the bottom ; %eparation and form distinct layer Aggregation and +oalescence
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Creamin% "articles rise to the top or fall to bottom .eversible To increase stailit): "article si,e reduced as ne as possible
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!inimal density di7erence 3igh viscosity - t*ic-eners: tragacanth microcrystalline cellulose o &!,ard creamin% - lesser density of internal phase o Do,n,ard creamin% - higher density of internal phase 2rea-in% %eparation of internal phase from emulsion /rreversible
large organic molecules interpenetrated by liquid %emirigid systems o A. Single phase gels - no apparent boundaries exist B. #agma or #il( - 4occules of small distinct particles - t#o-phase system +olloidal Dispersions: #
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"un%istatic !reser/ati/e !ethylparaben propylparaben Alco*ol 1K#1L - used as preservative in o=# emulsion
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Sol $ispersion of a solid substance in liquid solid or gas H)dro# #ater; Alco# alcohol; Aerosol – dispersion of solid in gaseous phase
)'amples of Oral )mulsions:
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Mineral (il Emulsion 8ubricating cathartic Castor (il Emulsion 8axative 2or preparation of colon for radiographic and endoscopic exam - (/eruse : excessive loss of #ater and electrolyte ; Simet*icone Emulsion - 9ater-dispersible form of simethicone - $efoaming agent for relief of painful symptoms of excessive gas in 5/ )'amples of &opical )mulsions: •
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=otions 6pplied to outer surface of the body Estrasor 5estradiol6 o # treatment of hot 4ashes and night s#eats caused by menopause o =otrimin 5clotrima$ole6 o Di!rolene 5etamet*asone di!ro!ionate6 S*am!oo %olution emulsion or suspension used to clean the hair
;E=S A'D MA;MAS ;els Consists of dispersions made up of o either small inorganic particles or
Corte, 0*1 +2"3
Di9erences et colloidal dis!ersions and true solutions:
)* 8arger particle si,e of disperse phase +*
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=)o!*ilic %olvent-lovingB disperse phase interacts #= dispersion medium $isperse readily upon addition to dispersion medium =)o!*oic %olvent-hatingB degree of attraction is small 5enerally composed of inorganic particles $o not disperse readily $oes not greatly a7ect viscosity of the vehicle Association or Am!*i!*ilic colloid Exhibit both lyophilic and lyophobic properties T*i7otro!) Iecome 4uid on agitation and resume solid=semisolid state after remaining undisturbed
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.eversible gel-sol formation 'atural colloids %elf-dispersing Artifcial colloids .equire special means for prompt dispersion
&erminolog Related to 1els: #
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Imiition Ta(ing up of liquid #ithout measurable increase in volume S,ellin% Ta(ing up of liquid #= an increase in volume 8iquids that solvate gel cause s#elling S)neresis /nteraction bet* dispersed phase is great $ispersing medium is squee,ed out and gel shrin(s 6 form of instability
8ero%el 8iquid is removed from gel and only frame#or( remains ;elatin s*eets+ tra%acant* rions+ acacia tears
+lassication and &pes of 1els: Primar) classifcation
)* Inor%anic - T#o-phase systems - Aluminum *)dro7ide %el+ entonite ma%ma +* (r%anic - %ingle-phase system - Caromer+ tra%acant*+ Plastiase
b* &atural and synthetic gums c* /norganic hydrogels Examples: Silica 2entonite Tra%acant* Pectin Sodium al%inate Met*)lcellulose Sodium CMC Alumina +* (r%ano%els * a* 3ydrocarbons – >elene or Plastiase Petrolatum b* 6nimal and vegetable fats c* %oap base greases d 3ydrophilic organogels – !ol)et*)lene %l)col 5Caro,a76
>ellies # %tructural coherent matrix contains a high proportion of liquid # 2ormed by adding t*ic-enin% a%ent tragacanth or carboxymethylcellulose; – resultant product is clear uniformly semisolid Preparation of #agmas and 1els: # #
)'amples of 1elling Agents: 1 Al%inic acid
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Knd classifcation
)* H)dro%els - /ngredients are dispersible as colloidal or soluble in #ater a*
Ma%mas and %els 5inor%anic6 "repared by freshly precipitating the disperse phase %ome are prepared by directly hydrating the inorganic chemical
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K Caromer 5Caro!ol6
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.esins #ith high molecular #eight allylpentaerythrital-cross-lin(ed acrylic acid- based polymers modied #ith C)F to CFal(yl acrylates - 2lu7y #hite po#ders #ith large bul( density F* and )J aqueous dispersion; o Caromer N4 G e7ective in thic( formulations Caromer N4P G for mucosal and o oral applications o Caromer N4B G forms spar(ling clear #ater or hydroalcoholic gelsB most e'cient CMC - concentrations of AJ to HJ of medium viscosity can be used to produce gel - %l)cerin may be added to prevent drying - incompatible #ith alcohol 4 CMC Sodium # %oluble in #ater Colloidal silicon dio7ide - used #ith other ingredients of similar refractive index to prepare transparent gels ;elatin # dispersed in hot #ater and cooled to form gels O Ma%nesium aluminum silicate 5ee%um6 - Concentrations of about )FJ forms a rm thixotropic gel - !aterial is inert and has fe# incompatibilities but is less used above p3 * J Met*)lcellulose # 8ong-chain substituted cellulose # Concentration up to about J N Plastiase<>elene - !ixture of J lo# molecular #eight polyethylene and KJ mineral oil 1B Polo7amer
11 PA - Used at conc of about +*J in the preparation of various ?ellies that dry rapidly #hen applied to the s(in 1K Po/idone - about )FJ to produce gels - increase solubility of poorly insoluble drugs 1 Sodium al%inate - )FJ to produce gels 14 Tra%acant* %um - Used to prepare gels that are most stable at p3 A to D )'amples of #agmas and 1els:
)* +* * A* * H* * D*
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2entonite ma%ma %uspending agent Thixotropic ge Sodium "luoride and P*os!*oric Acid ;el $ental care prophylactic "luocinonide ;el 6nti-in4ammatory corticosteroid Tretinoin ;el %timulates epidermal cell turnover Causes peeling Treatment of acne Mil- o. Ma%nesia -D*J magnesium hydroxide .eaction bet#een sodium hydroxide and magnesium sulfate %ide e7ect: diarrhea Starc* %l)cerite Topical vehicle and protectant =uricatin% >ell) 6ssist in medical procedures 6id in insertion of various devices Clear Aqueous ;el ,< Dimet*icone o Dimet*icone co!ol)ol – reduce stic(y feel of gelatin Gehicle Polo7amer ;el 2ase 6bsorption-enhancing topical vehicle #=isopropyl palmitate and lecithin;
E7am!les o. to!ical %els: o Er)t*rom)cin and en$o)l !ero7ide %el 52en$am)cin To!ical ;el6
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Clindam)cin to!ical %el 5Cleocin6 Clindam)cin and en$o)l !ero7ide %el 52en$aClin6 2en$o)l !ero7ide 5Desquam#8 1B6 - control and treatment of acne vulgaris H)droquinone %el 5Solaquin "orte ;el6 - bleach for hyperpigmented s(in Salic)lic acid %el 5Com!ound %el6 - (eratolytic Deso7imetasone %el 5To!icort6 and au%mented et*amet*asone di!ro!rionate %el 5Di!rolene6 # antipruriticB anti-in4ammatory
Antacids: Aluminum !*os!*ate o Aluminum *)dro7ide o - treatment of hyperacidity and peptic ulcers - disadvantage: constipation Di*)dro7)aluminum o aminoacetate ma%ma AER(S(=S - "ressuri,ed dosage forms - Emit a ne dispersion of liquid and=or solid materials - $ependence upon function of container valve assembly and propellant Pressuri$ed !ac-a%e - Term #hen referring to the aerosol container or completed product •
Product ma) e e7!elled as: Mist o Coarse+ ,et+ or dr) s!ra) o Stead) stream o Stale or .ast#rea-in% .oam o
"or in*alation t*era!) – form of ne liquid or as nely divided solid particles Dermatolo%ic s!ra) G coarserB may be po#der #et spray stream of liquid or ointment-li(e a%inal and rectal .oams S!ace s!ra)s # used to provide airborne mist room disinfectants deodori,ers # space insecticides Sur.ace s!ra)s # Carry active ingredient to a surface # $ermatologic aerosols TYPES (" AER(S(=S: )* In*alation aerosols - Metered#dose in*alers 5MDIs6 - "roduce ne particles for inhalatation through mouth and deposition in pulmonary tree - .elease measured quantities +* 'asal aerosols - 'asal MDIs - $elivery through nasal vestibule and deposition through nasal cavity -
Corte, 0*1 +2"3
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Contains active ingredient and ad?uncts +* Pro!ellant - =iquefed %as serves as propellant and vehicle; or com!ressed %as carbon dioxide nitrous oxide nitrogen; =iquefed %as o C*loro3uorocarons 5C"C6 - reduce amount of o,one in stratosphere - used if: a; there are no alternatives b; provides substantial health or other public benets c; does not involve signicant release of C2C E7am!les: dichlorodi4uoromethane dichlorotetra4uoroethane trichloromono4uoromethane •
Aerosol Sstems: "ressure can be controlled by: a; Type and amt of propellant b; &ature and amt of product concentrate •
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S!ace s!ra)s Contain greater proportion of propellant .elease #ith great pressure "oam aerosols Considered to be emulsions – liqueed propellant is partially emulsied "luorinated HC .elatively lo# order of toxicity &onirritating
&-o Phase Sstems )* =iquid !*ase – liqueed propellant and product concentrate +* a!or !*ase &hree$Phase Sstems )* ater#immiscile liquid !ro!ellant
Corte, 0*1 +2"3
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5reater density than product concentrate and resides at bottom +* Hi%*l) aqueous !roduct concentrate * a!or !*ase +ompressed 1as Sstems - &o reservoir of propellant - 3igher gas pressure is required
6dvantage of nitrogen as propellant: Inert Protecti/e in3uence (dorless and tasteless
E7ectiveness of aerosol depends on: )* "ormulation - !ust not chemically interact #ith container or other components +* Container !ust #ithstand pressure * /al/e asseml) resist erosion - must contribute to the form of product +ontainers a; %lass+ uncoated or !lastic coated - preferred if not for brittleness 6dvantages: fe#er problems #ith chemical compatibility not sub?ect to erosion more adaptive on design $isadvantage: must be precisely engineered for safety o Plastic coatin%s - render glass containers more resistant to accidental brea(age - prevents scattering of glass fragments b; metal
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Tin#!lated steel # most #idely used - seamed and soldered o Aluminum - seamless - greater safety against lea(age incompatibility and corrosion o Stainless steel # great deal of chemical resistance is required - high cost c; Plastics - "roblem: being permeated by vapor #ithin the container o
3al2e Assem,l - "ermit expulsion of contents of the can in the desired .orm+ desired rate+ !ro!er amount - !ust be inert "arts: )* Actuator - Iutton the user presses - "ermits easy opening and closing of valve - =ar%e orifces – for foams and solid streams +* Stems - %upports actuator - $elivers formulation in proper form to the chamber * ;as-et - "revents lea(age of formulation A* S!rin% 3olds gas(et in place - !echanism by #hich actuator retracts * Mountin% cu! - 3olds valve in place H* Housin% - 8in( dip tube stem and actuator - 3elps determine the delivery rate and form * Di! tue - Irings formulation from container to valve
Actuator+ stem+ *ousin%+ di! tue – made of plastic Mountin% cu!+ s!rin% – metal
Corte, 0*1 +2"3
;as-et – rubber or plastic resistant to formulation
#etered$Dose 4nhalers Metered /al/es - Employed #hen formulation is potent medication - !aterial is regulated by au7iliar) /al/e c*amer - /ntegrity is controlled by dual#/al/e mec*anism •
2actors that a7ect e7ectiveness of delivering medication: )* "article si,e of inhaled drug +* Ireathing patterns and depth of respiration 6reas of research in developing aerosol production: )* 6nalysis of dose uniformity +* "article si,e distribution patterns * .espirable fractions
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Translin%ual aerosol .ormulation o. nitro%l)cerin 5'itrolin%ual S!ra)6 %pray droplets onto or under tongue 6cute relief of an attac( or prophylaxis of angina pectoris &ot to be inhaled
Filling Operations: +old Filling - "roduct concentrate and propellant cooled to -A*-AF deg* Celsius - Coolin% s)stem: dry ice and acetone - 6queous systems canMt be lled – turn to ice Pressure Filling - 8iqueed gas is metered into valve stem from pressure burette - Used for most pharmaceutical aerosols 6dvantages: )* 8ess danger of moisture contamination +* 8ess propellant is lost &esting Filled +ontainers
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Tested under various environmental conditions for lea-s or ,ea-ness al/e disc*ar%e rate $etermined by discharging a portion of the contents of a previously #eighed aerosol
!ust #arn patients not to: - "uncture pressuri,ed containers - Use or store them near heat or open 4ame - /ncinerate them Proper Administration and 6se of Pharmaceutical Aerosols •
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E7tender de/ices
$isadvantage: )* $i'culty in applying in small areas +* 5reater expense 3aginal and Rectal Aerosols a%inal # Contains inserter # 2oams are o=# emulsions – #ater miscible and nongreasy Rectal o Procto.oam - pramoxine hydrochloride - relieve in4ammatory anorectal disorders "(AMS - Emulsion dosage form containing dispersed gas bubbles - 2lu7y semisolid consistency Medicated "oams - $ispersed phase: gas bubbles - Continuous phase: 6/ - "ac(aged in pressuri,ed containers - 6pplied to s(in and mucous membranes PREPARATI(' (" "(AMS )* 6ctive ingredient=s +* %urfactants * 6queous=nonaqueous liquids A* "ropellants o Stale .oam – propellant is internal o S!ra) or quic- -rea-in% .oam propellant is externalB create cooling sensations #= alcohol •
Topical administration – clean area and pat dry
&opical Aerosols Anti#in.ecti/e a%ents - "ovidone iodine tolnaftate thimerosal Adrenocortical steroid - Ietamethasone dipropionate and valerate dexamethasone triamcinolone acetonide =ocal anest*etic - $ibucaine 3Cl 6dvantages: )* Convenient +* 8ess messy •
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Corte, 0*1 +2"3
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Corte, 0*1 +2"3
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