Unit V Semisolid Dosage Forms.pdf

his presentation delves into the formulation, advantages, and applications of semisolid dosage forms, including creams, ointments, and gels. Learn about their unique properties, manufacturing processes, and considerations for drug delivery. Whether you're a student or a pharmaceutical professional, this presentation offers valuable insights into this essential aspect of medication delivery.

1. Semisolid Dosage Forms
-Prepared and presented by
Mr. Gaurav S. Patil
Assistant Professor, Dept. of Pharmaceutics
KVPS’s, Institute of Pharmaceutical Education, Boradi, Maharashtra
DepartmentofPharmaceutics
UNIT :V

2. Content
•Definition
•Classification
•Mechanism and Factor affecting dermal penetration of drugs
•Excipient used in semi-solid dosage forms
•Preparation of Ointments, Paste, Creams, and Gels
•Evaluation of semi-solid dosage forms.

3. Definition
•Definition:Semi-soliddosageformsarethedermatologicalpreparations
mainlymeantforexternalapplicationtotheskintoproducelocalorsystemic
effect.
•Examples:Ointment,Gel,Suppositories,Paste,Jellies,Creams.
•Theycontainoneormoreactiveingredientsdissolvedoruniformlydispersed
inasuitablebaseandanysuitableexcipientssuchasemulsifiers,viscosity
increasingagents,antimicrobialagents,antioxidants,orstabilizingagents
etc.

4. Classification

5. Mechanism of dermal penetration of drugs
Three potential routes for drug penetration
into skin:
1.Via Sweat Ducts (Para-cellular)
2.Across the stratum corneum (Trans-cellular)
3.Through the hair follicles with their associated
sebaceous glands

6. Mechanism of dermal penetration of drugs

7. Factors affecting dermal penetration of drugs
•Thedermalpenetrationofdrugsreferstotheabsorptionofmedications
throughtheskinandintothesystemiccirculation.
•Severalfactorsinfluencethisprocess,andthemechanismsinvolvedcanvary
dependingonthepropertiesofthedrugandtheskinbarrier.
•Thesefactorsaremainlycategorizedintotwomainheadings:
1.Biologicalfactors
2.Physiochemicalfactors.

8. Factors affecting dermal penetration of drugs
•Someofthekeyfactorsaffectingdermalpenetrationofdrugsandthemechanisms
atplay:

9. Factors affecting dermal penetration of drugs
BiologicalFactors:
1.Skincondition:
•Thickness:Thinnerskin,suchasontheface,neck,andflexorsurfaces,isgenerally
morepermeablethanthickerskin,likethesolesofthefeetorthepalmsofthehands.
•Diseasealtertheskincondition,skininflamed,withlossofstratumcorneumthus
permeabilityincreases.
•Intactandhealthyskinisamoreeffectivebarrierthancompromisedordamaged
skin,suchasinthecaseofcuts,burns,ordermatitis

10. Factors affecting dermal penetration of drugs
2.SkinAge:Skinofyoungandelderismorepermeablethanadulttissues.
3.Bloodflow:Increasebloodflowcouldreducetheamountoftimeapenetrant
remainsinthedermis,alsoraisetheconcentrationgradientacrosstheskin.
4.SkinMetabolism:Theskinmetabolizessteroidhormones,chemicalcarcinogens,
andsomedrugs.Skinalsometabolizes5%oftopicaldrugs.

11. Factors affecting dermal penetration of drugs
PhysicochemicalFactors:
1.Skinhydration:Whenthewatersaturatetheskin,thetissueswells,soften.Wrinklesand
hydrationofthestratumcorneumincreasesthepermeabilityoftheskin.
2.Temperature:Therateofpermeationincreasedexponentiallywithincreasingskinsurface
temperature.Duringthegraduallyincreasingofskintemperatureswellsthepolymerand
sustainedreleaseofdrugtostratumcorneum.
3.Molecularsizeandshape:Absorptionisapparentlyinverselyrelatedtomolecularweight.
Smallmoleculespenetratefasterthanlargerones.Effectofmolecularshapeisdifficultto
determineasitisrelatedtopartitioncoefficient.

12. Preparation of Ointments, Paste, Creams, and Gels

13. Ointments
1.Ointments:
•Definition:Ointmentsarethetopicalsemi-solidpreparationsmeantforexternal
applicationtotheskinormucousmembranetoproducelocalorsystemiceffect.
•Ointmentsusuallycontainamedicament(s)dissolved,suspendedoremulsifiedinan
ointmentbase.
•Theymaycontainsuitableantimicrobialpreservativetoavoidmicrobial
contamination.
•Theointmentsareusuallyactsasprotectiveoremollientforskin.

14. Ointments
•ClassificationofOintments:
1.Basedonthepropertyofpenetration
1.Epidermicointment:Meantforepidermisapplicationforlocaleffect.
2.Endodermicointment:Meantforactionondeeperlayerofcutaneoustissue.
3.Diadermicointment:Meantfordeeppenetrationandreleasethedrugthroughskin.
2.Basedonthetherapeuticuses
1.Antibioticointment
2.Antifungalointment
3.Anti-inflammatoryointment
4.Parastiticideointment

15. Ointments
•OintmentBases:Theointmentbaseisasubstanceorpartofanointment,whichis
actsasacarrierorvehicleforthemedicament.
•Whileselectingthesuitabletheointmentvariousfactorsaretakeninto
considerationsuchasdesiredaction,natureofmedicament,stabilityofointmentetc.
•Hence,anidealointmentbaseshouldpossessthefollowingproperties:
•Itshouldbeinert,smoothandodorless.
•Itshouldbephysicallyandchemicallystable.
•Itshouldnotretardhealingofthewound.Itshouldnotproduceirritationtotheskin.
•Itshouldbecompatiblewiththeskin.

16. Ointments
ClassificationofOintmentBases:.
1.Oleaginousbases
2.Absorptionbases
3.Emulsionbases
4.Watersolublebases

17. Ointments
1.Oleaginousbases:
•Oleaginousbasesarealsotermedashydrocarbonbases,onapplicationtotheskintheyhavean
emollientandprotectiveeffect.
•Itisdifficulttoremovehydrocarbonbasesfromskinduetotheiroilynature.
•Thesebasesconsistofvegetableoils,animalfatsandwaxes.
•Examplesofthesebasesincludes;softparaffin,hardparaffin,andliquidparaffin(mineraloils).
•Petrolatum(SoftParaffin):
•Itispurifiedmixtureofsemi-solidhydrocarbonsobtainedformpetroleum.
•Itisavailableintwovarietiesnamely,yellowsoftparaffinandwhitesoftparaffin.
•Bothofthesehavingmeltingpointbetween38-56
o
C.

18. Ointments
•Hardparaffin:
•Itispurifiedmixtureofsolidhydrocarbonsobtainedformpetrolatum.
•Itiscolorlessorwhite,translucent,odorlessandtastelesswaxlikesubstance.
•Itisusedtohardenorsoftentheointmentbase.
•Liquidparaffin:
•Itconsistofmixtureofliquidhydrocarbonsandobtainedfrompetroleumbydistillation.
•Itisalsoknownasliquidpetroleumormineraloil.
•Itiscolorless,odorless,tastelessandtransparentoilyliquid.
Theoleaginousbasesareloosingtheirimportancenowadaysduetoreasonslike,theirgreasy
andstickynature,donothelpfulinabsorptionofmedicaments.

19. Ointments
2.Absorptionbases:
•Thesearegenerallyanhydroussubstanceshavingpropertyofabsorbingconsiderable
amountofwaterbutstillretainingtheirointment-likeconsistency.
•Theyareoftwotypes:Non-emulsifiedbasesandWaterinoilemulsions.
•Thenon-emulsifiedbasesabsorbwaterandaqueoussolutionsproducingw/oemulsion.
•Examplesofnon-emulsifiedbases:woolfat,woolalcohol,andbeeswax.
•Thewaterinoilemulsionarecapableofabsorbingmorewater.Examples:Hydrouswoolfat
(lanolin).

20. Ointments
•Woolfat
•Itispurifiedfat-likesubstanceobtainedfromthewoolofsheep.Alsok/aanhydrous
lanolin.
•Itcanabsorb50%ofitsweightofwater.Itisimportantconstituentforsimpleointment
baseandeyeointmentbase.
•Hydrouswoolfat(Lanolin)
•Itispurifiedfat-likesubstanceobtainedfromthewoolofsheep.Itisalsoknowaslanolin.
•Itisinsolubleinwaterbutsolubleinetherandchloroform.
•Itconsistof70%w/wwoolfatand30%w/wpurifiedwater.

21. Ointments
•Beeswax:
•Itiswaxobtainedfromthehoneycombofbees
•Itisavailableinyellowbeeswaxandwhite-beeswax.
•Woolalcohol:
•Itisobtainedfromthewoolfatbytreatingitwithalkaliandseparatingthefraction
containingcholesterolandotheralcohols.
•Itisusedasemulsifyingagentforw/otypeofemulsion.
Thesebasehavenumerousadvantagessuchas;compatiblewithlargenumberof
medicaments,absorblargeamountofwater,theyareheatstable,quitegreasy,removed
easilyfromskin.

22. Ointments
3.Emulsionbases:
•Thesearesemi-solidorhavecreamlikeconsistency.Botho/wandw/oemulsionsareusedas
ointmentbase.
•Theo/wtypeemulsionbasesaremorepopulartypeofbasebecausetheyareeasily
removablefromtheskinorclothesbywashingwithwater.
•Whilethew/otypeofemulsionbasesaregreasyandsticky.
•Examples:HydrophilicointmentUSP

23. Ointments
4.Watersolublebases:
•Thesearegenerallyknownas“greaselessointmentbases”.
•Theyconsistofwatersolubleingredients,suchaspolyethyleneglycol(PEG)polymers
commonlyknownascarbowaxes.
•Thesecarbowaxesarewatersoluble,non-volatile,andinertsubstances.
•Examples:Gelatin,pectin,sodiumalginate,andtragacanthareusedaswatersolublebases.

24. Excipient's used in semisolid dosage forms
Ingredients used in the preparation
of Semi-solid dosage forms:
•Bases
•Preservative
•Humectants
•Antioxidants
•Emulsifier
•Gelling agent
•Permeation enhancer
•Buffers

25. Preparation of Ointments, Paste, Creams, and Gels

26. Preparation of Ointments, Creams and Paste
1.Triturationmethod:
•Mostcommonlyusedmethodforointmentpreparation.Thismethodisusedwhenbaseissoftand
medicamentisinsolubleinthebase.
StepwiseProcedure:
•Reducethesolidmedicamenttofinepowder.
•Medicamentismixedwithsmallamountofbaseonointmentslabwithstainlessstillspatula
untilhomogenousproductisformed.
•Addremainingquantityofbasewithuniformmixing.
•Add/incorporateanyliquidmedicamentifpresent.

27. 2.Fusionmethod:
Procedure:
•Thismethodisusefulwhenointmentbaseconsistofnumberofsolidingredientofdifferent
meltingpoints.
•Initiallyointmentbasesaremeltedindecreasingorderoftheirmeltingpoint(Substancewithhigh
meltingpointshouldbemeltfirstthensubsequent.).
•Thisavoidoverheatingoflowmeltingpointsubstances.
•Nowincorporatethemedicamentslowlyintothemeltedmass.
•Stiritthoroughlyuntilthemasscoolsdownandhomogenousproductisformed.
•Ifanyotherliquidingredientistobeaddedthenheatittothesametemp.asthatofmeltedbase.
•Thenmixthesetwoportionswithstirringuniformly.Avoidvigorousstirringtopreventair
entrapment.
Preparation of Ointments, Creams and Paste

28. 3.Chemicalreactionmethod:
Preparation of Ointments

29. 4.Emulsificationmethod:
Procedure:
Preparation of Ointments

30. •Containers: Ointments are dispensed in glass or plastic jars having screw
caps with impermeable liners. Amber colored glass containers are used for
ointments containing light sensitive drugs. Nowadays, ointments are
generally supplied in plastic or metallic collapsible tubes.
•Labeling: The ointment container should be labelled “for external use only”
•Storage: Ointments should be store in cool and dry place. Protected from the
sunlight and higher temperature.
Container, Labeling and Storage of Ointments

31. Creams
•Creams: Creams are the viscous semi-solid emulsions which are meant for
external application to the skin.
•They usually contain water soluble base due to which they can be easily
removed from the skin.
•They are softer and light weight in comparison to ointment
•They are of two types: Aqueous creams and Oily creams.

32. Creams
•Aqueous creams: In aqueous creams, the emulsions are o/w type. These
creams are relatively non-greasy than oily creams.
•They are further classified in various heading depending upon emulsifying
agent used for preparing them.
•Anionic emulsifying wax cream
•Cationic emulsifying wax cream
•Non-anionic emulsifying wax creams

33. Creams
•Oily creams: In aqueous creams, the emulsions are w/o type. These creams
are greasy in nature.
•They are further classified in various heading depending upon emulsifying
agent used for preparing them.
•Sterol creams:emulsifying agents are wool fat or wool alcohol.
•Soap creams: emulsifying agents are triehanolamine soap, calcium or borax soap.

34. Creams
•Containers: Creams are store in wide mouth squat jars. The container
should be well and tightly closed to avoid evaporation of water. Mouth of the
jar should be covered with disc of grease proof paper. Collapsible tubes are
prefer to store creams due to their low risk of contamination.
•Labeling: The ointment container should be labelled “for external use only”
•Storage: Ointments should be store in cool and dry place. Protected from the
sunlight and higher temperature.

35. Paste
•Paste: Paste are the semi-solid preparation meant for external application to
the skin surface.
•They are generally very thick and stiff in nature. They do not melt at ordinary
temperature and thus provide protective covering to the area where they
applied.
•Bases such as hydrocarbon bases, water miscible bases and water soluble
bases are used for the preparation of paste.

36. Difference between paste and ointments

37. Gels/Jellies
•Gels/Jellies: Gels/jellies are the transparent or translucent non-greasy,
semisolid preparations meant for external application to the skin or mucous
membrane.
•They are generally prepared from natural gums such as pectin, sodium
alginate or from synthetic derivatives such as methyl cellulose.
•Types of jellies: Medicate jellies, Lubricating jellies, and Miscellaneous jellies.

38. Gels/Jellies

39. Evaluation of Semi-solid dosage forms (ointments)
•Various evaluation parameters are taken into account for the evaluation of
semi-solid dosage forms (ointment, creams, paste, gels/jellies):
1.Drug content
2.Drug release rate from the bases
3.Rate of penetration of base
4.Consistency of preparation
5.Absorption of medicament into blood sream
6.Irritant effect

40. Evaluation of Semi-solid dosage forms (ointments)

41. Evaluation of Semi-solid dosage forms (ointment and creams)

42. Evaluation of Semi-solid dosage forms (ointment and creams)

43. Evaluation of Semi-solid dosage forms (ointment and creams)

44. Evaluation of Semi-solid dosage forms (ointment and creams)

45. Evaluation of Semi-solid dosage forms (ointment and creams)

46. Evaluation of Semi-solid dosage forms (Gels, creams, paste)
Evaluation test for gels and creams
•Rheological properties
•Determination of yield value
•Spread-ability
•Stability test
•Safety evaluations
Evaluation test for paste:
•Evaluation of heat stability
•Viscosity determination
•Particle size determination
•Compatibility with container etc.
Evaluation test for gels and creams

47. References:
1.Dispensing Pharmacy by R.M. Mehta, VallabhPrakashan, Page No: 230-259
2.Google.com/semi-solid_dosage_forms
3.Remington: Essential of Pharmaceutics