8.Ointments are the part of semisolid.pptx

Ontments

1. By, Mr . Dheeraj Chechare Lecturer , PRES’s College of Pharmacy ( D.Pharm )Sinnar . Semisolid Dosage Forms-Ointments

2. Definition Ointments  are semisolid preparations meant for external application to the skin or mucous membrane. They usually contain medicament which is either dissolved or suspended in the o intment base.

3. CLASSIFICATION OF OINTMENTS 1. On the basis of penetration 2. On the basis of therapeutic use 1. On the basis of penetration 1. Epidermic ointments- These ointments are intended to produce their action on the surface of the skin and produce local effect, they are not absorbed. They acts as protectives and antiseptics . 2.Endodermic ointments-These ointments are intended to release the medicaments that penetrate into the skin. They are partially absorbed and acts as emollients, stimulants and local irritants.

4. 3. Diadermic ointments-These ointments are intended to release the medicaments that pass through the skin and produce systemic effects. 2. ON THE BASIS OF THERAPEUTIC USE 1. Antibiotic Ointments- e.g Bacitracin 2. Antifungal Ointments- e.g Benzoic acid 3. Anti-inflammatory Ointments- e.g Fluocinolone acetonide 4 . Astringent ointments- e.g Zinc oxide and calamine

5. 5 . Counter-irritant Ointments- e.g Methyl salicylate 6 . Antidandruff Ointments- e.g. Salicylic acid 7 .Ointment used for psoriasis- e.g. Salicylic acid, coal tar 8 .Protective ointments- e.g. Calamine Zinc oxide.

6. Ointment Bases: • Serve as carrier or vehicle. • Factors to be consider while selecting ointment bases are- - Desired action - Nature of medicament to be incorporated - Stability of ointment

7. Properties of ideal ointment bases 1. Inert, odourless,non-irritating and non-sensitizing. 2. Compatible with skin pH and with the incorporated drug. 3. Good solvent and/or emulsifying agent. 4. Emollient, protective, non-greasy and easily removable. 5. Release medicament readily at the site of application. 6. Pharmaceutically elegant and possess good stability. 7. It should not retard healing of wound.

8. CLASSIFICATION OF OINTMENT BASES

9. 1.Oleagin o us bases These bases consist of water insoluble hydrocarbons, vegetable oils,animal fats & waxes.The constitution of hydrocarbon bases are soft paraffin,hard paraffin& liquid paraffin. Soft Paraffin Hard Paraffin Liquid Paraffin

10. a) Petrolatum (Soft Paraffin): It is purified mixture of semi-solid hydrocarbons obtained from petroleum. There are two types of soft paraffin one is yellow & other is white soft paraffin. White soft paraffin prepared by bleaching the yellow soft paraffin. The melting point of soft paraffin is 38 to 56 C. ⁰ • White soft paraffin not be used in ophthalmic ointment preparations because small amt of bleaching agents involved in that & they causes irritation in the eye

11. b) Hard Paraffin It is purified mixture of solid hydrocarbons & obtained from petrolatum. It is colourless or white translucent, odorless, tasteless wax like substance. It is used to harden or soften the ointment base.

12. c) Liquid Paraffin It consist of mixture of liquid hydrocarbons & obtained from petroleum by distillation. It is also called white mineral oil or liquid petroleum. It is colourless, odourless, tasteless it is soluble in ether & chloroform but its insoluble in water & alcohol. Now a days oleaginous bases are not used commonly because t hey are greasy, so its difficult to remove from skin & clothing. They retain body heat which may produce an uncomfortable feeling of warmth. They do not help in the absorption of medicaments.

13. 2.ABSORPTION BASES These bases are generally anhydrous substances which have the property of absorbing considerable quantity of water but still retaining their ointment like consistency. They have 2 types : 1. Non-emulsified bases 2. Water in oil emulsion bases 1. N on -Emul sified bases Those bases absorb water & aqueous solution producing W/O emulsion. e.g. Wool fat, Wool alcohol, Beeswax etc.. 2. W ater in oil Emul sion Bases : Those bases have the capability of absorbing more water & have the properties of non- emulsified bases.e.g. Hydrous wool fat (Lanolin)

14. a) Wool Fat It is also known as anhydrous lanoline & It is the purified fat-like substance obtained from wool of sheep. • It can be absorb about 50% of its weight of water. So it is used in ointments where the proportion of water or aqueous liquids too large. • It is mainly used in eye ointment base & in simple ointment base.

15. b)Wool Alcohol It is obtained from wool fat by treating with alkali & separate out cholesterol & other alcohols. • It contains not less than 30% of cholesterol. • It is used as an emulsifying agent for the preparation of w/o emulsion. • It is also used for improving the texture, stability & emollient properties of o/w emulsion .

16. c)Bees Wax It is purified wax obtained from honey comb of bees. • It is available in yellow & white form. • White bees wax prepared by bleaching treatment. • It is used for stiffening agent in paste & ointments.

17. ADVANTAGES OF ABSORPTION BASES • Compatible with large no of medicament • Absorbs large quantity of water or aqueous substances. • Relatively heat stable • Emulsified as well as unhydrous form can be used.

18. 3.EMULSION BASES These bases are semisolids or have a cream like consistancy.Both o/w & w/o type emulsions are used as oinments base.The oil in water type o emulsion are used as ointment base. The o/w type emulsion bases are more popular because they can be easily removed from the skin or clothes by washing with water.The w/o type of bases are greasy and sticky.

19. 4.WATER SOLUBLE BASES These are commonly known as “greaseless ointment bases”.The water soluble bases consist of water soluble ingredients such as polyethylene glycol polymers which are known as “Carbowaxes”. The carbowaxes are water soluble ,non-volatile and inert substances.Depending upon the molecular weight,carbowaxes are available in different consistencies i.e: liquids,semisolids & solids. Tragacanth,gelatin ,pectin,cellulose derivatives are also used as water soluble bases.

20. Selection of dermatological vehicles A.Dermatological factors: 1.Absorption and penetration: A nimal fats like lard and wool fat penetrate more readily than mineral oil like paraffin. 2.Effect on skin function: O leaginous bases may interfere with skin function and secretions, may irritate skin, o/w give cooling effect and mix readily with skin secretions. 3.Miscibility with skin secretions and serum : Skin secretions are more miscible with emulsion bases than oleaginous, hence less amount of drug required. o/w bases more useful for ointments meant for weeping and broken skin.(eczema)

21. 4. Compatibility with skin secretions. Neutral or slightly acidic are prefered having pH close to5.5 (Skin) as they are compatible and do not cause discomf ort. 5.Freedom from irritant effect: Bases should be non-irritant. Oleaginous cause some irritation hence not used in eye. 6.Emollient properties: Humectant like glycerin and propylene glycol keep skin soft and moist . Wool fat, lard, paraffin keep skin soft by preventing evaporation of water from skin. 7.Ease of application and removal. B.Pharmaceutical factors: 1.Stability 2.Solvent properties. 3.Emulsifying properties 4 Consistency.

22. 1 Stability: Fats and oils from animal and vegetable source undergo oxidation-antioxidant. O/W develop microbes after storage-preservatives. Emulsified base –phase separation –Temp. 2.Solvent Properties: Many are insoluble powders in oinments -uniform distribution-fine powder. Phenol-in solid form is caustic to skin and cause blisters-suitable base-keep in liquid form-mixture of hard and soft paraffin bases+beeswax+lard . In compound mercury ointment, olive oil is used to keep camphor in solution form. 3.Emulsifying properties: Hydrocarbon bases –poor water absorption-animal fats like wool fat has good absorption, hence it is used in eye ointments 4 . Consistency: Neither hard nor too soft, should withstand temp. hence combination of ointments bases like high and low m.p . –high mp bases like hard paraffin, beeswax, are used in in soft ointments and low mp -liquid paraffin in hard ointments Pharmaceutical F actors

23. 1- Trituration method The most common method used for preparation of ointments. The medicament is finely powdered and triturated with small amount of the base till homogenous dispersion is obtained. Then followed by addition of the remaining base with good mixing Ex: simple ointment. 2- Fusion method It is used when the ointment contains a number of solid ingredients of different m.p . such as bees wax, cetyl alcohol, stearic acid, hard paraffin.In this case it is necessary to melt these ingredients. The melting of ingredients should be in decreasing order of melting points . This avoids overheating. The medicament is then added to the melted ingredients and stirr thoroughly and uniformely until cooling and formation of homogenous product. Preparation of ointments

24. Liquid should be heated to nearly the same temperature of the melted base before adding it the melted bases . Vigorous stirring should be avoided when it starts thicken, otherwise air may get entrapped. Avoid rapid cooling too, may lead to non-uniform product. 3.Chemical reaction: eg iodine ointment.( Iodine,KI,wool fat,yellow soft paraffin,water ) 4. Emulsification method : Fats, oils and waxes melted on water bath to 70 o c and Aqueous soln of heat stable ingredients heated to same temp,add this soln to melted waxes with stirring. For O/W emulsion- combination of triethanol amine stearate soap and cetyl alcohol For w/o emulsion-beeswax and divalent calcium ions For semisolid o/w- water soluble soaps as emulsifier

25. Other additive in ointments Preservatives, antioxidants, perfumes and chelating agents may be incorporated in the ointment: Preservatives 1) Phenolics : phenol (0.2-0.5%) , chlorocresol ( 0.075- 0.12%) . 2) Methyl parapen (0.02-0.03%), propyl parapen (0.02-0.3%). 3) Benzyl alcohol (< or = 3%). preservatives prevent the bacterial growth when ointments stored for long time. Antioxidants prevent the oxidation decomposition of the ingredients such as: a) Lipophilic antioxidants: e.g., BHA & BHT b) Hydrophilic antioxidants (dissolved in aqueous phase) such as sodium metabisulfite or sodium Sulfite.

26. Humectants such as glycerin and propylene glycol and sorbitol may be added to prevent the loss of moisture. Pigments such as iron oxide may be added to give ointments a cosmetic like appearance specially in formulation intended for application to the face. Perfumes may be also incorporated to give ointment a pleasant odour .

27. Packaging Ointment jar and collapsible tubes of different sizes, shapes and capacities are used for storage of ointments. Amber glass containers are used for light sensitive preparations. Storage Ointments must be stored at an optimum temperature otherwise separation of phases may take place which is very difficult to remix to get uniform product Packaging and storage of ointments