Lecture 7 cream.pptx

Creams

1. Overall Aims of Course Upon successful completion of this course the student should be able to; Demonstrate basic knowledge and comprehensive understanding of principles of formulation, pharmaceutical excipients, and factors affecting of different semisolid, and moulded pharmaceutical dosage forms. Formulate, compound, dispense, label, store, distribute and manufacture different solid pharmaceutical dosage forms. Inform and advice patient and communities about more suitable and effective dosage form of different drugs and proper method of dispensing these effective dosage form.

2. Creams

3. Semisolid preparations containing one or more medicinal agents dissolved or dispersed in either a water-in-oil emulsion or an oil-in-water emulsion or in another type of water-washable base. Creams are formulated to provide preparation that are essentially miscible with skin secretion. They are intended to be applied to the skin or certain mucous membranes for protectiv e , therapeutic , or prophylactic purposes especially when occlusive effect is not necessary. Creams

4. Properties of creams The primary application of creams is as topical skin products. • Sometimes creams are preferable to ointments because they are easier to spread and remove. • Pharmaceutical manufacturers frequently manufacture topical preparations of a drug in both cream and ointment bases to satisfy the preference of the patient and physician

5. Dosage Forms TYPES OF CREAM On the basis of phase OIL- IN-WATER ( O/W )- As- Vanishing cream • WATER-IN-OIL (W/O )- As- cold cream Oil-in-water creams (aqueous creams) as bases  Oil-in-water (O/W) creams which are composed of small droplets of oil dispersed in a continuous phase.  More comfortable and cosmetically acceptable as they are less greasy and more easily washed off using water.  Emulsifying agents of natural origins ( bees wax, wool alcohols , wool fat).  Emollient and creamy, white or translucent and stiff.  E.g. Vanishing Cream

6. Dosage Forms Water-in-oil creams ( oily creams) as bases:  Water-in-oil (W/O) creams which are composed of small droplets of water dispersed in a continuous oily phase.  More difficult to handle but many drugs which are incorporated into creams are hydrophobic and will be released more readily from a W/O cream than an O/W cream.  More moisturizing as they provide an oily barrier which reduces water loss from the stratum corneum , the outermost layer of the skin.  e.g. Cold Cream

7. Dosage Forms MEDICATED CREAMS: Medicated creams are contains active pharmaceutical ingredients.  Cetrimide cream used as antiseptic.  Zinc oxide cream used as Sunblock .  Hydrocortisone cream - treat rashes . Cosmetic creams:  All purpose cream, baby cream, barrier cream, bleaching cream, cleansing cream, cold cream, hair cream, hand cream, vanishing cream.

8. Dosage Forms TRITURATION:  This is the term applied to the incorporation of finely divided insoluble powders or liquids into the base.  The powders are placed on the tile and the base is incorporated using the ‘doubling-up’ technique .  Liquids are usually incorporated by placing a small amount of ointment base on a tile and making a ‘well’ in the center. Small quantities of liquid are then added and mixed in.  Trituration can be successfully achieved using a mortar but this method is usually reserved for large quantities.

9. Dosage Forms LAVIGATION  This is the term applied to the incorporation of insoluble coarse powders into the base.  It is often termed ‘wet grinding’.  It is the process where the powder is rubbed down with either the molten base or semi-solid base.  A considerable shearing force is applied to avoid a gritty product.

10. Dosage Forms SELECTION OF APPROPRIATE BASE: DEPENDS UPON PURPOSE FOR WHICH CREAM IS GOING TO BE APPLIED:  DESIRED RELEASE OF DRUG SUBSTANCE FROM BASE.  DESIRABILITY OF TOPICAL ABSORPTION.  DESRABILITY OF OCCLUSION OF MOISTURE FROM SKIN.  STABILITY OF DRUG IN BASE.  DESIRABILITY OF SURFACE TO WHICH IT IS TO BE APPLIED.  SHOULD HAVE A SUITABLE PH.  NO DEHYDRATING EFFECT  NON IRRITANT AND NON SENSITISING.  COMPATIBLE WITH A LARGE NUMBER OF DRUGS.  MISCIBLE WITH SKIN SECRETIONS e.g SEBUM ,SWEAT etc

11. Dosage Forms PREPARATION PROCESS: Preparation of oil phase. Hydration of aqueous phase ingredients. Forming the emulsion. Dispersion of active ingredient.

12. Dosage Forms GENERAL METHOD OF PREPARATION: 1) As with other types of emulsion, hygiene is extremely important and all surfaces , spatulas and other equipment must be thoroughly cleaned with IDA . 2) Always make an excess as it is never possible to transfer the entire cream into the final container. 3) Determine which of the ingredients are miscible with the aqueous phase and which with the oily phase. 4) Dissolve the water-soluble ingredients in the aqueous phase. 5) Melt the fatty bases in an evaporating dish over a water bath at the lowest possible temperature. Start with the base with the highest melting point. These should then be cooled to 60°C.

13. Dosage Forms 6) Substances that are miscible with the oily phase should then be stirred into the melt. 7) The temperature of the aqueous phase should then be adjusted to 60°C. 8) The disperse phase should then be added to the continuous phase at the same temperature . 9) Incorporation of Solid ingredients to the prepared emulsion.

14. Dosage Forms The incorporation of solids into a cream base:  If the cream base has been prepared from first principle the solid can be incorporated into the cream as it cools.  Alternatively, if using a pre-prepared base, soluble and insoluble solids may be incorporated using the method employed for insoluble solids.  Soluble solids: Should be added to the molten cream at the lowest possible temperature and the mixture stirred until cold.  Insoluble solids: Should be incorporated using a glass tile and spatula . If there is more than one powder to be added, these should be triturated together in a mortar using the ‘ doubling-up’ technique prior to transfer to a glass tile.

15. Dosage Forms Non-volatile, miscible liquids: May be mixed with the molten cream in the evaporating basin. Alternatively, if a pre-prepared base is used, then incorporate as for volatile or immiscible liquids.  Volatile or immiscible liquids Coal tar solutions, should be triturated with the cream on the glass tile.

16. Dosage Forms ADVANTAGES:  They gives prolong contact in their site of application than any other pharmaceutical semisolid dosage forms.  Injured area can be dried quickly by creams than other semi-solid preparations .  Non-irritating when applied to the skin.  Easily water washable. Easy to wipe away.  Less greasy compared to ointment.  Easy to spread on the skin's surface (i.e. easy to apply).

17. DISADVANTAGES:  Stability is not as good as ointment.  They are less hydrophobic than other semisolid preparation, so risk of contamination is high than the others. IDEAL CHARACTERISTICS OF CREAMS: It should liquefy at body temperature . It should penetrate the epidermis (via natural opening). Its viscosity should be low enough to permit easy spreading. It should be non-toxic. It should be non-irritant. It should be non-inflammatory

18. PRESERVATION : AMONG THE ANTIMICROBIAL PRESERVATIVES USED TO INHIBIT MICROBIAL GROWTH IN TOPICAL PREPARATIONS ARE : METHYLPARABEN PROPYLPARABEN PHENOLS BENZOIC ACID SORBIC ACID

19. CONTAINERS USED FOR CREAMS: Wide mouthed jars. Collapsible Metal. Flexible Plastic tubes. Aluminum tubes.

20. FILLING:

21. DIFFERENCE BITWEEN CREAM AND OINTMENT: Creams Ointments Contain less than 50% hydrocarbans & more than 20% water . Contain more than 50% hydrocarbans & less than 20% water. Light in consistency, easy to spread over large surface. W/O or O/w emulsions. Thicker consistency, greasy, difficult to spread over surface. Skin dry up faster Stay longer on the surface of skin Preferred for oily skin Preferred for dry skin