semisolid dosage form-2

formulation, ointment bases, preparation methods.

1. SEMISOLID DOSAGE FORMS-2 Presented By: K. Arshad Ahmed Khan M.Pharm Departmernt of Pharmaceutics RIPER.

2. Formulation of semi solid dosage form Ingredients : Active pharmaceutical ingredients Bases Preservatives Humectants Anti oxidants Emulsifier Gelling agent Permeation enhancer Buffers

3. Bases It is one of the most important ingredient used in the formulation of semisolid dosage form Ointments and suppository base do not merely acts as the carrier of the medicaments, but they also control the extent of absorbtion of medicaments incorporated with them

4. Ideal properties of a base They should be: Compatible with skin ph and drug Inert ,non irritating and non sensitizing Good solvent and/or emulsifying agent Emollient , protective , non greasy and easily removable Release medicaments easily at the site of administration Pharmaceutical elegant and possess good stability.

5. Classification Of Bases

6. 1. Oleaginous ( hydrocarbon) bases: They consist of a combination of more than one oleaginous material such as water insoluble hydrophobic oils and fats They are highly compatible ; occlusive ; good emollients They are anhydrous, do not absorb water, readily(hydrophobic) insoluble in water, non washable Example : Vaseline,hard parafin , liquid paraffin,white ointment. Uses : protective, emollient and vehicle for solid drugs.

7. 2. Absorption ( Emulsifiable ) base: Have capacity to absorb considerable quantities of water or aqueous solution and turns to w/o without marked changes in the consistency. They are anhydrous, water insoluble and water unwashable . They have good emollient but poor occlusive property. Uses: protective, emollient and vehicle for aqueous solutions and solid drug.

8. 3. Emulsion bases: According to the type of emulsion these bases are classified as either W/O or O/W. W/O EMULSION BASE O/W EMULSION BASE Hydrous Hydrous Will absorb water Will absorb water Insoluble in water Insoluble in water Not washable washable

9. 4. Water soluble Bases: These include both hydrous and non hydrous dermatological non- emulsion bases which are water soluble and contain no oil phase. Water soluble, water washable, non greasable Because they softens with the addition of water, large amount of aqueous solutions are not effectively incorporated into the bases. Example : carbowax compounds such as the poly ethylene glycol bases containing pectin, cellulose, bentonite and gelatin.

10. Presevatives Some bases , although, resist microbial attack but because of their high water content, it require an anti microbial preservative. Commonly used preservative include: Methyl hydroxy benzoate Propyl hydroxy benzoate Chlorocresol Benzoic acid Phenyl mercuric nitrate

11. Antioxidant Oxygen is highly reactive atom that is capable of becoming of potentially damaging molecules commonly called “free radicals”. Free radicals are capable of attacking the healthy cells of the body, causing them to loose their structure and functions To prevent this an anti oxidant are added. Example : Butylated hydroxy anisole , Butylated hydroxy toluene

12. CLASSIFICATION OF ANTIOXIDANT ANTIOXIGENS REDUCING AGENT ANTIOXIDANT SYNERGIST Acts by reacting with the free radicals. e.g. Butylated hydroxy anisole (BHA) Butylated hydroxy tocopherols (BHT) (used for oil system) Have lower redox potential than drug,hence gets oxidized first. e.g. Ascorbic acid Potassium and sodium metabisulfite Thiosulfite (used for aqueous system) Chelating or sequestering agents, enhance the effect of anti oxidants. e.g. Citric acid Tartaric acid Lacithin

13. Gelling agents Gelling agent forms a gel dissolves in a liquid phase as a colloid mixture that forms a weakly cohesive internal structure. These are organic hydro colloids or hydro phillic inorganic substances. Example : tragacanth, sodium alginate, pectin, gelatin, cellulose derivatives. Material % Brook field viscosity Carbomer 94 1 resin NF 0.15 2900 Carbomer 94 1 resin NF 0.25 6300 Guar gum 1.50 8040 Methyl cellulose 2.00 5200 Sodium alginate 2.50 10400

14. Permeation enhancer Skin can acts as a barrier with the introduction of various penetration enhancers, penetration of the drug through the skin can be improv ed. Permeation enhancer Drug used Methanol,carvacrol, linalool Propranolol hydrochloride Limonene Indomethacin , ketoprofin Geraniol Nerolidol Diclofenic sodium Oleic acid Piroxicam

15. Emulsifier Anionic Cationic Non ionic Alkyl sulphates Soaps D odecyl benzene Sulfonates Lactylates Sulfosuccinates Monoglycerides Sulfonates Phosphate esters Silicones Taurates Quaternary ammonium compounds alkoxyalkylamines Polyoxyethylene Alkyl-aryl ethers Polyoxy ethylene Sorbitan esters Sorbitan fatty acid esters Glyceryl fatty acid esters

16. Humectants A humectant is a hygroscopic substance . It is often a molecule with several hydrophilic groups, most often hydroxyl group. Humectants are used to: Increase the solubility of active ingredients To elevate its skin preparation Elevate the hydration of the skin.

17. B uffers Buffers are added to variopus purpose such as: Compatibility with skin Drug solubility Drug Stability Influence on ionization of drug Example: Sodium acetate , Sodium Citrate , Potassium meta phosphate

18. V ehicles Purified water Water for Injection Water for injection may be used in ophthalmic semi solid preparation like eye ointments , gels etc

19. PREPARATION OF SEMI SOLIDS Trituration method Fusion method Chemical reaction method Emulsification method Ex. Ointments creams pastes Ex. Ointments creams pastes Ex. Ointments creams Ex. Ointments creams (Ointments, creams, pastes)

20. PREPARATION METHODS FOR SUPPOSITORIES Hand molding Heat molding Automatic machine molding Compression molding Ex. Rotary machine linear machine

21. METHOD OF PREPARATION Trituration Method

22. Grate the waxy base melt using water bath high m.p base 1 st mix low m.p in it melt base together dissolve oil soluble drug add small volume phase in large volume phase cooling unde stirring soft mass of 40 ⁰ c homogenization filling F usion method

23. Thank you…..