Semisolid Dosage Forms: Ointments Lecture One PDF

Semisolid Dosage Forms Ointments: LECTURE ONE  OUTLINE 1) Definition of dermatologicals 2) Their applications and functions 3) Ideal properties of semisolid dosage forms. 4) Definition of ointment 5) Medicinal application of ointment 6) Ointment bases 7) Preparation of ointments 8)...

Semisolid Dosage Forms Ointments: LECTURE ONE  OUTLINE 1) Definition of dermatologicals 2) Their applications and functions 3) Ideal properties of semisolid dosage forms. 4) Definition of ointment 5) Medicinal application of ointment 6) Ointment bases 7) Preparation of ointments 8) Storage and dispensing of ointments 9) Tests requirements for ointments Semisolid dosage forms:  Semisolid Dosage Forms Semisolid dosage forms are topical preparations for the skin or mucous membranes. Also known as dermatologicals/ unguents. They may be medicated or non medicated. Systemic drug absorption should always be considered when using topical products if the patient is pregnant or nursing, because drugs can enter the fetal blood supply and breast milk and be transferred to the fetus or nursing infant.  dermatologic applications LOCAL EFFECTS: A topical dermatological product is designed to deliver drug into the skin in treating dermal disorders, with the skin as the target organ. Protectants, lubricants, emollients, drying agents, astringents SYSTEMIC EFFECTS: A transdermal product is designed to deliver drugs through the skin (percutaneous absorption) to the general circulation. (with the skin not being the target organ).  Application areas for dermatologicals 1)LOTIONS -----  (INTERTRIGINOUS AREAS) 2)OINTMENTS……  (DRY SCALY LESIONS) 3) CREAMS……  (MOIST WEEPING LESIONS)  :IDEAL PROPERTIES OF SEMISOLID DOSAGE FORMS :PHYSICAL PROPERTIES a) Smooth texture b) Elegant in appearance c) Non dehydrating d) Non gritty e) Non greasy and non staining f) Non hygroscopic PHYSIOLOGICAL PROPERTIES: a) Non irritating b) Do not alter membrane / skin functioning c) Miscible with skin secretion d) Have low sensitization effect APPLICATION PROPERTIES: Easily applicable with efficient drug release.  OINTMENTS Ointments are hydrophobic oleaginous-based semisolid dosage forms, intended for external application to the skin or mucous membranes. Ointments may be medicated or not. Unmedicated ointments are used for the physical effects they provide as protectants, emollients, or lubricants. Ointment bases, may by used for their physical effects or as vehicles for medicated ointments.  OINTMENTS OINTMENT BASES: Ointment bases are generally classified by the USP into four groups: (a) oleaginous bases, (b) absorption bases, (c) water-removable bases, (d) water-soluble bases.  (a) Oleaginous Bases (hydrocarbon bases) Properties: The base is water free. Insoluble in water. Not washable by water. Anhydrous Occlusive Translucent Do not dry out. Water and aqueous preparations may be incorporated, but only in small amounts and with some difficulty. USES: mainly used for their emollient effect.  (a) Oleaginous Bases :SOURCES: 1) HYDROCARBONS a) Petrolatum: e.g vaseline b) White petrolatum e.g white vaseline c) Yellow ointment e.g simple ointment d) White ointment e) Liquid petrolatum e.g mineral oil f) Waxes 2) Animal oils e.g oleic acid 3) Vegetable oils e.g olive oil, cotton seed oil, castor oil 4)Synthetic esters: e.g Glyceryl monostearate  (a) Oleaginous Bases E.g 1 Petrolatum, USP, Vaseline® is a commercial purified mixture of semisolid hydrocarbons obtained from petroleum. It is an unctuous (oily) mass, varying in color from yellowish to light amber ( yellowish brown ). It melts at 38°C to 60°C and may be used alone or in combination with other agents as an ointment base. Petrolatum is also known as yellow petrolatum and petroleum jelly. A commercial product is Vaseline ®  (a) Oleaginous Bases E.g 2 White Petrolatum, USP, is a purified mixture of semisolid hydrocarbons from petroleum that has been wholly or nearly decolorized. It is used for the same purpose as petrolatum, but because of its lighter color, it is considered more aesthetically pleasing by some pharmacists and patients. White petrolatum is also known as white petroleum jelly. A commercial product is White Vaseline ®  (a) Oleaginous Bases E.g 3 Yellow Ointment, USP. This ointment has the following formula for the preparation of 1000 g: Yellow wax 50 g Petrolatum 950 g Yellow wax is the purified wax obtained from the honeycomb of the bee Apis mellifera. The ointment is prepared by melting the yellow wax on a water bath, adding the petrolatum until the mixture is uniform, then cooling and stirring until congealed (harden). Also called simple ointment, it has a slightly greater viscosity than plain petrolatum.  (a) Oleaginous Bases E.g 4 White Ointment, USP. This ointment differs from yellow ointment by substitution with white wax (bleached and purified yellow wax) and white petrolatum in the formula. on (b) Absorption Bases Absorption bases are of two types: (a)(Anhydrous absorption bases) : permit the incorporation of aqueous solutions resulting in the formation of water-in-oil (W/O) emulsions. » (e.g., hydrophilic petrolatum: Aquaphor ) » e.g anhydrous lanolin: Refined Wool Fat). (b) (Emulsion base): these are W/O emulsions that permit the incorporation of additional quantities of aqueous solutions  (e.g., hydrous lanolin: hydrous wool fat PROPERTIES OF ABSORPTION BASES 1) Absorption bases are not easily removed from the skin with water washing, because the external phase of the emulsion is oleaginous. 2) May possess some power of penetration into the deepest layers of the skin and therefore are used for “endodermic” ointment. 3) Greasy 4) Anhydrous 5) Insoluble in water 6) Not water washable  USES OF ABSORPTION BASES 1) Emollients: although they do not provide the degree of occlusion afforded by the oleaginous bases. 2) Pharmaceutical adjuncts: used to incorporate small volumes of aqueous solutions into hydrocarbon bases. (This is accomplished by incorporating the aqueous solution into the absorption base and then incorporating this mixture into the hydrocarbon base).  (b) Absorption Bases A commercial product, Aquaphor, a variation of hydrophilic petrolatum, has the capacity to absorb up to three times its weight in water and useful to help incorporate a water-soluble drug, e.g., tobramycin sulfate, into a oleaginous ointment base. Other examples :AQUABASE, POLYSORB This concept is used in the preparation of ophthalmic ointments.  (b) Absorption Bases Lanolin, USP (Anhydrous lanolin) : commercially known as Refined Wool Fat Obtained from the wool of sheep (Ovis aries), is a purified wax-like substance that has been cleaned, deodorized, and decolorized. It contains not more than 0.25% water. Additional water may be incorporated into lanolin by mixing. (c) Water-Removable Bases (properties) – Are oil-in-water emulsion that are capable of being washed from skin or clothing with water. – frequently referred to as “water- washable” ointment base. – Example: hydrophilic ointment made up of hydrophilic surfactant and petrolatum. – (i.e contains both water soluble and insoluble base). – Others are Vanishing Cream and  (c) Water-Removable Bases – Water-removable bases are oil-in-water emulsions resembling creams. – Because the external phase of the emulsion is aqueous, they are easily washed from skin and are often called water washable bases. – Have good emollient effects. – They may be diluted with water or aqueous solutions. They can absorb serous discharges. WATER REMOVABLE BASES Characteristics 1) Resemble creams in their appearance 2) May be diluted with water or with aqueous solution 3) Non-occlusive 4) Non -greasy 5) Water Removable (O/W Emulsion) 6) Insoluble in water 7) Water washable 8) Can absorb water  (c) Water-Removable Bases Hydrophilic Ointment, USP, has the following formula for the preparation of about 1000 g: Ingredient Amount (grams) Methylparaben 0.25 Propylparaben 0.15 Sodium lauryl sulfate 10.00 Propylene glycol 120.00 Stearyl alcohol 250.00 White petrolatum 250.00 Purified water 370.00 (d) Water-Soluble Bases 1) do not contain oleaginous components. 2) They are completely water washable 3) Often referred to as greaseless. 4) They penetrate the skin and better used for absorption of medicament and therefore used for “diadermic ointment”. 5) Because they soften greatly with the addition of water, large amounts of aqueous solutions are not effectively incorporated into these bases. 6) They mostly are used for incorporation of solid and non-aqueous substances.  (d) Water-Soluble Bases Other properties: Non-occlusive Non-greasy Lipid-free EXAMPLE: Polyethylene Glycol Ointment, NF PEG is a polymer of ethylene oxide and water represented by the formula H(OCH2CH2)nOH, in which n represents the average number of oxyethylene groups.  (d) Water-Soluble Bases The general formula for preparation of 1,000 g of PEG ointment is PEG 3350 400 g PEG 400 600 g Combining PEG 3350, a solid, with PEG 400, a liquid, results in a very pliable (fixable) semisolid ointment. If a firmer (harder) ointment is desired, the formula may be altered to contain up to equal parts of the two ingredients.  SUMMARY OF OINTMENT BASES (a) Oleaginous Bases hydrocarbon ointment bases Petrolatum, white petrolatum, white ointment, (White wax , White Petrolatum ) yellow ointment (Yellow wax , Petrolatum ) (b) Absorption Bases hydrophilic petrolatum ( Cholesterol, Stearyl alcohol , White wax , White petrolatum) lanolin (c)Water-Removable Bases Hydrophilic Ointment, USP, ( Methylparaben,Propylparaben ,Sodium lauryl sulfate ,Propylene glycol ,Stearyl alcohol , White petrolatum, Purified water ) (d) Water-Soluble Bases Polyethylene Glycol Ointment, NF Factors Of Selecting Ointment Bases 1. Physicochemical properties of the medicaments e.g stability in the base. 2. Patient’s conditions - as to the desired release rate of the drug from the base. 3. Intended site of application - ability of occlusion of moisture from the skin by the base. 4. Characteristics of the various   Ointment  What is Ointments?  Medicinal application of the Ointment  Ointment bases Preparation of the Ointments  Storage and dispensing   Ointment  What is Ointments?  Medicinal application of the Ointment Mix together (mortar &  Ointment bases pestle, Preparation of spatula & slab) roller mill the Ointments "levigating" the powder  Storage and dispensing (reduction of particle size in suspending agent compatible with the ointment base) Ointment Mill  In preparing ointment by spatulation, the pharmacist works the ointment with a stainless steel spatula but if the components react with metals (such as iodine, phenol, tannins, mercuric salts) the hard rubber is used.  Incorporation Of Solid – 1. The ointment base is placed on one side of the working surface. – 2. The powdered components (previously reduced into fine powders) are placed on the other side. – 3. Then a portion of the powder is mixed with a portion of the base until uniform. – 4. Repeat until all portions of the product and based are combined. – 5. The portions of prepared ointment are   Ointment  What is Ointments?  Medicinal application of the Ointment  Ointment bases  In porcelain dish all or some components of an Preparation of ointment melted together the Ointments and cooled with  Storage and constant stirring until dispensing congealed  add non-melting substances as the ointment is being cooled   Ointment  What is Ointments?  Medicinal application of the Ointment  Ointment bases  Preparation of the Ointments Storage and dispensing   Ointment  What is Ointments? Ointments should be stored  Medicinal in tightly closed and application of the Ointment completely filled containers  Ointment bases Changes in temperature  Preparation of the Ointments can lead to the crystallization of the drug Storage and and to changes in the dispensing ointment base. They are usually dispensed in jars of glass, tin or plastic material or in collapsible tubes.   Ointment  What is Ointments? Sterile ointments must be  Medicinal application of the dispensed in tubes or Ointment single dose units in order  Ointment bases  Preparation of the to protect the product Ointments against contamination during use. Storage and dispensing With tin tubes, there is a risk of corrosion with hydrophilic ointments.   Ointment  What is Ointments?  Medicinal application of the Ointment  Ointment bases  Preparation of the Ointments Prepare the ointment. Select an ointment jar that will just Storage and hold all of the formulation. dispensing Begin by taking some ointment... and fill the bottom of the ointment jar. Use the spatula to put ointment into the   Ointment  What is Ointments? Continue adding ointment to  Medicinal the jar again using the spatula application of the Ointment to put the ointment along the  Ointment bases sides of the jar.  Preparation of the As you fill the jar, stab the Ointments spatula into the ointment a Storage and couple of times. This will reveal air pockets that may dispensing have formed. Put the spatula halfway across the filled jar, and tilt in slightly.Rotate the   Ointment  What is Ointments?...and this is make a  Medicinal professional looking finish application of the Ointment on the top of the ointment.  Ointment bases Wipe off ointment from the  Preparation of the Ointments threads of the jar. Cap the ointment jar. Storage and dispensing TESTS REQUIREMENTS FOR OINTMENTS – Microbial Content: must meet acceptable standard for microbial level. – Must contain antimicrobial preservatives such as methylparaben,propyl paraben, phenols, benzoic acid, sorbic, quaternary ammonium salts – Minimum Fill Test – net weight and volume – Packaging, Storage, and Labeling – metal, plastic tubes, jar – Well close containers, light sensitive, light resistant  Additional requirements Labeling- type of base used (water soluble or insoluble) Examine the viscosity in-vitro drug release to ensure within lot and lot-to-lot uniformity.