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LANGA, AMHIL JEMINA J. | BSPh 2D WHITE OINTMENT, USP LESSON 6 This ointment differs from yellow ointment by...

LANGA, AMHIL JEMINA J. | BSPh 2D WHITE OINTMENT, USP LESSON 6 This ointment differs from yellow ointment by substitution of white wax (bleached and purified OINTMENTS yellow wax) and white petrolatum in the formula. Also known as Salve or Chrisma ABSORPTION BASES Semi-solid preparations that are applied to the skin or mucous membranes, often containing medicine. Absorption bases are of two types: Are easily spread, their plastic viscosity may be controlled by Those that permit the incorporation of aqueous solutions modification of the limitation. resulting in the formation of water-in-oil (w/o) emulsions (Hydrophilic petrolatum). USES: Those that are water-in-oil (w/o) emulsions (Emulsion bases) Emollients – which makes the skin more pliable that permit the incorporation of additional quantities of aqueous solutions (Lanolin). Protective barriers – which prevents harmful substances from coming in contact with the skin These bases serve as emollients but offer less occlusion compared to oleaginous bases and are difficult to wash off Vehicles – in which to incorporate medication. with water because their external phase is oleaginous (oily). These bases help incorporate small amounts of aqueous CLASSIFICATION BASED ON COMPOSITION solutions into hydrocarbon bases by first mixing them with an absorption base. OLEAGINOUS BASES Physical Properties: Anhydrous, water-insoluble, and non- washable, but capable of absorbing water. Also termed as Hydrocarbon bases. Permit the inclusion of water-soluble medicaments through When you apply it to the skin: prior solution and uptake of the solution as the internal It has an emollient effect phase. It protects against moisture loss It acts as an occlusive dressing It stays on the skin without drying out Hydrophilic Petrolatum, USP It’s immiscible with water and hard to wash off A white petrolatum combined with 8% white wax, 3% Water and aqueous preparations may be incorporated, but stearyl alcohol, and 3% cholesterol which are added only in small amounts with some difficulty. to a water-in-oil emulsifier. When incorporating powdered substances into hydrocarbon Ingredients: bases, liquid petrolatum (mineral oil) can be used as the Cholesterol levigating agent. Stearyl alcohol White wax PETROLATUM, USP White petrolatum Prepared from: Is a purified mixture of semisolid hydrocarbons Aquaphor - which employs wool alcohol to render obtained from petroleum. It is an unctuous mass, white petrolatum emulsifiable and is superior in its varying in color from yellowish to light amber. ability to absorb water. Polysorb - which uses Sobitan Sesquioleate and It is also known as Yellow Petrolatum and Petroleum Arlacel A as emulsifiers (Kessolin) and appears to be Jelly. superior to the USP base. A good base for oil-soluble ingredients. Lanolin, USP Forms an occlusive film on the skin. Absorbs less than 5% water under normal condition. Also known as: Anhydrous Lanolin or Wool Fat Does not become rancid Is obtained from the wool of sheep, is a purified wax like substance that has been cleaned, deodorized, Wax may be incorporated to stiffen the base. and decolorized. It contains not more than 0.25% water. Additional White PETROLATUM, USP water may be incorporated into lanolin by mixing. Is a purified mixture of semisolid hydrocarbons from Contains a high percentage of alcohol, esters and petroleum that has been wholly or nearby alcohol containing fatty acids. decolorized. It is used for the same purpose as petrolatum, but because of its lighter color, it is Absorbs twice its weight in water and melts between considered more esthetically pleasing by some 36°C and 42°C. pharmacists and patients. It is also known as White Petroleum Jelly Modified Lanolin, USP Ingredients: Yellow wax, Petrolatum Is a lanolin processed to reduce the content of free lanolin alcohols and any detergent and pesticide residue. WATER-REMOVABLE BASES Polyethylene Glycol (PEG) Ointment, NF Are oil-in-water emulsions commonly called Creams. Polyethylene glycol (PEG) is a polymer consisting of Because the external phase of the emulsion is aqueous, ethylene oxide and water, represented by the formula they are easily washed from the skin and are often called H(OCH₂CH₂)ₙOH, where “n” indicates the average water-washable bases. number of oxyethylene groups. The numeric designation of PEG corresponds to its average They may be diluted with water or aqueous solutions. They molecular weight. can absorb serous discharges. PEG having a molecular weight of: Hydrophilic Ointment, USP Below 600: clear, colorless liquids An oil-in-water emulsion employing Sodium Lauryl Between 600 - 1,000: semisolids Sulfate as an emulsifying agent. It absorbs about 30% to 50% W/W without losing consistency, and readily Above 1,000: wax-like materials miscible with water and thus can be removed from the As molecular weight increases, the viscosity of skin easily. PEGs also increases. (Directly Proportional) Ingredients: The range of average molecular weights for PEGs is White petrolatum from 200 to 8,000. sodium lauryl sulfate propylene glycol Ingredients: stearyl alcohol PEG 3350 purified water PEG 400 methylparaben propylparaben Consist of a blend of water-soluble polymeric glycol that forms a semi-solid base capable of solubilizing COLD CREAM water-soluble drugs and some water-insoluble drugs. Compatible with a wide range of drugs. A water-in-oil emulsion prepared by melting white Contains 40% PEG 4000 and 60% PEG 400. wax and spermaceti, expressed almond oil together, adding hot aqueous solution of sodium borate, stir Only a small amount of liquid (less than 5%) can be until cool added without affecting viscosity. Mineral oil may be used to make a more stable cold The mixture can be made stiffer by increasing the cream. PEG 4000 content to 60%. Almond oil may be used to make a better emollient base. Propylene Glycol and Propylene Glycol-Ethanol VANISHING CREAM Form a clear gel when mixed with 2% hydroxypropyl An oil-in-water emulsion which contains large cellulose percentage of water as well as humectants (Glycerin, Propylene glycol) - which retards surface evaporation This has become popular as dermatologic vehicles. of the product. The most common cream available in the market due to large amount of water contained and an acid (Stearic acid). An excess of stearic acid in the formula helps to form a thin film when the water evaporates. CLASSIFICATION BASED ON PENETRATION Other Water-Removable Bases EPIDERMIC OINTMENTS Dermovan - a hypoallergenic greaseless emulsion base. Demonstrate no or at the most very slight penetration. Unibase - a non-greasy emulsion base that absorbs about 30% of its weight in water and has a pH close to the skin. Petrolatum, Waxes, and their combinations WATER-SOLUBLE BASES ENDODERMIC OINTMENTS They do not contain oleaginous components. Possess some powers of penetration into the deeper layers of the skin. They are completely water washable and often referred to as greaseless. Vegetable oils, Lard, Wool fat, Lanolin, and/or its combinations they soften greatly with the addition of water Large amounts of aqueous solutions are not effectively DIADERMIC OINTMENTS incorporated into these bases. This penetrates the skin, providing a better opportunity for They are mostly used for incorporation of solid substances. the absorption of medicaments.  METHODS OF PREPARATIONS PACKAGING, STORING & LABELING Ointments are prepared using two general methods: Ointments and other semisolid preparations Incorporation and Fusion, depending on the nature of the are packaged in: ingredients. Large-mouthed ointment jars Insoluble substances should first be reduced to the finest possible form. Metal or plastic tubes These substances are then levigated before incorporation. Semisolid preparations must be stored in: Levigation is done by mixing the substance with a small Well-closed containers to protect against contamination amount of a compatible levigating agent or with the ointment A cool place to prevent product separation due to heat base itself. Opaque or light-resistant containers if they are light-sensitive INCORPORATION The USP directs labeling for certain ointments and creams, including: The substances are incorporated into the ointment by levigation. Proper storage conditions Dosing and administration instructions Materials used for INCORPORATION method are: MORTAR & PESTLE LESSON 7 used to incorporate substances into an ointment base, especially when large amounts or quantities of liquid need to be mixed into the base. CREAMS OINTMENT SLAB Are semi-solid preparations containing one or more medicinal agents dissolved or dispersed in either an oil-in consists of a ground-glass plate and is used with two water emulsion or in another type of water-washable base. 5-6 inch full-blade hard steel spatulas Patients and physicians prefer creams to ointments because Alternative tools: Hard rubber or tested plastic they are easier to spread and remove than many ointments. spatulas. The so-called Vanishing Creams are oil-in-water emulsions OINTMENT MILL containing large percentage of water and stearic acid or other oleaginous components. Also known as: Unguator After application of the cream, the water evaporates, leaving an electronic mortar and pestle. behind a thin residue film of stearic acid or other oleaginous component. It can be operated manually or through computer software. PREPARATIONS This device is ideal for producing ointments in batches of 5 pounds or more. Select Ingredients: Mineral oils OINTMENT PARCHMENT PAD Vegetable oils Fatty alcohols An ointment parchment pad should not have Fatty acids prolonged contact with the ointment, as this may Fatty esters cause the parchment to soften and tear. Melt Solid Excipients: Organic solvents such as ether, chloroform, and Melt the solid excipients during preparation. alcohol should not be used for dissolving the drug, as the drug may crystallize when the solvent Incorporate Emulsifying Agents: evaporates. Add: Nonionic surfactants Detergents FUSION Soaps Form Soaps: All or some components of an ointment are combined by Create soaps from: melting them together and cooling the mixture with constant Fatty acids in the oil phase stirring until it congeals. Hydrolyzed by a base in the aqueous phase during preparation. Components that do not melt are added to the congealing mixture as it cools and is stirred. Heat-labile substances and volatile components are added last, when the temperature of the mixture is low enough to prevent decomposition or volatilization.  COMPOSITION APPLICATION AND USE Topically applied onto the skin, eyes, nasally, vaginally and Four (4) main ingredients of cold cream: rectally. Water Oil Administered by the topical oromucosal routes. Emulsifier Thickening agent Antibiotic-containing gels can be administered by teat infusion in veterinary medicine to treat mastitis. APPLICATION AND USE PACKAGING AND STORAGE Primary application in topical skin products and in products used on mucous membranes, such as rectally and vaginally. Should be stored in tight containers to prevent water loss. The provision of a barrier to protect the skin. Avoid freezing. To aid in the retention of moisture. MISCELLANEOUS SEMI-SOLID DOSAGE FORM As emollient (having the quality of softening or soothing the PREPARATIONS skin.) As vehicle for drug substance such as local anesthetics, anti-inflammatories, hormones, antibiotics, antifungals or counter-irritants. PASTES Are semi-solid preparations intended for application to the GELS skin They are generally contain a large proportion of solid Also known as Jellies. material (such as 25%) than ointments and therefore are stiffer. Are semi-solid systems consisting of dispersions of small or large molecules in an aqueous liquid vehicle rendered jelly- When prepared with an oleaginous base they are greasy like by the addition of a gelling agents. than their counterpart ointments due to the reduced amount of the base. Are semi-solid that can have properties ranging from soft and weak to hard and tough. PREPARATIONS Are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state. Prepared like ointments by either: Has been defined phenomenologically as a soft, solid or Direct mixing. solid-like material consisting of two or more components, Heating to soften the base before incorporating comminuted one of which is a liquid, present in substantial quantity and sieved solids. When using a levigating agent, a portion of the base is GELLING AGENTS used instead of a liquid to avoid softening the paste. Macromolecules: Carbomer 934 Stiffness helps the paste remain in place after application. Cellulose derivatives: Carboxymethylcellulose or Effective for areas with serous secretions. Hydroxypropylmethylcellulose Natural gums: Tragacanth Not suitable for hairy parts of the body due to stiffness and impenetrability. Other agents: Drug substance When prepared with an oleaginous base, pastes are Water greasier than ointments because of the reduced amount of Co-solvents: Alcohol and/or propylene glycol base used. Antimicrobial preservatives: Methylparaben, propylparaben, or Chlorhexidine gluconate Stabilizers: Edetate disodium APPLICATION AND USE PREPARATIONS Applied on the skin, but not suited for hairy parts of the body– due to its stiffness and impenetrability. Form Gels: Disperse large organic molecules in the continuous phase. PRODUCTS Example: Heat starch to disperse. Cross-link dispersed molecules by changing the pH. ZINC OXIDE PASTE Example: Use carbomers. It is prepared by mixing 25% each of zinc oxide and starch Reduce the continuous phase to form jellies. with white petrolatum. Example: Use sucrose. Disperse APIs uniformly by: Vigorous mixing. Milling. Shaking (if less viscous). PLASTERS PACKAGING OF SEMI-SOLID Are solid or semi-solid adhesives masses spread upon a Topical dermatologic products backing material or paper, fabric, moleskin or plastic. The Jars adhesive material used is a rubber base or a synthetic resin. Tubes Adhesive tape used to be official under the title Adhesive Plaster, the use of this material being well known. Syringes Ophthalmic, nasal, vaginal and rectal solid products APPLICATION AND USE Tubes Applied to the skin to provide prolonged contact at the site. Syringes Medicated plasters provide effects at the site of application. They may be cut to size to conform to the surface to be covered. LESSON 8 Unmedicated plasters provide protection or mechanical support at the site of application. SUPPOSITORIES PRODUCTS Are solid dosage forms in which one or more active pharmaceutical ingredients (APIs) are dispersed in a Salicylic Acid Plaster suitable base molded or otherwise formed into a suitable shape for insertion into the rectum to provide local or use on the toes for the removal of corns with keratolytic systemic effect. action of Salicylic acid (10-40% concentration) Are solid dosage forms intended for insertion into body orifices where they melt, soften, or dissolve and GLYCEROGELATIN exert localized or systemic effects. Derived from the Latin word supponere which means “to Are plastic masses containing: place under”, as from sub (under) and ponere (to place). Gelatin (15%) Glycerin (40%) Used rectally, vaginally, and occasionally urethrally. Water (35%) LOCAL ACTION and an added medicinal substance (10%) as Zinc Oxide. once inserted, the base melts, softens or dissolves, distributing the medicaments it carries to the tissue of the PREPARATIONS region. Rectal - pain, constipation, irritation, itching, and Softening the gelatin in water for about 10 minutes. inflammation associated with hemorrhoids or other anorectal disorders. Heat on a steam bath until the gelatin is dissolved. Vaginal - contraceptives, antiseptics in feminine hygiene, Add the medicinal substance mixed with glycerin. antibacterial Allow the mixture to cool with stirring until congealed. SYSTEMIC ACTION the mucous membranes of the membranes of the rectum APPLICATION AND USE and vagina permit the absorption of many soluble drugs. Applied to the skin for longer residence. Rectal - is frequently as the site for the systemic absorption They are melted before application, cooled to slightly above Vaginal - is not as frequently used for this purpose. body temperature, and applied to the affected area with a fine brush. APPLICATION AND USE Following application, the glycerogelatin hardens, is usually covered with a bandage and is allowed to remain in place for a period of weeks. Suppositories come in various shapes and weights. They should be easy to insert into the intended orifice without causing discomfort and stay in place as needed. PRODUCTS Are intended for insertion into body orifices where they melt, soften, or dissolve and exert localized or systemic effects. Zinc Gelatin Use in the treatment of varicose ulcers. It was also known as “Zinc Gelatin boot” due to its ability to form a pressure bandage.  TYPES OF SUPPOSITORIES WATER-SOLUBLE and WATER-MISCIBLE BASES Polyethylene Glycols (PEG) RECTAL Polymers of ethylene oxide and water, available in various Are inserted into the rectum with the fingers. chain lengths, molecular weights, and physical states. Are cylindrical and have one or both ends tapered. Commonly used molecular weights include: PEG 300, 400, 600, 1000, 1500, 1540, 3350, 4000, 6000, 8000. Some are shaped like a bullet, a torpedo, or the little finger. Properties of Polyethylene Glycols (PEG) Length: Usually about 32 mm (1 ½ inches) Water-soluble but with slow dissolution. Does not melt at body temperature; dissolves slowly in Weight: body fluids. Adult: 2 g (made of cocoa butter, pencil-like shape) In rectum and vagina (limited fluids), they dissolve slowly Infants: 1 g but soften and spread. Polyethylene Glycols (PEG) at Room Temperature VAGINAL PEG 300, 400, 600 – clear, colorless liquid Also called Pessary or Pessaries PEG 1000 – white semi-solid Are usually globular, oviform, or cone-shaped PEG 1500, 1540 – fairly firm semi-solid Weight about 5 g - when made cocoa butter base PEG 3350, 4000, 6000 – firm, wax-like solids [ Weights may vary depending on the base use and the Glycerinated Gelatin individual manufacturer’s product ] Prepared by dissolving: Granular gelatin (20%), Glycerin URETHRAL (70%) and Adding a solution or suspension of medication (10%) Also called Bougies Tends to absorb moisture due to glycerin’s hygroscopic Are slender, pencil-shaped intended for insertion into the nature. (Must be protected from atmospheric moisture to male or female urethra. maintain consistency.) Size Female Male Commonly used in vaginal suppositories for prolonged, localized medicinal action. Diameter: 3-6 mm Slower to soften and mix with physiological fluids than Length: 70 mm (7 cm) 140 mm (14 cm) cocoa butter (Provides a more prolonged release.) about 2 g about 4 g Can also be formulated into urethral suppositories by Weight: (when made of (when made of dissolving: Granular gelatin (60%), Glycerin (20%) and cocoa butter) cocoa butter) Medicated aqueous portion (20%) BURGINARIUM Easier to insert than cocoa butter-based suppositories: Cocoa butter is brittle and softens rapidly at body same as urethral suppositories but shorter and thinner. temperature. TYPES WITH RESPECT TO THE VEHICLE OR BASES USED BASES first type FATTY or OLEAGINOUS BASES Prepared with Cocoa/Cacao Butter or Theobroma Oil. Cocoa Butter (Theobroma Oil) CACAO BUTTER Most widely used suppository base. Softens with additives like phenol, camphor, chloral Ideal for rectal suppositories; less suitable for vaginal and hydrate, and other volatile oils. urethral use. This can be countered by adding wax or spermaceti to raise the melting point in warm weather White wax can replace part of cocoa butter to adjust melting point. THEOBROMA OIL Melts at body temperature, allowing the suppository to act Hydrogenated Fatty Acids of Vegetable Oils effectively. Includes Kernel oil and Cottonseed oil. second type Glycerin with Higher Molecular Weight Fatty Acids Prepared with Glycerin and Gelatin. Fat-based compounds with glycerin and higher molecular Water-soluble or water-miscible bases. weight fatty acids, such as: Palmitic acid & Stearic acid Used to provide continuous medicating or germicidal action. Examples include Glyceryl Monostearate and Glyceryl Created by mixing an aqueous solution or suspension of the Monopalmitate. medicament with glycerin and gelatin. third type PACKAGING & STORAGE Glycerin or Soap Suppositories made from Castile soap. PACKAGING Acts partly by mechanical means and partly by dissolving to Glycerin and glycerinated gelatin suppositories are produce mild irritation. packaged in tightly closed containers to prevent moisture Primarily stimulates peristalsis when present in the rectum. changes. Commonly used for small children as an alternative to Suppositories with a cocoa butter base are individually laxatives. wrapped or placed in compartment boxes to prevent contact and adhesion. METHODS OF PREPARATIONS Suppositories containing light-sensitive drugs are individually wrapped in opaque materials, like metallic foil, MOLDING (FUSION) to protect from light exposure. STORAGE Suppository Molds Cocoa butter suppositories must be stored below 30°C and Principal method for commercial suppository production preferably in a refrigerator (2°C to 8°C). Capable of producing 6–12 or more suppositories Glycerinated suppositories can be stored at controlled room temperature (20°C to 25°C). Molds are made from stainless steel, aluminum, brass, nickel-copper alloys, or plastic Suppositories made from a polyethylene glycol base may be stored at usual room temperature. Common bases used include cocoa butter, polyethylene glycol, and glycerinated gelatin Mineral oil is used for lubrication THE 3 OFFICIAL BASES Preparation Steps Cocoa Butter or Theobroma Oil 1. Melting the base High Molecular Weight Polyethylene Glycol (PEG) 2. Incorporating medicaments 3. Pouring the melted mixture into molds Glycerinated Gelatin 4. Allowing it to cool and solidify into suppositories 5. Removing the formed suppositories from the mold Lubrication of the Molds INSERTS Cocoa butter or polyethylene glycol usually do not Are solid dosage forms that is inserted into a naturally require lubrication as they contract on cooling for easy occurring (nonsurgical) body cavity other than the mouth or removal rectum, including the vagina and urethra. Glycerinated gelatin typically requires lubrication; a thin layer of mineral oil applied with a finger is sufficient VAGINAL INSERTS Special Considerations Usually ovoid in shape Thermolabile drugs and insoluble powders require Packaged with a plastic inserter for easy placement careful handling; insoluble powders may settle during within the vagina pouring, causing non-uniform drug distribution Contains the same types of anti-infective and Hard crystalline materials should be dissolved in a minimal hormonal substances as vaginal suppositories solvent volume before incorporation, examples include iodine and merbromine APPLICATION AND USE Vegetable extracts can be incorporated by moistening with a few drops of alcohol and levigating with melted cocoa Tablets are intended to disintegrate within the butter vagina, releasing their medication Some are gelatin capsules containing medication COMPRESSION for intravaginal release Is generally employed when cocoa butter is used as a base. PREPARATIONS Capable of producing a 2 g suppository. Filler: Lactose Preparation: Disintegrating Agent: Starch Uniform mixture of drug and base (hand-rolling method) Mixture is placed into a chamber mold. Dispersing Agent: Polyvinylpyrrolidone Mold is then cooled. Lubricant: Magnesium Stearate HAND ROLLING & SHAPING Involves molding the suppository with the fingers after the formation of plastic mass. MEDICATION STICKS ADVANTAGES Avoids GI absorption issues from pH, enzymes, and drug Convenient form for administering topical medications interactions with food or other drugs. Development is notable due to its connection with the history Suitable alternative for patients with vomiting or diarrhea. of cosmetics, which parallels human history Bypasses the first-pass effect. Cylindrical in shape, generally ranging from 5-25 g Noninvasive, more convenient than injections. Used for both cosmetics and medical purposes, includes styptic pencils and lip balm sticks which became available in Provides extended therapy with a single application, the early 1940’s. improving patient compliance. Today, medication sticks provide pharmacists, patients and Prolongs activity of drugs with short half-lives through primary care providers with a unique, convenient, relatively controlled release. stable, easy-to-prepare dosage form for the topical delivery of drugs. Allows rapid termination of drug therapy by removing the application. APPLICATION AND USE Enables quick identification in emergencies due to visible features on the delivery system. They come in different sizes and shapes, are readily transportable, and can be applied directly to the affected site of the body. DISADVANTAGES The stick is pushed up from the bottom or using a screw- Only relatively potent drugs are suitable for transdermal type device to raise the stick. delivery due to skin’s natural barrier limiting drug entry. Some patients may experience contact dermatitis at the PREPARATIONS application site, potentially requiring discontinuation of use. Medication sticks are prepared similar to suppositories (except that the melt is poured into the administering device, PATCHES or tube.) Designed to deliver a consistent and controlled dosage for extended systemic therapy. PACKAGING Due to the skin’s barrier properties, only a few drugs They are generally packaged in an applicator tube for topical possess the necessary physicochemical and therapeutic administration, and the applicator can be adjusted to properties for sustained transdermal delivery. continually expose new, fresh stick from inside the tube. Successful transdermal products include scopolamine, nicotine, estradiol, fentanyl, testosterone, and glyceryl trinitrate patches. MODIFIED-RELEASED DOSAGE FORMS AND DRUG DELIVERY SYSTEMS The Lidoderm 5% patch (Lidocaine) includes adhesive TRANSDERMAL DRUG DELIVERY material with 5% lidocaine on a nonwoven polyester felt SYSTEM (TDDSs) backing, covered with a PET film release liner, removed before application. The patch measures 10 x 14 cm, with each containing 700 Facilitates drug passage through the skin into general mg of lidocaine in an aqueous base. circulation for systemic effect. Percutaneous Absorption: APPLICATION AND USE Evident through measurable blood levels, detectable drug/metabolite excretion in urine, and patient response to To treat post herpetic neuralgia. therapy. Applied to intact skin to cover the most painful area. Therapeutic blood concentration is determined by comparing patient response to drug blood levels. Depending upon the direction for use, the patient can apply up to three patches, only once for up to 12 hours within a Ideal drug penetration reaches the underlying blood supply 24-hour period. without accumulating in dermal layers. Examples: Transdermal Scopolamine TAPES Transdermal Nitroglycerin Suitable for delivering drugs directly to the skin. Transdermal Clonidine Transdermal Nicotine Composed of a drug impregnated into a flexible, durable Transdermal Estradiol fabric or synthetic material, coated with an adhesive. Transdermal Testosterone Transdermal Contraceptive System Drug typically in a dry state; adhesive layer secures the tape Transdermal Methylphenidate without additional bandaging. Unlike transdermal patches, it does not control the drug release rate. Drug content is specified per surface area relative to the tape’s skin-exposed surface. Applying an occlusive dressing over the tape can increase drug delivery to deeper skin layers and may enhance systemic absorption. APPLICATION A portion of the tape slightly larger than the area to be treated is cut and removed from the backing paper. It should be applied to folds in the skin but rather to a smooth skin surface. t should be applied to dry skin.