PDDS 211 Midterm Post-Laboratory 2024 PDF
Document Details
2024
Van Allen Indiongco
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Summary
This is a midterm post-laboratory document for PDDS 211, covering semi-solid dosage forms such as ointments, creams, and pastes. It details various classifications, properties, and preparation methods. The document explains the use of different bases, and lists examples.
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Pdds 211 midterM: post laboratory Van Allen Indiongco Definition of terms ❑ Humectant ▪ A substance that causes water to be retained because of its hygroscopic properties ❑ Occlusive ▪ A substance that promotes retention of water in the skin by forming a hydrophobic barrie...
Pdds 211 midterM: post laboratory Van Allen Indiongco Definition of terms ❑ Humectant ▪ A substance that causes water to be retained because of its hygroscopic properties ❑ Occlusive ▪ A substance that promotes retention of water in the skin by forming a hydrophobic barrier Definition of terms ❑ Protective ▪ A substance that protects injured or exposed skin surfaces from harmful or annoying stimuli ❑ Emollient ▪ Agent that softens the skin or soothes irritation in skin or mucous membrane overview ❑Semisolid Dosage Forms ▪ Ointments ▪ Pastes ▪ Creams ▪ Plasters ▪ Glycerites ▪ Cataplasms ▪ Cements ❑Pharmaceutical Inserts ▪ Suppositories ▪ Vaginal inserts Semisolid dosage form ❑Ideal Properties of Semisolid Dosage Forms ▪ Physical properties ⮚Smooth texture ⮚Elegant in appearance ⮚Non-dehydrating ⮚Non-gritty ⮚Non-greasy ⮚Non-staining ⮚Non-hygroscopic ▪ Physiological properties ⮚Non-irritating ⮚Do not alter membrane function ⮚Miscible with skin secretion ▪ Application properties ⮚Easy applicable with efficient drug release ⮚High aqueous washability Semisolid dosage forms ❑Ointment ▪ Semisolid preparation intended for external application to the skin and mucous membranes Semisolid dosage forms ❑ Ointment ▪ They can be: ⮚ Medicated Act solely on the surface of the skin to produce local effect (e.g. antifungal) Release the medication which penetrates into the skin (e.g. cortisone cream) Release the medication for systemic absorption through the skin ⮚ Non-medicated Used for physical effect they provide as protectants, emollient, or lubricants Classification of ointments ❑Oleaginous bases (HC bases) ▪ Used to prepare epidermic ointments ▪ Have emollient effect, humectant (prevents escape of moisture) ▪ Can remain on skin for long periods without drying out ▪ With water: immiscible ▪ Anhydrous ▪ Permit incorporation of powdered substances with the use of levigating agent Classification of ointments ❑Oleaginous bases (HC bases) ▪ Examples: ⮚Yellow petrolatum “Petrolatum USP” Purified semisolid HC obtained from petroleum ⮚White petrolatum Wholly or nearly decolorized petrolatum ⮚Yellow ointment Yellow wax from Apis mellifera + petrolatum ⮚White ointment Bleached and purified yellow wax + white petrolatum Classification of ointments ❑Absorption bases ▪ Not easily removed from the skin with water washing since the external phase is oleaginous (w/o emulsions) ▪ They permit incorporation of aqueous solution ▪ May serve as emollient, although they do not provide the degree of occlusion afforded by the HC bases Absorption bases ❑ Sub-classification: ▪ Anhydrous AB ⮚ Permit the incorporation of aqueous solution, forming w/o emulsions ▪ Water-in-oil emulsion AB ⮚ Permits the incorporation of addition quantities of aqueous solutions Absorption bases ❑ Sub-classification: ▪ Anhydrous AB ⮚ Permit the incorporation of aqueous solution, forming w/o emulsions ▪ Water-in-oil emulsion AB ⮚ Permits the incorporation of addition quantities of aqueous solutions Absorption bases ❑ Anhydrous AB ▪ Uses: protectant, emollient, vehicle for aqueous solutions vehicle for solids and drugs ▪ Examples: ⮚ Hydrophilic Petrolatum, USP Composition: (white petrolatum + 8% beeswax + 3% stearyl alcohol + 3% cholesterol added to w/o emulsifier) ⮚ Lanolin, USP (anhydrous lanolin) Obtained from the wool of the sheep (Ovis aries) Absorption bases ❑ Water-in-oil emulsion AB ▪ Uses: emollient, cleansing cream, vehicle for liquids and solids ▪ Examples: ⮚ Hydrous lanolin ⮚ Rose water ointment Classification of ointments ❑Water-removable bases ▪ Water washable bases or greaseless base ▪ Commonly called creams ▪ O/W emulsion ▪ Example: Hydrophilic Ointment, USP ❑Water-soluble bases ▪ Do not contain oleaginous components ▪ Completely water washable ▪ Example: carbowax (PEG) Preparation of ointments ❑Incorporation method ▪ Components are mixed until a uniform preparation is attained ❑Fusion method ▪ All or some components are combined by being melted together and cooled with constant stirring until congealed; heat labile substances are added last when the temp of the mixture is low Semisolid dosage forms ❑Creams ▪ Semisolid preparations containing one or more medicinal agents dissolved dispersed in either W/O or O/W emulsion or in another type of water-washable base. ▪ Easier to spread and removed than ointments Semisolid dosage forms ❑Creams ▪ Examples: ⮚Vanishing cream O/W emulsion Water + stearic acid Most common cream available in market ⮚Cold cream “Galen’s cerate” W/O emulsion Semisolid dosage forms ❑Pastes ▪ Very still, very absorptive, non- greasy and highly concentrated application ▪ Contains high solid content (about 25%) and are there fore stiffer than ointments ▪ Usually employed for their protection action Semisolid dosage forms ❑ Gels “jellies” ▪ Semisolid systems consisting of dispersions of small or large molecules in an aqueous liquid vehicle rendered jellylike by the addition of gelling agent ▪ Example: Dalacin T® Semisolid dosage forms ❑ Gels “jellies” ▪ Single-phase gels ⮚ Macromolecules are uniformly distributed through a liquid ▪ Two-phase gels “magmas” ⮚ A gel mass consisting of floccules of small distinct particles ⮚ Example: Milk of magnesia “magnesia magma” Semisolid dosage forms ❑Plasters ▪ Solid or semisolid adhesive masses spread upon a suitable backing material and intended for external application Semisolid dosage forms ❑Glycerogelatins or glycerites ▪ Plastic masses containing gelatin (15%), glycerin (40%), water (35%), and an added medicinal substance (10%) such as zinc oxide ▪ Stable to microorganism due to high glycerin content ▪ Applied to the affected area with the use of fine brush for long term residence Semisolid dosage forms ❑Cataplasms “Poultice” ▪ Soft, moist mass of meal, herbs, seed, etc., usually applied hot on a cloth that consists of gruel-like consistency Semisolid dosage forms ❑Cements ▪ For dental filling for exposed gums or tissues Pharmaceutical inserts ❑Suppositories ▪ Solid dosage forms intended for insertion into body orifices ▪ Melt, soften, and dissolve and exert either local or systemic effect suppositories Pharmaceutical inserts ❑Types of suppositories Suppository Weight Size Shape Age Gender Bullet or Infants Rectal 2g 32 mm Both torpedo (½ size of adult) Oviform or Vaginal 5g None Adults Female globular M: 4 g M: 140 mm Urethral Pencil-like Adults Both F: 2 g F: 70 mm suppositories Round Long Teardrop Bullet Tampon oval oval suppository ❑ Method of preparation ▪ Hand-rolled ⮚ A plastic-like mass is prepared by triturating grated cocoa butter and API in a mortar ⮚ The mass is formed into a ball in the palm of the hands, then rolled into a uniform cylinder with a large spatula and small, flat board on a pill tile ▪ Molded ⮚ By melting the suppository base first before dissolving the API and poured into a suppository mold ⮚ “Fusion method” Suppository bases ❑Fatty or oleaginous bases ▪ Cocoa butter: most widely used ▪ Witepsol: Fatty acid (C12-18) ▪ Wecobee: coconut oil Suppository bases ❑Water-soluble and water miscible bases ▪ Glycerinated gelatin ▪ PEG polymers (300-8000) ❑Miscellaneous bases ▪ Mixture of oleaginous and water soluble or water-miscible material (example: polyoxyl 40 stearate) Pharmaceutical inserts ❑Implantation pellets or inserts ▪ Solid dosage forms implanted under the skin by surgical special injectors for continuous release of medications Pharmaceutical inserts ❑Transdermal DDS ▪ Also called synthetic drug carrier system ▪ A design to support the passage of drug substance from the surface of the skin ▪ Facilitate the passage of drug substances through the skin and into the general circulation for systemic effect Transdermal DDS ❑Transdermal Parts ▪ Microporous membrane: controls the release of the drug ▪ Drug reservoir: where the drug is kept ▪ Adhesive paper ▪ Protective peel strip Transdermal administration ❑Electroporation ▪ Is a TDDS enhanced by the application of short, high-voltage electric pulses to create aqueous pores in the lipid bilayer of skin and thereby facilitate drug diffusion ❑Iontophoresis ▪ Is a TDDS enhanced by the used of applied low voltage electric current to facilitate drug diffusion through the skin Transdermal administration ❑Phonophoresis ▪ Is a TDDS enhanced by the application of low-frequency ultrasound to facilitate drug diffusion through the skin ❑High velocity powder particles ▪ Is a TDDS using supersonic shockwaves of helium gas to enhance drug diffusion through the skin