DISPERSE SYSTEMS
SUSPENSION -          Finely divided particles distribute somewhat uniformly  throughouta vehicle in which the drug exhibits a minimum degree of solubility -          GOOD SUSPENSION: particle diameter: 1 to 50 micrometer -          MICROPULVERIZATION;Producing fine powders: 10 to 50 micrometer -          FLUID ENERGY/JET MILLING/ MICRONIZING--Under 10 um      ……Floc/floccules- intentional formation of loose aggregates of particles, forming type of lattice that resist complete settling. It breaks up easily with small amount of agitation
EMULSIONS -          Dispersion in which the dispersed phase is composed of small globules of a liquid distributed throughout a vehicle in which it is immiscible
Theories of Emulsification
1.       Surface tension theory
2.       Oriented wedge theory	Assumes mono-molecular layers of emulsifying agent curved around the droplet of the internal phase of the emulsion
3.       Interfacial film theory	Places the emulsifying agent  at the interface between theoil and water, surrounding the droplets of the internal phase as a thin layer of film adsorbed on the surface of the drops

 

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SOLUTIONS
SOLUBILITY ( parts of solvent to dissolve 1 part of solute )
Very Soluble		Less than 1
Freely Soluble		1-10
Soluble		10-30
Sparingly Soluble		30- 100
Slightly Soluble		100-1,000
VERY Slightly Soluble		1,000-10,000
Practically INSOLUBLE		More than > 10,000
SOLVENTS FOR LIQUID PREPS
1.       Alcohol, USP Ethyl alcohol--à 94.9 -96% v/v C2 H5 OH	Under 6 yo- 0.5% limit 6-12 yo-  5% limit 12 yo above-  10 %	2nd to water as most useful -          Preferred because of miscibility to water and dissolve water insoluble ingredients -          DEHYDRATED ALCOHOL, 99.5%, essentially no water
2.       Diluted Alcohol, NF è 49 % alcohol		MIXED ALCOHOL + PURIFIED WATER Contract upon mixing e.g: 50 mL + 50 mL= 97 mL
3.       Rubbing Alcohol è 70 % v/v
4.       Glycerin (Glycerol)		Clear syrupy liquid, miscible both water and alcohol Preservative
5.       ISOPROPYL ALCOHOL à70 % v/v
6.       Propylene Glycol
7.       Purified Water, USP
Examples of non Medicated  Syrups
1.       Cherry syrup		Tart falvor, for drugs requiring acid medium
2.       Orange flavor		Citric acid- source of flavour Vehicle drugs stable in acid medium
3.       Cocoa		For bitter tasting drugs
4.       raspberry		Disguise salty or sour taste of slaine meidcaments
Preparation of Syrups
(a)    solution with the AID OF HEAT		Prepare syrup as quickly as possible INVERSION- hydrolytic rxn SUCROSE + HEAT à monosaccharides (dextrose or glucose + fructose or levulose) Color darkens—because of LEVULOSE Mixed= invert sugar, sweeter Speed of inversion- increase with acids SUCROSE OVERHEATED- turns to amber
(b)   Solution by Agitation without the Aid of Heat
(c)    Addition of Sucrose to a Medicated Liquid		Medicated liquid- tincture; fluidextract
(d)   Percolation		Ex. Ipecac syrup from Cephaelis ipecacuanha
ELIXIRS – clear, sweetened hydroalcoholic solutions; usually flavoured -          Preferred than syrups from manufacturing standpoint (ease of prep ; stable characteristics) è 10- 12 % ALCOHOL; self preserving è Should be stored in air tight container; VOLATILE
PREPARATIONS
1.       Simple solution with agitation		Aqueous soln ADDED to Alcoholic soln, not reverse : to maintain highest possible alcoholic strength at all times TALC – frequent FILTER AID, used in prep elixirs, absorbs excessive OILS and assist their removal
2.       Admixture of two or more  liquid ingredients
TINCTURES – Alcoholic or hydroalcoholic solutions prepared from vegetable materials or chemical substances -          15-80% alcohol -          Ex: PAREGORIC, USP- camphorated tincture of OPIUM -              OPIUM TICTURE, USP- LAUDANUM--- MUCH MORE POTENT THAN PAREGORIC
SPRAYS- aqueous or oleaginous solutions in the form of coarse tablets droplets or as finely divided solids to be applied topically, usually to the nasopharyngeal cavity
EXAMPLES OF SOLUTIONS
		SKIN
1.       Hydrogen Peroxide- clear colorless may or without odor of ozone 2.5to 3.5% v/v 0.05% preservative		30% H2O2—liberates 100x its volume of oxygenà 100-vol peroxide   Dilute soln: 3%H2O2- liberates 10 x its vol of oxygen
2.       POVIDONE IODINE TOPICAL SOLUTION		Chemical complex of IODINE + POLYVINYLPYRROLIDINE 10% skin uses ©Betadine
3.       THIMEROSAL TOPICAL SOLN		Water soluble MERCURIAL antibacterial agent 0.1% thimerosal ©merthiolate
		VAGINAL AND RECTAL
1.       VAGINAL DOUCHES
2.       Retention enemas
3.       Evacuation enema		Cleanse the bowel
		TOPICAL TINCTURES
1.       IODINE TINCTURE		2% iodine + 2.4 % Na iodide = SODIUM TRIIODIDE Na triiodideà prevents formation of ethyl iodide/loss of antibac àwater solubility ;reddish brown
2.       COMPOUND BENZOIN TINCTURE AKA: Friar’s balsam, Wade’s drops, Jerusalem’s balsam etc		10% benzoin, aloe, tolu balsam, storax Protectant; against bedsores, ulcers, cracked nipples
3.       THIMEROSAL TINCTURE		Compare to thimerosal Soln; NO NaCL, No Na borate Copper decomposes tincture ORANGE RED with GREEN FLUORESCENSCE
		TOPICAL ORAL SOLN
		…
		MISCELLANEOUS SOLNS
1.       AROMATIC WATERS		n  Clear, aqueous solns, saturated with volatile oils or aromatic or volatile substances NOT WIDELY USED ANYMORE
2.       DILUTED ACID		n  Aqueous solns prepared by diluting the corresponding conc acids wit purified water (w/v % basis) n  LITTLE USE NOWADAYS n  Ex: 1% acetic acid- surgery n  0.25% acetic acid – bladder irrigating soln
3.       SPIRITS		n  Alcoholic or hydroalcoholic soln of volatile substances n  FLavoring etc n  EX: AROMATIC AMMONIA SPIRIT; CAMPHOR SPIRIT n  Over 60% ALCOHOL
		NON-AQUEOUS SOLNS
1.       LINIMENTS		n  Alcoholic or oleaginous solns or emulsions of various medicinal substances intended to be rubbed on skin n  SHAKE WELL
2.       COLLOIDION		n  Clear or slightly opalescent viscous liquid prepared by dissolving PYROXYLIN (4% w.v) in 3 ether and 1 alcohol mixture
3.       FLEXIBLE COLLOIDION		n  Adding 2% CAMPHOR and  3% CASTOR OIL
4.       SALICYLIC ACID COLLOIDION		n  10% SALICYLIC ACID in FLEXIBLE COLLOIDION
EXTRACTION
Terms Menstruum- solvent or solvent mixture FLUIDEXTRACTS- liquid prep of vegetable drugs prepared by PERCOLATION EXTRACTS- concentrated prep of vegetable or animal drugs obtained by removal of the active constituents     METHODS OF EXTRACTION: 1.       Maceration- macerare means to soak 15-20 C; 3 days or until the soluble matter dissolved 2.       PERCOLATION-per (through) colare (strain) è In which the comminuted drug is extracted of its soluble constituent by slow passage of suitable solvent through column of drug

 

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OINTMENTS, CREAMS, PASTE, GELS, TRANSDERMALS PATCHES

OINTMENTS -          Semisolid -          Medicated or unmedicated -          Unmedicated: PROTECTANTS, EMOLLIENTS, LUBRICANTS -
OINTMENT BASES
1.       Oleaginous Base “Hydrocarbon base”	-          Emollient effect -          Occlusive -          Long periods without drying out -          Hard to incorporate with aqueous preparations (water) *Powdered substances: Liquid petrolatum (mineral oil)- use as levigating agent		Petrolatum, USP –purified mix, yellowish, light-amber Yellow petrolatum, jelly     White petrolatum- purified, DECOLORIZED WHITE petrolatum PETROLEUM JELLY …Vaseline   Yellow ointment- Simple Ointment Yellow wax (50 g) + Petrolatum (950 g) *yellow wax: Apis mellifera   White Ointment Uses  WHITE WAX
2.       ABSORPTION BASE	a.        W/O (e.g Lanolin) b.      O/W (e.g Hydrophilic petrolatum)   -Not easily removed because of external phase oil - USEFUL AS ADJUNCTS TO INCORPORATE small vols of aqueous into HYDROCARBON BASE		AQUAPHOR à  Hydrophilic Petrolatum (melt- stearyl alc + whitewax + cholesterol + white petrolatum)     Lanolin, USP -obtain from SHEEP Ovis aries purified waxlike; cleaned, deodorized, decolorized (less 0.25% water)
3.       WATER-REMOVABLE BASE        Water- washable	Oil in WATER O/W -          Easily washed out from skin -          Absorb serous discharges		Hydrophilic OINTMENT ( + parabens, Na lauryl sulphate, water)
4.       WATER-SOLUBLE Bases Greaseless	NO OLEAGINOUS Mostly used for incorporation Of SOLID SUBSTANCES		Polyethylene Glycol Ointment (PEG) -          Polymer of ethylene oxide and water MW less 600- clear 600-1000 - semisolid MW above 1000- white
PREPARATION OF OINTMENTS
1.       INCORPORATION		Mixed until uniform preparation achieved By mortar pestle Unguator-mixing device INCORPORATION OF SOLIDS -          Geometric dilution- small portion of powder is added with a portion of base until uniform -          Levigating- mixing solid in avehicle to make smooth dispersion (e.g mineral oil) -          Pulverization by Intervention- for gummy materials( camphor) INCORPORATION OF LIQUIDS   -          HYDROPHILIC+ enough Hydrophobic= blend; then add to rest HYDROPHOBIC
2.       FUSION		All or some of the components of an ointment are combined by being MELTED together and COOLED with CONSTANT STIRRING until CONGEALED -          Heat labile or volatile: ADDED LAST -          Substance with highest melting point- are heated to their lowest temp they can melt
COMPENDIAL REQUIREMENTS
1.       Absence of		Staphylococcus aureus Pseudomonas aeruginosa
CREAMS -          Semi-solid -          One or more medicinal agents dissolved or dispersed in either W/O or O/W emulsions containing large amounts of WATER, STEARIC ACID, or other oleaginous substances -          After application, water EVAPORATES, leaving thin film of stearic acid -          VS OINTMENTS: EASIER TO SPREAD OR REMOVE
GELS -          Semi-solid systems consisting of dispersion of small or large molecules in an aqueous liquid vehicle rendered jelly like -
Gelling agents		Carbomers : Tragacanths, -methycellulose
Single Phase Gel		Uniformly dispersed throughout the liquid No boundaries between macromolecules and liquid
Two phase system		“Magma” Gel mas  consisting of floccules of small distinct particles Ex: MILK OF MAGNESIA, thixotrope
PASTE -          CONTAIN LARGER AMOUNT OF SOLID (SUCH AS 25%) -          STIFFER THAN OINTMENT -           Ex: Zinc Oxide Paste (LASSAR’s Plain Zinc Paste)
PLASTER -          Solid or semisolid adhesive masses spread on backing paper, fabric moleskin, plastic -          EX: Salicylic Acid plaster (remove corns)
GLYCEROGELATINS -          Plastic masses containing: gelatin (15%); glycerine (40%), water (35%), medicinal substance (10%) -          Ex: Zinc Gelatin (varicose)
TYPES OF PLASTICS
HDPE		Superior moisture barrier, less resilient
LDPE		Soft, resilient, good moisture barrier
Polypropylene (PP)		High level of heat resistance
PET (polyethylene terephthalate)		Transparency; high degree of product compatibility

 

TRANSDERMAL DRUG DELIVERY SYSTEMS -          Facilitate passage of therapeutic quantities of drug substances through the skin and general circulation for their systemic effects -          STRATUM CORNEUM; MAJOR RATE LIMITING BARRIER TO TRANSERMAL DRUG TRANSPORT -          MW 100 TO 800 -          Ideal MW: MW 400 or less Enhance drug delivery by: -          Iontophoresis: delivery of  a charged chemical compound across skin membrane using electric field -          Sonophoresis: High frequency ultrasound -          Ex: Transdermal Scopolamine: for motion sickness -          Nitroglycerin transdermal: Nitro-dur, Nitrodisc, Minitran -                   To avoid tolerance: 12-14 hr patch on; 12 to 14 hrs patch off

 

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