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Drug Delivery - Tablet Coating 1

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toniagil's version from 2013-04-03 05:42

Section 1

Question Answer
what are the nine purposes of tablet coating?1. Protect the drug from environment, eg, air, moisture, light. 2. Mask unpleasant taste and odor. 3. Easier swallowing 4. Improve product identity. 5. Minimize cross contamination due to powder dust generated during high-speed packaging operations. 6. Improve product appearance. 7.Reduce incompatibility between drugs in the tablet. 8.Reduce abrasion and attrition. 9.Modify drug-release, as in enteric-coated products.
what is primarily used for sugar coating?sucrose
why is sucrose primarily used for sugar coating?• Sucrose is one of the few materials that produce smooth, high-quality coating that is basically dry and tack (stickiness)-free at the completion of the coating process.
Why has sugar coating popularity declined?requires skilled manpower, protracted and tedious
name the six steps of sugar coating.1. sealing 2. subcoating 3 smoothing 4. color coating 5. polishing 6. printing
• To protect the drug and other ingredients from water (major constituent of the coating formulation).sealing
what does the sealing consist of?• Alcoholic solutions (10-30% solids) of resins such as shellac, zein, and cellulose acetate phthalate.
sugar coating often results in a __________ increase in weight.50-100%
at what step does the increase in weight occur during the sugar coating process?subcoating
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Section 2

Question Answer
step of sugar coating in which • A solution of gelatin, acacia, and sucrose solution is applied to the sealed tablet cores, followed by a dusting powder application
what is the purpose of dusting powder?reduces stickiness and allow tablet buildup.
what does the dusting powder consist of?calcium carbonate, titanium dioxide, talc, sucrose, and powdered acacia.
what forms the subcoat?alternate layers of gum (from solution) and powder.
What must happen before color coating is applied?smoothing
how does smoothing occur?A solution containing 60-70% sugar solids and 1-5% titanium dioxide (as an opacifier) is applied.
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Section 3

Question Answer
what is considered the most critical step of sugar coating?Color coating
color coating involves multiple applications of a solution containing ______% sugar solids and appropriate colorants.60-70%
what are the coloring materials used in color coating?are either water-soluble dyes or water-insoluble pigments.
the water-soluble dyes in color coating is dissolved in what before being applied in small quantities to the tablets?? syrup
how many individual applications of colored syrup may be necessary?60
how long does color coating take?up to 25 hours
when pigments are used in color coating they are dispensed in?syrup
when does the color develop more rapidly resulting in thinner coats that dry more rapidly with a shorter processing time during color coating?if the pigment is opague or is combined with an opacifier (titanium dioxide)
what are the pigments used in color coating?inorganic pigments (eg, titanium dioxide, iron oxides) or certified lakes.
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Section 4

Question Answer
what is the purpose of polishing in sugar coating?elegance since they are dull after color coating
what is the polish composed of and what is it dispensed in?• Mixtures of waxes (beeswax, camauba wax, candelila wax or hard paraffin) in a polishing pan are applied to the tablets as powders or as dispersions in organic solvents.
what is the purpose of printing?for identification purposes
when is printing done?before and after polishing
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Section 5

Question Answer
thin film deposited onto surface of substratefilm coating
what is film coating applicable to?tablets, powders, granule, nonpareils, and capsules.
how is film coating applied?continuously by spraying the coating liquid onto a moving mass of product.
why was the film coating technique introduced in the 1950's?because ofthe shortcomings of the sugar coating process that was predominantly used.
what are the five advantages of film coating?1.• Minimal weight increase (usually 2-3% of tablet core weight). 2.• Much shorter processing time. 3.• Increased process efficiency and output. 4. • Increased flexibility in formulations. 5. • Improved resistance to chipping of the coat.
• In the early years of film coating, ________________ solvents were used to enhance evaporation and decrease processing time.volatile organic solvents
• Due to significant improvements in the equipment technology, _______________coating liquids are used nowadays.water-based coating
What has replaced conventional pans which are faster at drying?side-vented pans and fluid-bed equipment
what are the materials used in film coating?• Polymer, plasticizer, colorant, and vehicle.
Each white to off-white, oval, film-coated FACTIVE tablet has breaklines and GE 320 debossed on both faces and contains?gemifloxacin mesylate equivalent to 320 mg gemifloxacin
the inactive ingredients in film coating are?crospovidone, hydroxypropyl methylcellulose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, povidone, and titanium dioxide.
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Section 6

Question Answer
the film coating polymer should be?soluble in a variety of solvents and capable of forming coatings with suitable mechanical properties.
the polymer must dissolve in the ?GI fluids to allow release of the drug.
Cellulose ethers, especially ________________________are preferred in film coating.hydroxypropyl methylcellulose
what are the less preferred cellose eithers of film coating?hydroxypropyl cellulose and methycellulose
what are the alternatives to cellulose ethers in film coating?acrylic copolymers and vinyl polymers (eg, polyvinyl alcohol.
how are polymers applied?as solutions in water or organic solvents
what is in the coating formulation to improve flexibility of the film and its adhesion to the substrate?a plasticizer
Typical plasticizers include glycerin, propylene glycol, polyethylene glycols, citrate esters (eg, triethyl citrate), or phthalate esters (eg, diethyl phthalate).
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Section 7

Question Answer
Colorants are used to improve appearance and to help with identification of the product.
Colorants can be composed of?water-soluble dyes (not used in organic solvents) or certified lakes, particularly aluminum lakes
• Typical film-coating formulations contain ______% w/w coating solids in the requisite vehicle 5-20%
what concentration is preferred in the case of aqueous formulations?the higher concentrations
__________% of the total solid is polymer. _______%is plasticizer and __________% is pigment60-70%=polymer 6-7%=plasticizer 20-30%=pigment
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