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Unformatted text preview: University of Wyoming PHCY 6100 Solid Dosage Forms: TABLETS
1. Def. Solid dosage forms prepared by compression or molding of powdered/granulated
drugs and with the aid of suitable pharmaceutical excipients. 2. Characteristics: a) Most frequently prescribed commercial dosage form
b) Stable, elegant and effective
c) Convenient for handling, identification and administration
d) Commercially available only in fixed dosage strengths
e) Many formats (e.g. Valium® is triangular), sizes, colors, shapes (flat, convex), scored in
halves, with elegant engravings, etc (determined by the format of die and punch used, by
the amount of fill and amount of pressure applied to the fill).
3. Types a) Compressed Tablets: to be swallowed, made by single compression of all ingredients.
b) Multiple Compressed Tablets: for separation of incompatible drugs or for modified release.
Multiple-layered tablets: multiple feed and multiple compression of fill within a single
Tablet-within-a-tablet: core tablet is placed precisely within the die for compression with
c) Sugar-coated tablets:
Several layers of colored or uncolored sugar solution (sucrose, gelatin, acacia or
Time and expertise
Final tablet may have an increase of up to 50 % of size and weight of uncoated tablet.
Imprinting _ FDA 1995_ product-specific identification codes and distinctive symbols.
Polishing: cloth or canvas impregnated with carnauba wax or beeswax or spraying with
wax dissolved in acetone.
Final tumbling with talc for high luster.
d) Film-coated tablets:
Thin layer of aqueous or non-aqueous polymer solution (plastic-like material): cellulose
acetate phthalate; cellulose ether polymers.
Protection, color, durability, less bulkiness, less time consuming.
e) Gelatin-coated: capsule-shaped compressed tablet (caplets)
f) Enteric coated tablets:
Applied to whole tablet or to drug particles or granules: single or multiple layers
Materials: shellac, phthalate derivatives 1 University of Wyoming PHCY 6100 Protection of drug, patient gastric mucosa, or enhanced absorption.
Based on transit time required for the passage of the dosage form from the stomach
into the intestines or based upon the pH of environment.
g) Buccal Tablets: placed in the cheek pouch, dissolve slowly, absorption through the oral
h) Sublingual Tablets: placed under the tongue, prompt dissolution, absorption through the
i) Lozenges, Troches, Drops or Pastilles: tablets, hard sugar candy-like or gummy-like solid
forms, dissolve or disintegrate slowly in the oral cavity, high degree of compression; heat
stable active ingredients; usually for local effects.
j) Lollipops: sugar-based lozenge on a stick; Fentanyl Actiq to relieve breakthrough chronic
k) Chewable Tablets: chewed/dissolved in the mouth, made with creamy base (mannitol,
sorbitol, xylitol = sugar-free), negative heat of solution and cool mouth feel upon
dissolution; flavored and colored; children & adults who have difficulty swallowing.
l) Effervescent Tablets: compression of effervescent salts that liberate carbon dioxide when
dissolved in water, should NOT be swallowed whole.
m) Molded tablets: molding and soft compaction; hand-operated tablet press.
n) Tablets Triturates: “old fashioned” tablets containing small amounts of potent drugs and
prepared with minimal compression to allow ease of crushing for compounding or rapid
o) Rapid Dissolving Tablets (RDT): dissolution within 15-30 sec. and swallowing of the liquid;
very water-soluble excipients that attract water into the tablet; children and elderly;
inherent problems: drug loading, taste masking and friability
Zydis technology = lyophilization (foaming of a mixture of gelatin, sugars, drug, etc and
pouring into a mold).
DuraSolv, OraSolv, Flashtab, Wowtab technologies = compression (super-disintegrants
+ small quantity of effervescent material).
p) Extended-release Tablets: release of medication in a pre-determined manner over an
q) Vaginal Tablets: = or inserts; uncoated, bullet-shaped or ovoid; plastic inserter devices;
4. Quality Control for compressed tablets: defined by the U.S.P. a) WEIGHT: determined by the quantity of fill in the die of tablet press.
Weight variation for dosage form uniformity: 10 tabs, individual and average weight
Assay for homogeneous drug distribution.
b) CONTENT UNIFORMITY: 10 tabs; active ingredient is between 85-115% ± 6%. 2 University of Wyoming PHCY 6100 c) THICKNESS: measured through a caliper, a hand gauge or automated equipment; depends
Diameter of the die
Amount of fill
Compaction characteristic of fill
d) HARDNESS, BREAKING STRENGTH or FRIABILITY:
Measurement of pressure/force (in Lb or Kg) required to break each tablet;
Depends on type of tablet and degree of compression used during manufacture.
Friabilator: measures the tendency of a tablet to crumble (rotating tumbling container).
Tablets are weighed before and after rotation and weight loss is determined (maximum
loss allowed by USP is 1%).
e) DISINTEGRATION: time required for a tablet to disintegrate when placed in an apparatus
containing water at 37°C (usually 30 min for compressed tabs) or simulated gastric fluid (1
hr) + intestinal fluid (for enteric-coated tabs).
In vitro testing
Quality assurance during manufacturing
Bioequivalence from batch to batch: scale-up batches
Mandatory for approval of marketing: FDA and regulatory agencies of other countries.
Influences the absorption and bioavailability.
5. Preparation of Tablets (compressed) a) WET GRANULATION
Powdered ingredients (drugs + fillers + disintegrating agents + glidants + other
excipients) are weighed and blended
Sifted (to eliminate clumps)
Mixed with a liquid binder or adhesive mixture (10-20% aqueous solution of cornstarch,
25-50% sol. of glucose, molasses, gums such as acacia, sol. of cellulose derivatives,
Pass through screen (#6-8 mesh size)= granules or pellets.
Drying in thermostatically controlled oven.
Sizing by dry screening (#12-20 mesh)
Granules + dry lubricant (Mg/Ca/Zn Stearate, talc, stearic acid) = blending
Compression in tableting machine 3 University of Wyoming PHCY 6100 (i) Single-punch tablet press (ii) Rotary tablet machine with multiple punches: high speed production _ lamination
and capping ALL-IN-ONE-GRANULATION METHOD: sophisticated machinery; preparation of
granulation is by Fluid-bed process or Microwave vacuum process.
b) DRY GRANULATION
For materials that are degraded in presence of moisture or high heat.
Weighing of powdered ingredients (drugs + fillers + disintegrating agents, etc),
blending, cohesive properties
Powders are compressed in slugging machine or roller compaction (binding agents:
methylcellulose or hydroxyl-methylcellulose at 6-12%)
Flat “slugs” or pellets
Slugs are crushed (mill) and sized (screen)
Granules + dry lubricant (Mg/Ca/Zn Stearate, talc)
Compression in tableting machine
c) DIRECT COMPRESSION
Excipients have free-flowing and cohesive properties: Potassium chloride, Methenamine,
Dibasic calcium phosphate.
d) MOLDING: involves forcing a dampened mass into the cavities of a tablet mold (plastic or
metal) consisting of two plates, one with holes and the other with pegs.
6. Tablet dedusting: to remove loose powder; elegance; prior to coating. 7. Tablet Coating:
For compressed tablets
For protection of drug from air and humidity
To protect gastric mucosa of irritating drugs
To mask taste,
For especial release of drug (enteric coated)
To provide aesthetics and distinction to a product (color, imprinting of manufacturer’s
symbol or information).
(i) SUGAR COATING (ii) FILM COATING (iii) ENTERIC COATING 4 University of Wyoming 8. PHCY 6100 Packaging and Storage a) Containers: bottles, blister
c) Desiccant packet x cotton ball
d) Reduced potency of volatile drugs: nitroglycerin (glass container and no packing materials
in contact with tabs). 5 ...
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- Fall '10