TABLETS Flashcards
What are Tablets?
1) Solid dosage forms containing medicinal substances prepared with the aid of suitable excipients
2) May vary in characteristics based on intended use and method of manufacture
advantages of tablets
1) Accurate dosage/minimum variability
2) Absence of alcohol
3) Concentration variability
4) Elegance
5) Patient acceptance
6) Convenience (light and compact)
7) Tamper resistant
8) Low cost
9) Easiest/cheapest to package and ship
10) Production identification
11) Ease of administration
12) Special release profiles possible
13) Suited for large-scale production
Tablet Disadvantages
1) Difficult to extemporaneously prepare
2) Difficult for some patients to swallow
3) Some drugs resist compression
4) Difficulty to formulate some agents - poorly wetting drugs, slow-dissolving drugs, intermediate to large dosages
Types of Tablets
Compressed Multiple Compressed Sugar-coated Film-coated Gelatin-Coated Enteric-Coated Buccal and Sublingual Chewable Effervescent Molded/Triturates Immediate Release Rapidly Disintegrating or Dissolving Extended Release Vaginal Tablets Hypodermic Dispensing
Multiple Compressed Tablets (Layered tablets)
1) Prepared by subjecting the powder blend to multiple compression operations
2) The result may be a multiple-layer tablet or a tablet within a tablet, the inner tablet being the core and the outer portion being the shell
What are Sugar-Coated Tablets ?
Disadvantage?
1) Water soluble sugar coating that dissolves quickly after swallowing
2) Protects drug from environment and masks objectionable tastes or odors
3) Disadvantages: increases the weight and size of tablet
What are Film-Coated Tablets? What are features?
1) compressed tablets coated with a thin layer of a polymer capable of forming a skin-like film
2) usually colored and usually more durable, less bulky, and easier to apply than sugar-coat
3) Ruptures and exposes content at desired location in the GIT
Gelatin-Coated Tablets
1) gelcap: is a capsule-shaped compressed tablet that allows the coated product to be about one-third smaller than a capsule filled with an equivalent amount of powder
2) Gelatin coating facilitates swallowing
3) more tamper evident than unsealed capsules
Enteric-Coated Tablets
1) Delayed-release properties
2) Designed to pass unchanged through the stomach to the intestines
3) Useful when the drug substance is destroyed by gastric acid or is particularly irritating to the gastric mucosa or when bypass of the stomach substantially enhances drug absorption
Buccal and Sublingual Tablets
1) Buccal – tabletsintended to erode slowly in the buccal pouch
2) Sublingual – tablets intended to dissolve quickly under the tongue
3) Enhance oral absorption of drugs destroyed by gastric fluids and/or poorly absorbed from the GIT
4) Lozenges
Chewable Tablets
1) rapid disintegration when chewed or allowed to dissolve in the mouth
2) have a creamy base, usually of specially flavored and colored mannitol
3) useful for administration of large tablets to children and adults who have difficulty swallowing solid dosage forms
Effervescent Tablets
1) Prepared by compression of granular effervescent salts that release gas when in contact with water.
2) bubble action” can assist in breaking up the tablets and enhancing the dissolution of the active drug
Molded Tablets/Tablet Triturates
1) Molded – Softsoluble tablets designed for rapid dissolution that are prepared by molding instead of compression
2) Tablet triturates – small, usually cylindrical, molded, or compressed tablets containing small amounts of usually potent drugs ( minimal amount of pressure is applied)
Immediate-Release Tablets
Disintegrate and release the active ingredient with no special rate-controlling features, such as special coatings and other techniques
What are Rapidly Disintegrating or Dissolving Tablets ( Rapid release tablets) and disadvantage?
1) Disintegrated or dissolve to release active ingredient in the mouth rapidly – within 1 minute
2) Might be prepared using lyophilization or direct compression
3) Water-soluble excipients wick water into the tablet for rapid disintegration or dissolution
4) Disadvantages: drug loading, taste masking, friability, manufacturing costs, and stability of the product
5) Making it more firm and less friable may increase dissolution time. A balance generally must be achieved between friability and the speed of dissolution.
Extended-Release Tablets
1) Release the active ingredient in a predetermined manner over an extended period
2) Also called controlled-release
Vaginal Tablets
1) Uncoated, bullet-shaped, or ovoid tablets inserted into the vagina for local effects
2) Prepared by compression and shaped to fit snugly on plastic inserter devices that accompany the product
3) Also called vaginal inserts
Hypodermic and Dispensing Tablets
1) No longer in use in the US
2) Hypodermic tablets were used in the extemporaneous preparation of parenteral solutions
3) Dispensing tablets ( compounding tablets) contained large amounts of highly potent substances that the pharmacist could quickly obtain premeasured amounts for compounding
Compressed Tablets
1) Solid dosage forms prepared with suitable excipients and tablet machines capable of exerting great pressure in compacting the powdered or granulated material
2) Tablet diameters and shapes are determined by the die and punches used in compression
Diluents or Fillers
Add the necessary bulk to a formulation to prepare tablets of the desired size
Diluents or Fillers examples
Dibasic calcium phosphate Lactose Sucrose Mannitol Microcrystalline cellulose Powdered cellulose Starch
Binders or Adhesives
Promote adhesion of the particles
Binders or Adhesives examples
Acacia, Alginic acid, Carboxymethylcellulose, Gelatin, Liquid glucose
Methylcellulose, hydroxy methylcellulose, Povidone
Pregelatinized starch
Disintegrants
swell or expand on exposure to moisture
effect the rupture or breakup of the tablet in the gastrointestinal tract
Promote breakup of tablets after administration to smaller pieces for ready drug availability
Disintegrants examples
Microcrystalline cellulose
Sodium starch glycolate
Starch
Glidants
Improve powder flow
Colloidal silica, Cornstarch, Talc
Lubricants/Antiadherents
1) Reduce friction to punch/die during tablet compression and facilitate tablet ejection
2) Prevent tablet components from sticking to machinery during production
3) Reduce punch/die wear
4) Improve powder flow properties
Lubricants/Antiadherents examples
Calcium stearate Magnesium stearate Stearic acid Zinc stearate Talc
Preparation of Compressed Tablets
Wet Granulation
Dry Granulation
Direct Compression
Wet Granulation
Components mixed with granulating fluid, dried and milled to produce granules with good flow and compression properties