Tablets

• Pharmaceutical tablets


  A solid dosage form containing drug substance with or without suitable diluents and are prepared either by compression or molding
• Advantages of tablets


  • Production Aspect: Large-scale production at the lowest cost, High stability, Convenience in packaging, shipping, and dispensing
  • User Aspect: Greatest dose precision & least content variability, Portability, Ease of administration, Can provide control of drug release
• Disadvantages of tablets


  • Not all drugs are compressible, Drugs with poor wetting, slow dissolution, and intermediate to large dosages, Bitter taste drugs, drugs with an objectionable odor, or sensitivity to oxygen or moisture
• Types of tablets


  • Compressed Tablets
  • Molded Tablets
  • Coated Tablets
  • Multi-compressed Tablets
  • Sugarcoated Tablets
  • Film-coated Tablets
  • Enteric-coated Tablets
  • Buccal Tablets
  • Sublingual Tablets
  • Chewable Tablets
  • Effervescent Tablets
  • Tablet Triturates
  • Hypodermic Tablets
  • Dispensing Tablets
  • Controlled-Release Tablets
  • Vaginal Tablets
  • Immediate-Release (IR) Tablets
  • Rapidly Disintegrating Tablets
  • Extended-Release Tablets
• Compressed Tablets


  Formed by compression of powdered, crystalline, or granular materials by the application of high pressures, utilizing steel punches and die
• Molded Tablets


  Prepared by molding, soft and soluble, rapid dissolution
• Multi-compressed Tablets


  Examples: Compression-coated tablets, Layered tablet, Inlay tablets
• Buccal Tablets


  Flat, oval tablets intended to be dissolved in the buccal cavity, 4-6 hrs disintegration time
• Sublingual Tablets


  Placed under the tongue, used for its rapid action, goes directly to the systemic circulation, 5-10 mins disintegration time
• Chewable Tablets


  Chewed from the mouth, advisable for patients with difficulty swallowing, Mannitol is used as a sweetening agent and diluent due to its cooling effect
• Effervescent Tablets


  Released CO2 to enhance the solubility of the drug, Uncoated, contains NaHCO3, tartaric acid, citric acid

  
• Hypodermic Tablets


  Soft, readily soluble tablets, Dissolved in a suitable vehicle (water for injections) and administered by parenteral route, No longer available
• Dispensing Tablets

  For potent substances, An ingredient used to compound prescriptions, No longer used
• Vaginal Tablets

  Uncoated and bullet- or ovoid- shaped tablets for a localized effect, contain antibacterial (against Hemophilia vaginitis) and antifungals (against C. albicans)
• Sugarcoated Tablets

  Compressed tablets containing a sugar coating, Advantages: Mask taste, Protect the enclosed drug, Disadvantages: Adds weight (50%), Time-consuming, Requires expertise
• Film-coated Tablets

  Involves inactivation of thin plastics-like material on the tablet, Cellulose acetate phthalate, Advantages over SCT: Adds only 2% of the weight, Less time consume (1 layer), Not require expertise, More durable, less bulky
• Enteric-coated Tablets

  Tablets meant to disintegrate at the intestine (pH less than 4), Reasons: for greater absorption, prevent gastric irritation, offers protection for a drug destroyed by acid
• Immediate-Release (IR) Tablets

  Immediate disintegration and release of medication, No special rate-controlling features, such as special coatings and other techniques
• Rapidly Disintegrating Tablets

  Orally-dispersible tablets, quick disintegrating tablets, mouth dissolving tablets, fast-disintegrating tablets, fast-dissolving tablets, rapid-dissolving tablets, or porous tablets, When placed in the mouth, it will rapidly disintegrate, For patients who with difficulty swallowing
• Extended-Release Tablets


  Provides a prompt release of API followed by a gradual release of the remaining amount, Allows a reduction in dosing frequency from that necessitated by conventional dosage forms, such as a solution or an immediate-release dosage form
• Lozenges

  Disc/square-shaped solid dosage forms containing a medicinal agent and generally a flavoring substance in a hard candy or sugar base
• Implants


  Small tablet compressed without excipients, must be sterile, Example: contraceptives
• Diluents


  Increase the volume of a formulation to prepare tablets of the desired size, Examples: Lactose, Mannitol, Xylitol, Starch, sucrose, mannitol, xylitol, dicalcium phosphate, calcium sulfate, cellulose, kaolin, mannitol, sodium chloride, dry starch, and powdered sugar
• Binders


  Agents used to impart cohesive qualities to the powdered material to ensure the tablet remains intact after compression, as well as improving the free-flowing qualities by the formulation of granules of desired hardness and size
• Binder types


  • Natural Polymers: Starch, Pregelatinized starch, Gelatin, Alginic acid, Sodium alginate
  • Synthetic Polymers: PVP, Methylcellulose, HPMC, Polymethacrylates, Sodium CMC
  • Sugars: Glucose, Sucrose, Sorbitol
  • Natural Gums: Acacia gum, Xanthan gum, Tragacanth, Karaya gum, Guar gum
  • Miscellaneous: Polyethylene Glycol, Ethylcellulose, Waxes, Water, Alcohol
• Disintegrants


  Facilitates disintegration or breaking apart of tablets when in contact with body fluids, Examples: Starch, Pregelatinized starch, Sodium starch glycolate, Sodium CMC, Croscarmellose, Microcrystalline cellulose, PVP, Crospovidone, Clays (Magnesium aluminum silicate)
• Glidants and Lubricants


  Improve the flowability of tablet formulation, Prevent wear and tear on the tablet press, Classes: Glidants, Lubricants, Anti-adherents
• Powdered materials used in tablet formulation


  • Ensure tablet remains intact after compression
  • Improve free-flowing qualities by formulation of granules of desired hardness and size
• Types of polymers


  • Natural Polymers
  • Synthetic Polymers
• Tablet excipients


  • Sugars
  • Natural Gums
  • Miscellaneous
• Sugars


  • Glucose
  • Sucrose
  • Sorbitol
• Disintegrants


  • Facilitate disintegration or breaking apart of tablets when in contact with body fluids
• Glidants


  • Promote the flow of the tablet granulation or powder by reducing friction among particles
• Antiadherents


  • Reduce sticking or adhesion of the tablet granulation or powder to the faces of the punches or the die walls
• Lubricants


  • Reduce the friction that occurs between the walls of the tablet and the walls of the die cavity when the tablet is ejected, usually not more than 1%
• Glidants


  • Starch
  • Talc
  • Silicon dioxide
• Antiadherents


  • Talc
  • Most lubricants
• Sugar-coating solution


  • Liquid glucose
  • Sucrose
• Film-coating solution

  • Hydroxyethylcellulose
  • Hydroxylpropylcellulose
  • Hydroxypropylmethylcellulose
  • Methylcellulose (Methocel®)
  • Ethylcellulose (Ethocel®)
• Enteric-coating solution


  • Cellulose acetate phthalate
  • Shellac