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Tablets Presentation Transcript

  • 1. Tablets TABLE TS By Wilwin
  • 2. scope Introduction Types Of tablets Advantages and Disadvantages Formulation additives Tablet compression Processing Problems Evaluation Of tablets References
  • 3. Introduction In 1843, a patent was granted to Thomas Brockedon (Englishman) for manufacturing pills and lozenges. 1980 nearly 300 monographs for tablets. Over 2/3rd dosage forms are tablets. Def: Tablets are flat or biconvex discs of unit dosage forms containing one or more active ingredients, compressed along with necessary additives.
  • 4. Types of tablets Tablets Ingested Orally: Compressed Tablets Or Standard Compressed Tablets. • Both type of action – systemic effect and local effect. •Rapid disintegration and drug release •Mostly Antacids and adsorbents. Multiple Compressed Tablets: For incompatible components these are: (1)Layered Tablets: • either two layered (for two components) or three layered (for three components) tablet.
  • 5. Tablets Ingested Orally (2)Compressed coated Type: •Compressed coated type- either tablet within a tablet or tablet within a tablet within a tablet. Tablet in this category are usually prepared for two reasons •1. To separate physically or chemically incompatible ingredients. •2. To produce repeat action or prolong action product. Compression coated tablets
  • 6. Tablets Ingested Orally Repeat Action Tablets :Sugar coated or multiple compressed tablets are usually coated with shellac or an enteric polymer so that it will not release its drug in stomach but intestine. Delayed Action And enteric coated Tablets Delayed action tablets are intended to release the drug after some time delay or after passing the drug through the GIT. Enteric coatings are applied mainly for drugs that are irritating. Sugar coated tablet: Primary role is to produce an elegant, glossy, easy to swallow, widely utilized in preparing multivitamin tablets. Sugar coating doubled the tablet weight. Now polymers are used with sugar solution.
  • 7. Tablets Ingested Orally Film Coated Tablets •Advantage of film coated over sugar coated tablets is better mechanical strength and flexibility of the coating, little increase in tablet weight. •These are developed as an alternative procedure to the preparation of coated tablets in which the drug is not required for coating. Chewable Tablets •Easily administered for infants and elderly persons •These are intended to be chewed in the mouth before swallowing. Used for large tablet of antacid, bitter or foul testing drugs are not suitable for this type tablet.
  • 8.  Tablets Used In Oral Cavity Buccal And Sublingual Tablets •Drugs used by this route are for quick systematic action. The tablets are designed not to be disintegrate but slowly dissolve. •Troches And Lozenges These are mainly for treating soar throat and to control coughing in common cold. •Dental Cones These are designed to place in the empty socket after tooth extraction.  Tablets Administered By Other Routes •Implantation tablets To provide prolonged drug effects. used for administration of growth hormone to food producing animal. •Vaginal Tablets These are designed to undergo slow dissolution and drug release in vaginal cavity.
  • 9.  Tablets Used To Prepare Solutions • Effervescent Tablets Tablets are designed to produce a solution rapidly with the release of carbon dioxide. • Dispensing tablets Tablets are intended to be added to a given volume of water to produce a solution of a given drug concentration. • Hypodermic tablets These tablets are composed of one or more drugs with water-soluble ingredients. Drug is added to sterile water to prepare sterile solution, which is injectable.
  • 10. Advantages  Production aspect – Large scale production at lowest cost – Easiest and cheapest to package and ship – High stability  User aspect (doctor, pharmacist, patient) – Easy to handling – Lightest and most compact – Greatest dose precision & least content variability – Coating can mark unpleasant tastes & improve pt. acceptability
  • 11. Disadvantages  Some drugs resist compression into dense compacts.  Drugs with poor wetting, slow dissolution, intermediate to large dosages may be difficult or impossible to formulate and manufacture as a tablet that provide adequate or full drug bioavailability.  Bitter taste drugs, drugs with an objectionable odor, or sensitive to oxygen or moisture may require encapsulation or entrapment prior to compression or the tablets may require coating.  Difficult to swallow in case of children and unconscious patients.
  • 12. Ingredients used in tablet formulations Drugs (API) Diluents: Diluents are fillers used to make required bulk of the tablet when the drug dosage itself is inadequate to produce the bulk. Properties Of diluents: •They must be non toxic & physiologically inert. •They must be free from all microbial contamination. •They do not alter the bioavailability of drug. Commonly used tablet diluents Lactose-(anhydrous), spray dried lactose ,Directly compressed starch-Sta Rx 1500,Dicalcium Phosphate dihydrate ,e.t.c.,
  • 13.  Binders and Adhesives: These materials are added either dry or in wet- form to form granules or to form cohesive compacts for directly compressed tablet. Example: Acacia, tragacanth, Cellulose derivatives-Methyl cellulose, Hydroxy propyl methyl cellulose, Hydroxy propyl cellulose, Starch paste,e. t.c.,  Disintegrants To promote breakup of the tablets To promote rapid release of the drug Example: Starch- 5-20% of tablet weight, Starch derivative – Primogel and Explotab (1-8%) , Cellulose derivatives .  Lubricants – To reduce the friction during tablet ejection between the walls of the tablet and the walls of the die cavity Example: Stearic acid, Magnesium stearate, Talc, PEG (Polyethylene glycols), Surfactants
  • 14. • Glidants – Reducing friction between the particles – To improve the flow properties of the granulations Example: - Corn Starch – 5-10% conc., Talc-5% conc., Silica derivative - Colloidal silicas such as Cab-O-Sil, Syloid, Aerosil in 0.25-3% conc. • Antiadherants – To prevent adherence of the granules to the punch faces and dies. Examples:-Talc ,corn starch ,metallic steroids.
  • 15. ORGANOLEPTIC AGENTS Sweetening Agents: Sugar, mannitol. Saccharine (artificial): 500 time’s sweeter than sucrose Coloring agents: The use of colors and dyes in a tablet has three purposes: •Masking of off color drugs •Product Identification •Production of more elegant product Example: FD & C yellow 6-sunset yellow ,FD & C yellow 5- Tartrazine Flavoring agents: •These are mostly used in Chewable Tablets •E.g. Flavor oils
  • 16. Tablet production Granulation Properties: Particle size & shape: Particle size of granulation affect the average tablet weight, weight variation, disintegration time, friability, granule flow ability. Surface area: Dissolution of a drug depends on surface area of powder materials or granules. Density: Granule density may influence compressibility, tablet porosity, dissolution and other properties.
  • 17.  Strength & Friability: Granules are aggregation of component particles that is held together by bonds of infinite strength. Friability is the ability to formation of fines or fragments.  Flow properties: For the movement of granules from hopper to die cavity sufficient flow properties are essential.  Angle of repose: It is maximum angle between the surface of a pile of powder and horizontal plane. Angle of Repose≤ 30 → Free flowing material Angle of Repose ≥ 40 → Poorly flowing material  Hopper Flow rate: Granules are allowed to flow from the conical hopper onto a recording balance device and dw/dt is calculated .
  • 18. Tableting methods • Wet methods – Wet granulation • Dry methods – Dry granulation – Direct compression
  • 19. WET GRANULATION: Raw materials → Weighing → Screening → Wet massing → Wet Sieving/Milling → Drying → Dry Screening → Mixing → Compression  The powder mass is wetted with the binding solution until the mass has the consistency of damp snow.  If the granulation is over wetted the granules will be hard, if not wetted sufficiently, the resulting granules will be too soft, breaking down during lubrication.  The wet mass is forced through a suitable sieve.  Moist materials from wet milling steps is placed on large trays and placed in drying chambers.  After drying granulation, the lubricant or glidants are added as fine powder to promote flow of granules.  These granules then compressed to get tablet.
  • 20. DRY GRANULATION:  Raw material → weighing → Screen → Mixing → Slugging → Milling → Screening → Mixing → Compression  Compression granulation involves the compaction of the components of a tablet formulation by means of flat punch. These compact masses are called slug and the process is called slugging.  Slugs are then milled and screened to produce a granular form. DIRECT COMPRESSION:  Raw material → Weighing → Screening → Mixing →Compression.  This method is applicable for crystalline chemicals having good compressible characteristics and flow properties such as: Potassium salt (chlorate, chloride, bromide), Sodium chloride, Ammonium chloride, Methenamine etc.  Tablets are compressed directly from powder blends of the active ingredient and suitable excipients  No pretreatment of the powder blends by wet or dry granulation procedures is necessary.
  • 21. A comparative processing chart of dif ferent granulation techniques
  • 23. TABLET COMPRESSION Compression: Compression is the process of applying pressure to a material with the help of a Tablet punching machine.  Transitional repacking/particle rearrangement  Deformation at point of contact  Fragmentation and deformation  Bonding • Mechanical Theory • Inter molecular theory • Liquid –Surface film Theory  Decompression  Ejection
  • 24. Single punch machine  The compression is applied by the upper punch making the single punch machine a “stamping press.”
  • 25. Multi-station rotary presses • The head of the tablet machine holds the upper punches, dies and lower punches in place rotates • As the head rotates, the punches are guided up and down by fixed cam tracks, which control the sequence of filling, compression and ejection. • The portions of the head that hold the upper and lower punches are called the upper and lower turrets. • The portion holding the dies is called the die table • The pull down cam (C) guides the lower punches to the bottom, allowing the dies to overfill. • The punches then pass over a weight-control cam (E), which reduces the fill in the dies to the desired amount.
  • 26. • A swipe off blade (D) at the end of the feed frame removes the excess granulation and directs it around the turret and back into the front of the feed frame. • The lower punches travel over the lower compression roll (F) while simultaneously the upper punches ride beneath the upper compression roll (G). • The upper punches enter a fixed distance into the dies, while the lower punches are raised to squeeze and compact the granulation within the dies. • After the moment of compression, the upper punches are withdrawn as they follow the upper punch raising cam (H). • The lower punches ride up the cam (I) which brings the tablets flush with or slightly above the surface of the dies. • The tablets strike a sweep off blade affixed to the front of the feed frame (A) and slide down a chute into a receptacle. • At the same time, the lower punches re-enter the pull down cam (C) and the cycle is repeated.
  • 27. Single punch tablet machine (left) & 16 station rotary tablet machine(R)
  • 28. Processing Problems • Capping & Lamination: Complete or partial loss of top and bottom crowns of a tablet from the main body is called capping. • The separation of a tablet into two or more distinct layers is called lamination. Causes: Air entrapment , Deep concave punch ,Incorrect setting of the press , Compression of too dry material . Remedy: By precompression ,Slowing Tableting ,Reducing final compression force , Using flat punch ,Using hygroscopic materials to maintain proper moisture level eg. - PEG-4000 and Methyl Cellulose lamination. capping.
  • 29. • Picking & Sticking: Surface materials from a tablet that is sticking to the punch and being removed from the tablet surface is picking. Sticking refers to tablet materials adhering to the die wall. Causes: Picking occurs when punch tips are engraving or embossing. Small enclosed areas in letters A. • Mottling: It is an unequal distribution of colors on a tablet with light and dark areas on tablet surface. Cause: 1. Use of a drug whose color differs from tablet excipients 2. Use of a drug whose dehydration products are colored Remedy: 1. The use of colorant 2. Disperse a dry colour additive during powder binding steps.
  • 30. • Weight Variation: Variation of tablet weight also causes variation of active medicament which change the bioavailability. Cause: (a) Granule size & size distribution: Variations in the ratio of small to large granules and difference in granule size determine the void space between particles are filled. (b) Poor Flow: The die fill process in based on a continuous and uniform flow of granules from the hopper through the feed frame. Bridging (1) Arching or Bridging: Granules separate at the neck of the hopper and flow stops completely.. Rat holling (2) Rat Holling: In this case particles segregate near the wall of the hopper and at the centre flow continues forming hole. In rat holling flow rate decreases. Addition of glidant can overcome these problems.
  • 31. (c) Punch Variation: When length of lower punches is unequal, the fill in each die varies which causes weight variations of tablet. (d) Poor Mixing: Some times lubricants and glidants are not thoroughly distributed. The flow of particles then impaired and the granules do not move efficiently into the dies. • Hardness Variation: Hardness depends on the weight of materials and space between upper and lower punch at the moment of compression. • Double Impression: This involves only punches that have monogram or engraving. If the monogram present in upper punch, slight rotation of punch after precompression produce double impression and vice versa.
  • 32. Evaluation of Tablet 1.GENERAL APPEARANCE: The general appearance of a tablet, its identity and general elegance is essential for consumer acceptance. The control of general appearance involves the measurement of size, shape, colour, presence or absence of odour, taste etc. Size & Shape: Tablet thickness can be measured by micrometer or by other device. Tablet thickness should be controlled within a ± 5% variation of standard value. Unique identification marking: These marking utilize some form of embossing, engraving or printing. These markings include company name or symbol, product code, product name etc. Organoleptic properties: Color distribution must be uniform with no mottling. For visual color comparison compare the color of sample against standard color. • The presence of odour in a batch of tablet indicates a stability problem Presence of odour could be characteristic of the drug (Vitamin), added ingredients (flavouring agent).
  • 33. 2.Weight variation test: weigh randomly 20 tablets individually in a batch. Determine the average weight of 20 tablets. Compare individual tablet weight to average weight • As per I.P. ,  If the tablet weight is, < 80mg , % deviation allowed up to 10% > 80mg , % deviation allowed up to 7.5% > 250mg , % deviation allowed up to 5% If any of the tablet from the batch deviates from the above specifications, another 10 tablets are selected from the same batch and the procedure is repeated. Of 30 tablets , not more than 1 tablet should deviate.
  • 34. 3.Content uniformity test: It is used to ensure that every tablet contains the amount of drug substance intended with little variation. Procedure: o 10 tablets are assayed, o 9 tablets should have % limit of 85-115%. o If more than 1 tablet deviates from 85-115%, o 20 tablets are assayed o Not more than 1 tablet should have the % limit of 75-125% 4. Hardness test: • It is defined as the force required to break a tablet in a diametric compression test. Tablet requires a certain amount of strength or hardness and resistance to friability to withstand mechanical shocks of handling in manufacture, packaging and shipping
  • 35. . Types of hardness testers are used. 1. Monsanto hardness tester . 2. Strong cob tester. 3. Pfizer tester. •. For, Conventional tablets hardness : 2.5- 5 kg/cm2 Dispersible/ chewable tablets hardness: 2.25- 2.5 kg/cm2 Extended release tablets hardness : 5- 7.5 kg/cm2 5. Friability test: •. The instrument used is Roche friabilator. •. It consists of a acrylic drum having 280-290mm diameter with a thickness of 30mm. Acrylic drum is mounted on a horizontal axis of a drive motor. •. Drum is operated at a speed of 25rpm.&Allowed revolutions for each tablet is 100. •. Allowable range: loss 0.5 - 1% weight hardness tester
  • 36. Disintegration test: Disintegration is the breakdown of tablet crust in to finely divided particulate matter or into granules once the tablet is exposed to the gastric fluids . Type of tablets uncoated conventional tablets 15min sugar coated tablets 60 min. film coated tablets • Time Of disintegration 30 min For enteric coated tablets: Disintegration fluid for first 2hrs- 0.1NHcl. After 2hrs, replace with 6.8pH phosphate buffer Disintegration time – 60 min .
  • 37. • For dispersible tablets: Temperature – 22-240c Disintegration time < 5min. Uniformity of dispersion: place 2 tablets in 100ml of water and stirr gently .the tablet should undergo dispersion within 5 min, which should pass through a sieve screen of 22 mesh. • For effervescent tablets: Temperature- 200-300c Place one tablet in a 250ml beaker containing water, numerous gas bubbles are evolved. Disintegration time- 3min.
  • 38. Dissolution Test (U.S.P.): It is the solubilization of the drug or active moiety in to the dissolution media. Different types of dissolution apparatus: Apparatus -I-Rotating Basket type. Apparatus -II- Rotating Paddle type. Apparatus-3-Reciprocating cylindrical type. Apparatus-4-Flow through cell. Apparatus-5-Paddle over disk. Apparatus-6-Cylindrical apparatus. Apparatus-7-Reciprocating disc apparatus.
  • 39. • Procedure: Acceptance criteria: S1= 6 tablets are taken S2=S1+6 tablets are taken Acceptable: If all of the Acceptable: If average of 12 tablets are not less than tablets is ≥Q and no tablet is Q ±5% less than Q-15% If S1 fails If S2 fails S3= 12+12 tablets are taken Average of 24 ≥ Q% not more than 2 tablets should be less than Q-15% and None should be less than Q-25%
  • 40.  The theory and practice of Industrial pharmacy, by Leon Lachmann and Herbert .A.Lieberman,3rd edition. Page no: 294 to 336.  Pharmaceutical dosage forms tablet volume-1 edited by Herbert A.Liberman, Leon Lachman, and Joseph B. Schwartz, page no:88 to 121.  Pharmaceutical dosage forms tablet volume-2 edited by Herbert A.Liberman, Leon Lachman, and Joseph B. Schwartz, page no :201 to 211  Indian pharmacopoeia 2010 vol-2, page No: 751 to 754  The science and practice of pharmacy by Remington Volume I -905 to 916.   www.wikipidia .com