Direct Compression Of Tablet PDF

DIRECT COMPRESSION OF TABLET Pharmaceutics department Industrial pharmacy lab Introduction The most common method of drug delivery is the oral solid dosage form, of which tablet and capsules are predominate. Tablet are more widely accepted and used compared to capsules for a number of reaso...

DIRECT COMPRESSION OF TABLET Pharmaceutics department Industrial pharmacy lab Introduction The most common method of drug delivery is the oral solid dosage form, of which tablet and capsules are predominate. Tablet are more widely accepted and used compared to capsules for a number of reasons including cost, ease of handling and packaging, ease of identification and manufacturing efficiency. Tablets may be defined as solid unit pharmaceutical dosage forms containing medicaments with or without suitable excipients & prepared either by compression or molding. Tablets are prepared by the compression method and are hence called the “Compressed Tablets” usually circular in shape and may be flat or biconvex. Excipients: 1. Diluents, binders, glidents and lubricants to ensure efficient tableting; 2. Disintegrates: to promote tablet break up in the digestive tract; 3. Sweeteners or flavors: to enhance the taste; 4. Polymer coating: it is to applied to make the tablet smoother and easier to swallow, to control the release rate of the active ingredient, to make it more resistant to the environment. Methods of tablet compression Direct Compression Direct compression is the simplest and most economical method for the manufacturing of tablets because it require less processing steps than other techniques. Advantages of direct compression 1. Cost Effectiveness Economic due to fewer unit operations 2. Stability Direct compression is more suitable for moisture and heat sensitive APIs, since it eliminates wetting and drying steps and increases the stability of active ingredients by reducing detrimental effects. 3.Faster Dissolution The tablets prepared by direct compression disintegrate into API particles instead of granules that directly come into contact with dissolution fluid and exhibits comparatively faster dissolution. Disadvantages of direct compression 1.Segregation The dry state of the material during mixing may induce static charge and lead to segregation. This may lead to the problems like weight variation and content uniformity. 2. Cost Directly compressible excipients are products produced by special techniques, such as spray drying. Hence, the products are relatively costly than the respective raw materials. 3. A non compressible large-dose drug may present problems with direct compression, which are usually restricted to 30% of a DC formula. To facilitate compression could require an amount of diluent so large that the resultant tablet is costly and difficult to swallow. 4. Differences in particle size and bulk density between drug and diluent may result in poor content uniformity of the drug in the compressed tablet , this is of special concern with low dose drugs. Stages of powder compression Filling Stage: A powder mixture is added into the hopper which flows down into the fill tray whilst the lower punches are pulled downwards by the fill cam. The powder then falls into the die bores by gravity. On some tablet presses, a force feeder is used which moves the powder over the top of the die to fill the die bores more efficiently. compression stage: where both the upper and lower punches are brought together under high pressure to form a tablet. Both upper and lower punches move between two compression rollers which bring them together and compress the powder. Ejection of tablet : once tablet has been formed inside the die, The upper punch is lifted out of the die bore whilst the lower punch will go over the ejection cam and the tablet ejected. a. Filling of the die b. Repacking of powder and initial compaction, c. Maximum compaction, d. decompaction, e. The final tablet properties of ideal directly compressible adjuvants 1. High flowability and compressibility. 2. Inert and compatible 3. Particle size range should be close to the active ingredients. 4. High pressure hardness profile 5. High dilution potential Dilution potential can be defined as the amount of an active ingredient that can be satisfactorily compressed in to tablets with the given directly compressible excipient. A directly compressible adjuvant should have high dilution potential so that the final dosage form has a minimum possible weight. The dilution potential is influenced by the compressibility of the active pharmaceutical ingredient Examples on directly compressible diluents 1.Spray dried lactose: is one of the most widely used filler- binders for direct compaction, it is prepared by partial crystallization of lactose and then dried by spray drying keeping the level of moisture below 3%. Yellow discoloration occurs due to a reaction between amine compounds and spray-dried lactose. 2.Microcrystalline cellulose (Avicel)® it is a unique diluent There are two grades, PH 101 (powder) and PH 102 (granules). 3.Calcium hydrogen phosphate dihydrate (Emcompress)® May reduce the absorption of antibiotic product as tetracycline. Formulation of Aspirin Tablet Aspirin or acetylsalicylic acid is perhaps the most commonly used analgesic and antipyretic medication. Acetylsalicylic acid appears as odorless white crystals or crystalline powder with a slightly bitter taste. Aspirin 150 mg Maize starch 20 mg Microcrystalline cellulose 30 mg Talc 2 mg Prepare 10 tablets Procedure 1.Weigh all ingredients and mix them (except lubricant) in a bottle for 5 minutes. 2. Add lubricant and mix for 1 minute then compress. Sure, here is the quiz with answers based on the text about Direct Compression: 1 What is the simplest and most economical method for manufacturing tablets? ◦ Answer: Direct compression. 2 Why is direct compression considered cost-effective? ◦ Answer: It requires fewer unit operations. 3 How does direct compression benefit moisture and heat-sensitive APIs? ◦ Answer: It eliminates wetting and drying steps, increasing the stability of active ingredients by reducing detrimental effects. 4 What is one advantage of direct compression related to dissolution? ◦ Answer: Tablets prepared by direct compression disintegrate into API particles, leading to faster dissolution. 5 What problem can arise due to the dry state of materials during mixing in direct compression? ◦ Answer: It may induce static charge and lead to segregation, causing weight variation and content uniformity issues. 6 Why are directly compressible excipients relatively costly? ◦ Answer: They are produced by special techniques, such as spray drying. 7 What issue can a non-compressible large-dose drug present in direct compression? ◦ Answer: It may require a large amount of diluent, making the resultant tablet costly and difficult to swallow. 8 What percentage of a direct compression formula is usually restricted for non-compressible large-dose drugs? ◦ Answer: 30%. 9 How can differences in particle size and bulk density between drug and diluent affect the tablet? ◦ Answer: They may result in poor content uniformity of the drug in the compressed tablet. 10 What is one disadvantage of direct compression related to content uniformity? ◦ Answer: Differences in particle size and bulk density between drug and diluent can lead to poor content uniformity. 11 What is the impact of static charge during mixing in direct compression? ◦ Answer: It can lead to segregation of materials.