Manufacturing Tabltes:tablets dosage form advantages and disadvantages

In the tablet-pressing process, it is important that all ingredients be dry, powdered, and of uniform grain size as much as possible. The main guideline in manufacture is to ensure that the appropriate amount of active ingredient is equal in each tablet so ingredients should be well-mixed. Compressed tablets are exerted to great pressure in order to compact the material. If a sufficiently homogenous mix of the components cannot be obtained with simple mixing, the ingredients must be granulated prior to compression to assure an even distribution of the active compound in the final tablet. Two basic techniques are used to prepare powders for granulation into a tablet: wet granulation and dry granulation.

Powders that can be mixed well do not require granulation and can be compressed into tablets through Direct Compression

Direct Compression
This method is used when a group of ingredients can be blended and placed in a tablet press to make a tablet without any of the ingredients having to be changed. This is not very common because many tablets have active pharamaceutical ingredients which will not allow for direct compression due to their concentration or the excipients used in formulation are not conducive to direct compression.

Granulation is the process of collecting particles together by creating bonds between them. There are several different methods of granulation. The most popular, which is used by over 70% of formulation in tablet manufacture is wet granulation. Dry granulation is another method used to form granules.

Wet granulation for tablets
Wet granulation is a process of using a liquid binder or adhesive to the power mixture. The amount of liquid can be properly managed, and overwetting will cause the granules to be too hard and underwetting will cause the granules to be too soft and friable. Aqueous solutions have the advantage of being safer to deal with than solvents.

Procedure of Wet Granulation for tablets
Step 1: Weighing and Blending - the active ingredient, filler, disintegration agents, are weighed and mixed.
Step 2: The wet granulate is prepared by adding the liquid binder/adhesive. Examples of binders/adhesives include aqueous preparations of cornstarch, natural gums such as acacia, cellulose derivatives such as methyl cellulose, CMC, gelatins, and povidone. Ingredients are placed within a granulator which helps ensure correct density of the composition.
Step 3: Screening the damp mass into pellets or granules
Step 4: Drying the granulation
Step 5: Dry screening: After the granules are dried, pass through a screen of smaller size than the one used for the wet mass to select granules of uniform size to allow even fill in the die cavity
Step 6: Lubrication- A dry lubricant, antiadherent and glidant are added to the granules either by dusting over the spread-out granules or by blending with the granules. Its reduces friction between the tablet and the walls of the die cavity. Antiadherent reduces sticking of the tablet to the die and punch.
Step 7: Tableting: Last step in which the tablet is fed into the die cavity and then compressed between a lower and an upper punch.
Water may be used as the liquid binder, but sometimes many actives are not compatible with water. Water mixed into the powder can form bonds between powder particles that are strong enough to lock them in together. However, once the water dries, the powders may fall apart and therefore might not be strong enough to create and hold a bond. Povidone also known as polyvinyl pyrrolidone (PVP) is one of the most commonly used pharmaceutical binders. PVP and a solvent are mixed with the powders to form a bond during the process, and the solvent evaporates. Once the solvent evaporates and powders have formed a densely held mass, then the granulation is milled which results in formation of granules

Dry granulation for tablets
Wet granulation is a process of using a liquid binder or adhesive to the power mixture. The amount of liquid can be properly managed, and overwetting will cause the granules to be too hard and underwetting will cause the granules to be too soft and friable. Aqueous solutions have the advantage of being safer to deal with than solvents.

Procedure of Wet Granulation for tablets
Step 1: Weighing and Blending - the active ingredient, filler, disintegration agents, are weighed and mixed.
Step 2: The wet granulate is prepared by adding the liquid binder/adhesive. Examples of binders/adhesives include aqueous preparations of cornstarch, natural gums such as acacia, cellulose derivatives such as methyl cellulose, CMC, gelatins, and povidone. Ingredients are placed within a granulator which helps ensure correct density of the composition.
Step 3: Screening the damp mass into pellets or granules
Step 4: Drying the granulation
Step 5: Dry screening: After the granules are dried, pass through a screen of smaller size than the one used for the wet mass to select granules of uniform size to allow even fill in the die cavity
Step 6: Lubrication- A dry lubricant, antiadherent and glidant are added to the granules either by dusting over the spread-out granules or by blending with the granules. Its reduces friction between the tablet and the walls of the die cavity. Antiadherent reduces sticking of the tablet to the die and punch.
Step 7: Tableting: Last step in which the tablet is fed into the die cavity and then compressed between a lower and an upper punch.
Water may be used as the liquid binder, but sometimes many actives are not compatible with water. Water mixed into the powder can form bonds between powder particles that are strong enough to lock them in together. However, once the water dries, the powders may fall apart and therefore might not be strong enough to create and hold a bond. Povidone also known as polyvinyl pyrrolidone (PVP) is one of the most commonly used pharmaceutical binders. PVP and a solvent are mixed with the powders to form a bond during the process, and the solvent evaporates. Once the solvent evaporates and powders have formed a densely held mass, then the granulation is milled which results in formation of granules


Dry granulation for tablets
This process is used when the product needed to be granulated may be sensitive to moisture and heat. Dry granulation can be conducted on a press using slugging tooling or on a roller compactor commonly referred to as a chilsonator. Dry granulation equipment offers a wide range of pressure and roll types to attain proper densification. However the process may require repeated compaction steps to attain the proper granule end point.

Process times are often reduced and equipment requirements are streamlined; therefore the cost is reduced. However, dry granulation often produces a higher percentage of fines or noncompacted products, which could compromise the quality or create yield problems for the tablet. It requires drugs or excipients with cohesive properties.


Some granular chemicals are suitable for direct compression (free flowing) e.g. potassium chloride.
Tableting excipients with good flow characteristics and compressibility allow for direct compression of a variety of drugs.

Fluidized bed granulation
It is a multiple step process performed in the same vessel to pre-heat, granulate and dry the powders. It is today a commonly used method in pharmaceuticals because it allows the individual company to more fully control the powder preparation process. It requires only one piece of machinery that mixes all the powders and granules on a bed of air.


Tablet Compaction SimulatorTablet formulations are designed and tested using a laboratory machine called a Tablet Compaction Simulator or Powder Compaction Simulator. This is a computer controlled device that can measure the punch positions, punch pressures, friction forces, die wall pressures, and sometimes the tablet internal temperature during the compaction event. Numerous experiments with small quantities of different mixtures can be performed to optimise a formulation. Mathematically corrected punch motions can be programmed to simulate any type and model of production tablet press. Small differences in production machine stiffness can change the strain rate during compaction by large amounts, affecting temperature and compaction behaviour. To simulate true production conditions in today's high speed tablet presses, modern Compaction Simulators are very powerful and strong.

Initial quantities of active pharmaceutical ingredients are very expensive to produce, and using a Compaction Simulator reduces the amount of powder required for development.

Load controlled tests are particularly useful for designing multi-layer tablets where layer interface conditions must be studied.

Test data recorded by the Simulators must meet the regulations for security, completeness and quality to support new or modified drug filings, and show that the designed manufacturing process is robust and reliable

Tablet coating: tablets dosage form advantages and disadvantages

Many tablets today are coated after being pressed. Although sugar-coating was popular in the past, the process has many drawbacks. Modern tablet coatings are polymer and polysaccharide based, with plasticizers and pigments included. Tablet coatings must be stable and strong enough to survive the handling of the tablet, must not make tablets stick together during the coating process, and must follow the fine contours of embossed characters or logos on tablets. Coatings can also facilitate printing on tablets, if required. Coatings are necessary for tablets that have an unpleasant taste, and a smoother finish makes large tablets easier to swallow. Tablet coatings are also useful to extend the shelf-life of components that are sensitive to moisture or oxidation. Opaque materials like titanium dioxide can protect light-sensitive actives from photodegradation. Special coatings (for example with pearlescent effects) can enhance brand recognition.

If the active ingredient of a tablet is sensitive to acid, or is irritant to the stomach lining, an enteric coating can be used, which is resistant to stomach acid and dissolves in the high pH of the intestines. Enteric coatings are also used for medicines that can be negatively affected by taking a long time to reach the small intestine where they are absorbed. Coatings are often chosen to control the rate of dissolution of the drug in the gastro-intestinal tract. Some drugs will be absorbed better at different points in the digestive system. If the highest percentage of absorption of a drug takes place in the stomach, a coating that dissolves quickly and easily in acid will be selected. If the rate of absorption is best in the large intestine or colon, then a coating that is acid resistant and dissolves slowly would be used to ensure it reached that point before dispersing. The area of the gastro-intestinal tract with the best absorption for any particular drug is usually determined by clinical trials.

This is the last stage in tablet formulation and it is done to protect the tablet from temperature and humidity constraints. It is also done to mask the taste, give it special characteristics, distinction to the product, and prevent inadvertent contact with the drug substance. The most common forms of tablet coating are sugar coating and film coating.

Coating is also performed for the following reasons:

Controlling site of drug release
Providing controlled, continuous release or reduce the frequency of drug dosing
Maintaining physical or chemical drug integrity
Enhancing product acceptance and appearance
Sugar coating is done by rolling the tablets in heavy syrup, in a similar process to candy making. It is done to give tablets an attractive appearance and to make pill-taking less unpleasant. However the process is tedious and time-consuming and it requires the expertise of highly skilled technician. It also adds a substantial amount of weight to the tablet which can create some problems in packaging and distribution.

In comparison to sugar coating, film coating is more durable, less bulky, and less time consuming. But it creates more difficulty in hiding tablet appearance. The purpose of this coating is to prevent dissolution of the tablet in the stomach, where the stomach acid may degrade the active ingredient, or where the time of passage may compromise its effectiveness, in favor of dissolution in the small intestine, where the active principle is better absorbed.this website http://www.tabletsdosageform.blogspot.com/ is dedicated for educting pharmaceuticle students
tablets dosage form advantages and disadvantages

Tablet presses:tablets dosage form advantages and disadvantages

Tablet presses, also called tableting machines, range from small, inexpensive bench-top models that make one tablet at a time (single-station presses), no more than a few thousand an hour, and with only around a half-ton pressure, to large, computerized, industrial models (multi-station rotary or eccentric presses) that can make hundreds of thousands to millions of tablets an hour with much greater pressure. Some tablet presses can make extremely large tablets, such as some of the toilet cleaning and deodorizing products or dishwasher soap. Others can make smaller tablets, from regular aspirin to some the size of a bb gun pellet. Tablet presses may also be used to form tablets out of a wide variety of materials, from powdered metals to cookie crumbs. The tablet press is an essential piece of machinery for any pharmaceutical and nutraceutical manufacturer.

Pill-splitters
It is sometimes necessary to split tablets into halves or quarters. Tablets are easier to break accurately if scored, but there are devices called pill-splitters which cut unscored and scored tablets. Tablets with special coatings (for example enteric coatings or controlled-release coatings) should not be broken before use, as this will expose the tablet core to the digestive juices, short-circuiting the intended delayed-release effect.this website http://www.tabletsdosageform.blogspot.com/ is dedicated for educting pharmaceuticle students
tablets dosage form advantages and disadvantages

Tablet Dosage form

Tablet Dosage Form: Tablets dosage form advantages and disadvantages

A tablet is usually a compressed preparation that contains:

5-10% of the drug (active substance);
80% of fillers, disintegrants, lubricants, glidants, and binders; and
10% of compounds which ensure easy disintegration, disaggregation, and dissolution of the tablet in the stomach or the intestine.
The disintegration time can be modified for a rapid effect or for sustained release.

Special coatings can make the tablet resistant to the stomach acids such that it only disintegrates in the duodenum as a result of enzyme action or alkaline pH.

Pills can be coated with sugar, varnish, or wax to diguise the taste.

Some tablets are designed with an osmotically active core, surrounded by an impermeable membrane with a pore in it. This allows the drug to percolate out from the tablet at a constant rate as the tablet moves through the digestive tract.

Why Clean Room Face Masks are Necessary within Critical Environments

While we strive to remain as clean and hygienic as possible, the truth of the matter is that human beings, by sheer nature, carry a plethora of contaminant sources on a daily basis. While we tend to build up immunity to the various germs that plague us, we are unfortunately incapable of fully preventing the spreading of these bacteria. Because we the people are a significantly prevalent source of contamination, clean room face masks have become a necessity in critical environments. Face masks have certainly evolved from when they were originally worn in medical facilities years and years ago. Today's clean room face masks have been properly designed to reduce germ dispersion through the mouth, and more specifically, to protect controlled environments from human contamination.
Clean room face masks tend to boast superior properties of filtration efficiency as well as comfort. Because many clean room workers and operators are required to wear their gear for extended durations of time, clean room face masks may be customized according to each individual's specific needs. The outer material of clean room face masks typically consists of fractured film, which is an ideal consistency for extremely critical environments. Ear-loops are often made with polyurethane because of its non-shedding properties. Additionally, the ear-loops are typically knitted so as to remain comfortable for long periods of wear. In another effort to enhance comfort and eradicate shedding, headbands are also often made with polyurethane.

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 Covering the head is often a complicated task because of our own needs as well as the needs of the particular environment that we will inhabit. It is important to make sure that no facial hair is exposed as it offers yet another way for contamination to enter a clean room. Although the primary goal of sporting a clean room face mask is to reduce the waste that we may bring into an area, it also serves to protect us from potentially hazardous chemicals or solutions. Being exposed to various chemicals does have the potential to trigger negative reactions within us. While different clean rooms boast different classifications, it is always better to be as cautious as possible so as not to contaminate anything within the space. Classifications are determined by the number of particles in the air allowed per cubic foot. Standards vary depending upon both the industry and the application, though it is usually safe to assume that intense preventative measures should be taken against any level of contamination whenever possible.

Ideal for use in pharmaceutical, medical, and biotechnological environments among many others, clean room face masks help to reduce the amount of contamination within an environment and thus inevitably lessen the number of product recalls that can occur within these industries. Government agencies demand strict guidelines for all of their projects and plans, thus clean room face masks are essential when operating within these sites as well.

Although clean room face masks are a crucial contamination control product, there are a variety of other products that must be implemented and used simultaneously in order to maintain the levels of cleanliness demanded by most critical environments. Clean room equipment and products are vital to the productivity, profitability, and safety of a critical environment. Aside from reducing contamination within these locations, controlled products can help to positively impact the lives of others while improving the quality of life globally.

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The Importance of Bacteria Identification in Clean Rooms

A comprehensive environmental monitoring program of clean rooms should include routine monitoring of both viable and non-viable airborne particulates. Although there is no requirement for the microbial identification of all contaminants present in these controlled environments, an environmental control program shall include an appropriate level of bacteria identification obtained from sampling. There are several methods of bacterial identification available.
The first step for correct bacterial identification, especially concerning a clean room isolate, is the Gram staining, since it can provide elucidative clues about the source of the microbial contamination. If microbial identification of isolates reveals Gram-positive cocci, the source of contamination can be derived from humans. If bacteria identification of isolates reveals Gram-positive rods, the source of contamination can be derived from dust or strains resistant to disinfectants. If bacterial identification of isolates reveals Gram-negative rods, the source of contamination can be derived from water or any moistened surface.
Microbial identification in pharmaceutical clean rooms is required for several reasons associated with quality assurance: determination of organisms from the manufacturing environment; bacteria identification from final product testing; demonstrating absence of named organisms from non-sterile products and water; quality control of fermentation stocks in biotechnology; and confirmation of test organisms in validation processes.
More and more, the Food and Drug Administration (FDA) is expecting bacterial identification to aid in determining the usual flora for a specific site, to evaluate the effectiveness of cleaning and to troubleshoot the source of contamination that can occur when action levels are exceeded or sterility tests become contaminated

Lab Equipment for Clean Rooms and Critical Environment

There are some facets of medicine, industry and scientific research where there is a need for an environment as completely free as possible of any outside pollutants or substances that could bring in unwanted factors or variables to whatever procedure is being investigated, developed or operated on. For this purpose, laboratories with critical environments called 'clean rooms' have been developed. There are a huge variety of types of facilities and apparatus and clothing designed and available for a very wide range of research and control laboratories. Cole-Parmer stocks the equipment you need for a clean room as well as all the usual laboratory equipment and all the glassware you require. A clean room's level of contamination has to be a controlled one, with a specified level of contamination, which is the number of particles per cubic meter. For instance, the air in a typical urban street contains approximately 35,000,000 particles per cubic meter. An ISO 1 clean room may have no particles at all of a size above 0.5 microns, and only 12 particles per cubic meter or smaller than that. The critical environments developed may be as large as a whole huge factory premises manufacturing sensitive foods or materials, biotechnology, electronic technology, medicines, or they can be as small as a pre-term baby's incubator. Obviously, the degree of sterility will vary greatly. Some 'clean rooms' may be moderate, such as an ICU hospital ward where all instruments and equipment is sterilized but protective clothing may be limited to a face mask and sterile gloves. In an operating theater, sterile gowns, foot and head coverings are usually added. The room is generally isolated from entrance by anyone who is not involved in the actual surgery or medical procedure. In very critical environments, more sophisticated clothing is sometimes worn, even to the extent of helmets and separate breathing apparatus. Cole-parmer have a range of protective clothing, pro-clean overalls, gloves, head and foot covers, and masks to prevent contamination. Everything inside the clean room is sterilized and/or decontaminated. Even cleaning materials and tools are specialized for use inside the controlled environment, and kept sterile. Cole-Parmer supply all the necessary specialized cleaning agents, mops and brushes you need. Airflow, filtration, air pressure, humidity and temperature are generally also controlled. The entrances and exits are where the highest precautions are normally taken, with a 'gray room' where clothing is changed before entering a vacuum chamber, air lock, or air shower, where even the sterile clothing is decontaminated before entrance into the clean room itself. Cole-Parmer provide extremely useful layered adhesive-coated mats that capture dirt and dust so you don't track it into the clean room. When the top layer is dirty, you peel that layer off to expose a fresh surface underneath. As you can see, there is a whole industry devoted to the production of conditions for sterility and decontamination, ranging from architecture, building and engineering, to protective clothing manufacture, as well as machinery, apparatus, tools and equipment. You will find most of the apparatus and equipment you need at Cole-Parmer specialists.