Ordinary tablets made by mixing drugs and excipients, commonly known as plain tablets

Tablets that are coated with a film on the surface of ordinary tablets.

Depending on the coating material, the coated tablets can have corresponding names.

It usually contains sodium bicarbonate and organic acid. When it meets water, the two react to generate a large amount of carbon dioxide gas, which is effervescent.

Generally speaking, the drugs contained in effervescent tablets should be water-soluble, and citric acid, tartaric acid, etc. can be used as organic acids.

Sucrose, mannitol, sorbitol, mint, flavorings, etc. are usually added to adjust the taste.

Tablets that disintegrate quickly in water and disperse evenly before taking.

You can drink it directly after dispersing it in water, or you can take the tablet directly in your mouth or swallow it.

Generally speaking, the drugs contained in dispersible tablets are poorly soluble and appear in a suspended state after dispersion, such as roxithromycin dispersible tablets.

Suspending agents, such as guar gum, should be added to dispersible tablets to increase the viscosity or consistency of the suspension to maintain the suspended state after dispersion.

Tablets that release drug slowly and non-constantly in a defined release medium

Compared with the corresponding ordinary preparations, it has the characteristics of less frequent administration, longer action time, and less toxic and side effects.

Tablets that release drug slowly and at a constant rate in a defined release medium.

Compared with corresponding extended-release tablets, blood drug concentration is more stable

A tablet composed of two or more layers.

Each layer contains different drugs and excipients, which can avoid compatibility changes between different drugs in compound preparations, or make a double-layer tablet with a combination of sustained release and immediate release.

Tablets that disintegrate rapidly in the mouth generally exert systemic effects after swallowing.

The characteristic is that no water is needed when taking medicine, which is especially suitable for patients with swallowing difficulties or the elderly and children.

Sorbitol, erythrose, mannitol, etc. are often added as flavoring agents and fillers

It refers to tablets that can be quickly dissolved when placed under the tongue, and the drug is absorbed through the sublingual mucosa to exert systemic effects.

It can avoid the first-pass effect of the liver on drugs and is mainly used for the treatment of emergencies, such as nitroglycerin sublingual tablets for the treatment of angina pectoris.

Refers to tablets that slowly dissolve in the mouth to produce local or systemic effects.

The drugs in the lozenges should be easily soluble and mainly have local anti-inflammatory, sterilizing, astringent, analgesic or local anesthetic effects, such as compound grass coral lozenges, etc.

It refers to tablets that are pasted in the oral cavity and have local or systemic effects after absorption through the mucosa, slowly releasing drugs in the oral cavity and used for the treatment of oral and throat diseases, such as metronidazole oral patches.

Refers to non-coated tablets that can be dissolved in water before use.

Generally used for mouthwash, disinfection, wound washing, etc., such as compound borax mouthwash tablets, rifampicin (eye) tablets, etc.

Refers to tablets that are placed in the vagina and work.

It mainly plays local anti-inflammatory, sterilizing, spermicidal and astringent effects, and can also be used for sex hormone drugs.

①Diluents are also called fillers.

②The diameter of tablets is generally not less than 6 mm, and the tablet weight is usually more than 100 mg, otherwise it will be inconvenient to use.

③The role of diluent

Starches include corn starch, wheat starch, potato starch, etc., among which corn starch is the most commonly used.

Corn starch particle size is 5-30 um

Moisture content in the range of 10%-14%

It has adhesive properties, poor fluidity and compression moldability, but stable properties.

It can be compatible with most drugs, has good appearance and color, and is cheap. It is the most commonly used excipient in solid preparations.

It is often mixed with sucrose powder, dextrin, etc. which have good compressibility.

Extracted from sugar cane and sugar beets.

Very soluble in water and almost insoluble in absolute ethanol.

Stable at room temperature and moderate humidity, unstable at high temperatures (110~145°C) or acidic conditions, turning into invert sugar (glucose and fructose)

This product has strong adhesive force and can enhance the hardness of tablets, but it is highly hygroscopic. Long-term storage will make the tablets too hard and delay disintegration or dissolution.

Dextrin is a polymer obtained by heating and modifying partially hydrolyzed starch in a dry state. It is easily soluble in boiling water and insoluble in ethanol.

It has a strong tendency of aggregation and agglomeration. Improper use will cause pitting, watermarks, etc. on the surface, and sometimes cause tablet disintegration or slow dissolution.

Often used in conjunction with sucrose and starch.

It is extracted from milk and is divided into alpha-lactose anhydrous, alpha-lactose monohydrate and B-lactose. Alpha-lactose monohydrate is commonly used.

α-Lactose monohydrate is soluble in water but insoluble in ethanol.

Tablets made from lactose have a smooth surface, stable properties, and are compatible with most drugs.

The lactose produced by the spray drying method is spherical in shape, has good fluidity and compressibility, and can be used for direct tableting of the powder.

Starch is partially or completely gelatinized. The variety currently on the market is partially pregelatinized starch.

Soluble 10%~20% in cold water, insoluble in ethanol.

It has good fluidity, compressibility, lubricity and dry adhesion, and has good disintegration effect.

As a multifunctional excipient, it is often used for direct tableting of powders.

It is produced from pure cotton fiber through hydrolysis.

It is a white or off-white powder, odorless and tasteless, composed of porous particles.

It has strong binding force and good compressibility. It is also known as "dry binder" and can be used as powder for direct tableting.

Generally, tablets with more than 20% microcrystalline cellulose have better disintegration properties.

Some inorganic calcium salts are commonly used, such as calcium sulfate, calcium hydrogen phosphate, calcium carbonate, calcium sulfate dihydrate, etc.

Among them, calcium sulfate dihydrate is more commonly used. It has stable properties, is odorless and tasteless, is slightly soluble in water, and can be compatible with a variety of drugs. The tablets produced have a smooth appearance, good hardness and disintegration, and have no adsorption effect on drugs. .

Mannitol and sorbitol are isomers of each other.

The sweetness is about half that of sucrose. It absorbs heat when dissolved and has a cooling feeling. It is suitable for chewable tablets, orally disintegrating tablets, etc. But it is more expensive and is often used in conjunction with sucrose.

Erythrose (eri th rito l), its sweetness is 80% of sucrose, it dissolves quickly, has a strong cooling sensation, does not generate heat after oral administration, and does not drop the pH in the mouth (good for protecting teeth), etc. It is an excellent excipient for preparing orally disintegrating tablets, but it is expensive.

It refers to a liquid that has no viscosity itself but induces viscosity in materials by wetting them. Commonly used wetting agents include distilled water and ethanol.

Distilled water

ethanol

Starch slurry

cellulose derivatives

Povidone (PVP)

Gelatin

capillary action

expansion effect

moist heat

gas production

Additive method

Inner addition

Internal and external addition

It is a classic disintegrant, dried at 100~105℃ for 1 hour, and the moisture content is below 8%.

Dry starch has strong water absorption, and its water expansion rate is about 186%.

Dry starch is suitable for tablets of water-insoluble or slightly soluble drugs, but has poor disintegration effect on easily soluble drugs.

It is the sodium salt of the acid methyl ether of starch. It is insoluble in water and has a very significant swelling effect when absorbing water. Its expansion rate after absorbing water is 300 times its original volume.

Is a "super disintegrant"

Among them, LH-11 has the largest particle size and is often used as a disintegrant for direct compression tablets.

LH-21 has moderate particle size and is mainly used as a disintegrant for wet granulation tablets.

Due to its large surface area and porosity, it has the ability to rapidly absorb water and expand. The water expansion rate is generally between 500% and 700%.

It is also a "super disintegrant".

Carmellose sodium is obtained through chemical cross-linking. It is insoluble in water, but can absorb water several times its own weight and expand to 4-8 times its original volume, so it has good disintegration effect.

The disintegration effect is better when combined with carboxymethyl starch sodium, but the disintegration effect will be reduced when combined with dry starch

It is insoluble in water, but quickly shows capillary action and excellent hydration ability in water. The maximum water absorption capacity is 60%, the expansion ratio is 2.25~2.30, and there is no gelling tendency.

The disintegration performance of PVPP is very superior and it is also a "super disintegrant"

It is a special disintegrant specially used for effervescent tablets. The most commonly used is a mixture of sodium bicarbonate and citric acid.

Carbon dioxide gas is produced when exposed to water, causing the tablet to rapidly disintegrate within minutes.

Tablets containing this disintegrant should be packaged properly to avoid moisture which may cause the disintegrant to become ineffective.

Reduce the friction between particles, thereby improving powder fluidity;

Generally, during tableting, it is necessary to prevent materials from adhering to the surface of the punch and die to ensure the smooth progress of the tableting operation and make the tablet surface smooth.

It is a lubricant in a narrow sense, that is, it reduces the friction between the material and the die wall to ensure uniform pressure distribution during tablet pressing and pushing, and smooth tablet pushing from the die hole.

Improve electrostatic distribution on particle surface

Improve particle surface roughness and reduce friction

Improve the selective adsorption of particles and weaken the van der Waals force between particles

Magnesium stearate

Micropowder silica gel (aerosil)

talcum powder

Hydrogenated vegetable oil

Polyethylene glycols (PEG)

Sodium lauryl sulfate

First, wrap the plain tablets with an impermeable isolation layer to prevent moisture from infiltrating into the tablet core during the subsequent sugar coating process.

The materials used for the isolation layer are mostly water-insoluble film-forming materials, such as corn gluten, shellac, cellulose acetate phthalate (CAP), etc., which are dissolved in ethanol.

In order to eliminate the edges and corners of the tablet, a thicker powder coating layer is applied to the outside of the isolation layer.

The main materials are syrup and talc. The concentration of the syrup is 65%~75% (g/g), and the talcum powder is powder that has passed through a 100-mesh sieve.

The shape of the tablet core should be a biconvex tablet with very thin edges, which can reduce weight gain and be beautiful.

The surface of the powder coating layer is relatively rough and loose, so it is coated with sugar to make the surface smooth, smooth, delicate and solid.

The key points of the operation are to add slightly dilute syrup, gradually reduce the amount, blow dry at low temperature (40°C), and generally wrap 10 to 15 layers.

Adding food coloring to the syrup can be coated with colored icing. The main purpose is to facilitate identification and appearance. Generally, it needs to be coated in 8 to 15 layers.

In order to increase the gloss and hydrophobicity of the tablet surface, the commonly used material is Sichuan wax.

It usually consists of coating material (film former), plasticizer (plasticizer), release speed regulator, gloss enhancer, solid materials, colorants and solvents.

advantage

According to the function of clothing layer

Plasticizers can change the physical and mechanical properties of polymer films, making them more pliable and conducive to coating.

There must be chemical similarity between the polymer and the plasticizer. For example, glycerin, propylene glycol, PEG, etc. have hydroxyl groups and can be used as plasticizers for some cellulose clothing materials.

Aliphatic non-polar polymers include refined coconut oil, castor oil, corn oil, liquid paraffin, glyceryl monoacetate, glyceryl triacetate, dibutyl sebacate and dibutyl phthalate (diethyl ester). )wait.

Release rate modifiers are also called pore-forming agents.

Generally, they are small molecule sugars, salts or polymer materials with excellent water solubility, such as sucrose, sodium chloride, surfactants and PEG.

When some polymers are too viscous during the coating process, solid powder lubricants are added to prevent the particles or tablets from adhering, such as talc, magnesium stearate, etc.

The application of pigments is mainly to facilitate identification, prevent counterfeiting, and meet the requirements of product beauty. It also has a light-shielding effect.

Classification