1. First wet granulation mechanism <br> <br> liquid binder wetting the surface of the powder medicament, so that adhesion between the generation of particles, and the liquid is made constant under the effect of external mechanical forces and bridging The shape and size of the granules, after drying, are finally consolidated in the form of a solid bridge. Wet granulation mainly includes processes such as making soft materials, making wet granules, drying wet granules and granules.
2. Effect of wet granulation factors <br> <br> the raw grain properties, the choice of binder, granulating blender and the time factor, mesh, drying equipment and so on.
2.1 Properties of raw materials 2.1.1 The powder is fine, the texture is loose, the drying and the viscosity are poor, and the solubility in water is small; the adhesive with stronger viscosity is used, and the amount of the binder is more.
2.1.2 The solubility in water is large, and the raw materials are inherently viscous; the wetting agent or the less viscous binder is used, and the amount of the binder is relatively small.
2.1.3 sensitive to moisture, easy to hydrolyze; can not use water as a solvent for the binder, using anhydrous ethanol or other organic solvent as a solvent for the binder.
2.1.4 It is sensitive to heat and easy to decompose; try not to use water as the solvent of the binder, and choose the solubility of ethanol as the solvent of the binder to reduce the drying time of the particles and reduce the drying temperature.
2.1.5 is stable to moisture and heat; use lower cost water as solvent for the binder.
2.2 Wetting agents and adhesives 2.2.1 Wetting agents (moisteningagents):
The material is wetted to produce a viscosity of sufficient strength to facilitate the formation of the liquid of the particles. The wetting agent itself is non-tacky or not very viscous, but it wets the material and induces the viscosity of the material itself, allowing it to coalesce into a soft material and form a granule. Such as: distilled water, ethanol. Where the drug itself is sticky, but the water can cause deterioration or wetness, the viscosity is too strong, making the granulation difficult, the humidity is uneven, the drying is difficult, or the prepared granules are hardened after drying. The suitable concentration of ethanol can be used for wetting. Agent. The concentration of ethanol depends on the nature of the drug and the ambient temperature, and is generally from 30% to 70% or more. To a certain extent, ethanol is a dispersant that reduces the viscosity between the particles and makes the viscous material easy to granulate.
2.2.2 Adhesives: A non-tacky or less viscous material can be aggregated into granules or compression-molded viscous solid powders or viscous liquids. Such as povidone (PVP), hypromellose (HPMC), sodium carboxymethylcellulose (CMC-Na), syrup and the like.
2.2.2.1 Povidone (PVP): white or milky white powder, non-toxic, high melting point, heat stable at 150 ° C), chemically stable, soluble in water and ethanol into a viscous gelatinous liquid, good Adhesive. PVP has different specifications and models, commonly used PVPK30 as a binder, its common concentration is 3%-15%. For example, PVPK30 is used as a binder for granulation in azithromycin granules at a concentration of 5%.
2.2.2.2 Aqueous solution of syrup sucrose, which has strong viscosity and is suitable for phytochemicals with loose texture and strong elasticity, and chemical drugs with loose texture and loss of crystal water, commonly used 50%-70% (g/g) Aqueous solution. When the sucrose concentration is as high as 70% (g/g), it is a supersaturated solution at room temperature, and can only be used when it is hot, otherwise crystals are easily precipitated.
2.2.2.3 Carboxymethylcellulose sodium (CMC-Na): The usual concentration is 1%-2%. The application of zui in the medicament is a product with a degree of substitution equal to 0.7, soluble in water, insoluble in an organic solvent, and soluble in 40% ethanol solution.
2.2.3 Selection of binder 2.2.3.1 The choice of binder is related to the nature of the original excipient itself, the solvent of the binder, the mixing time, and the binder concentration: if the raw material powder is fine, the texture is loose, and the solubility in water is small. The raw material itself is poorly viscous and the amount of the binder is more. On the contrary, the amount is less.
2.2.3.2 When the amount of excipients in the prescription accounts for more than 80%, the binder should be selected with special emphasis on the characteristics of the excipients without affecting the nature of the main drug. If sucrose is used as an auxiliary material, when the amount is more than 80%, it is necessary to consider the characteristic that "sucrose has too strong water viscosity", and a non-aqueous solvent is used to dissolve the binder (only soluble in water and insoluble in organic solvent) The binder is not suitable), reducing the viscosity between the particles and relatively enhancing the viscosity inside the particles. For example, the ratio of sucrose in the prescription of azithromycin granules exceeds 80%, and the granulation when 5% PVPK30 is prepared by using 95% ethanol as binder is more granulated than 5% PVPK30 prepared by using 20% ​​ethanol as binder. The effect is good, the former can achieve granulation up to 90%, and the latter granulation is only 50%. This shows that the same adhesive, the viscosity and granulation effect are different when different solvents are used.
2.3 Pelletizing and cutting time When the soft material is made, the mixing time should be moderately controlled. Generally, it is mastered by experience. It can be clumped by hand without sticking to the hand, and the finger can be broken and opened. The stirring time is long, the viscosity is too strong, and the granulation is difficult; the stirring time is short, the viscosity is not strong, and the granulation property is not good.
2.4 Screens commonly used are four kinds of screens: nylon wire, galvanized iron wire, stainless steel and plate. The nylon wire mesh is good for the soft material, which is suitable for the "wet but not sticky but good granulation". Other screens are prone to metal chips (broken wire) or broken stainless steel ribbons that affect the quality of the product. In addition, when the wet particles are swayed by the swaying granular mechanism, the tightness of the screen installation has a great influence on the quality of the granules: if the screen is loosely installed during granulation, the drum can be reciprocally rotated and stirred to increase the soft material. The viscous, prepared wet granules are thick and tight. On the contrary, the obtained granules are fine and loose. Therefore, the tightness of the screen installed in production should be moderate.
2.5 Drying and Drying Equipment 2.5.1 Drying is the process of removing moisture from wet materials by gasification. Wet particles should be noted during the drying process: wet particles should be dried as soon as possible, the drying speed of the particles should be strictly controlled, and the temperature should be gradually increased during the drying process.
2.5.2 Drying equipment includes van dryers, spray dryers, fluidized bed dryers (also called boiling dryers). The fluidized bed dryer is commonly used in scale production, which is characterized by simple structure, convenient operation, relatively strong relative movement of particles and hot air flow, large contact area and fast drying speed, and is suitable for heat sensitive materials. The horizontal fluidized bed dryer is suitable for drying granule particles with good effect.
And improvement of technical problems encountered when applying 3. The wet granulation technique in the production of granules of a modified example <br> <br> dry syrup amoxicillin binding to granule production method of the wet granulation technique exemplified in the particles Application improvements.
3.1 Amoxicillin dry syrup production process The raw materials, pulverized auxiliary materials (mainly sucrose) were mixed for 5 minutes, 1% CMC-Na slurry was added, granulated for 180 seconds, and 14 mesh stainless steel sieve was used with YK-160 rocking granulator. The net is granulated, dried, and the particles below 14 mesh are taken.
3.2 Problems encountered in changing from dry syrup to granules 3.2.1 According to the production process of dry syrup, the particle size of disposable granulation is less than 30%, and each time the unqualified granules are regranulated, so Production of a batch of anti-replicating particles must be repeated several times to achieve the above standards, which wastes labor and energy, increases production costs, and affects product stability.
3.2.2 When wet granulation is used to mix soft materials and granulated directly with rocking granules, it is easy to block the screen (stainless steel). After using the soft material, it was dried by a boiling dryer for 2 minutes and then granulated with a rocking granule. As a result, agglomeration occurred, the hardness was large, and the sieve mesh was easily squeezed. A large number of stainless steel screens are replaced for each batch.
3.2.3 The granules are looser and the hardness is not enough. The fine powder appears after boiling and drying.
3.2.4 Due to the high viscosity of the soft material, the granulation of the stainless steel screen is prone to breakage, resulting in the broken stainless steel wire in the granules. Every time it appears, it must be stopped for selection, which wastes working hours and has a dirty belt. The serious consequences. It is imperative to switch to other screens.
3.3 Improvement of wet granulation technology Process improvement under the premise of the original prescription.
3.3.1 Improvement of Adhesive 3.3.1.1. In this formulation, 1% CMC-Na is used as a binder. Since it can only be dissolved in a high concentration of 43% ethanol solution, the method of increasing the concentration of ethanol in the solvent is used. Nowhere.
3.3.1.2 Add 1% CMC-Na first, then add appropriate amount of ethanol to granulate, the effect is not good.
3.3.1.3 has been used first with 1% CMC-Na, plus syrup granulation, the effect is not good.
3.3.1.4 Because the amount of sucrose in this prescription is large, the viscosity is too strong after being wetted by water, and granulation can be carried out by the method of “wetting and dispersing with ethanol first and then adding binderâ€. That is, the granulation is carried out by "wetting and dispersing with ethanol, adding CMC-Na binder, and adding syrup after zui", and the effect is good.
3.3.2 Use nylon screen because nylon screen is suitable for "wet but not sticky but good granulation" soft material granules, using "first add ethanol to wet dispersion, then add CMC-Na binder,zui It is granulated with syrup and is very suitable for nylon screens. The problem of using a stainless steel wire mesh to mix broken stainless steel wire in the granules is solved. For the material which is too viscous and difficult to granulate after changing to the nylon screen, the method can basically be adopted, that is, the granulation is carried out by the method of “wetting and dispersing with ethanol first, and then adding a binderâ€.
3.3.3 Control the mixing time of the soft material Through the experiment, the stirring time after adding the wetting agent and the binder was found out.
3.4 Amoxicillin Granule Production Process Through the improvement of wet granulation technology and production verification, the mature process for producing amoxicillin granules has been summarized.
3.4.1 Improved process Mix the raw materials and pulverized auxiliary materials (mainly sucrose) for 5 minutes, stop stirring, add 95% ethanol, stir for 120 seconds, add 1% CMC-Na slurry to the prescription, and stir to 60 seconds. The syrup was added, stirred for 120 seconds, granulated by a 14-mesh nylon mesh using a YK-160 rocking granulator, and dried, and the granules of a 12-60 mesh sieve were taken.
3.4.2 Improved granule production process The particle size pass rate of one-time granulation is over 90%, which solves the problem of granulation difficult, greatly improves production efficiency, and produces uniform granules and suitable hardness. , achieved good results.
3.4.3 After accelerated test and sample retention observation, the quality is stable and the indicators meet the quality standards.
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Reolink WiFi cameras can be added to Reolink PoE NVRs if they are in the same LAN. Here we'll guide you to finish this process following the steps below.Reolink WiFi cameras can be added to Reolink PoE NVRs if they are in the same LAN. Here we'll guide you to finish this process following the steps below.Reolink WiFi cameras can be added to Reolink PoE NVRs if they are in the same LAN. Here we'll guide you to finish this process following the steps below.Reolink WiFi cameras can be added to Reolink PoE NVRs if they are in the same LAN. Here we'll guide you to finish this process following the steps below.
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