influence of manufacturing process on physical and flow characteristic and compatibility of powder

Influence of manufacturing process on physical and flow characteristic and

compactibility of powder

Ghazwa shawash

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Influence of manufacturing process on physical characteristic

What is manufacturing process?We have a lot of manufacturing

process according to the type of drug we deal with; solid or liquid ,but in general manufacturing process (when we talk a bout solid drug) is blending , compression , temperature , granulation , drying ,coating , milling , carrying the material from one place to Another.


What is physical characteristic?Physical characteristic of the drug is

the dissolution ,disintegration, hardness thickness , content uniformity , particle size distribution , water content , organic liquid content , Friability .


1)In pharmaceutical preparation we use coating for modifying the drug release , coating can be achieved by precipitation. Propranolol tablets are coated with a cellulose acetate and glycerin , in a study they found that modifying preparation parameters like temperature of the precipitation path and polymer concentration, pore former concentration give us Asymmetric membranes and a desired release rates can be obtained (A zero order release of propranolol was obtained from the coated tablets) .the release was independent of the pH and the rate of agitation of the dissolution medium .


In pharmaceutical industries we prefer granulation instead of direct compression , so many studies are done for manufacturing processing of granulation, they study the influence of various granulation parameters and formulations on granule size distribution.


1)they studied the influence of various granulation parameters ; they found that a.Increasing inlet air humidity and b.granulation liquid feed rate resulted in greater median granule size as expected but when a. liquid feed Pulsing is used they found that median granule size decreased clearly. This effect was strong, especially with a. high inlet air humidity and b. rapid liquid feed rate processes, Granulation liquid feed pulsing is an effective way to modify the particle size of final granules


We use granulation for many purpose one of them is to over come segregation problem, but we must control granule size so that we will not face the same problem. in the study they found that the a. new roller compaction and b. milling conditions reduced the potential for segregation by minimizing the granulation potency variability as a function of particle size and so Improving the content uniformity of a low-dose tablet formulation


Chitosan succinate was proved effective in modulating buspirone HCl release from HPMC matrices for pH-independent release through ionic complex formation.

1) In the study they found that The extent of the interaction of Chitosan succinate and buspirone HCl was highest in wet mixtures and was found to be dependent on the pH of the granulation liquid.

2) But when Chitosan succinate in high amount (depending on the level and mode of incorporation) was incorporated in buspirone HCl –containing (HPMC) matrices, tablets using dry mixing and wet granulation this modulating buspirone HCl release from HPMC matrices for pH-independent release through ionic complex formation


Another manufacturing process is the temperature dissolution, in the study they found that novel temperature controlled surface dissolution of excipient particles for carrier based dry powder inhaler formulations they found that at :

1) 30 degrees C ; the level of lactose fines was reduced .

2) 35 degrees C, there was an increase in fine particle fraction .


1)In order to obtain the optimal particle size distribution for pharmaceutical powders in dry powder inhalers the particles have to be micronized. In most cases the process of micronisation is connected with a high input of energy such as 1.feed pressure, 2.feed rate and 3.grind pressure ,which may induce disorder and defects on the surface of the drug particles and as a result changes in the crystallinity Consequently, changes in the physical stability of the powders may occur ; they studied that on salbutamol sulphate , and found that the 1.feed pressure and 2.rate have negligible influence on the powder quality but the 3.grind pressure is of utmost importance with respect to particle size distribution and the physical powder stability

Influence of manufacturing process on flow characteristic

What is flow characteristic?Ability of powder to flow on its own

gravity in the uniform way to the die to get a tablet that has the desired weight of excepient and drug.


We say that pharmaceutical preparation prefer granulation instead of direct compression , but we have wet and dry granulation , in the study they found that Granules from both granulation methods possessed an acceptable flow characteristics .


1)Many powders , because of their small size or surface characteristic , are cohesive and do not flow well. poor flow will often result in a wide weight variation within the final product due to variable fill of tablet dies , so to improve flow properties, granulation is used , in the study they found that if we a. Increase the granulation time ,b. the impeller speed c. and the amount of binder all resulted in an increase in granule size, whilst a. high fill ratios resulted in an increased proportion of fines .

2)The speed of the chopper did not affect granule size distribution for the formulations tested .

3)They found that larger scale machines, resulted in granules which were smaller than those prepared in the laboratory-scale equipment .

Influence of manufacturing process on compactibility of powder

What is compactibility?compactibility is a synonym for

compressibility which is the measure of the relative volume change of solid as a response to a pressure change and it is affected by porosity


We say that we have tow types of granulation wet and dry , in the study of effects of the compactibility of granules produced by wet and dry granulation The wet processed granules showed in general larger compression properties ;This was explained as these granules were mechanically stronger and had a higher initial porosity .


As we said before that porosity affect on compressibility , in the study they found that

1)increasing moisture content of the granulation and decreasing wet massing time or impeller speed increased granulation compressibility.

2)But increasing impeller speed and/or wet massing time decreased granule porosity, which led to decreased granulation compressibility.

influence of manufacturing process on physical and flow characteristic and compatibility of powder

Technology