Скачать или смотреть Incompatibility In Prescription | Chemical Incompatibility | Bright Pharma

Incompatibility In Prescription | Chemical Incompatibility | Bright Pharma

Chemical incompatibility may be as a result of chemical interactions between the ingredients of a prescription and a toxic or inactive product may be formed.
While dispensing such prescriptions the precautions should be taken either to prevent the formation of harmful product or to correct them and the prescriber must be informed in this regard.

Chemical incompatibility is often occur due to the oxidation-reduction, acid base hydrolysis or combination reactions.
These reactions may be noticed by precipitation, effervescence, decomposition, colour change or by explosion. The prescription having chemical incompatibility should be dispensed only after its correction by the prescriber.
Chemical incompatibilities are of two types
1 tolerated
2 adjusted

tolerated Incompatibility
In tolerated incompatibilities the chemical interaction may be minimised by changing the order of mixing or mixing the solutions in dilute forms but no alteration is made in the formulation.

adjusted incompatibility
in adjusted incompatibilities the chemical interaction can be prevented by addition or substitution of one of the reacting ingredient of a prescription with another of equal therapeutic value
for example caffeine citrate can be substituted with caffeine in sodium salicylate and caffeine citrate mixture
the chemical incompatibility maybe Intentional when the prescriber knowingly prescribes the incompatible drug.
Unintentional when the prescriber prescribes the drugs without knowing that there is a incompatibility between the prescribed drugs.

Precipitate Yielding Interactions
Generally it is observed that reaction between strong solutions process at a faster rate and precipitate formed are thick which do not diffuse readily
The light diffusible precipitates are formed when dilute solution of reacting substances are mixed hence the reacting substances should be diluted to the maximum extent before mixing them.
The precipitates so formed maybe diffusible or indiffusible.
The method A and B is followed in dispensing the prescription yielding diffusible and indiffusible precipitates respectively.

Method A
The method is followed when diffusible precipitates are formed in very small quantity.
Divide the vehicle into 2 equal portions. Dissolve one of the reacting substances in one of the portion and other in other portion Mix the two portions by slowly adding one portion into the other by rapid stirring.

Method B
The method is followed when indiffusible precipitates are formed in large quantity. Divide the vehicle into two equal portions. Dissolve one of the reacting substances in one portion.
Weigh a suitable quantity of compound Tragacanth powder 2gm per 100 ml of finished product and transfer in a mortar and use part of second portion of vehicle to produce a smooth mucilage.
Then add other active substances.
Mix the two portions by slowly adding one portion to the other with rapid stirring.
A secondary label SHAKE THE BOTTLE USE should be fixed on the container whenever method A a method B is followed in dispensing the prescription.