- there are many sources which affects the product or sometime process which is use in the manufacturing process .
some major sources are follows ;-
[1] RAW MATERIAL : - impuritites known to be associated with these chemicals may be carried out through the manufacturing process and contaminate the final product.
- if impurities are present in raw material which are used in pharmaceutical preparation then those impurities may be present in the final product ,normally those manufacturing process to the final product and due to this reason our final product may be contaminated.
eg 1; preparation method of Nacl(rock salt) it can be prepared by the reaction of calsium sulphate and magnisium chloride prepare rock salt contains some amount of Caso4 and Mgcl2 ,thus sodium chloride prepare from the source will contains traces of calsium and magnisium compound.
-impurities such as Arsenic, lead and other heavy metals are present in raw material and hence are found in substances , so it is necessary to use pure chemicals and substances as a raw material far the manufacturing process.
eg 2; copper sulphate may be prepared by the reaction of sulphuric acid on copper turnings are known to have iron and arsenic as an impurities large quantities of these impurities are present in the raw material (copper turnigs) then these may be present in the final product .
- dur to this reason i.p. precribes some limits of tolerance for arsenic as an impurity to be not more then 8 parts per million in copper sulphate some unites are prescribed for iron as an impurity in i.p.(indian pharmacopoeia) .
[2] REAGENTS USED IN PHARMACEUTICAL PROCESS : - if reagents used in the manufacturing process are not completly removed by washing then some impurities may be present in the final product.
eg; ammonium mercury may be prepared by adding a solution of mercuric chloride to the dilute ammonia solution in this process mercuric chloride shows solution nature and ammoniated mercury shows ppt.
- the precipitate of ammoniated mercury contains ammonium hydroxide as an impurity . thus this precipitate is required to wash with old water to remove impurities of ammonium hydroxide.
- if it is not remove completly by washing with water than these types of impurities may be present in the final product.
REAGENTS - a reagents is a substances or compound added to a reaction mixture or system to cause a chemical reaction or added to the mixture if a reaction occure.
the term reagent and reactant are often used.
[3] METHOD OR PROCESS USED IN MANUFACTURING : - many drugs and chemicals are manufactured from different raw material by using different method.
- sometime impurities are incorporated into the main material during the manufacturing process and type of impurities present in the during various.
- in certain drug or chemical a multiple steps synthesis procedure are used which produces various intermediate steps or compounds in this condition purification or removel of impurities is also importance other wise these impurities may be contaminited our final product.
- normaly there are various side reaction occurs in different - different process.
- impurities of the product side reaction also occurs in the substances this may introduce new impurities by any reagent or other chemical(contamination).
eg; some time reagent may produce impurity.
- calcium carbonite is obtain by the reaction of soluble calcium salt a soluble carbonate salt and due to this final product will contains some traces of alkali which can be remove by washing process.
- sometime some chemical agent can be use to remove impurities.
eg; potessium bromide contains traces of barium which is added in the manufacturing process to remove eccess of sulphate.
[4] SOLVENTS - water is the cheapest solvent and freely available normality distiled water is used in pharmaceutical method.
- Types of water -
:- tap water - tap water contains ions(ca,mg,na,cl,so4.etc,)
:- salt water - its obtained by allowing the tap water to pass through the sodium form at zealite which removes divalent ions or contains like ca ion and mg ion from tap water by exchange at sodium so salt water contains not and chlorine ion has an impurities.
No comments:
Post a Comment