advantage and disdvantage of parenteral

 

 

 

   Definatio of Sterile products :

 dosage forms of therapeutic agents that are free of viable microorganism and foreign particles.  principally these include  Parenteral products    &         Ophthalmic products  
Parenteral dosage forms Opthalamic dosage forms 

Parenteral products  :

Derived from Greek words Para – and Enteron that mean outside of the intestine 
So parenteral administration includes the administration of drugs by any route other than intestine.  

They are required  to meet the pharmaceutical quality standards as descriped in pharmacopeias and to besafe for the intended purpose of use. 
 

must meet the following minimum They

compendia criteria:  To be sterile and pyrogen - free

1-To be clear or practically exempt of visible particle and t o b e f r e e f r o m s u b - v i s i b l e p a r ti c l e s a s r e q u i r e d b y pharmacopeias BP, USP and EP.

2-No evidence of phase separation for the emulsions, or aggregates formation for aqueous dispersions such as injectable Mab (monoclonal antibody) preparations

3-In case of suspensions, the use of appropriate particle size and any sediment should be readily dispersed upon s h a k i n g t o g i v e s t a b l e f o r m u l a ti o n s a n d e n s u r e t h e correct dose to be withdrawn and injected . 

4- They must meet the following minimum compendia criteria:  All ingredients and process involved in the preparation of these products must be selected and designed to eliminate as much as possible contamination of all types whether of physical, chemical or microbial origin . 

5-Solvents or vehicles used must meet special purity and other standards. 

6- Restrictions on b u f f e r s , s t a b ili z e r s , a n ti m i c r o b i a l preservative. 

7-Do not use coloring agents.  8- Must be prepared under aseptic conditions. 

9- Specific and high quality packaging.  

Advantages 

• The parenteral products bypasses the 1 st line of body d e f e n s e , t h e s k i n a n d m u c u s m e m b r a n e t o r e a c h systemic circulation. 

• Insure delivery of adequate concentration of drugs to diseased tissues e.g. direct intracerebroventricular injection of aminoglycoside  

• Control certain parameters as time of drug onset, tissue concentration and rate of drug elimination 

• G u a r a n t e e d o s a g e a n d d r u g c o m p li a n c e e . g. I . M . monthly long acting penicillin 

• D e li v e r c e r t a i n b i o l o g i c a l e f f e c t t h a t c a n n o t b e delivered orally e.g. insulin

 • Used when oral route not available e.g. in aspirated comatose or uncooperative persons
Advantages 

• To provide local effect so as to avoid systemic t o x i c e f f e c t e . g. m e t h o t r e x a t e intrathecal injection. 

• Supply s h o r t a n d l o n g t e r m n u t r iti o n a l needs and permit rapid correction of fluid and liquid imbalance • Give local effect as local anesthesia

 • Many new drugs particularly those derived from new development in biotechnologically can only be given by parenteral bcz they are inactivated in GIT if given orally.  

Disadvantages

*The manufacturing process is more complicated due to the requirement for aseptic technique .
*Frequent pain and discomfort of injections

*I n c o r r e c t d r u g o r d o s e i s o f t e n i m p o s s i b l e t o counteract particularly through I.V.

*R e s t r i c ti o n t o p a r e n t e r a l u s e i n h o s p it a l s o r w it h specialized persons

*Expensive (require technical and trained persons)   

*Sensitivity or allergic reaction at the site of injection may occur

*Parenteral admisteration require   an appartiate injection techniqe . I f pereformed increctly y, for example using the wrong size needle or cannula, it can cause damage to nerves, muscle and vasculature and may adversely affect drug absorption.