14/04/2012
Why Polyvinyl Pouches should be preferred over PE Bottles?
In general both packaging forms meet the standard norms’ requirements but PVC bags have some distinct advantages over PE Bottles:
1) PVC bags are relatively older technology (since 1950’s), have been tested for decades and have stood the test of time. While the first PE-bottles appeared in the world market only in the seventies and have not shown any distinct advantage over PVC bags..
2) Bags are self-collapsible. Hence it does not require Air venting. In most hospitals, it is common to find in-use I.V. fluids vented with questionable sterile hypodermic needles
leading to greater chances of air borne contamination. Venting as is presently done in most hospitals is undesirable practice from Microbiological point of view.
3) Self-collapsible pouches are made only from virgin grade PVC material as compared to PE bottles of MDPE/HDPE. Single layered mono materials of PE or PP are used for the production of bottles. The bottle cap is usually made of the same material with a wall thicknesses of < 300µm is produced. The HDPE/MDPE bottles or the caps may be from reused plastic scrap.
4) While the bags cannot be reused, but the Scrap material of PE bottles can be reused in further production processes or used to manufacture bottle caps.
5) Since the Batch coding is done directly on the Bags the chances of manipulation is negligible while labels can be removed and changed on PE bottles making it unsafe. The labels in some cases may come out during transportation; storage and handling and therefore the details may get mixed up.
6) Bags have better transparency hence change in colour & turbidity is visible and in case of a variation the same can be discarded before use. Change in colour may be due to decomposition of drug or interaction with containers. Turbidity may be caused by particulate matter, precipitation or microbial growth, which may go unnoticed in PE bottles.
7) The BP-bottle consists of 3 parts:
• Bottle, produced and sealed
• Cap, premanufactured,
• Pre-inserted disc of synthetic ungalvanized rubber or TPE
While PVC bags have only Bags and Stoppers.
Due to higher no. of components chances of contamination, cross contamination and interactions are more.
8) PE cannot claim their complete Terminal sterilization as they cannot withstand temp above 110 deg C and also are permeable to Water Vapour, which may lead to quality failure/Fungal growth. While PVC pouches are exposed to >120 deg C without any problems.
9) Since these are high volume products the Storage space required with PE bottles is much higher as compared to PVC pouches and very difficult to manage specially in Big Hospitals and in demanding circumstances..
A REPORT
PE Poly Ethylene belongs to poly olefin family and comes under Thermoplastics.
1. LDPE - Low Density Poly Ethylene
2. MDPE- Medium Density poly Ethylene
3. HDPE- High Density Poly Ethylene.
In Europe and other countries, Heat sterilization cycles are being used for MDPE, HDPE with Lower temperatures and longer cycle times. This modified cycle makes it possible to use MDPE/HDPE wherever modified sterilization cycles are accepted.
Permeability rates of MDPE/HDPE - Data obtained from Modern Plastics Encyclopedia.
Plastics Gm/100 sq.inc/24 hrs/mil @ 37.8 deg c Cc/100 sq.in/ mil / 24 hrs/atm @ 25 deg c
Water Vapour Oxygen Carbon di oxide
LDPE 1.0 To 1.5 500 2700
MDPE 0.7 250 To 535 1000 To 2500
HDPE 0.3 185 580
Disadvantages of PE:
1. Transparency is less and therefor change in Turbidity, which is an initial indication for growth, is masked.
2. Cannot withstand temperature above 110 deg C
3. Attacked by Rodents if stored improperly.
Conclusion;
PE cannot claim their Terminal sterilization is perfect because they cannot withstand temp above 110 deg C, If they do not maintain their container wall thickness properly it will permeate water vapour inside and it will lead to quality failure/Fungal growth.
