Pharmaceutical PVC (polyvinyl chloride) and PVDC (polyvinylidene chloride) are both commonly used packaging materials in the pharmaceutical industry. Although they have some similarities, there are significant differences between the two:
Structure
PVC (polyvinyl chloride) is a single-layer rigid film.
PVDC is the abbreviation of PVC/PVDC rigid film. It is a PVC (polyvinyl chloride) rigid film with a PVDC (polyvinylidene chloride) coating.
Barrier properties
PVC rigid film: basic barrier material, with general barrier properties for water vapor and oxygen, suitable for drugs with low requirements for moisture and oxygen isolation. Since PVC has relatively strong air permeability, it is suitable for drugs that are not easily affected by moisture, such as ordinary tablets.
PVDC rigid film: has higher barrier properties, especially in moisture and oxygen resistance. PVDC is often used as a packaging material for highly moisture-sensitive drugs, especially for protecting drugs in humid environments with large temperature differences.
Water vapor transmission rate (WVTR) and oxygen transmission rate (OTR) are affected by the composition and thickness of the coating.
| Product name | WVTR | OTR |
| PVC hard film | ≤3.0 | / |
| PVC/PVDC40gsm | ≤0.8 | ≤3.0 |
| PVC/PVDC60gsm | ≤0.6 | |
| PVC/PVDC90gsm | ≤0.4 |
Application scenario
Medicinal PVC hard film: widely used in blister packaging of basic drugs such as tablets and capsules. It is low in price and easy to process, suitable for drug packaging with low barrier requirements.
Medicinal PVDC hard film: mostly used for packaging of drugs that are sensitive to moisture and oxygen, such as antibiotics, vitamins, eye drops, vaccines, etc. PVDC is usually attached to PVC or other materials in the form of a coating to improve the overall barrier properties of the packaging.
Transparency
PVC: High transparency, easy to observe the status of the drug in the package, good user experience.
PVDC: Transparency usually decreases with the thickness of the coating.
Processing cost
PVC hard film has always been a very common product in the market, and the cost performance of medical grade and food grade is higher than that of industrial grade.
PVDC price is linked to the amount of PVDC coating. The larger the amount, the higher the price.