Formulation and Performance Evaluation of Eco-Friendly Smart Blister Packaging with a Colorimetric Expiry Indicator for Temperature-Sensitive Drugs

Abstract

Pharmaceuticals and vaccines are sensitive to temperatures and other bio-pharmaceuticals and thermolabile oral drugs are also very susceptible to a drop in their strength once exposed to conditions beyond the recommended storage conditions. Traditional PVC-aluminum blister does not offer real-time numerical repulsive exposure of thermal fluctuation and also adds to the pharmaceutical plastic waste. The objective of the present study was to design and test a smart blister packaging system, which is eco-friendly and consists of biodegradable cavity films and an irreversible natural-dye suffered colorimetric expiry indicator that is able to signal runaway degradation by temperature. Melt-casting and thermoforming were used to prepare two bio-polymer matrices PLA-nanoclay composite and starch-cellulose to produce structurally stable blister films. One of the bio-pigment colorimetric sensors was imprinted on a cellulose substrate and stickered with non-toxic binders to avoid movement into any drug cavity. Mechanical strength, barrier to moisture and oxygen, indicator functionality, environmental safety and biodegradability were thoroughly evaluated. It was found that both biodegradable films complied with pharmaceutical requirements of tensile strength, puncture resistance, elongation and seal integrity, with PLA composites films exhibiting barrier properties comparable to PVC. The colorimetric indicator was capable of responding to an irreversible high-contrast change of color within minutes at 32–35D, which is exactly the behavior of irreversible degradation of thermolabile drugs. Both films were tested by soil-burial and composting tests as being safely and non-toxicly biodegraded with no pigment or chemical migration. The aggregate results support the possibility of the sustainability and intelligent expiry communication integration, on the unit-dose level. The suggested system, the smart biodegradable blister, is a low-cost, scalable, and easy-readable system, which will be beneficial to patient safety, reduce medication errors, and promote environmentally conscious pharmaceutical packaging practices, especially in the low-resource healthcare environment.

Keywords:

 Smart Blister Packaging, Colorimetric Expiry Indicator, Biodegradable Polymers, Temperature-Sensitive Drugs