At the end of every drug formulation process, drugs are usually protected against biological contamination and all adverse external factors like moisture, light, oxygen, mechanical shock, temperature etc., which can alter the physical properties, chemical properties and pharmacological effect of the formulation. This alteration in the physical properties, chemical properties and pharmacological effect of a drug leads to the formation of new entities that are less active or inactive and has toxic by-products with adverse reactions.




It is very important to get your product safely to the patient which they are prescribed such that when the patient uses it, the sole purpose of prescribing the drug is achieved. In this post, I will be answering the “what questions” of packaging materials which are geared towards making sure that drugs arrive safely in the hands of the patients for whom they are prescribed. These questions include:

1. What are packaging materials?
2. What are the various packaging materials used in the pharmaceutical industries?
3. What are the factors you should consider when choosing packaging material for a drug product?
4. What are the possible interactions between the primary packaging materials and the dosage forms?

What are packaging materials?

Packaging materials are materials employed in the construction of packaging containers for pharmaceutical formulation with the intention of preserving the integrity of the formulation. They are referred to as primary packaging if they have a direct contact with the formulation. Secondary packaging materials not only protect the formulation, but also protect the primary packaging and they do not come in contact with the formulation.

What are the various packaging materials used in the pharmaceutical industries?

The most commonly used packaging materials in the pharmaceutical industry are glass, plastics and metals. They are used as containers for pharmaceutical formulations.

A. Glass containers

Glass containers, depending on the type are used for useful for packaging acidic and neutral preparations (type I glass containers), acidic and neutral aqueous preparations for parenteral use (type II glass containers), anhydrous liquids and other dry products (type III glass containers), and non-parenteral products intended for oral or topical use (type IV glass containers)

B. Plastic containers

Plastic containers in recent years have been used in the packaging of many dosage forms. This can be attributed to the numerous advantages they possess over glass and metal containers.

C. Metal containers

Aluminum and stainless steel are the metals of choice for both primary and secondary packaging for dosage forms like tablets, capsules, pastilles, powders and liquid products. A significant part of this usage has been lost to other packaging material over the years.

What are the factors you should consider when choosing packaging material for a drug product?

Your choice of packaging materials for a pharmaceutical formulations depend on the following factors

1. Compatibility and safety concerns

Compatibility and safety concerns of packaging materials raised by the route of administration of the drug product and the nature of the dosage form (e.g., solid, semi-solid or liquid based) are considered from two perspectives; and samples of a drug which are selected for stability studies should be packaged in the same manner as they will be for marketing and distribution.

a. Compatibility of the packaging material with the formulation; making sure that the packaging material does not have any adverse effect on the formulation through chemical reactions, leaching of packaging materials, absorption or adsorption.

b. Compatibility of the formulation with the packaging material; making sure that the properties and/or the protective functions of packaging materials are not compromised by the formulation.

2. The degree of protection required

Active pharmaceutical ingredients are usually more stable than when they are formulated into dosage forms. Decomposition occurs due to the presence of excipients, moisture, oxygen, light, temperature etc. Degradation of the dosage form can also be as a result of the formulation process used during formulation.  The degree of protection required is a function of the formulation in question and for this reason; the packaging material used for photosensitive material should possess the ability to protect the formulation from light. This is also applicable to hygroscopic, easily oxidized drug products and so on.

3. Cost

In order to make your drugs affordable, cost effectiveness of packaging materials should be considered. Manufactures should endavour not to compromise the integrity of their formulation while cutting cost rather they should look for a better way to reduce cost which can by reduction of wastage of packaging material.

4. Convenience

How easy is it for a patient to use a formulation in terms of size, weight, method of opening or reclosing if appropriate during administration of the dosage form should be considered while choosing packaging material for a dosage form.

5. Legibility

The legibility of printing is an important factor to consider while choosing and designing a package for your formulations as it serves as a source of information and identification of a formulation as explained in The Importance of Giving Your Product a Perfect Finish.

6. Presentation for over-the-counter (OTC) drugs

Packaging plays a great role in branding and display because it contributes to a great extent to the marketing strategy surrounding a formulation. When this choice is properly made, a company’s formulation is usually noticed first.

What are the possible interactions between the primary packaging materials and the dosage forms?

There are numerous possibilities of interactions between (primary) packaging materials and pharmaceutical products. These interactions according to Guidelines on packaging for pharmaceutical Products include but are not limited to the followings:

• the release of chemicals from components of the packaging materials;
• the release of visible and/or subvisible particles;
• the absorption or adsorption of pharmaceutical components by the packaging materials;
• chemical reactions between the pharmaceutical product and the packaging materials;
• the degradation of packaging components in contact with the pharmaceutical products;
• The influence of the manufacturing process (e.g. sterilization) on the container.

You may also like to know Why you should give your product a perfect finish.




Conclusion
The importance of making the right choice of packaging material for a pharmaceutical formulation cannot be over emphasized. This is not limited to drug manufacturing companies but also applicable in other manufacturing firms that manufacture products other than drugs. In selecting a packaging material for a formulation, it is important to note that a packaging material found acceptable for one drug product may not be appropriate for another. A manufacturer should make sure that each proposed packaging material and its components are suitable for the intended use.

Reference
World Health Organization (2002). Annex 9: Guidelines on packaging for pharmaceutical Products. WHO Technical Report Series, No. 902.

The title of this post is How to Make the Right Choice of Packaging Materials