The routes of administration of medications and their packaging

The choice of the route of administration of a given medication plays a crucial role in medical treatment, as it affects the entire pharmacokinetic process of the active ingredient introduced into the body. Therefore, there are different types of primary pharmaceutical packaging each designed to precisely meet the specific needs of the drug and the patient, and to enhance the mode of administration.

The main primary packaging systems for pharmaceutical use include:

• Packaging for oral administration
• Packaging for parenteral administration
• Packaging for topical administration
• Packaging for ocular administration
• Packaging for nasal administration
• Packaging for pulmonary administration

The world of primary packaging for medicines includes all systems that come into direct contact with the drug, such as containment systems, whether bottles, pill bottles or vials, and closure systems, such as capsules and ferrules. All the accessories, such as pipettes and droppers, that enable correct dosing and proper and safe administration, must also be taken into consideration.

Packaging and oral administration

The primary packaging for liquid oral drugs such as syrups mainly includes:

• Multi-dose containers, i.e. bottles. Depending on the specific requirements of the medicine, these can be made of glass or plastic. The packages can be strengthened by specific additives that increase the barrier properties against moisture, oxygen or light.
• Single-dose containers, such as vials or small bottles, suitable for administering a single dose of the drug.
• Advanced reconstitution systems, i.e. dual-chamber kits that allow the powdered drug to be mixed into an aqueous solution immediately prior to administration. The active excipient, stored separately in a reservoir inside the closure, is released via a mechanical action and mixed with the solvent in the main chamber.

The types of primary packaging for solid oral drugs, including pills, tablets and gel capsules, available on the market are:

• Bottles and pill bottles of various sizes, also made of glass or plastic.
• Blister packs, consisting of sealed cavities containing the drug.

Semi-solid drugs, such as creams and ointments, are usually packaged in metal tubes or plastic or glass containers.

Generally speaking, plastic closures are used for the packaging of oral medicines, whether solid or liquid, which can be tamper-proof and thus indicate whether the container has already been opened, or child-proof.

In addition to containers and closures, it is essential to consider dosing accessories, including:

• Droppers applied directly onto the bottle or assembled together with the pharmaceutical closure. These dispensing systems vary depending on the specific nature of the drug and the required dosing precision. There are: suction pipettes, whereby - by means of pressure exerted on the upper end of the pipette - liquid is sucked into a bulb and then released; horizontal droppers, i.e. inserts applied to the neck of the bottle that release the drops by slightly tilting the bottle; and, finally, vertical droppers, which operate in a similar way, allowing a controlled flow and drop rate.
• Accessories that are supplied separated from the package body, such as measuring cups, syringes and spoons. These can be graduated, with greater or lesser precision, as required.

Packaging and parenteral administration

Intravenous, or parenteral administration, typical of vaccines and saline solutions, for example, involves the introduction of the drug directly into the body, through intravenous, intramuscular or subcutaneous injections. The packaging of drugs intended for this mode of administration must be subject to particular care and precision, starting with the use of extremely high-quality materials, the use of extremely safe production processes, and strict controls.

In particular, the following are used:

• Glass vials and bottles mostly made of Type I glass, also known as borosilicate glass, which is extremely resistant and chemically stable.
• Plastic vials and bottles: these are made from advanced polymers and are particularly suitable for sensitive biological products.
• Rubber closures or rubber stoppers:These are used not just to seal the container, but also to perfectly isolate the medicine, ensuring sterility and preventing any form of contamination.
• Aluminium ferrules: The rubber closure is in turn sealed by a removable aluminium outer layer.

Packaging and topical or ocular administration

Topically administered drugs, such as antifungals for nails, are applied directly to the skin or mucous membranes. This mode of administration includes creams, ointments and lotions. The packaging of these products often includes tubes, bottles or packages that provide for precise and hygienic application of the drug. There are also specific accessories included in the packaging for this purpose, such as spatulas or brushes, which aid the user in the application.

Ophthalmic medication, such as eye drops, are packaged in sterile, single-dose or multi-dose bottles. The dosing method is extremely important, which must be supported by precise dispensers that can dispense a precise amount of the drug. Innovative ways of administering these medicines include bottles with ergonomic applicators, which allow safer and more comfortable dispensing, or, advanced systems that provide nebulisation.

Packaging and pulmonary or inhalation administration

Some drugs, such as asthma medication, are administered by inhalation to reach the airways directly. Devices for this type of medicine are inhalers or aerosols, i.e. pressurised packages that expel the product through a valve. There are generally two macro-types of inhaler systems:

• Pressurised metered dose inhalers (pMDIs): devices that deliver drugs in aerosol form by dispersing, suspending or emulsifying an API in a solvent/propellant. The pMDIs consists of a pressurised cylinder inside a plastic case, with a mouthpiece attached. When the user activates the dispenser, a precise quantity of the drug is released.
• Dry powder inhalers (DPIs): devices that deliver the drug through negative pressure exerted directly by the user's breathing. The device usually contains a capsule that is punctured or opened to release the drug. There are single-dose dispensers on the market, where the drug is loaded in single-dose capsules, and multi-dose dispensers, which hold up to 100 doses of the drug.

When designing these systems, it is essential to consider the force of the pressure exerted when expelling the product, in order for the drug to be administered correctly and at the same time protect the patient using it.

How packaging innovation can support drug efficacy

Over time, numerous innovations have emerged in the field of pharmaceutical packaging: from early child-resistant packaging to systems that facilitate dosing, and more advanced delivery devices that improve therapy adherence and the overall patient experience by exploiting IoT tools. These include, for example, smart pill dispensers that dispense pills in a controlled manner and also use a connected app to send notifications to the patient's smartphone to facilitate the organisation and monitoring of medication dosage.

Another area of research is the development of new 'accessible' packaging systems, designed to facilitate use by more vulnerable people, such as the disabled or elderly. In particular, these solutions allow for easy opening, often even possible using just one hand and without the use of excessive force; or simplified dosing and dispensing methods, such as bottles that release the medicine in controlled doses by exerting only light pressure.

Ultimately, the routes of administration for medicines and their packaging are key elements in ensuring efficacy, safety and adherence to drug therapy. They are an integral part of the treatment process and an important point of contact between the patient and the medical treatment. Investing in the design of safe, informative and user-friendly packaging is essential for promoting people's health and well-being.