From variable doses to child-resistant blisters

Recent innovations in pharmaceutical packs include a system for dispensing creams with a variable quantity of active ingredient, and labels that allow large amounts of data to be included on them. Hilary Ayshford* reports

This time last year, it was novel forms of blister packs and developments in child resistant and tamper evident closures that were driving forward the pharmaceutical packaging sector. Looking back over the past 12 months, however, packaging companies seem to have been turning their attention increasingly to dispensing systems — with and without propellants.

Perhaps the most innovative launch of the year was a dispensing pack which not only allows two liquid product components to be dispensed simultaneously but also varies the proportions of each component from 0–100%. Developed by German company Variotec, the company claims the Dialpack can be used for a variety of products, including pharmaceuticals like cortisone cream, giving a variable concentration of the active. It is now being used for Variosun, thought to be the first sun lotion with an adjustable sun protection factor from 2 to 30.

The patented Dialpack dispenser consists of two cartridges, each containing a separate component and each with its own pump. Inside the mixing head is a mixing nozzle, where the two components come together for dispensing.

The ratio of the mix can be predetermined by means of an adjustment wheel on the outside of the container. The wheel is connected to a disk inside the containers, and turning it moves the pumps away from their vertical alignment by the corresponding value.

Operating the dispenser head causes the pump levers to move downwards and the pumps to operate. The angle of the pump from the vertical is what causes the proportion to vary — the closer the top of the pump lever to the dispenser head, the greater the depth of the pump stroke and the more of that component is dispensed. Similarly, the further away the pump lever is from the dispenser head, the shorter the pump stroke and the less fluid is dispensed.

Product levels can be seen through windows in the pack, and the cartridges inside are individually replaceable, so the dispenser can be reused. Also, because the system prevents air entering, it avoids deterioration of the product and lessens the need for preservatives, Variotec says. The adjustment wheel also has a 'locked' position to prevent accidental dispensing of the product during transportation.

The inability of creams and lotions to self-level means that conventional pumps tend to draw product from the centre of the container leaving residue clinging to the sides. Englass Dispensing and Packaging Systems, of Leicester, UK, solved a dispensing dilemma for Oriflame Ireland's Canoderm antiallergy cream with a customised version of its High Viscosity Dispensing System (HVDS).

The HVDS dispenser has an innovative 'follower-plate' which fits around the dispenser stem and rests on top of the product. As the level of product in the container drops, the follower-plate also moves down the container, ensuring that the product remains level at all times, and dramatically reducing the residue left behind. Oriflame's version of the dispenser features a spring loaded outlet ball valve to prevent air being sucked back into the dispenser.

Aerosol technology has been incorporated in two inventions by Peter Chown, of PCM Group based in King's Lynn. The first of these is the EverClean toothbrush, developed in recognition of the irony that the object we use to clean our teeth is a haven for bacteria, viruses and fungal infections which can survive on the bristles for several days and re-infect the user.

It uses an aerosol in the base to deliver a controlled amount of sterilising agent through a hollow tube in the handle and disperses it through holes at the base of each bristle. The solution is confined by a cap which fits neatly over the toothbrush head and prevents airborne contamination. The concept also claims to overcome one of the major flaws in toothbrush design and manufacture. At present the bristle filaments are pushed into the head and held in place by a small piece of wire, creating a perfect trap in which bacteria can breed. 'The industry has tried to solve this problem by using expensive equipment that melts the bristle into the hole of the head. The problem is by-passed altogether with the EverClean,' Chown explains.

The aerosol-in-the-handle technique has a number of other potential applications, including and medicines for site-specific care, particularly in the mouth and throat area. The EverClean toothbrush and its associated applications are being commercialised by high-tech company CFB, which is understood to be in discussions with several leading manufacturers of hygiene products.

The second PCM development is a double-ended aerosol, which can either contain two different products in separate compartments or a single product with different actuators at each end for a coarse or a fine spray.

The aerosols can be made from either aluminium or tinplate and there is no limit on the dimensions suitable for this concept. In the case of tinplate, the two containers would be soldered together at the base, while aluminium canisters would be joined by means of a heavy duty shrinksleeve. The containers could be filled on standard aerosol lines, according to Chown. The only adaptation required would be the addition of a container turnover unit.

The double-ended aerosol is suitable for a variety of uses, including medical products. World patents are pending and PCM intends to license the concept on a world-wide basis.

Inprint has introduced a label designed for clinical trials packs. It enables the customer to overprint batch codes and expiry dates in multiple positions on the leaflet label. A portion of the label can then be removed and placed on to the Case Report Form showing the overprinted information. Overlamination allows the customer to write any additional information, such as date dispensed, onto the label with a ball-point pen. It has been designed to create a single printed piece component, eliminating the potential of mismatch between printed label and prited leaflet.

The requirements to put ever more product information onto the packaging has led to a number of imaginative developments by label manufacturers. A new style leaflet label which doubles the space available for patient and medical information has been developed by Jarvis Porter Healthcare. Double-Dri combines two sheets of paper that are each printed on both sides. A special dry-peel adhesive allows the sheets to be easily separated by pulling a corner tab. The two sheets can then be read on both sides.

JP Healthcare says Double-Dri leaflets can be supplied on the reel or folded, and will help meet the growing demand for extra information in medicine packs, and for multi-lingual printing.

Last year also saw the launch of an e-commerce website, www.yet2.com, for the trading of intellectual property and technology. The technology and know-how, made available by major blue-chip companies, are available for sale or license exclusively through the website.

Among the listings on the site is an easy-open child-resistant blister pack which allows medicines, pills and other potentially hazardous tablet-type chemicals to be packaged in a dual-chamber blister cavity, consisting of a holding chamber and a discharge chamber. The technologies described on the website are available for sale or licence.