Choosing the Best Imprinting Machine for your Pharmaceutical Product Identity

 Choosing the Best Imprinting Machine for your Pharmaceutical Product Identity
Jonathan Bry, 
P.E. Project Engineer 
Ackley Machine Corporation


Oral Solid Dosage Formulations (OSDF) bring progress with medicines that improve health and quality of life. The process to progress however, goes unseen by customers when they do not recognize your pharmaceutical product as the artwork it is. Every OSDF must be imprinted with an identifiable code by regulation, but is being identified enough after it all? Every aspect of your product has been refined to a sheen of perfection that the uninitiated are simply unaware of, and an artist’s signature isn’t identified; it’s recognized. This recognition instills reassurance in a potential customer and contains value lost unless seized. This security compels them to reach higher on the shelf and take pride that they are worth the quality of your product. Despite the sigh of relief that signing a canvas brings the artist, the industry of imprinting is nuanced with ambiguities that rob the catharsis from drug development’s flourish. 

Three factors hold you back from those last brushstrokes. If you know your dosage, logo medium, and production level, you can get to market faster than your competition and with better representation for your brand.

Much like the namesake of this magazine, the canvases we call dosages can be grouped into tablets and capsules. Their size and material will define the tools and media you can use to shape your logo and scrutiny should be used with this first step. Under the focus of imprinting, tablets are self-inclusive but capsules fall into subcategories of softgels and 2-piece capsules. These types are specified by their shape, size, and coating so be sure to have strong quantitative descriptions of each before beginning. By locking in your product’s type and specification, you help yourself converge on the best option as imprinting options are specialized by dosage type. For example, until recently the only option for imprinting tablets was ink printing (more on this later). Softgels are predominately imprinted with ink, but current trends are shifting to favor laser marking due to the high achieved imprint consistency. The inherent sheen of softgels presents difficult adhesion surfaces if manufacturers have varying surface lubricity. If you have tried ink printing your softgels before with lower yields, it may be time to consider laser marking. Due to the tight curvature of 2-piece capsules, most imprinting is done by method of spin-printing to wrap the logo around the face of the capsule. The latter method should be considered more involved than traditional ink-printing and will require more expensive equipment to meet the same throughput, but is still feasible. Most facilities value this technology because traditional printing would result in too small of a logo to be legible on two-piece capsules. A deeper understanding of the brush is required to better leverage it. The most talented artists understand how the paint affects the canvas before touching it. 

In selection of medium for their art, Impressionists chose oils over acrylic paints to highlight motion of their strokes over the fluency of the colors across hues. Both acrylics and oils are compatible with canvas, but they affect it differently. Machine builders design your imprinter to organize and present your product to the imprinting technology across all fruitions, but the selection of imprinting technology dictates the efficacy of your vision. The particular dosage designer values the medium as much as the canvas on which it lies in much the same way. In today’s industry, the majority of imprinting is accomplished via ink printing and laser-marking. Most ink printing is completed using rotogravure technology due to its consistent quality and high throughput. In this technology a “design roll” is manufactured for each prospective logo. It is essentially a stainless steel cylinder with an array of your logo etched on an otherwise pristinely smooth surface. The debossed surfaces of the cylinder collect ink as it rolls into an ink pan and passes the inked logo to a cylinder it rolls across called a transfer roll. The entire system is geared to move in time with a conveyor below that carries your dosages. The transfer roll stamps them as they pass underneath. When you are considering two-piece capsules with spin-printing, the process is much the same, except the design roll and transfer roll spin faster than the conveyor that carries your product. This causes the product to ‘spin’ in place and allows the logo to lay across the circumference. 

On the other side, today’s laser-marking is accomplished by firing a concentrated beam of light through a system of mirrors called galvanometers that draw the logo across the surface of the tablet. Despite the laborious-sounding nature of drawing an individual logo per tablet, the speeds of today’s laser-marking imprinter systems reach up to 500,000 pieces per hour. 

Much in the same way that with an ink printer you choose the ink color you are imprinting with; you must choose a wavelength of light to laser-mark your dosages. Some customers are intimidated by material compatibility with laser imprinting systems, but the reality is that experts are just selecting a laser (UV, Infrared, Green, etc) that has a high absorbance in your OSDF. Today we are able to test for “good mark-ability” with machines called spectrometers before lasers are specified for a product. Be sure to consult the experts on what absorption peaks are best for marking your product. This step can drastically increase throughput and viability of your system and should not be overlooked. The most common peaks in our industry are the wavelengths 355nm, 9.3um, and 10.6um, which again are just numbers used to define the light in your laser. 

The emerging technology defying the norms of imprinting tablets we discussed earlier is the UV laser (355nm). Unlike the more renowned CO2/Infrared laser, which creates off- white markings, this wavelength creates a dark gray imprint that lends itself very well to white tablets through oxidation. While most think that only white tablets can be used for a UV laser, pioneering artists see high contrast markings on dark colored tablets and even softgels. The unifying criteria for UV laser efficacy is not tied to the misnomer of white, but to the opacifier concentration used in outer coating formulation. It is independent of color. The most common opacifier that reacts well with UV marking is titanium dioxide, but there are actually three known opacifiers that will create the same behavior. The opacifiers and the nominal mass percentages for imprinting can be found below: 

  • Titanium Dioxide (White in color) – 2-4% concentration 
  • Ferric Oxide (Yellow in color) – 0.1-0.5% concentration 
  • Red Ferric Oxide (Red in color) – 0.1%-0.5% concentration 

When comparing lasers, you should also consider that a UV laser will essentially draw your logos with a finer-tipped pen than a CO2/Infrared laser. If you have smaller, more intricate logos, you should consider a UV laser and a CO2/Infrared laser for larger logos and logos with more solid-fill. You selected the canvas and paired it with a medium to imprint your work but, are there any other considerations for when to choose one over the other? Absolutely. 

Each stroke of the brush and letter of an identifying logo follows the artist that chose it throughout and after the process. Much in the same way that paint forever stains the canvas, the selection of imprinting hardware cannot be removed without rigorous revision. This choice drives the submission of regulatory documentation as well as SOP design and ancillary equipment selection. There are key differences with both of these methods besides applicable OSDF types. Ink printing remains the highest throughput method of imprinting, but requires consumables and maintenance that laser-marking does not. Ink printers are ubiquitously accepted as safe for ink- printing as long as FDA guidelines for ink selection and contact parts are heeded, but laser marking is technically more sterile in that it does not actually touch the product. Either choice will require ancillary equipment with a laser-marking system needing a fume extractor to harvest the particles removed to create markings. An ink printer will typically use an ink maintenance system to balance the viscosity of printing ink and achieve consistent print quality. Much of the start- up and tuning of laser-marking machines has been automated to make them more plug-and-play than ink printers, though you will pay more for them up front. If you require flexibility in your printing including frequent changing of logos, scannable QR codes or continuously updating alpha-numeric sequences, you will want a laser-marking system. The best laser- marking machine builders today can remotely upload and change logos or troubleshoot systems without hopping on a plane or shipping equipment. However, if you require flexibility in color of your imprints, you will need an ink-printing system. 

You perfected your art and you know the equipment you need, but you still need a studio to embody your work effectively. Depending on the market for your product, some artists may need more volume than others. As you defined your tablet and mulled over the imprinting type, understanding your production needs will help you finalize your equipment decision.

There are currently options available for small laboratory installations to high-volume productions. On the small production side, R&D machines are small, manually fed devices that allow developers to experiment with logos before com- mitting to more costly equipment. From there, automation steps in to facilitate single-lane machines that take bulk product, orientate it, and imprint it (up to 60,000 pieces per hour for ink and 60,000 pieces per hour with laser). Multi-lane ‘cantilever’ systems are available that expand on this with ‘medium’ production levels up to 200,000 pieces per hour. The widest format of multi-lane machines for high production needs can achieve up to 500,000 pieces per hour for ink or laser and 400,000 for a combination ink AND laser imprinter. If your development requires high production imprinting options on both sides of your OSDF, a drum-fed machine will be a good-fit for your operation with outputs up to 150,000 pieces per hour. These machines have size constraints for efficient feeding OSDF’s. The single-lane automated VIP machine is the most stringent one to fit, for example (See Figure 1). 

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If your product does not meet these criteria, all is not lost – you will just need to call and discuss the best-fit machine with a sales engineer. These machine types examples, offered by Ackley Machine Corporation, are organized from most stringent dosage dimensions to least stringent: VIP Laser VIP Ink Printer Drum Machine Cantilever and Variable Ramp However, if accuracy in print is a driver, the drum machine is the most accurate marker/printer. From here, there are several add-ons that further the consistency and quality of your branding. These new technologies ensure each Little Mona Lisa smiles the same as the next. The rigorous regulation of the pharmaceutical industry created a need for high efficiency single tablet inspection/rejection that can be added on any automated- feed machine. Instead of batch inspection, each OSDF can be individually inspected and reviewed against your facility’s conformance requirements. On top of individual inspection for defects, the latest developments allow for indexing and organizing of softgels so that ink printing and laser logos do not fall on the seam of the product. Manufacturers refer to this as ‘Seamless Technology’. 

So much unrecognized effort goes into drug development and if the informed customer doesn’t connect with your product, they will always reach for the cheaper option. What makes your drug different in-store is how the customer feels about it and recognizes it. When generic formulations match performance and composition of your preferred brand it truly becomes a question of what is outside that counts. In a store with several pharmaceuticals performing the same function, what will distinguish yours from the rest to establish a connection with your customers? Will it be your price or your signature?


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