KNOW-HOW  

The focus is on the eyes

In the Eye Care Tech­nolo­gies divison – a sep­a­rate product field of Harro Höfliger – every­thing revolves around solu­tions for the pro­duc­tion and pack­aging of oph­thalmic products.

Contact lenses inspire the imag­i­na­tion in many ways. In the block­buster “Mis­sion Impos­sible”, they make it pos­sible to pho­to­graph secret doc­u­ments in the blink of an eye. During the Olympic Games, the British sprinter Lin­ford Christie made clever use of it as an adver­tising space for his sponsor’s logo. Even the eye color can be inten­si­fied or tem­porarily changed, if desired. For most con­tact lens wearers, how­ever, the ultra-thin vision aids that pro­vide all-around clear vision are pri­marily an alter­na­tive to cor­rec­tive glasses.

The majority of people with poor sight opt for soft con­tact lenses, which are avail­able in a wide variety of designs: daily, weekly, 14-day or monthly lenses. Pre­cise man­u­fac­turing processes and com­pre­hen­sive quality con­trols guar­antee that con­tact lenses not only reli­ably cor­rect visual defects but are also gentle on highly sen­si­tive eyes.

Jochen Stein, Director Eye Care Tech­nolo­gies at Harro Höfliger, knows about the demanding processes: “For more than 20 years, this com­pany has been dealing with eye care prod­ucts and offers, among other things, fully auto­mated solu­tions cov­ering the entire value chain for con­tact lenses all the way to their dis­tri­b­u­tion. In addi­tion to lens man­u­fac­turing, whether bifocal or mul­ti­focal, for short-sight­ed­ness or for long-sight­ed­ness, for the cor­rec­tion of astig­ma­tism or even as an implantable intraoc­ular lens, we cover all of the fol­lowing pack­aging steps. That is, pri­mary pack­aging into blis­ters for product pro­tec­tion, sec­ondary pack­aging into car­tons and ter­tiary pack­aging into ship­ping cases – nat­u­rally including all in-process con­trols and labeling.”

“We pro­vide intel­li­gent solu­tions for lot size 1, for example for introc­ular lenses that are tai­lored to the indi­vidual patient.“Jochen Stein, Director Eye Care Tech­nolo­gies at Harro Höfliger

Gentle han­dling of the sen­si­tive lenses

Nowa­days, com­mer­cial con­tact lenses are mainly made by molding sil­i­cone hydrogel or hydrogel and then pack­aged into blis­ters. At the begin­ning, there is an injec­tion mold into which a liquid monomer mix­ture is dosed. Adding energy in the form of tem­per­a­ture or UV light trig­gers poly­mer­iza­tion and results in curing of the lens.

How­ever, before fur­ther pro­cessing, it must become soft again and retain mois­ture. After the so-called hydra­tion, it is care­fully released from the mold in a fully auto­mated process and then indi­vid­u­ally pack­aged into blis­ters with saline solu­tion. Harro Höfliger tech­nology is used to seal the blis­ters and laser code them with data such as, for example, lens type, eye­sight and diameter.

Fully auto­matic car­toning is one of Harro Höfliger’s key strengths. Jochen Stein: “In addi­tion to pack­aging machines for large vol­umes, we also offer intel­li­gent solu­tions for lot size 1 such as may be required for intraoc­ular lenses (IOLs). These implantable lenses are cus­tomized for each patient and, for instance, are inserted into the eye during cataract surgeries.”

Harro Höfliger’s portfolio:

1. Dosing of monomer mix­ture into injec­tion mold

2. Attaching of a second mold

3. Curing of the lens by heat or UV light

4. Removal of the mold after poly­mer­iza­tion is complete

5. Hydra­tion of the cured lens

6. Camera inspec­tion for quality control

7. Removal of lens for pack­aging process

8. Dosing of saline solu­tion into the single blisters

9. Sealing of the blis­ters and printing

10. Pack­aging of the blis­ters into cartons

Prod­ucts for eye care

Max­imum pre­ci­sion is also cru­cial for another med­ical device from the Eye Care Tech­nolo­gies range: Injec­tion sys­tems specif­i­cally designed for the eye. In line with their turnkey approach, Harro Höfliger not only offers reli­able joining tech­niques for the sen­si­tive indi­vidual com­po­nents, but also solu­tions for the sub­se­quent pack­aging. The know-how in filling, assembly, pack­aging and labeling of eye care devices also plays an impor­tant role when it comes to eye drops, gels and ointments.

Eye drops are not only filled into classic vials and as hygienic single doses into blow-fill-seal plastic ampoules. Even two-chamber tubes for oph­thalmic mix­ture appli­ca­tions are pos­sible, as offered by Neopac with their Fleximed® Easymix tube. Two com­po­nents are sep­a­rated by a seam in a med­ical tube. The thin bar­rier opens under pressue. With this method, two liq­uids as well as one liquid and one powder com­po­nent can be mixed.

Filling and sealing of the plastic lam­i­nate tube and the cen­tral bar are per­formed on machines from Harro Höfliger. Depending on the appli­ca­tion, the tubes can be equipped with dif­ferent clo­sures, appli­ca­tion and dis­pensing aids.

Filling and welding of tubes with eye drops takes place on machines from Harro Höfliger.

Smart future

By the way, high-tech lenses should not be reserved for Hol­ly­wood scripts, they could also pro­vide added med­ical value. Con­tact lenses with biosen­sors, for instance, are under devel­op­ment. Pos­sible appli­ca­tions include the mea­sure­ment of blood sugar levels in the tear fluid and alert in case of devi­ating values – a smart trend that could make quite a few finger pricks obsolete.

Research is also being con­ducted on vir­tual-reality-lenses that dig­i­tally extend the real world and feed in infor­ma­tion such as heart rate or even nav­i­ga­tion data on mini-dis­plays. When that will be? We will see.

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Photos: Adobe Stock / jayzynism, Janine Kyofsky