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GL18 White Tamper-Evident Closure with Integrated Syringe Plug

  • Product Code: GL18TEW-ISP
GL18 white tamper-evident closure with integrated syringe plug, PEHD/PELD. Fits all GL18 bottles 5ml–100ml. Syringe-withdrawal dosing. Ideal for oral liquid medicines and vitamin preparations.
MOQ and lead time applies – Please contact us for further details
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The GL18 White Tamper-Evident Closure with Integrated Syringe Plug (GL18TEW-ISP) combines first-open tamper evidence with a syringe-compatible plug insert in a single GL18 cap assembly, manufactured in PEHD and PELD. The integral tamper-evident ring — moulded as part of the PEHD cap body — provides visible first-open evidence confirming the product has not been accessed prior to purchase, while the PELD syringe plug insert enables the user to withdraw a precise measured volume of liquid using an oral dosing syringe inserted directly through the plug. This combination makes the GL18TEW-ISP the appropriate closure for retail oral liquid medicines, vitamin and mineral liquid supplements, oral tinctures, and healthcare preparations where both syringe-based volumetric dosing and consumer-facing tamper evidence are required simultaneously — and where child-resistant packaging is not a mandatory regulatory requirement for the product category.

Syringe-withdrawal dosing delivers a higher degree of volumetric accuracy than drop counting, as the user draws an exact volume directly into the barrel of a calibrated oral syringe rather than estimating dose by drop number. The self-sealing PELD plug flexes to admit the syringe tip on insertion and reseals on withdrawal, maintaining closure integrity between doses. As part of the GL18 system (also known as NW18 or DIN168), the GL18TEW-ISP is fully interchangeable across all GL18 glass dropper bottles in the BlueSky range — 5ml to 100ml, in both amber and clear glass. Please note that a separate tamper-evident syringe plug closure is available in PP/PELD material (GL18TEWPP-ISP) — contact BlueSky’s team to confirm which material specification is most appropriate for your formulation and filling process. Contact BlueSky to confirm stock availability, MOQ, TE ring type, and syringe compatibility before specifying.

Additional information

Material

PEHD/PELD
Neck size

GL18

Integral Tamper-Evident Ring — Retail Consumer Assurance

The tamper-evident ring is moulded as an integral part of the PEHD cap body, with TE bridges providing visible evidence of first opening. When the cap is opened for the first time the bridges break and the ring remains on the bottle neck, giving consumers immediate confirmation that the product has not been accessed prior to purchase. For retail oral liquid supplements, vitamin preparations, and healthcare liquids sold through pharmacy and health retail channels, tamper evidence is a standard consumer expectation and a commercial requirement for credible retail presentation. Please contact BlueSky’s team to confirm the specific TE ring type for this closure before specifying.

Integrated Syringe Plug — Accurate Volume Withdrawal

The PELD syringe plug insert is a self-sealing device that allows an oral dosing syringe to be inserted directly through the plug and into the bottle, enabling the user to withdraw a precise measured volume rather than counting drops. The plug flexes to admit the syringe tip on insertion and reseals on withdrawal, maintaining the integrity of the closure between doses and preventing leakage or contamination during storage. Syringe compatibility should be confirmed with BlueSky’s team prior to production.

Syringe-Based Dosing — More Accurate Than Drop Counting

Syringe-withdrawal dosing allows the user to draw an exact volume directly into the barrel of a calibrated oral syringe, delivering significantly higher volumetric accuracy than drop counting — where variability in bottle angle, liquid viscosity, surface tension, and drop speed can meaningfully affect the actual volume delivered per dose. For oral liquid supplements, vitamin preparations, and healthcare products where dose accuracy matters to the consumer or to the product’s therapeutic or nutritional claim, syringe-based dosing is the more reliable and consumer-reassuring dispensing method.

PEHD/PELD Two-Material Construction

The cap body is manufactured in PEHD (high-density polyethylene), providing structural rigidity, chemical resistance, and the integral TE ring mechanism. The syringe plug insert is manufactured in PELD (low-density polyethylene), which provides the flexibility required for the plug to self-seal around the syringe tip on insertion and withdrawal. Both materials offer broad compatibility with aqueous oral liquid formulations, vitamin preparations, alcohol-based tinctures, and herbal extracts. Formulation compatibility testing is always recommended prior to committing to production.

Tamper Evidence Without Child Resistance — Retail Healthcare Positioning

The GL18TEW-ISP provides first-open tamper evidence combined with syringe-withdrawal dosing — without a child-resistant opening mechanism. This positions it correctly for retail oral liquid supplements and healthcare preparations sold through pharmacy and health retail channels where tamper evidence is commercially expected but child-resistant packaging is not a mandatory requirement for the product category. For products where child access to the liquid contents presents a safety risk — such as concentrated pharmaceutical preparations or products subject to child-safety packaging legislation — the GL18TEWPP-ISP or a CRC syringe plug configuration is the more appropriate specification. Please contact BlueSky’s team to discuss the correct closure specification for your regulatory requirements.

Universal GL18 Compatibility — 5ml to 100ml

The GL18TEW-ISP is compatible with all GL18 glass dropper bottles in the BlueSky range — 5ml, 10ml, 15ml, 20ml, 30ml, 50ml, and 100ml — in both amber and clear glass. The GL18 neck standard maintains a consistent inner bore diameter of 10.65mm ± 0.15mm across all bottle volumes, meaning this closure specification does not change when bottle size changes within the range. For light-sensitive vitamin and nutraceutical formulations, amber glass is typically the recommended specification.

  • Liquid vitamins and supplements
  • Oral tinctures and herbal extracts
  • Healthcare oral liquid preparations
  • Homeopathic oral preparations
  • Nutraceutical dosing formulations
  • Veterinary oral liquids
  • OTC wellness and health supplements

Delivery & Returns

Orders for products in our ‘In Stock’ ranges will normally be delivered within two working days. Our product ranges labelled as ‘Product MOQ Applicable’ may be subject to a lead time which will be confirmed to you when we receive your order. For information relating to delivery charges, please refer to the ‘Is there a carriage charge?’ section in our FAQs page.

In some instances, goods can be returned. Please view our full refunds policy in our terms and conditions here: Terms & Conditions.

Core Product Range

We endeavour to hold continuous stock of this product. We expect to stock these ranges for a significant period of time in the future. This ensures you can build ranges around them and rely on their availability both now and in the coming years.

In Stock

We hold these products in our UK warehouses for you and they are available for rapid delivery.

Product MOQ Applicable

These products are not currently available from our UK held stock. However, we can supply you from our flexible and solid, global supply chain. Please note that there are minimum order quantities (MOQs) associated with this product, and lead times may vary depending on the quantity ordered. For more information on MOQs and lead times, please contact: sales@blueskysolutionsuk.com

Additionally, we can create bespoke products for you whether through colour, decoration, or bespoke tooling - to your specification. Our team of product experts will work with you to understand your requirements and place the necessary orders.

Delivery & Returns

Frequently Asked
Questions

How does the syringe plug work and what syringe is needed?

The PELD syringe plug is a self-sealing insert within the closure cap. An oral dosing syringe is pushed through the plug seal, which flexes to admit the syringe tip and reseals when the syringe is withdrawn — preventing leakage and maintaining closure integrity between doses. The oral dosing syringe is not supplied with the closure. Please contact BlueSky’s team with details of your preferred oral dosing syringe to confirm tip compatibility with the plug geometry before committing to production.

What is the difference between this closure and the GL18TEWPP-ISP?

Both closures combine a tamper-evident ring with an integrated syringe plug delivering the same syringe-withdrawal dosing function, but the cap body material differs: the GL18TEW-ISP uses PEHD, while the GL18TEWPP-ISP uses PP. Both materials offer broad chemical compatibility with oral liquid formulations, but may differ in specific formulation compatibility, TE ring construction, and filling process suitability. Please contact BlueSky’s team to confirm which material specification is most appropriate for your formulation and production requirements before specifying.

When should I choose this closure over a vertical dropper with tamper evidence?

Syringe-withdrawal dosing and vertical dropper dosing are both high-accuracy dispensing methods, but they suit different end-user contexts. The vertical dropper (GL18TEW-IVD) delivers drops by gravity when the bottle is inverted — the user counts drops to reach a target dose. The syringe plug (GL18TEW-ISP) allows the user to draw an exact volume into a calibrated syringe barrel — more intuitive for consumers who are already using an oral syringe as part of a dosing routine, and particularly suited to paediatric applications or where a specific volume rather than a drop count is the prescribed dose format.

Does this closure provide child resistance as well as tamper evidence?

No. The GL18TEW-ISP provides tamper evidence — visible first-open evidence — but is not a child-resistant closure. For products requiring child resistance alongside syringe-plug dosing and tamper evidence, please contact BlueSky’s team to discuss the available CRC syringe plug configuration options within the GL18 system. Your regulatory advisor can confirm whether child-resistant packaging is a legal requirement for your specific product category and market.

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