Glass Dropper Bottles

GL18 is an international standard neck finish for small-volume glass dropper bottles. The critical dimension is an inner bore diameter of 10.65 mm ± 0.15 mm, which governs compatibility with all closures and accessories — caps, droppers, liners, pourers, and orifice reducers. The same GL18 neck is used across different bottle volumes (typically 5 ml to 50 ml), so a closure or dropper specified for one size will fit the full range.

Yes — all GL18 / NW18 closures and accessories are interchangeable across different bottle volumes, provided the bottle has the correct GL18 neck finish. Common bottle volumes using this neck include 5 ml, 10 ml, 15 ml, 20 ml, 30 ml, and 50 ml. Changing bottle size does not require a change of closure, dropper, or liner.

A vertical dropper requires the bottle to be inverted fully (180°) and delivers drops by gravity with high precision (±10% from target dose weight). It is designed for pharmaceutical oral drops where accurate dosing matters. A rim dropper requires only a 45° tilt and is used for applications where approximate dispensing is acceptable — essential oils, mouthwash, and cosmetic serums, for example. Rim droppers are not suitable where a precise dose is required.

To select the correct dropper geometry, you need to share: (1) the physical properties of your liquid — viscosity, surface tension, and density; (2) the target dose or drop weight; and (3) a safety data sheet for your formulation so compatibility can be assessed. Drop speed is typically targeted at 60–120 drops per minute, in line with European Pharmacopoeia monograph 0672, unless you specify otherwise.

With an OVII cap, the tamper-evident ring is moulded as an integral part of the cap in a single injection moulding step. This makes the OVII slightly more cost-effective but the TE bridges can be a point of weakness. With an OVIII cap, the ring and cap body are produced separately and assembled together — this results in a more reliable and cleaner tamper-evident function, making OVIII the preferred choice for pharmaceutical and regulated applications.

CRC (child-resistant closure) caps are available with or without a tamper-evident band. When specified with TE, you get both child resistance (ISO 8317 certified) and tamper evidence in a single closure — important for household pharmaceutical products and OTC medicines. The CRC mechanism works independently of the TE band, so both functions can coexist without compromise.

An integrated dropper (vertical or rim) is a passive device — liquid flows through it when the bottle is tilted or inverted. A dropper pipette is an active assembly comprising a hole cap, a rubber bulb (teat), and a glass or plastic pipette. The user squeezes the bulb to draw liquid up into the pipette, then releases it onto the target area. Pipettes are not suitable for precise drop counting but excel at targeted, clean application — ideal for cosmetic serums, CBD oils, and oral preparations where user convenience is a priority.

Glass dropper bottles are typically available in Type I (borosilicate, clear and dark amber — highest chemical resistance, suitable for pharmaceutical and injectable applications), Type II (soda-lime, light amber — treated to improve hydrolytic resistance), and Type III (soda-lime, clear — for less demanding applications, general cosmetic use). For oral pharmaceutical drops, Type I is typically specified. For cosmetics and essential oils, Type III clear or amber is common. Amber glass provides UV protection for light-sensitive formulations.

Liner selection is driven by four factors: (1) formulation chemistry — aggressive solvents or essential oils demand PTFE (Teflon) or butyl rubber; (2) oxygen sensitivity — oxidation-prone actives like vitamin C benefit from a PET or AL lining; (3) moisture and humidity — high-humidity environments or hygroscopic liquids benefit from aluminium lining; (4) regulatory requirements — pharmaceutical oral drops typically specify butyl rubber. We can advise on the appropriate liner once you share the formulation type or its safety data sheet.

Standard colours across the cap and dropper pipette range are black and white. Custom and brand-matched colours are available on request, subject to minimum order quantities. For dropper pipette hole caps, the minimum is 25,000 units for standard combinations, 50,000 for new combinations of existing products, and 250,000 for a new article with a new colour or shape. Get in touch to discuss your requirements.