TYPES OF CLOSURES USED FORPACKAGING OF DOSAGE FORMS
closures are devices and techniques used to close or seal a bottle, jug, jar, tube, can, etc. Closures can be a cap, cover, lid, plug, etc. closures tightly packs the container to exclude oxygen,carbondioxide,moisture , microorganisms ,prevents the loss of water and other volatile substances from the product
Purpose of closures : Many containers and packages require a means of closing. It can be a separate device or seal or sometimes a integral latch or lock. Depending on the contents and container, closures have several functions: Keep the container closed and the contents contained for the specified shelf life until time of opening Provide a barrier to dirt, oxygen, moisture, etc. Control of permeation is critical to many types of products: foods, chemicals, etc. Keep the product secure from undesired premature opening Provide a means of reclosing or reusing the container Assist in dispensing and use of product Allow reasonable ease to open the container by the intended user. Difficult to open containers may cause wrap rage. The force or torque required to open a closure is an important consideration for packaging engineers Many types of packaging with their closures are regulated for strength, safety, security, communication, recycling, and environmental requirements.
Types of closures(a)RUBBER CLOSURES(b)CAPS & OVERSEALS screw cap crown cap Snap on Friction fit (c)SPECIAL TYPES Tamper-evident Dispensing Child-resistant
Rubber consists of several ingredients,one of them is elastomer.rubber compounds used in pharmaceutical packaging contain only limited number of ingredients,which are difficult to extract.these closures do not pose a problem and can used in contact with large number of drug preparations. Rubber closures for containers for aqueous parenteral preparations have been classified into 2 types,according toB.P.Type I are to be preferred:Type II closures are those,which have mechanical properties suitable for special use,cannot meet the requirements as severs as those for the 1st category because of the chemical composition. Fragmentation test and self sealability of closures of parenteral preparation is given by…..
Place a volume of water corresponding to nominal volume minus 4ml in each of 12 clean vials Close vial with closure and secure caps for 16hoursPierce the closures with 21 SWG hypodermic needle and inject 1ml water and remove 1ml air Repeat the above operation 4times for each closureCount the number of fragments visible to the naked eyeTotal number of fragments should not be more than 10 except butyl rubber where the fragment should not exceed 15
SELF SEALABILITY (IP 1996) TEST FOR RUBBER CLOSURES APPLICABLE TO MULTIDOSECONTAINERS ONLY Fill 10 vials with water to nominal volume and close the vials with closure,secure the cap Pierce the cap 10times at different sites with 21SWG hypodermic needle
Immerse the vials in 0.1%w/v solution of methylene blue under reduced external pressure for 10min Restore the normal pressure and keep the container immersed for 30minutes Wash the vials.None of the vials should contain trace of coloured solution
CAPS AND OVERSEALS :These are used to secure the rubber closure to the container in order to maintain the integrity of the seal under normal conditions of handling and storage.It includes: Screw capA screw cap or closure is a common type of closure for bottles, jars, and tubesCommon screw closures: Plastic bottle with plastic screw cap, Dispensing closure for salad dressing (with inner seal), Break- away closure for syrup, Dispensing pump closure, Dispensing closure (with inner seal), Spray pump, Metal closure on glass jar, Child resistant closure, Cap on toothpaste, Measuring cap
A "sports cap", which appears on many water bottles, seen in closed configuration at left an in open configuration at right, availing the water to pass around the central blue piece. Usage A screw closure is a mechanical device which is screwed on and off of a "finish" on a container. Either continuous threads or lugs are used. It must be engineered to be cost-effective, to provide an effective seal (and barrier), to be compatible with the contents, to be easily opened by the consumer, often to be reclosable, and to comply with product, package, and environmental laws and regulations. Some closures need to be tamper resistant and have child-resistant packaging features.
Crown cap Crown capsMain article: Bottle cap Beverage bottles are frequently closed with crown beverage caps. These are shallow metal caps that are crimped into locking position around the head of the bottle. Bottle capFor the Nestlé candy, see Bottle Caps (candy). A generic 21-teeth crown cork bottle cap
Bottle caps are a type of closure used to seal the openings of bottles of many types. They can be small circular pieces of metal, usually steel with plastic backings, and for plastic bottles a plastic cap is used instead. A bottle cap is typically colorfully decorated with the logo of the brand of beverage. Caps can also be plastic, sometimes with a pour spout. Flip-Top caps like Flapper closures provide controlled dispensing of dry products Other types plastic bottle screw Bottle closurepull-off bottle cap used to sealcap a plastic bottle
Snap on Some closures snap on . For opening , the top is designed to pry off, or break off, or have a built in dispenserFriction fit
Some containers have a loose lid for a closure. Laboratory glassware often has ground glass joints that allow the pieces to be fitted together easily. An Interference fit or friction fit requires some force to close and open, providing additional security. Paint cans often have a friction fit plug.
Special types of clousres Tamper evident Layers of tamper resistance: carton with adhesive, shrink band, cap, innerseal Main article: Tamper resistant Main article: Tamper-evidentResistance to tampering is required for some types of products. Containerclosures can be one of several layers of packaging to deter tampering and toprovide evidence of attempts at tampering.Various types of tamper evidentpackagings are listed.They are-
Film wrappers breakable cap ring systems Blister packs sealed tubes Bubble packs plastic blind end sealed tubes Heat shrunk bands or wrappers sealed cartons Paper foil for plastic packs aerosol containers,and Bottle with inner mouth seals metal and composite cans Tape seals Dispensing A wide variety of convenience dispensing features can be built in to closures. Spray bottles and cans with aerosol spray have special closure requirements. Pour spouts, measuring attachments, sifting devices, etc. are common.Child-resistantMain article: Child-resistant packagingChild-resistant packaging or C-R packaging has special closures designed to reduce the risk ofchildren ingesting dangerous items. This is often accomplished by the use of a special safety cap.It is required by regulation for prescription drugs, over-the-counter medications, pesticides, andhousehold chemicals.
Examples . spray bottlecoffee tin – square can with friction fit closurerubber stoppers on flasks
spray duster with long tube for dispensing Closure and roll-on device for deoderantInverted catsup bottle with innerseal and dispensing closureBottle of Geritol with a child resistant cap