Container and closure: Mrs. Chetana d. modi Container and closure Closures : Closures An effective closure must prevent the contents from escaping and allow no substance to enter the container. The adequacy of the seal depends on Resiliency of the liner Flatness of the sealing surface on the container The tightness r torque with which it is applied. Five basic designs of closures: Five basic designs of closures Threaded screw cap Lug cap Crown cap Roll on closures Non-reusable roll-on closures Pilerproof closures 1. Threaded screw cap: 1. Threaded screw cap Threads engage with the corresponding threads on the neck of the container. Liners are pressed against the opening of the container that seals the product by overcoming sealing surface irregularities. Made of metal e.g tinplate or aluminium. Also made from plastics e.g. thermosetting and thermoplastic materials. Metal caps are coated inside with enamel or lacquer for resistance to corrosion. 2. Lug cap: 2. Lug cap Same as threaded screw cap but interrupted thread on glass finish instead of continuous thread. Engage a lug on the cap sidewall and sealed by pressing but requires quarter turn. Used for both normal atmospheric-pressure and vacuum-pressure closing. Widely used in food industry and also for parenteral equipments. 3. Crown cap (crimp on): 3. Crown cap (crimp on) Used for crimped closure for beverage bottles Remain unchanged for more than 50 years. 4. roll-on closures: 4. roll-on closures Made up from aluminum so sealed securely, opened easily and resealed effectively. Used for packaging of food, beverages, chemicals, and pharmaceutical. Resealable , non- resealable and pilerproof type roll-on closure are available for glass, plastic bottles and jars. Available in form of straight-sided, threadless shell After filling forms the threads on the packaging line. Allows for dimensional variation and fits a specific container. 5. Pilerproof closures: 5. Pilerproof closures Same as roll-on closure but greater skirt length. Additional length extends below the threaded portion to form a bank. Which fastened to the basic cap by a series of narrow metal “bridges”. When cap is removed bridges break and bank remains in place on the neck of the container. Non-reusable roll-on closures: Non-reusable roll-on closures Require unthreaded glass finishes. The skirts of these closures are rolled under retaining rings on the glass container. They are tear-off tabs that make them tamperproof and pilerproof. Closure liners: Closure liners A liner may be defined as any material that is inserted in a cap to effect a seal between the closure and the container. Made of resilient backing and facing material. Backing material must be soft enough to take up any irregularities in the sealing surface and elastic enough to recover its original shape when removed and replaced. It is glued into cap with adhesive or cap can be made with undercut so free to rotate. Factors in selecting a liner: Factors in selecting a liner Chemically inert with product Gas and vapor transmission rate E.g of liner material Polyethylene Saran Aluminum foil Tinfoil Polyester Vinylite Yellow-oil Types of liner: Types of liner Torque testing: Torque testing The owens-illiois torque tester is used for tourque testing to check cap tightness on a packaging line because To prevent evaporation or leakage of the product Breakage of the plastic molded closure Application of a cap too tight to be removed. Rubber stoppers: Rubber stoppers To make stoppers, cap liners and bulbs for dropper assemblies. For multi-dose vials and disposable syringes. Rubber polymers are used e.g. natural, neoprene and butyl rubbers. Ingredient in rubber stoppers are Rubber, vulcanizing agent, accelerator/activator, extended filler, reinforced filler, softener/plasticizer, antioxidant, pigment, waxes. Complications associated with rubber stoppers: Complications associated with rubber stoppers Complex to manufacture May absorb active ingredient, antibacterial preservative from parenteral products Interfere with chemical analysis of the active ingredient Affect the toxicity or pyrogenicity of the injectable product Affect the chemical and physical stability of the preparation. Thermosetting resins: Thermosetting resins Phenolic and urea are mostly used. First soften under heat and then cures and hardens to a final state. Shaping must occur in first stage of softening. Once it is molded, no change in shape even upon reapplication of heat and pressure. Fabricated by compression molding. The manufacturing process is relatively slow but with better control and quick response to change in temperature and material flow. Phenolics : Phenolics Available in different grades and in dark colors (black and brown). Rigid, heat and chemical resistance and good strength. But color limitation. Withstand the torquing forces of capping machine and maintains a tight seal over a long period of time. Resistant to dilute acids and alkalies Strong alkalies decompose phenolics. Urea : Urea Hard translucent material takes coloring well. More expensive than phenolics . Heat resistance. Elegant colors are available Withstand high temperature. Absorb water under wet conditions but no serious effect on product. Not affected by organic acids but affected by alkalies and strong acids. Good resistance to all types of oils and greases Can’t be steam sterilized. Thermoplastic resins: Thermoplastic resins Polystyrene, polyethylene and polypropylenes are mostly used. Each material have specific advantages depending on their physical and chemical properties desired for the application and on the particular product being packaged.