Leakage of ointment from Aluminum tube preventive measures

How to eliminate leakage of cream from aluminum tube pack of cream:

 Ointment and cream dosage form are temperature sensitive, slight change in storage condition can liquefy the cream and ointment the liquefied cream or ointment try to ooze out of the filled and packed tube from the back side folding on the tube. 

 There was a market complaint from the market for leakage of the ointment from the back side of the tube. The melting point of the ointment was 40 degrees Celsius. That means the cream, if at all exposed to a little higher temperature even up to 30 Degree, will get thinner. And try to come out from the gaps in between the folds at the back side of the aluminum tube. 

 To get a complete solution for the problem of leakage from the product one should understand the process of manufacturing of aluminum tubes, extrusion process of aluminum tubes, and lackering and coloring printing process. Aluminum slug is pressed under high pressure inside a dai, due to high pressure aluminum being soft metal spread evenly over the dai cavity and form a tubular structure, which is finished and formed as a collapsible aluminum tube for packing of ointment and cream inside the tube. 

 During formation of an aluminum tube from aluminum slug a small particle if entrapped inside the sludge or inside the dai, creates small small pin holes, therefore there is a chance that an aluminum tube may have a pinhole during production. Therefore, just before filling the aluminum tubes, alu. tubes must be visually inspected under light for presence of pinholes. 

 

Aluminum being reactive with environmental oxygen, it forms aluminum oxide and it can react with product and degrade the product, therefore product with quaternary salts may degrade in and loose the purity or assay get lowered, during storage. 

 Therefore, the inner surface of the aluminum tube is coated with inert material which does not get removed by oily as well as water, one of such materials is shellac. 

 What should be done to eliminate the leakage of cream from aluminum tubes? 

 The aluminum tube, when folded three times from top to first fold closes the opening, second fold turns the opening inside the fold, third fold turns the second fold inside, followed by crimping on these three folds, due to which there is now very less possibility for a cream to come out. But there are some products like ointment that are very oily which oozes even out from the folds, therefore to prevent such leakage, aluminum tubes at the end are provided with latex rings from inside, which in the first fold seals and make the aluminum tube air tight.