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E-Articles - Leather
WHAT IS IT?
Leather is a non-woven mass of collagen fibers, derived from the skin of animals, that has been rendered biorefractive.
WHAT IS LEATHER’S MOST IMPORTANT PROPERTY?
Leather’s most important property is that it will not rot under its normal conditions of use. This property of resistance to biological degradation is called biorefractiveness. Biorefractiveness is leather’s most important property because without it, leather would not be use
Leather is a non-woven mass of collagen fibers, derived from the skin of animals, that has been rendered biorefractive.
WHAT IS LEATHER’S MOST IMPORTANT PROPERTY?
Leather’s most important property is that it will not rot under its normal conditions of use. This property of resistance to biological degradation is called biorefractiveness. Biorefractiveness is leather’s most important property because without it, leather would not be use
According to USFDA, a combination product is one composed of any combination of a drug and device; biological product and device; drug and biological product
ful for anything.
WHAT OTHER IMPORTANT PROPERTIES DOES LEATHER HAVE?
Toughness and flexibility in combination are leather’s outstanding material properties. This combination of properties is the reason why leather is so useful. Because accepts dies and pigments readily, leather can be made in many colors. It is also formed into shapes easily with simple tools. Thus leather can be formed into objects that are both useful and beautiful.
HOW IS LEA
WHAT OTHER IMPORTANT PROPERTIES DOES LEATHER HAVE?
Toughness and flexibility in combination are leather’s outstanding material properties. This combination of properties is the reason why leather is so useful. Because accepts dies and pigments readily, leather can be made in many colors. It is also formed into shapes easily with simple tools. Thus leather can be formed into objects that are both useful and beautiful.
HOW IS LEA
; or drug, device, and biological product and fixed dose combination would include two or more combinations of drug.
Examples of combination products may in
Examples of combination products may in
THER MADE BIOREFRACTIVE?
Leather is made permanently resistant to biological attack through the tanning process. The chemicals used to tan leather bond with the collagen proteins that form the fibers in leather, and render the protein indigestible to bacteria. The thoroughness and completeness of this chemical reaction is key to making good leather.
WHERE DOES LEATHER COME FROM?
Leather is made from the skin and hide of animals. The raw skin cons
Leather is made permanently resistant to biological attack through the tanning process. The chemicals used to tan leather bond with the collagen proteins that form the fibers in leather, and render the protein indigestible to bacteria. The thoroughness and completeness of this chemical reaction is key to making good leather.
WHERE DOES LEATHER COME FROM?
Leather is made from the skin and hide of animals. The raw skin cons
lude drug-coated devices, drugs packaged with delivery devices in medical kits, and drugs and devices packaged separately but intended to be used together.
ists of hair, follicles, sweat glands, and fibrous proteins. The longest and largest fibers are found on the flesh side of the skin and can be as large as 0.01 mm in diameter and several centimeters long. Finer fibers are located at near the surface of the skin, and these finer fibers are able to give leather a silky feel. Generally speaking, the smaller the animal, the finer the fibers. For example, calfskin leather is considered to be silkier tha
here is enormous increase in the number of combination products entering the market in the recent years. Combination products have proven advantages but fixe
n cattle hide leather.
WHAT KIND OF PROTEINS ARE FOUND IN ANIMAL SKINS?
Collagen, elastin, albumen, and keratin and the kinds of proteins found in animal skin. Raw animal hides also fats in the form of triglycerides and mixed esters. In chemical composition, raw cattle hides contain 5% - 15% fats, and the balance is protein. Raw hides commonly have blood, dirt, and manure adhering to them. Keratin is the primary protein of hair.
HOW ARE RAW HIDE
WHAT KIND OF PROTEINS ARE FOUND IN ANIMAL SKINS?
Collagen, elastin, albumen, and keratin and the kinds of proteins found in animal skin. Raw animal hides also fats in the form of triglycerides and mixed esters. In chemical composition, raw cattle hides contain 5% - 15% fats, and the balance is protein. Raw hides commonly have blood, dirt, and manure adhering to them. Keratin is the primary protein of hair.
HOW ARE RAW HIDE
d dose combinations are still in the process of convincing regulatory authority on their advantages over the single ingredient formulations.
Combination pro
Combination pro
PRESERVED IF THEY ARE NOT TANNED?
Salt is commonly used to preserve hides before they are tanned. Tanning is the chemical process in which preservation is made permanent. Salting hides preserves them but because salt is easily washed away, preservation by salting in not permanent.
In modern practice, animal hides, and in particular cattle hides, are cured in a bath of cold brine. Hides are first washed in cold water to remove dirt, manure, blood,
Salt is commonly used to preserve hides before they are tanned. Tanning is the chemical process in which preservation is made permanent. Salting hides preserves them but because salt is easily washed away, preservation by salting in not permanent.
In modern practice, animal hides, and in particular cattle hides, are cured in a bath of cold brine. Hides are first washed in cold water to remove dirt, manure, blood,
ucts have become life saving products for the pharmaceutical companies who doesn’t have many innovative molecules in their product pipeline and have been inc
and loosely adhering flesh. Non-useful parts of the skin such as ears and tail are trimmed from the hide, and then the hide is soaked in an agitated brine bath for 24 to 48 hours. This period of time is necessary to ensure that salt is thoroughly and completely absorbed in the mass of hides.
WHAT HAPPENS AT THE TANNERY?
At the tannery, the cured but untanned hides are first soaked in fresh water, and the salt is removed. In addition, loose fat, d
WHAT HAPPENS AT THE TANNERY?
At the tannery, the cured but untanned hides are first soaked in fresh water, and the salt is removed. In addition, loose fat, d
easingly used in the product life cycle management. Even the companies having product patents are trying to extend their product life cycle through the combi
irt, and manure are removed also. Then the hides are dehaired.
In modern practice, hair is removed from hides by a chemical process. Lime and sodium sulfide attack the sulfur-based crosslinks in the protein keratin at a pH of 12-12.5. Keratin is the protein that is the primary chemical constituent of hair. Over a period of 4 to 12 hours, the keratin protein is broken down under the attack of sodium sulfide in alkaline conditions. The hides are th
In modern practice, hair is removed from hides by a chemical process. Lime and sodium sulfide attack the sulfur-based crosslinks in the protein keratin at a pH of 12-12.5. Keratin is the protein that is the primary chemical constituent of hair. Over a period of 4 to 12 hours, the keratin protein is broken down under the attack of sodium sulfide in alkaline conditions. The hides are th
nation products and maximize the revenues. But the companies involved in this practice are overlooking that they are burdening the patients both economically
en washed for an additional 12 to 20 hours in lime-water. Osmotic pressure causes the hides to swell to about double their original size during this process. The waste products of dehairing are then removed by washing the hides with fresh water. After the removal of keratin, the proteins left in the hide are: elastin, albumin, and collagen.
At this stage the hides can be subject to their first purely physical modification. Hides are often thicker
At this stage the hides can be subject to their first purely physical modification. Hides are often thicker
and physically. They need to rightly judge the benefits of the combination products and they have to even look at the risks involved when combining the produ
than the final leather product needs to be. Thus they need to be cut to the desired thickness, and this is done with a horizontal belt-knife. Hides can be cut horizontally to an accuracy of 0.1 mm. This process is called splitting.
In modern practice, the hides at this stage are delimed and bated. Ammonium salts and acids are used to reduce the pH in the hide and to remove the lime. Bating refers to a proteolytic enzyme that destroys the elastin.
In modern practice, the hides at this stage are delimed and bated. Ammonium salts and acids are used to reduce the pH in the hide and to remove the lime. Bating refers to a proteolytic enzyme that destroys the elastin.
ts. Some of the combination products were well accepted by physicians while others suffered. Companies involved in development of combination products are fi
The presence of elastin in the final product would make it too stiff, and so it has to be removed.
The final step prior to tanning is called pickling. In this step, the albumin is removed leaving the collagen behind. The bated hides are soaked in a solution containing 1%-2% sulfuric acid and 3% to 4% sodium chloride. The purpose of the sodium chloride is to prevent further osmotic swelling. The sulfuric acid solubilizes the albumin.
With the alb
The final step prior to tanning is called pickling. In this step, the albumin is removed leaving the collagen behind. The bated hides are soaked in a solution containing 1%-2% sulfuric acid and 3% to 4% sodium chloride. The purpose of the sodium chloride is to prevent further osmotic swelling. The sulfuric acid solubilizes the albumin.
With the alb
ding difficulty in defining their combination products and facing various challenges from selecting a combination to marketing it.
Following aspects would a
Following aspects would a
umin removed, the hide, now comprised primarily of collagen fibers, is ready for tanning.
TANNING
Tanning is the chemical process which renders the hide biorefractive and changes hide into leather. There are two principle processes of tanning: the chrome process and the vegetable process. Because of its speed and efficiency, the chrome process is the primary method by which leather is tanned. Vegetable tanning was for centuries the only method of
TANNING
Tanning is the chemical process which renders the hide biorefractive and changes hide into leather. There are two principle processes of tanning: the chrome process and the vegetable process. Because of its speed and efficiency, the chrome process is the primary method by which leather is tanned. Vegetable tanning was for centuries the only method of
dd to the challenges in developing combination products:
Which markets to tap where the combination products can do fairly well?
Which combination prod
Which markets to tap where the combination products can do fairly well?
Which combination prod
tanning, and it is still used when flexibility and workability in the leather is needed. Even here, leather partly tanned by the chrome process is the raw material of the vegetable tanning process.
The hide from which the albumin has been removed by the salt/sulfuric acid solution is treated with a solution of basic chromium sulfate. The pH of the chromium solution being at 2.5 and is gradually raised through the addition of sodium bicarbonate to 4.
The hide from which the albumin has been removed by the salt/sulfuric acid solution is treated with a solution of basic chromium sulfate. The pH of the chromium solution being at 2.5 and is gradually raised through the addition of sodium bicarbonate to 4.
cts are meaningful and rational?
Which therapeutic categories to select?
Which Combinations can address unmet needs of the patients?
Do combin
Which therapeutic categories to select?
Which Combinations can address unmet needs of the patients?
Do combin
0. The tanning reaction proceeds rapidly at pH 3.0, and the pH is kept below that at the beginning to ensure that the hide is thoroughly saturated with chromium solution before the reaction is driven to completion. (In all these processes, from brine preservation to tanning the rate determining step has been mass transport through the hides.)
In the tanning reaction, the basic chromium sulfate complex reacts with the carboxyl groups of adjacent prot
In the tanning reaction, the basic chromium sulfate complex reacts with the carboxyl groups of adjacent prot
tions increase the patient compliance?
What would be the developing cost?
How to tackle the risks encountered during combination product developmen
What would be the developing cost?
How to tackle the risks encountered during combination product developmen
ein molecules in the hide, forming a crosslink. At a pH of 3.5 to 4.0, the crosslinking reaction is made irreversible through the loss of an acidic hydrogen. Formic acid is used to help eliminate side reactions, and the use of formic acid substantially reduces the time of processing.
When the reaction is complete, the chrome tanning solution is wrung from the hide and, if necessary, the hide is shaved to the desired thickness. At this point the wet
When the reaction is complete, the chrome tanning solution is wrung from the hide and, if necessary, the hide is shaved to the desired thickness. At this point the wet
t?
As combination products don't fit into the traditional categories of drugs, medical devices, or biological products, the USFDA is in the process of devel
As combination products don't fit into the traditional categories of drugs, medical devices, or biological products, the USFDA is in the process of devel
tanned hide is blue in color and does not possess a leather feel. That is imparted by the vegetable process.
Vegetable tanning employs polyphenolic compounds that are obtained from certain plants. Pyrogallol, pyrocatechol and catechin are important active ingredients. These compounds are or contain polyhydric benzene rings and they work by replacing bound water through a reaction of hydrogen bonds with peptide bonds of the protein. Vegetable tann
Vegetable tanning employs polyphenolic compounds that are obtained from certain plants. Pyrogallol, pyrocatechol and catechin are important active ingredients. These compounds are or contain polyhydric benzene rings and they work by replacing bound water through a reaction of hydrogen bonds with peptide bonds of the protein. Vegetable tann
ping new procedures for reviewing their safety, efficacy and quality.
Professional from academic institutions, pharmaceutical industries, health care indust
Professional from academic institutions, pharmaceutical industries, health care indust
ing does not significantly crosslink proteins, making the leather easy to shape, emboss, or tool. Vegetable tanning leather is the choice of hand-craft work.
DRYING, COLORING, FATLIQUORING
Freshly tanned leather is ready for processing into the final form desired. It is rinsed of the tanning solution and dried. To prevent shrinkage while drying, it is held or stretched by any of several means while it is slowly dried with dry air and gentle heat.
DRYING, COLORING, FATLIQUORING
Freshly tanned leather is ready for processing into the final form desired. It is rinsed of the tanning solution and dried. To prevent shrinkage while drying, it is held or stretched by any of several means while it is slowly dried with dry air and gentle heat.
y and representatives from various regulatory agencies are working out to design the regulatory requirements for manufacture and sale of combination products
Here again, mass transport is an important consideration. Too rapid a dry can result in undesirable secondary actions.
Leather readily accepts pigments and dies, and the chromium present in the leather is often used as a mordant. Dies can be used to deeply penetrate the leather in the cases of leather that might easily be scuffed. Alternatively, it can be given a surface treatment that shows leather grain, a polymeric surface, or a high polish.
T
Leather readily accepts pigments and dies, and the chromium present in the leather is often used as a mordant. Dies can be used to deeply penetrate the leather in the cases of leather that might easily be scuffed. Alternatively, it can be given a surface treatment that shows leather grain, a polymeric surface, or a high polish.
T
.
As there is an increasing trend of the combination products companies manufacturing such products should be able to tackle the problems involved in the de
As there is an increasing trend of the combination products companies manufacturing such products should be able to tackle the problems involved in the de
o prevent cracking, to remain pliable and to lubricate the fibers, the leather is stuffed with oils and greases in a process known as fatliquoring. Sulfated or sulfonated animal fats or fish oils are commonly used. These oils are able to penetrate the leather and be adsorbed onto the fibers because of a strong wetting action.
The leather may be subjected to a mechanical flexing process to soften it up. It may also be buffed to improve it appearance
The leather may be subjected to a mechanical flexing process to soften it up. It may also be buffed to improve it appearance
elopment. They need to be wiser in analyzing the market trends and the regulatory requirements.
Companies that provide selfless information through particip
Companies that provide selfless information through particip
and remove flaws, such as scars.
FINAL FINISHING
Leather that has been processed up to through the fatliquoring stage and partly cut to shape can be purchased on the wholesale market by craftsmen who make finished leather objects. Final shaping and coating is done by the craftsman. The craftsman cuts, shapes, tools, decorates, and otherwise forms the leather into the final leather object, and puts on a final finish that imparts the color and shine
FINAL FINISHING
Leather that has been processed up to through the fatliquoring stage and partly cut to shape can be purchased on the wholesale market by craftsmen who make finished leather objects. Final shaping and coating is done by the craftsman. The craftsman cuts, shapes, tools, decorates, and otherwise forms the leather into the final leather object, and puts on a final finish that imparts the color and shine
tion in industry events and feedback to regulatory authorities would be able to face the challenges and will be successful in developing combination products
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