This invention relates to a soft Calcium Hydroxyapatite & a method for preparation thereof used for filling gaps in human bone. The calcium Hydroxyapatite is a soft material.
Some times parts of bone are lost due to accidents, diseases or surgical operations. Conventionally bone chips from the iliac crest hip bone of the patient are used to fill the gap in the bone. This method involves another operation on the already compromised patient. Therefore, it is associated with risk of complications & problems.
Human bones are made of Calcium Phosphate in the form of a special molecular structure, which is called Calcium Hydroxyapatite. In this, Calcium is in the ratio of approximately 3.6 to 1 phosphate. In short it is called HA. Herein after in this specification it will be referred as HA. Over the years of use it is proven that HA can be safely used to fill the gaps in the bone. HA causes healing of bone over period of time by creeping substitution and forming complete bone. HA acts as an osteo-conductive material, which allows bone to heal and leads to bone growth.
There are several ways to obtain HA. Naturally it can be obtained from any bone by removing organic part of it. Conventionally, animal bone and bovine bone is used to make natural HA. There are several methods to synthesize it.
HA is normally available in form of rigid & fragile granules, blocks, powder or paste. However, it is associated with the following drawbacks:
Hence, it is required to develop a soft Calcium Hydroxyapatite for filling gaps in human bone, which can address the aforesaid drawbacks.
An object of this invention is to propose a soft Calcium Hydroxyapatite & a method for preparation thereof used for filling gaps in human bone.
Another object of this invention is to propose a soft Calcium Hydroxyapatite used for filling gaps in human bone, which is soft.
Still another object of this invention is to propose a novel calcium hydroxyapatite which can be packed in cavity of bone to take shape of the cavity.
Still another object of this invention is to propose a novel calcium hydroxyapatite which can be molded by hand.
Still another object of this invention is to make HA, which does not spill out of the cavity of bone after filling.
Still another object of this invention is to propose a novel Calcium Hydroxyapatite & a method for preparation thereof used for filling gaps in human bone in which the calcium Hydorxyapatite makes wide area intimate contact with surrounding bone tissue.
The method of preparation of calcium Hydroxyapatite comprises reaction of calcium salt with a water soluble polymer to obtain a solution. Said solution thus obtained is further subjected to reaction with phosphate salt to obtain aqueous HA, which is kept for some time. This is followed by washing with water and freeze drying so as to obtain soft calcium Hydroxyapatite (HA) of the present invention. It is soft, stable and sponge like with cellular matrix.
According to this invention, there is provided a method for preparation of soft calcium Hydroxyapatite comprising steps of:
The present invention is directed to a novel Calcium Hydroxyapatite & a method for preparation thereof used for filling gaps in human bone. Method of preparation of soft calcium Hydroxyapatite comprising preparation of two solutions, in which a salt with calcium ion is mixed with a polymer, which is further mixed with another salt having phosphate ion. The salt with calcium ion is such as calcium Nitrate (CaNo3), and the salt with phosphate ion is such as Diammonium phosphate (NH4)2HPO4. The polymer is for example Poly vinyl alcohol without restricting scope of the invention to the same. Thus, the present invention is not restricted to the examples given hereinabove, other salt of calcium ion and phosphate ion, and other polymer readily apparent to a person skilled in the art are understood to be within the scope of the invention. The amount of calcium salt, polymer and phosphate salt is 40-60%, 10-30% and 20-40% respectively. The reaction between calcium salt and Polymer is as follows:
Calcium salt+Polymer−A solution of polymer with Calcium salt.
The solution thus obtained is further subjected to reaction with phosphate salt to obtain aqueous HA, which is as follows:
Calcium salt+Phosphate salt->Ammonium Nitrate+Aqueous HA.
Ammonium Nitrate is slowly washed out because it is soluble.
The HA thus obtained is kept for 1-15 days in still condition. Thereafter, top fluid is decanted followed by addition of fresh water, which is continued for 3-10 days. Thereafter, it is frozen at −10° C. to −30° C. followed by freeze drying at −10 to −25° C. to obtain soft calcium Hydroxyapatite (HA).
The calcium Hydroxyapatite is stable compound, which remains stable at normal room temperature.
Thus, said freeze drying gives rise a sponge like cake with cellular matrix.
When the resultant dried cake is immersed in water, it becomes soft like sponge by absorbing water. It can be pressed to take any form. When filled into a cavity of bone, it does not spill out & makes a wide area contact with bony cage around.
Calcium Nitrate (CaNO3) in an amount of 50-150 gm was mixed with 10-40 gm of Poly vinyl alcohol to obtain a solution. The solution was further added with 20-60 gm of Diammonium Phosphate (NH4)2HPO4.
This resulted in aqueous HA together with Ammonium Nitrate, which was slowly washed out. Thereafter, HA was kept for 12 days in still condition. This was followed by decantation of top fluid followed by addition of fresh water for 9 days. Then it was frozen at −10° C. followed by freeze drying at −10° to obtain soft calcium Hydroxyapatite (HA).
Soft material to take shape of the cavity in bone.
Does not spill out of the cavity after filling.
Wider area intimate contact with surrounding bone tissue:
Reliable for use.
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:
Number | Date | Country | Kind |
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77/KOL/2013 | Jan 2013 | IN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IN2014/000045 | 1/22/2014 | WO | 00 |