| Hydroxyapaltite calcium phosphate granules, method for preparing same and uses thereof -> Monitor Keywords |
|
|
 
Hydroxyapaltite calcium phosphate granules, method for preparing same and uses thereofRelated Patent Categories: Chemistry Of Inorganic Compounds, Phosphorus Or Compound Thereof, Oxygen Containing, Metal Or Ammonium ContainingHydroxyapaltite calcium phosphate granules, method for preparing same and uses thereof description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070183955, Hydroxyapaltite calcium phosphate granules, method for preparing same and uses thereof. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] The invention relates to a calcium phosphate excipient and concerns in particular calcium phosphates that have x-ray diffraction patterns characteristic of mineral hydroxyapatite. [0002] More precisely, the invention pertains in particular to calcium phosphates in the form of granules presenting an x-ray diffraction pattern characteristic of hydroxyapatite and good compressibility and flow characteristics in direct compression applications. [0003] The invention also concerns a particularly economical preparation process for said granules. [0004] Finally, the invention also relates to the use of said granules as excipients in the tablets obtained, preferably by direct compression. [0005] The forming of dry materials into tablets is done preferentially by making use of the direct compression technique. [0006] In fact, the direct compression technique requires the fewest treatment steps and prevents the active ingredients from coming into contact with potentially harmful solvents such as water or organic solvents. [0007] The reduction in the number of treatment steps and the absence of solvents reduces costs and thus reduces the degradation of active ingredients. [0008] The formation of tablets by direct compression requires the use of a material in the form of tablets or of a vehicle known under the term excipient. The ideal excipient is one that is nonreactive with regard to the active ingredients in the formulation. [0009] The ideal excipient must also be easily compressible, while forming solid tablets with smooth tablet surfaces. The resistance of the tablet in the majority of applications must also be as high as possible for a minimal compressive force. [0010] The ideal excipient must also flow very well, without any segregation. This is necessary in order to fill the molds of high-speed tableting machines without risk of obstruction and without any variation in the weight of the material that fills the molds. [0011] The majority of powdered materials are impractical for forming tablets by direct compression in high-speed tableting machines due to problems relating to flow. [0012] These powdered materials can often be granulated by various means, for example, by pressure agglomeration, precompression of the powder into granules or by passing the powder between two compression rollers. [0013] Other granulation methods for powders are wet agglomeration followed by drying such as, for example, a rotating-plate agglomeration device or a device in the form of a fluidized bed. [0014] Spray drying, with or without agglomeration additive (for example PVP) can also easily be used. [0015] Precompacting powders to produce materials that flow well often has a harmful effect on the compressibility of the material in granulate form. [0016] These additional steps in treating the excipient add an additional cost and thus make the process less economical. [0017] Using calcium phosphates as excipients is known. Thus calcium phosphates such as calcium hydrogen phosphate dihydrate [dicalcium phosphate duo-hydrate; CaHPO.sub.4-2H.sub.2O; brushite] anhydrous calcium hydrogen phosphate [anhydrous dicalcium phosphate, CaHPO.sub.4; monetite] and hydroxyapatite [Ca.sub.5(PO.sub.4).sub.3(OH), which is referenced commercially by the term "tricalcium phosphate"]. [0018] The ideal chemical formula of hydroxyapatite is Ca.sub.5(PO.sub.4).sub.3(OH). It is, however, well known in the literature that the crystalline lattice that has this ideal formula is extremely tolerant with regard to substitutions of anions and cations in the lattice. [0019] The substitution of cations with elements such as magnesium, strontium, barium, sodium, lead and a large number of other atoms is well known. [0020] The substitution of anions can take three different forms. [0021] First, a portion of the trivalent phosphate groups (PO.sub.4.sup.3-) can be replaced by HPO.sub.4 .sup.2-, which leads to a non-stoichiometric apatite. [0022] Second, the trivalent phosphate groups (PO.sub.4.sup.3-) can be replaced by other complex anions such as carbonates or vanadates. [0023] Third, the hydroxyl group (OH.sup.-) can be partially or completely replaced by other anions such as fluoride or chloride. [0024] A coupled substitution in which one ion is replaced by another ion of a different charge and the charge neutrality is maintained by further substitutions in the ions of the lattice with different charges or by vacancies is also well known. Continue reading about Hydroxyapaltite calcium phosphate granules, method for preparing same and uses thereof... Full patent description for Hydroxyapaltite calcium phosphate granules, method for preparing same and uses thereof Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Hydroxyapaltite calcium phosphate granules, method for preparing same and uses thereof patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Hydroxyapaltite calcium phosphate granules, method for preparing same and uses thereof or other areas of interest. ### Previous Patent Application: Additive for non-aqueous electrolyte in battery, non-aqueous electrolyte for battery and non-aqueos electrolyte battery Next Patent Application: Ammonium hydroxide treatments for semiconductor substrates Industry Class: Chemistry of inorganic compounds ### FreshPatents.com Support Thank you for viewing the Hydroxyapaltite calcium phosphate granules, method for preparing same and uses thereof patent info. IP-related news and info Results in 0.23516 seconds Other interesting Feshpatents.com categories: Novartis , Pfizer , Philips , Polaroid , Procter & Gamble , 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
