JP2005060307A - Osteogenic agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new osteogenic agent. <P>SOLUTION: The bone around a site neighboring a bone tissue can be easily made by sustainedly releasing statin at the site. The osteogenic agent comprises 1. preparing a topically sustainedly releasing preparation from the statin or a derivative thereof, and 2. having the component of a carrier for the topically sustainedly releasing preparation selected from (1) calcium sulfate, (2) calcium phosphate and (3) calcium carbonate. The statin or the derivative thereof is topically administered. The topical administration comprises directly filling the preparation into a bone-deficient site such as a tooth-extracted recess and a cavity of pustule, a fracture site, the surrounding of an artificial implant such as an artificial dental root, and an absorbed alveolar bone site. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel osteogenic agent. More specifically, the present invention relates to an osteogenesis agent characterized in that a statin or a derivative thereof is used as a local sustained release preparation.

Bone grafts and artificial bone substitutes are used when the amount of bone is locally insufficient in the treatment of dentistry and orthopedic areas. Although autologous bone transplantation is a clinically effective method, it is problematic in that the invasion of the bone collection site is large and the amount of bone collected is limited. Another problem is that the risk of infection cannot be ruled out in multi-family bone transplantation. The bone substitute material has a high affinity for bone, but has a problem in that it lacks an osteoinductive action. Clinically, there is a need for a method that can easily cope with a shortage of local bone mass.
Statins widely used worldwide as therapeutic drugs for hypercholesterolemia inhibit cholesterol synthesis by inhibiting the rate-limiting enzyme of cholesterol biosynthesis. These statins promote the transcriptional activity of osteoblast BMP2 (one of the osteoinductive factors), promote bone formation in organ culture systems, and are orally administered to ovariectomized rats, an experimental model of postmenopausal osteoporosis Then, Mundy et al. Reported that it shows a therapeutic effect (Non-patent Document 1). However, there has been no report observing clear bone formation after a single application of statins locally. The use of statins for inhibiting osteoclast formation is also known (Patent Document 1).
Mundy, G., Garrett, R., Harris, S., et al .: Stimulation of bone formation in vitro and in rodents by Statins. Science 286: 1946-1949, 1999 JP 2003-104883 A

  An object of the present invention is to provide a novel bone formation agent.

We have found that bone can be easily created around the statin by slowly releasing the statin at a site close to the bone tissue, and the present invention has been completed. That is, it consists of the following.
(Additional same as claims)

  By providing sustained release to statins, we succeeded in providing locally administrable bone-forming agents mainly composed of statins.

  In the present invention, statins and derivatives thereof include lovastatin, simvastatin, pravastatin, fluvastatin, stravastatin, cerivastatin, vastatin, and mevastatin. Selected from the group consisting of (rosuvastatin) and itavastatin. These are widely known as selective and competitive inhibitors of HMG-CoA reductase and are useful as hypolipidemic and / or hypocholesterolemic agents. These statins are known to inhibit the formation of osteoclasts.

  As a means for sustained release of statins used in the present invention, various matrix substances generally used in the bone formation region can be used. Conventional methods for administering statins have been systemic, and have not been fully involved in osteogenesis without fully exhibiting their efficacy. This may be presumably due to inadequate harmony between statin biosynthesis and bone formation. Examples of matrix substances that can be used in the present invention include collagen, particularly type I collagen, polysaccharides such as hyaluronic acid, chondroitin sulfate, chito acid, and biodegradable synthetic polymers represented by PLA / PLGA, particularly various calcium compounds. Can be suitably used.

  For the sustained release of statins of the present invention, the statin and the sustained release substance are blended in the range of 2 to 40 with respect to 100 of the sustained release substance. The blending conditions are selected according to the properties of each sustained release substance. The properties of the sustained-release substance containing statins prepared may be solidified or kept at room temperature, and a composition that maintains an appropriate viscosity is preferred from the viewpoint of ease of treatment depending on the purpose. It is also preferable to have a property that maintains viscosity at body temperature or higher but solidifies at body temperature. These are prepared by a device known per se.

  The statin or derivative thereof of the present invention is administered topically. The term “local” means that the preparation is directly filled around a bone defect site such as an extraction fossa or a cyst cavity, a fracture site, an artificial implant such as an artificial tooth root, or an absorbed alveolar bone site. The filling amount is determined according to the clinical judgment in the bone defect. The administration time is not particularly limited as long as it is local administration. The number of administration is usually 1 time, but it can be appropriately compensated by clinical follow-up.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the following examples.

(Example 1)
Calcium sulfate used as drug carrier Experimental method: The experimental animals were 10-week-old inbred wistar male rats, which were reared with free rat chow and tap water throughout the experimental period. The drug simvastatin (Wako Pure Chemical, hereinafter abbreviated as S), which is one of the statins, was used, and gypsum (Calcium Sulfate, Calcined for thin-layer chromatography) was used as the drug carrier.
Gypsum was kneaded with sterilized distilled water at a mixed water ratio of 0.4 to prepare a gypsum bar having a diameter of 0.5 mm and a length of 15 mm. A plaster bar containing 2 mg of S was prepared in the same manner. The experimental animals were divided into 3 groups. After extracting the right mandibular incisor, do not apply anything to the extraction fossa in one group (control group), insert only a plaster bar into the extraction fossa in the next group (P group), and S for the next group A plaster bar containing was inserted (P + S group). Rats were sacrificed 2 weeks and 4 weeks after the operation, the mandible was removed, fixed with 10% neutral formalin solution, and then a bone mineral content measuring device (Dual-Energy X-ray Absorptiometry, DXA, DCS-600: Aloka) Was used to analyze the amount of bone mineral at the extracted tooth portion shown in FIG. Soft X-ray photography was also performed to observe the bone morphology of the extracted tooth.

Results: In both the 2 and 4 weeks after surgery, the bone around the extraction socket was thickened in the P + S group compared to the other groups, and the degree of thickening was strong 4 weeks after the surgery. It was. FIG. 2 shows macroscopic findings and soft X-ray photographs of the mandible at 4 weeks after surgery in the control group and P + S group. Fig. 3 shows bone mineral content (BMC: mg), measurement area (AREA: mm ² ), and bone density (BMD: mg / mm ² ) of the extracted alveolar bone 2 weeks and 4 weeks after surgery obtained by DXA Indicates. BMD is represented by BMC / AREA. Significant differences were observed between the P + S group and the control group, and between the P + S group and the P group in all measured values at 2 weeks and 4 weeks after the operation.

  Since gypsum is rapidly absorbed, it may be used as a fixing material or space occlusion material in bone defect sites such as cyst cavities in oral surgery. Statin, a therapeutic drug for hyperlipidemia, is thought to promote osteogenesis by promoting the expression of BMP-2 in osteoblasts. Since no significant difference was found between the control group and the P group in the bone density measurement results, it can be assumed that gypsum alone has no effect in promoting the healing of the extraction cavity. Since the measured value of the P + S group was higher than that of the other groups, administration of the drug S to the extraction socket is considered to have an effect of promoting the extraction socket healing. From the results of macroscopic findings, soft X-ray photographs, and area measurements, bone formation outside the jawbone is evident in the P + S group. From the X-ray image, it was confirmed that this bone formation was an increase in cortical bone thickness. Since osteogenesis outside the jawbone was observed only in the P + S group and not in the P group, it is considered to be an effect of S.

  In this study, it was shown that application of S to the extraction fossa using gypsum as a carrier promotes the healing of the extraction fossa and increases the bone outside the alveolar bone (FIG. 4-1). S is a simple compound, chemically stable and inexpensive, and has been confirmed to be safe. By applying S to the extraction socket, it is clinically predicted to promote healing of the extraction socket and suppress the decrease and shrinkage of the jaw crest (Fig. 4-2).

(Example 2)
Collagen (bovine type I atelocollagen, 2% solution) or calcium sulfate was used as a carrier, and 2 mg of simvastatin was mixed and applied to the lower incisor extraction cavity of the rat. Four weeks later, the bone mass was measured at the extracted part using a bone mineral content measuring device (Dual-Energy X-ray Absorptiometry, DXA, DCS-600: Aloka).
Bone Mineral Content (BMC, mg / cm ² ), 4 weeks later

n = 6, statistical test is done by Fisher's PLSD, risk is 5%

  As shown in Table 1, simvastatin alone (shown as S in the table), collagen alone (shown as Col in the table), simvastatin applied as a carrier (shown as Col + S in the table), or calcium sulfate When (gypsum) was used alone (indicated as Ca in the table), bone mass did not increase. However, when simvastatin was applied using calcium sulfate (gypsum) as a carrier (indicated as Ca + S in the table), bone mass increased. It is known that hardened calcium sulfate is gradually degraded in vivo. When calcium sulfate is used as a carrier in this experiment, it is considered that simvastatin was gradually released. On the other hand, when simvastatin is used alone or when 1% collagen is used as a carrier, the drug is not sufficiently retained, and the drug has diffused and disappeared in the early stage after application. It seems that he did not wake up.

(Example 3)
A mixture of lactic acid and glycolic acid copolymer PLGA, calcium carbonate and α-TCP or β-TCP was used as a carrier, and 1 mg of simvastatin was mixed and applied to the extracted incisors of the mandibular incisors of rats. Eight weeks later, the bone mass was measured at the extracted part using a bone mineral content measuring device (Dual-Energy X-ray Absorptiometry, DXA, DCS-600: Aloka).
Bone Mineral Content (BMC, mg / cm ² ), after 8 weeks
n = 6 (control group only 5), statistical test is done by Fisher's PLSD, risk rate is 5%

  As shown in Table 2, in this experiment, PLGA5-50 (Mitsui Chemical Fine Co., Ltd.), calcium carbonate (Wako Pure Chemicals, Wako), α-TCP (α-tricalcium phosphate, Wako), β-TCP ( β-tricalcium phosphate (Wako) and 1-4-dioxane (Wako) were mixed to make a carrier. 0.5 g α-TCP or β-TCP was mixed with 1 g PLGA5-50, 9 g 1,4-dioxane, 0.5 g calcium carbonate, and simvastatin was further mixed therewith and freeze-dried. Dioxane is used as a solvent and eventually volatilizes. It has been confirmed that this carrier gradually decomposes in vivo and releases the drug gradually. In the table, control is no additive, A is PLGA5-50, calcium carbonate and α-TCP are added, B is PLGA5-50, calcium carbonate and β-TCP are added, AS and Means that simvastatin, PLGA5-50, calcium carbonate and α-TCP are added, and BS means a preparation containing simvastatin, PLGA5-50, calcium carbonate and β-TCP. The results show that the control is significantly different from AS and BS, A is significantly different from AS, AS is significantly different from control, A, B and BS, B is significant to AS and BS There was a difference, BS was significantly different from the control, AS and B.

  The present invention provides a novel osteogenic agent and has great utility in the field of bone-related medicine.

The analysis area | region of the bone mineral content of a tooth extraction part is shown. Macroscopic findings and soft X-ray photographs of the mandible at 4 weeks after surgery in the control and P + S groups. Bone mineral content of the extracted alveolar bone 2 weeks after surgery obtained by DXA (BMC: mg) Bone mineral density (BMC: mg) of the extracted alveolar bone 4 weeks after surgery obtained by DXA Measurement area of extracted alveolar bone 2 weeks after surgery obtained by DXA (AREA: mm ² ) Measurement area of the extracted alveolar bone 4 weeks after surgery obtained by DXA (AREA: mm ² ) Bone density of extracted alveolar bone 2 weeks after surgery obtained by DXA (BMD: mg / mm ² ) Bone density of extracted alveolar bone 4 weeks after surgery obtained by DXA (BMD: mg / mm ² ) The clinical effect by local administration of the drug after tooth extraction The effect when simvastatin is locally administered to the rat mandibular incisor tooth extraction socket is shown. After extracting the rat mandibular incisor, simvastatin was locally administered to the extraction socket using calcium sulfate as a carrier. One month later, the animals were sacrificed and examined histologically. FIG. 3 is a transverse tissue image (toluidine blue staining) of the mandible shown in FIG. The left is a control group left untouched after extraction, and the right is a simvastatin administration group. In the simvastatin administration group, bone formation outside the alveolar bone is promoted, and bone thickening is remarkable. The clinical effect by local administration to the extraction socket of a statin is shown. After extraction, the ridge is reduced and dwarfed, which often makes treatment with dentures and dental implants difficult. By allowing sustained release of drugs such as statins locally in the tooth extraction socket after tooth extraction, it is possible to prevent the jaw crest from being lowered or shortened. As a result, treatment with a denture or a dental implant can be easily performed.

Claims (5)

A bone formation agent characterized by preparing a statin or a derivative thereof in a topical sustained-release preparation. A method for producing an osteogenesis agent, comprising preparing a statin or a derivative thereof in a local sustained-release preparation. A bone regenerating agent comprising a statin or a derivative thereof as a main component, which is administered by local sustained release. A pharmaceutical kit for osteogenesis agent comprising a statin or a derivative thereof and a local sustained release carrier. The pharmaceutical kit for osteogenic agents according to claim 4, wherein the components of the local sustained release carrier are selected from the following.
1) Calcium sulfate 2) Calcium phosphate 3) Calcium carbonate