Eggshell-source calcium lactate effervescent tablet and preparation method thereof

Abstract

The invention belongs to the field of effervescent tablets, and particularly relates to an egg shell source calcium lactate effervescent tablet with egg shells as raw materials and a preparation method of the egg shell source calcium lactate effervescent tablet. The preparation method of the egg shell source calcium lactate effervescent tablet comprises the following steps: carrying out shell membrane separation on egg shells, then drying, crushing and calcining, carrying out organic acid reaction on the obtained calcium oxide by using a lactic acid solution, filtering the reaction product, concentrating the filtrate under reduced pressure, and drying and crystallizing the concentrated solution to obtain the egg shell source calcium lactate. The effervescent tablet is prepared from the following raw materials: eggshell-source calcium lactate, an effervescent system and an additive. The effervescent tablet prepared by the method has the technical advantages of good solubility (high solution clarity), strong stability, good taste and the like.

Description

Technical Field

[0001] This invention belongs to the field of effervescent tablets, specifically relating to an eggshell-derived calcium lactate effervescent tablet made from eggshells and its preparation method. Background Technology

[0002] Calcium plays a vital role in all aspects of human life, participating in various important physiological processes such as bone and teeth formation, muscle contraction, and nerve conduction. Calcium deficiency can lead to osteoporosis, rickets, and other diseases. With increasing public awareness of health, the demand for calcium supplements is rising. Currently, the market offers a variety of calcium supplements, including calcium carbonate, calcium citrate, and calcium gluconate. However, despite the wide variety, these supplements have several limitations. For example, calcium carbonate and calcium citrate have low solubility and low bioavailability, calcium gluconate has low calcium content, and some chemically synthesized calcium sources pose potential safety risks.

[0003] Eggshells are a natural source of calcium, with calcium carbonate being the most important component, accounting for over 95%. Compared to calcium carbonate, calcium lactate has a higher calcium content and is more soluble in water and easier for the human body to absorb. Processing eggshells into calcium lactate not only improves calcium bioavailability and achieves efficient resource utilization and reduces production costs, but also has environmental benefits. However, current technologies and formulations for converting eggshells into directly usable calcium supplements are not yet perfect, especially in the preparation of effervescent tablets, where problems such as poor stability and easy formation of turbidity and precipitation exist.

[0004] The main methods for converting eggshells into readily usable calcium supplements are:

[0005] 1. The invention described in CN109824504A provides a process for preparing calcium lactate from eggshells, overcoming the low yield problem in existing methods for preparing calcium lactate from eggshells. This process for preparing calcium lactate from eggshells includes the following steps:

[0006] (1) Collect and wash the eggshells, separate the eggshells and shell membranes, crush the eggshells and sieve them to obtain eggshell powder;

[0007] (2) Add eggshell powder to a certain amount of water, then add lactic acid solution to react, and add CaO powder to adjust the pH after the reaction.

[0008] (3) Filter by suction, adjust the filtrate to neutral with lactic acid, crystallize, and when a large number of white crystals appear in the filtrate, filter by suction again, and the filtrate crystallizes again. Repeat 2-3 times, and wash the crystallized product with anhydrous ethanol to obtain semi-finished product A.

[0009] (4) Filter semi-finished product A again to obtain semi-finished product B, and let it stand to allow the anhydrous ethanol to evaporate, to obtain semi-finished product C.

[0010] (5) Place the semi-finished product C in a drying oven at 40-70℃ and dry for 410-1020 minutes to obtain the finished product.

[0011] 2. The invention CN117304017A provides a method for preparing eggshell-derived calcium lactate and calcium citrate, comprising the following steps:

[0012] Step 1: Shell membrane separation and preparation of eggshell powder:

[0013] Clean eggshells are dried at a constant temperature of 55-65℃ for 4-6 hours, then pulverized and passed through an 80-mesh sieve and a 200-mesh sieve. Eggshell powder with a particle size <0.074mm is obtained. Water is added, and the mixture is stirred and separated in three stages at a constant speed of 400-600 rpm. The first stage involves stirring for 18-22 minutes, followed by standing for 25-35 minutes, then pouring off the supernatant and collecting the shell membrane. The second stage involves stirring for 13-17 minutes, followed by standing for 15-20 minutes, then pouring off the supernatant and collecting the shell membrane. The third stage involves stirring for 8-10 minutes, followed by standing for 8-12 minutes, then pouring off the supernatant and collecting the shell membrane. The combined supernatant is then dried at a constant temperature of 55-65℃ to obtain eggshell powder.

[0014] Step 2: Preparation of eggshell-derived calcium lactate concentrate and calcium acetate solid:

[0015] Weigh out the eggshell powder from step 1 separately, and slowly add lactic acid and acetic acid to neutralize them, obtaining calcium lactate mother liquor and calcium acetate crude liquor, which are then passed through a 200-mesh sieve. After heating to 85-88℃, take 0.5-3% by mass of Ca(OH)2, first slowly add 75% of the Ca(OH)2, and simultaneously adjust the pH to 8-9. After an interval of 2-3 minutes, continue heating to 90-95℃, and slowly add the remaining Ca(OH)2 while stirring, adjusting the pH to 10. Continue stirring until a large amount of flocculent precipitate appears. Filter at 80-85℃ and dry at a constant temperature of <80℃ to obtain concentrated calcium lactate and solid calcium acetate, respectively.

[0016] Step 3: Eggshell-derived calcium lactate and calcium citrate finished products:

[0017] Calcium lactate concentrate was spray-dried to obtain calcium lactate powder. Citric acid solution was added to calcium acetate for a second neutralization reaction according to the molecular weight ratio of citric acid to calcium acetate of 3:(1.8-2.2). The mixture was dried in a constant temperature drying oven at <80℃ to obtain crude calcium citrate. The crude product was then added to boiling water at 100℃ or higher, filtered while hot, and dried to obtain the finished calcium citrate product. Summary of the Invention

[0018] The technical problem to be solved by the present invention is to provide a method and formula for preparing calcium lactate effervescent tablets using eggshells as raw materials. The effervescent tablets have the advantages of good solubility (high solution clarity) and good taste.

[0019] To address the above problems, this invention provides a method for preparing eggshell-derived calcium lactate effervescent tablets, comprising the following steps:

[0020] I. Preparation of calcium lactate from eggshells, following these steps:

[0021] 1.1) Preprocessing:

[0022] Soak eggshells in a 5-10% sodium hydroxide solution until the shell membrane separates. Rinse the eggshells with clean water after removing the membrane (to remove surface impurities and egg liquid). Then dry them and crush them. Calcine the crushed eggshell powder (completely calcined in a muffle furnace) to obtain calcium oxide.

[0023] Note: Complete calcination is intended to prevent the generation of carbon dioxide in later stages of the reaction from affecting the yield;

[0024] 1.2) Organic acid reaction:

[0025] Add the calcium oxide obtained in step 1.1) to distilled water, wherein the solid-liquid ratio of calcium oxide to distilled water is 1 g: 9~11 mL; then add a lactic acid solution with a concentration of 5~7 mol / L (preferably 6 mol / L) until the pH is 6±0.3; stir the reaction at 50~60℃ until the reaction system becomes clear (generally 1.5~2.5 hours).

[0026] Explanation: When calcium oxide is added to distilled water, it forms calcium hydroxide, which causes the system to become cloudy. Lactic acid will react with calcium hydroxide to form soluble calcium lactate and water. Therefore, when the reaction system becomes clear, it means that the calcium hydroxide has been basically reacted.

[0027] 1.3) Separation and purification:

[0028] Filter the product obtained in step 1.2) (to remove unreacted impurities), take the filtrate (which contains calcium lactate), and concentrate the filtrate under reduced pressure at 60~75℃ until the volume is concentrated to 1 / 3~1 / 2 of the original volume of the filtrate.

[0029] The concentrated solution is then dried at 50-60℃ for 6-8 hours to crystallize (calcium lactate precipitates); followed by post-processing to obtain eggshell-derived calcium lactate (high-purity eggshell-derived calcium lactate).

[0030] II. Preparation of Effervescent Tablets:

[0031] The raw materials for effervescent tablets consist of eggshell-derived calcium lactate, an effervescent system, and additives. Eggshell-derived calcium lactate accounts for 30% to 35% of the raw materials for effervescent tablets, the effervescent system accounts for 40% to 60% of the total mass of the raw materials for effervescent tablets, and the remainder is additives.

[0032] The raw materials for effervescent tablets are compressed into tablets to obtain effervescent tablets.

[0033] Note: In this invention, calcium lactate from eggshells is used as the main calcium source to provide the human body with abundant calcium and meet the body's calcium supplementation needs.

[0034] As an improvement to the preparation method of the eggshell-derived calcium lactate effervescent tablets of the present invention, in step 1.1):

[0035] Calcination was carried out at 950±50℃ for 3±0.2 hours.

[0036] Dry in an oven at 50-60℃ for 3-4 hours.

[0037] Grind until it passes through an 80-120 mesh sieve.

[0038] As a further improvement to the preparation method of the eggshell-derived calcium lactate effervescent tablets of the present invention, in step 1.2):

[0039] The stirring speed is 200~300 r / min.

[0040] As a further improvement to the preparation method of the eggshell-derived calcium lactate effervescent tablets of the present invention, the post-treatment in step 1.3) is: alcohol washing, drying, and sieving (through an 80-100 mesh sieve).

[0041] As a further improvement to the preparation method of the eggshell-derived calcium lactate effervescent tablets of the present invention, in step two:

[0042] The effervescent system is composed of sodium bicarbonate: citric acid: lactic acid in a mass ratio of (3-5): (0.5-1): (2-3).

[0043] Explanation: Sodium bicarbonate and citric acid are key components for effervescent effects. They react chemically in water to produce a large amount of carbon dioxide gas, causing the effervescent tablet to disintegrate rapidly. However, excessive citric acid can react with calcium to form calcium citrate precipitate, resulting in a cloudy solution. Therefore, this invention partially replaces citric acid with lactic acid to create the aforementioned effervescent system. This effervescent system improves the solubility of the effervescent tablet, making the product more acceptable to consumers.

[0044] In the formulation of the calcium lactate effervescent tablets of the present invention, the preferred mass ratio of calcium lactate: sodium bicarbonate: citric acid: lactic acid is (3.75~6): (3.75~6): 1: (1.8~3.6).

[0045] As a further improvement to the preparation method of the eggshell-derived calcium lactate effervescent tablets of the present invention, in step two: the additives are conventional additives, including whole milk powder, sweeteners (e.g., aspartame), potassium sorbate, flavoring agents (e.g., sweet orange flavor), binders (e.g., cross-linked polyvinylpyrrolidone, PVP), and lubricants (e.g., polyethylene glycol 6000, PEG6000).

[0046] The tableting process is a conventional technique: the eggshell-derived calcium lactate, the effervescent system, and additives other than binders and lubricants are mixed and stirred evenly according to the appropriate proportions set in this invention. Then, cross-linked polyvinylpyrrolidone (PVP) binder is added, mixed evenly, granulated, and passed through a 20-mesh sieve. Next, polyethylene glycol 6000 (PEG6000) lubricant is added, stirred and mixed evenly, passed through a 20-mesh sieve, and then compressed into tablets to obtain calcium lactate effervescent tablets.

[0047] The present invention also provides eggshell-derived calcium lactate effervescent tablets prepared using any of the above methods.

[0048] That is, the present invention provides a method for preparing calcium lactate effervescent tablets with high bioavailability, good taste and strong stability, and its unique formulation.

[0049] The beneficial effects of this invention are mainly reflected in:

[0050] This invention uses eggshells as raw material to prepare calcium lactate, turning waste into treasure, reducing production costs, and the preparation process is simple and easy to industrialize. The calcium lactate effervescent tablets obtained through formula adjustment have the following advantages:

[0051] 1. It has good solubility, disintegrates rapidly upon contact with water, releases carbon dioxide, forms foam, and leaves no sediment;

[0052] 2. High absorption rate; calcium lactate is easily absorbed and utilized by the human body.

[0053] 3. Refreshing taste: By properly adjusting the excipients, the taste and stability of effervescent tablets are improved, enhancing the user experience.

[0054] In summary, this invention discloses a method and formulation for preparing calcium lactate effervescent tablets using eggshells as raw material. Calcium lactate is prepared from eggshells through a lactic acid neutralization reaction, improving the bioavailability of calcium. In the formulation of the calcium lactate effervescent tablets, according to the formula set by this invention, lactic acid partially replaces citric acid, significantly improving the solubility and stability of the effervescent tablets. Attached Figure Description

[0055] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0056] Figure 1 The calcium lactate effervescent tablets prepared for this embodiment of the invention and their clarity after reconstitution. Detailed Implementation

[0057] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto:

[0058] Example 1: A method for preparing eggshell-derived calcium lactate effervescent tablets, comprising the following steps:

[0059] I. Preparation of Eggshell-Derived Calcium Lactate

[0060] (1) Pretreatment:

[0061] Eggshells (with membrane) were collected and soaked in an 8% (by mass) sodium hydroxide solution for approximately 40 minutes. After the membrane separated, the eggshells were rinsed thoroughly with running water to remove surface impurities and egg liquid. The membrane-free eggshells were then dried in an oven at 50°C for 4 hours. The dried eggshells were then pulverized and passed through an 80-mesh sieve. The resulting eggshell powder was placed in a muffle furnace and calcined completely at 950°C for 3 hours in air. The resulting product was named calcium oxide (containing a small amount of impurities). This process avoids the later reaction of eggshells with lactic acid to produce carbon dioxide, which would affect the yield.

[0062] (2) Organic acid reaction:

[0063] Take 3 g of calcium oxide obtained in step (1) and add it to 30 mL of distilled water. Then add a 6 mol / L lactic acid aqueous solution until the pH is about 6. Then react at 50℃ and 200 r / min for 2 hours. During the reaction, calcium oxide reacts with lactic acid to form calcium lactate. Therefore, the resulting reaction solution becomes clear.

[0064] Explanation: When calcium oxide is added to distilled water, it forms calcium hydroxide, which causes the system to become cloudy. Lactic acid will react with calcium hydroxide to form soluble calcium lactate and water. Therefore, when the reaction system becomes clear, it means that the calcium hydroxide has been basically reacted.

[0065] (3) Separation and purification:

[0066] After the reaction in step (2) is completed, filter while hot to remove unreacted impurities and obtain a filtrate containing calcium lactate.

[0067] The filtrate containing calcium lactate was concentrated by rotary evaporation under reduced pressure (pressure 0.09 MPa) at about 65°C until its volume was reduced to 1 / 3 of the original volume. The resulting concentrate was dried in an oven at 55°C for 8 hours to crystallize the calcium lactate, which was then passed through an 80-mesh sieve to obtain crude calcium lactate.

[0068] The crude calcium lactate was washed twice with anhydrous ethanol, filtered, and dried again in an oven at 55°C for 8 hours. After passing through an 80-mesh sieve, eggshell-derived calcium lactate was obtained. The purity was determined by conventional EDTA complexometric titration, and the purity reached 95%. Therefore, it can be named high-purity eggshell-derived calcium lactate (hereinafter referred to as eggshell-derived calcium lactate).

[0069] II. Using calcium lactate effervescent tablets, formula one:

[0070] By weight percentage, the ingredients are: 30% calcium lactate from eggshell, 30% sodium bicarbonate, 17% lactic acid, 6% citric acid, 7% whole milk powder, 5% crosporopyrrolidone, 2% PEG 6000, 2% potassium sorbate, 0.5% aspartame (sweetener), and 0.5% fruit flavoring.

[0071] Based on 100g, the ingredients are: 30g of eggshell-derived calcium lactate, 30g of sodium bicarbonate, 17g of lactic acid, 6g of anhydrous citric acid, 7g of whole milk powder, 5g of cross-linked polyvinylpyrrolidone, 2g of PEG 6000, 2g of potassium sorbate, 0.5g of aspartame, and 0.5g of fruit flavor (sweet orange flavor).

[0072] Following the above proportions, eggshell-derived calcium lactate, sodium bicarbonate, anhydrous citric acid, lactic acid, whole milk powder, sweetener aspartame, potassium sorbate, and flavoring agent fruit flavoring are mixed and stirred evenly. Then, cross-linked polyvinylpyrrolidone (PVP) binder is added and mixed evenly before granulation (passing through a 20-mesh sieve). Finally, polyethylene glycol 6000 (PEG6000) lubricant is added and stirred evenly. The mixture is then passed through a 20-mesh sieve and compressed into tablets to obtain calcium lactate effervescent tablets.

[0073] Example 2: A method for preparing eggshell-derived calcium lactate effervescent tablets, compared to Example 1, with the following changes:

[0074] In step (2), the phrase "add a 6 mol / L lactic acid aqueous solution until the pH is about 6 and then react at 50°C and 200 r / min for 2 hours" is changed to "add a 5 mol / L lactic acid aqueous solution until the pH is about 6 and then react at 55°C and 200 r / min for about 2 hours". At this time, the reaction solution also becomes clear; the rest is the same as in Example 1.

[0075] Example 3: A method for preparing eggshell-derived calcium lactate effervescent tablets, with the following changes compared to Example 1:

[0076] In step (2), “add a 6 mol / L lactic acid aqueous solution until pH=6, and then react at 50°C and 200 r / min for 2 hours” is changed to “add a 7 mol / L lactic acid solution until pH=6, and react at 60°C and 200 r / min for about 1 hour”. At this time, the reaction solution also becomes clear; the rest is the same as in Example 1.

[0077] Example 4: A method for preparing eggshell-derived calcium lactate effervescent tablets, with the following changes compared to Example 1:

[0078] II. Use the following formula for calcium lactate effervescent tablets:

[0079] By weight percentage, the ingredients are: 30% calcium lactate from eggshell, 30% sodium bicarbonate, 16% lactic acid, 7% citric acid, 7% whole milk powder, 5% crosporopyrrolidone, 2% PEG 6000, 2% potassium sorbate, 0.5% aspartame, and 0.5% fruit flavoring.

[0080] The rest is the same as in Example 1.

[0081] Example 5: A method for preparing eggshell-derived calcium lactate effervescent tablets, compared to Example 2, with the following changes:

[0082] II. Use the following formula for calcium lactate effervescent tablets:

[0083] By weight percentage, the ingredients are: 30% calcium lactate from eggshell, 30% sodium bicarbonate, 18% lactic acid, 5% citric acid, 7% whole milk powder, 5% crosporopyrrolidone, 2% PEG 6000, 2% potassium sorbate, 0.5% aspartame, and 0.5% fruit flavoring.

[0084] The rest is the same as in Example 2.

[0085] Example 6: A method for preparing eggshell-derived calcium lactate effervescent tablets, compared to Example 3, with the following changes:

[0086] II. The following formula for calcium lactate effervescent tablets is adopted:

[0087] By weight percentage, the ingredients are: 30% eggshell-derived calcium lactate, 30% sodium bicarbonate, 15% lactic acid, 8% citric acid, 7% whole milk powder, 5% crosporopyrrolidone, 2% PEG 6000, 2% potassium sorbate, 0.5% aspartame, and 0.5% fruit flavoring.

[0088] The rest is the same as in Example 3.

[0089] The eggshell-derived calcium lactate effervescent tablets obtained in Examples 1-6 were subjected to the following experiments: the mass of each effervescent tablet was approximately 0.7g.

[0090] Experiment 1: Determination of Calcium Lactate Content

[0091] The content of calcium lactate was determined by conventional EDTA complexometric titration.

[0092] Eggshell-derived calcium lactate effervescent tablets were used as samples.

[0093] Calcium carboxylic acid indicator: Mix 0.1 g of calcium reagent sodium carboxylate with 10 g of sodium chloride dried at 110℃ and grind them together for later use.

[0094] Weigh 0.3 g of the sample dried to constant weight at 7℃ and sieved (through a 20-mesh sieve). Dissolve the sample in 50 mL of water with 2 mL of 20% hydrochloric acid added. While stirring, add 15 mL of 0.05 mol / L disodium ethylenediaminetetraacetate (EDTA) standard titrant. Add 5 mL of 100 g / L sodium hydroxide solution and 0.1 g of calcium carboxylic acid indicator. Titrate with EDTA standard titrant until the solution turns blue, which is the endpoint.

[0095] The mass fraction W1 of calcium lactate is calculated using the following formula:

[0096]

[0097] In the formula: V: Total volume (mL) of EDTA standard titrant solution consumed.

[0098] c: Concentration of the standard titrant (mol / L) of disodium ethylenediaminetetraacetate (EDTA) titration solution;

[0099] M: Molar mass of calcium lactate (g / mol);

[0100] m: Mass of the sample (g);

[0101] 1000: Conversion factor.

[0102] Experiment 2: Disintegration Time Measurement

[0103] The disintegration time limit test method was performed according to the General Chapter 0921 of Part IV of the 2020 edition of the Chinese Pharmacopoeia.

[0104] Set up a constant temperature water bath and keep the water temperature in the beaker at around 37°C. Place the prepared calcium lactate effervescent tablets into the beaker, ensuring that the sample is completely submerged. Observe the sample disintegration and record the time it takes for the sample to completely disintegrate.

[0105] Experiment 3. Sensory evaluation methods

[0106] Eight volunteers were invited to the sensory analysis laboratory to rate the product's disintegration time, clarity, and taste. Clarity and taste were scored on a 10-point scale, with 1-4 points considered acceptable, 5-7 points good, and 8-10 points excellent. During the evaluation, each sensory evaluator conducted their evaluation independently, without interference from others. After each sample was evaluated, the evaluators rinsed their mouths with water, and there was a minimum 5-minute interval between evaluations to avoid affecting the evaluators' scores. The final score was the average of all scores.

[0107] Table 1. Disintegration Time and Sensory Evaluation Scores

[0108] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Calcium content (mg / tablet) 45 36 40 42 33 40 Disintegration timeout (s) 185 172 196 165 201 160 Clarity 9 9 9 8 9 8 taste 9 9 8 8 9 8

[0109] Comparative Example 1: The "17% lactic acid and 6% citric acid" in Example 1 were changed to "23% citric acid", and the rest were the same as in Example 1.

[0110] The results were as follows: the formula in Example 1 was adjusted to 23% citric acid, with the rest remaining the same as in Example 1. After tableting, the disintegration time of the effervescent tablets was measured to be 295 s, with a clarity score of 4 and a taste score of 4.

[0111] In summary, excessive addition of citric acid can cause it to react with calcium to produce calcium citrate precipitate, resulting in turbidity of the solution. Therefore, this invention uses lactic acid to partially replace citric acid.

[0112] Comparative Example 2-1: The "soaking in 8% sodium hydroxide solution" in Example 1 was changed to "soaking in clean water"; the shell membrane separation treatment time was extended from the original 40 minutes to 1.5 hours, and the rest was the same as in Example 1.

[0113] The purity of the obtained eggshell-derived calcium lactate was 93%, and the calcium content after conversion was approximately 40 mg after tableting. The disintegration time of the effervescent tablet was measured to be 198 s, with a clarity of 9 and a taste of 9.

[0114] Comparative Example 2-2: The phrase "soaked in 8% sodium hydroxide solution" in Example 1 was changed to "soaked in 15% sodium hydroxide solution"; the rest was the same as in Example 1.

[0115] Soaking the eggshells in a 15% sodium hydroxide solution resulted in some loss of calcium lactate. The purity of the obtained eggshell-derived calcium lactate was 96%, which translates to a calcium content of approximately 42 mg after tableting. The disintegration time of the effervescent tablets was measured to be 178 s, with a clarity score of 9 and a taste score of 9.

[0116] In summary: while water can also separate substances, it will be slower; soaking in a higher concentration of sodium hydroxide solution is corrosive, and the reaction with calcium carbonate will produce bubbles, release heat, and exacerbate corrosion, so it is not recommended.

[0117] Finally, it should be noted that the above examples are merely some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing eggshell-derived calcium lactate effervescent tablets, characterized in that... Includes the following steps: I. Preparation of calcium lactate from eggshells, following these steps: 1.1) Preprocessing: Soak eggshells in a 5-10% sodium hydroxide solution until the shell membrane separates. Rinse the eggshells with water after removing the membrane. Then dry them and crush them. Calcine the crushed eggshell powder to obtain calcium oxide. 1.2) Organic acid reaction: Add the calcium oxide obtained in step 1.1) to distilled water, wherein the solid-liquid ratio of calcium oxide to distilled water is 1 g: 9~11 mL; then add a lactic acid solution with a concentration of 5~7 mol / L until the pH is 6±0.3; stir the reaction at 50~60℃ until the reaction system becomes clear; 1.3) Separation and purification: Filter the product obtained in step 1.2), take the filtrate, and concentrate the filtrate under reduced pressure at 60~75℃ until the volume is concentrated to 1 / 3~1 / 2 of the original volume of the filtrate. The concentrate is then dried at 50-60℃ for 6-8 hours; followed by post-processing to obtain eggshell-derived calcium lactate. II. Preparation of Effervescent Tablets: The raw materials for effervescent tablets consist of eggshell-derived calcium lactate, an effervescent system, and additives. Eggshell-derived calcium lactate accounts for 30% to 35% of the raw materials for effervescent tablets, the effervescent system accounts for 40% to 60% of the total mass of the raw materials for effervescent tablets, and the remainder is additives. The raw materials for effervescent tablets are compressed into tablets to obtain effervescent tablets.

2. The method for preparing eggshell-derived calcium lactate effervescent tablets according to claim 1, characterized in that... In step 1.1): Calcination was carried out at 950±50℃ for 3±0.2 hours. Dry in an oven at 50-60℃ for 3-4 hours. Grind until it passes through an 80-120 mesh sieve.

3. The method for preparing eggshell-derived calcium lactate effervescent tablets according to claim 2, characterized in that... In step 1.2): The stirring speed is 200~300 r / min.

4. The method for preparing eggshell-derived calcium lactate effervescent tablets according to claim 3, characterized in that... The post-processing in step 1.3) is as follows: alcohol washing, drying, and sieving.

5. The method for preparing eggshell-derived calcium lactate effervescent tablets according to any one of claims 1 to 4, characterized in that... In step two: The effervescent system is composed of sodium bicarbonate: citric acid: lactic acid in a mass ratio of (3-5): (0.5-1): (2-3).

6. The method for preparing eggshell-derived calcium lactate effervescent tablets according to claim 5, characterized in that... In step two: the additives include whole milk powder, sweetener, potassium sorbate, flavoring agent, binder, and lubricant.

7. Eggshell-derived calcium lactate effervescent tablets prepared by any one of claims 1 to 6.

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