An additive for improving the disintegration stability of belladonna extract and its preparation method

Abstract

This invention discloses an additive for improving the disintegration stability of belladonna extract and its preparation method, belonging to the field of pharmaceutical additive preparation technology. It addresses the technical problem that existing belladonna extract additives need further improvement in the disintegration performance and structural stability of belladonna extract tablets. This invention utilizes a histidine-phosphorylated pullulan phase and a guanidino-boronic acid-tyramine polyasparagine phase to synergistically construct a dual-locked belladonna extract disintegration stabilization additive, which is then used in the preparation of belladonna extract tablets. During tableting, this additive facilitates the formation of a more continuous particle bond and stress-bearing framework. After the tablet comes into contact with an aqueous medium, it promotes the continuous connection of medium penetration, tablet core wetting, disintegration propulsion, and content release. Simultaneously, it can mitigate local instability of the tablet core's internal structure under humid and hot conditions, thus simultaneously addressing the issues of tableting, disintegration, drug release, and storage retention.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical additives, specifically to an additive for improving the disintegration stability of belladonna extract and its preparation method. Background Technology

[0002] In the preparation of belladonna extract tablets, conventional disintegrants, fillers, or flow aids such as sodium carboxymethyl starch, crospovidone, cellulose derivatives, and lactose are typically used. These are combined with adjustments to the excipient ratio, granulation method, and tableting parameters to improve the tablet's forming properties, disintegration behavior, and drug release. For raw materials such as traditional Chinese medicine or plant extract powders, which have certain hygroscopic, viscous, and complex compression characteristics, traditional processes often combine formulation design and process optimization to comprehensively control tablet hardness, internal pore structure, media penetration pathways, and performance changes during storage. This allows the extract tablets to achieve suitable forming properties, disintegration, dissolution, and stability under high drug loading conditions.

[0003] However, belladonna extract itself is highly hygroscopic and viscous, easily forming localized dense areas inside the tablet core. When relying solely on conventional hydrophilic polymers or ordinary disintegrants to regulate disintegration behavior, the wetting and diffusion process after the medium enters the tablet is often not balanced enough, tending to preferentially act on locally wettable areas, resulting in inconsistent internal pathway development. Consequently, tablet disintegration initiation often exhibits the characteristic of local initiation and overall lag, the connection between the disintegration process and the content release process is not tight enough, the average disintegration time fluctuates greatly, and the release efficiency and uniformity within 30 minutes are also difficult to maintain stably. The continuity and coordination of the overall liquid entry and drug release process still need to be improved.

[0004] Meanwhile, during tableting and subsequent storage, the conventional excipient system has relatively limited effect on the organization of the contact interface between extract particles and the support of the tablet core skeleton. The particles are mostly exhibited as simple physical stacking, and the internal force transmission path is not continuous enough, which can easily lead to local insufficient compaction, stress concentration or brittleness concentration, thus affecting the formation of tablet hardness and the consistency between tablets. Under high temperature and high humidity conditions, the moisture absorption and softening of the extract may further cause local interface loosening and changes in compaction structure, resulting in tablets exhibiting phenomena such as decreased hardness, delayed disintegration and dissolution behavior drift.

[0005] Therefore, there is still room for further coordination and optimization between traditional technologies in terms of mechanical support, disintegration equilibrium, and performance maintenance under humid and hot conditions. In view of this technical deficiency, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an additive for improving the disintegration stability of belladonna extract and its preparation method, thereby solving the technical problem that existing belladonna extract additives need to further improve the disintegration performance and structural stability of belladonna extract tablets.

[0007] The objective of this invention can be achieved through the following technical solution: a method for preparing an additive to improve the disintegration stability of belladonna extract, comprising the following steps:

[0008] S1. Histidine-phosphorylated pullulan, guanidino-boronic acid-tyramined polyasparagine, deionized water and anhydrous ethanol are added to the reaction vessel and stirred. After mixing evenly, the pH of the reaction system is adjusted to 8.4-8.9 with sodium carbonate. The reaction vessel is then heated to 28-32℃ and stirred for 3-5 hours. The borate ester pre-complex is obtained after post-treatment.

[0009] S2. Add the borate ester pre-complex and deionized water to the reactor and stir. After mixing evenly, add gluconate-δ-lactone. Then, keep the reactor at 25-30℃ and stir for 5-7 hours. After the reaction is completed, spray dry the resulting slurry to obtain the double-locked belladonna extract disintegration stabilizer additive.

[0010] Further, in step S1, the ratio of histidine-phosphorylated pullulan, guanidino-boronic acid-tyramine-modified polyasparagine, anhydrous ethanol and deionized water is 5-6 g: 5-6 g: 100-140 mL: 70-95 mL. The post-treatment includes: removing the solvent under reduced pressure after the reaction is completed, and freeze-drying the obtained material for 5-6 h to obtain the borate ester pre-complex.

[0011] Furthermore, in step S2, the ratio of borate ester pre-complex, deionized water, and gluconate-δ-lactone is 8-10g:140-190mL:1.0-1.4g.

[0012] Furthermore, the preparation method of the histidine-phosphorylated pullulan is as follows: histidine-grafted pullulan, deionized water and sodium carbonate are added to a reaction vessel and stirred. After mixing evenly, 10wt% sodium trimetaphosphate aqueous solution is added. The reaction vessel is heated to 42-48℃ and stirred for 5-7 hours. The result is obtained by post-treatment.

[0013] Furthermore, in the preparation of the histidine-phosphorylated pullulan substrate, the ratio of histidine-grafted pullulan, deionized water, sodium carbonate, and 10wt% sodium trimetaphosphate aqueous solution is 6-7g:180-230mL:1.6-2.4g:2.0-2.8g. The post-treatment includes: adjusting the pH of the reaction system to 6.8-7.2 with 10wt% hydrochloric acid aqueous solution after the reaction, transferring the reaction solution to a dialysis bag with a molecular weight cutoff of 3000-5000 Da, dialyzing with deionized water for 36-48h, and then freeze-drying for 8-12h to obtain histidine-phosphorylated pullulan.

[0014] Furthermore, the histidine-grafted pullulan is prepared by the following method:

[0015] A1. Add pullulan polysaccharide and deionized water to the reaction vessel and stir. After mixing evenly, add oxidant. Control the reaction vessel at 20-25℃ and keep it in the dark for 5-7 hours while stirring. Post-treatment yields dialdehyde pullulan.

[0016] A2. Add pullulan dialdehyde and deionized water to the reaction vessel and stir. After mixing evenly, add L-histidine and stir evenly. Adjust the pH of the reaction system to 5.8-6.5 with 10wt% hydrochloric acid aqueous solution. Then add sodium cyanoborohydride. Subsequently, heat the reaction vessel to 28-32℃ and keep it at this temperature for 10-14 hours. The post-treatment yields histidine-grafted pullulan.

[0017] Further, in step A1, the ratio of pullulan polysaccharide, deionized water, and oxidant is 10-12g:480-580mL:2.8-3.8g, and the oxidant is a 7-9wt% sodium periodate aqueous solution. The post-treatment includes: after the reaction is completed, the reaction solution is transferred to a dialysis bag with a molecular weight cutoff of 3000-5000Da, dialyzed with deionized water for 36-48h, and then freeze-dried for 6-10h to obtain dialdehyde pullulan;

[0018] In step A2, the ratio of pullulan dialdehyde, deionized water, L-histidine, and sodium cyanoborohydride is 8-10g:280-360mL:4.2-5.8g:1.2-1.8g. The post-treatment includes: after the reaction is completed, the reaction solution is transferred to a dialysis bag with a molecular weight cutoff of 3000-5000 Da, dialyzed with deionized water for 36-48h, and then freeze-dried for 8-12h to obtain histidine-grafted pullulan.

[0019] Furthermore, the guanidino-boronic acid-tyramine-modified polyasparagine is prepared by the following method:

[0020] B1. Add L-aspartic acid and 85wt% phosphoric acid aqueous solution to the reactor and mix evenly. Under nitrogen protection, heat the reactor to 155-165℃ and keep it at this temperature for 0.8-1.2h. Then heat the reactor to 205-220℃ and keep it at this temperature for 2.5-3.5h. Post-treatment yields polysuccinimide.

[0021] B2. Add polysuccinimide and dimethylformamide to the reaction vessel and stir to disperse. After mixing evenly, add guanidine, 4-aminophenylboronic acid and tyramine in sequence. Under nitrogen protection, heat the reaction vessel to 55-60℃ and keep it at this temperature for 16-20 hours. Post-treatment yields guanidine-boronic acid-tyramine-modified polyasparagine.

[0022] Further, in step B1, the ratio of L-aspartic acid to 85wt% phosphoric acid aqueous solution is 18-22g:0.5-0.8mL, and the post-processing includes: after the reaction is completed, cooling the solid obtained from the reaction and pulverizing it, and passing it through a 40-60 mesh sieve to obtain polysuccinimide;

[0023] Further, in step B2, the ratio of polysuccinimide, dimethylformamide, guanidine, 4-aminophenylboronic acid, and tyramine is 10-12g:160-220mL:4g:2.6-3.8g:3.8-5.2g. The post-treatment includes: after the reaction is completed, the solvent is evaporated under reduced pressure, the remaining material is dispersed in deionized water to form a 2-4wt% dispersion and transferred to a dialysis bag with a molecular weight cutoff of 5000-8000Da. Dialysis is performed with deionized water for 48-72h, followed by freeze drying for 10-14h to obtain guanidine-boronic acid-tyramined polyasparagine.

[0024] The present invention also discloses an additive for improving the disintegration stability of belladonna extract, which is prepared by a method for preparing an additive for improving the disintegration stability of belladonna extract.

[0025] The present invention has the following beneficial effects:

[0026] 1. When the dual-locked belladonna extract disintegration stabilization additive prepared in this invention enters the tablet system, the histidine-phosphorylated pullulan phase can naturally undertake the continuous process of medium introduction, core wetting, and internal pathway development when the tablet comes into contact with an aqueous medium, so that the medium penetration into the tablet is not limited to a local area. The guanidino-boronic acid-tyramine polyasparagine phase that coexists with it ensures that the compacted structure maintains good integrity when it changes from a dense state to a dispersible state after being liquid-received, without local premature collapse or loosening disorder. Based on this phase configuration, the disintegration initiation of the tablet is smoother, and the connection between the disintegration process and the content release process is closer. This is conducive to the convergence of the average disintegration time to a shorter range and makes the release process within 30 minutes more complete and balanced.

[0027] 2. During the tableting process, the guanidino-boronic acid-tyramine polyasparagine phase in the dual-locked belladonna extract disintegration stabilization additive prepared in this invention participates more directly in the organization of the particle contact interface and the establishment of the stress-bearing skeleton, so that the belladonna extract and the filler excipients form a more continuous bonding area under pressure, thereby making the stress transmission path inside the tablet core more complete. At the same time, the histidine-phosphorylated pullulan phase provides a flexible connection and distribution regulation function that is compatible with it within the same additive, which alleviates the local aggregation, uneven compaction and brittle concentration caused by the viscosity of the extract. As a result, while the tablet obtains the necessary mechanical support, the internal composition distribution and compaction state are more consistent, resulting in more stable hardness formation, reduced adverse tendencies related to inter-tablet differences, and easier maintenance of content uniformity in a more coordinated state.

[0028] 3. In high-temperature and high-humidity environments, the dual-locked belladonna extract disintegration stabilizing additive prepared in this invention does not merely exist as a static excipient. The histidine-phosphorylated pullulan phase is more inclined to regulate the internal moisture content and microenvironment distribution of the tablet, making it less likely for external moisture to form concentrated disturbances in local areas. The guanidino-boronic acid-tyramine polyasparagine phase continuously provides structural support to the particle interface and tablet core skeleton, thereby limiting the concentrated occurrence of interface loosening, softening, and compaction collapse. The synergistic configuration of the two functional phases in the same additive makes the microscopic changes experienced by the tablet after hydrothermal treatment more like a gradual and dispersed structural rearrangement rather than a sudden instability. Accordingly, the hardness retention, disintegration behavior continuity, and 30-minute dissolution state maintenance are more continuous, and the drift of related properties with changes in storage conditions is relatively small. Detailed Implementation

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] This embodiment provides a method for preparing histidine-phosphorylated pullulan, including the following steps:

[0032] Step I: Preparation of pullulan dialdehyde

[0033] Weigh 10.0g pullulan polysaccharide and 480.0mL deionized water and add them to the reaction vessel. Stir and mix well. Then add 2.8g of 7wt% sodium periodate aqueous solution. Keep the reaction vessel at 20℃ and keep it in the dark for 5-7 hours. After the reaction is completed, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3000Da and dialyze with deionized water for 36 hours. Then freeze-dry for 6 hours to obtain dialdehyde pullulan.

[0034] Step II: Preparation of histidine-grafted pullulan

[0035] Weigh out 8.0 g of pullulan dialdehyde and 280.0 mL of deionized water and add them to the reaction vessel. Stir and mix well. Then add 4.2 g of L-histidine and stir well. Adjust the pH of the reaction system to 5.8 with 10 wt% hydrochloric acid aqueous solution. Then add 1.2 g of sodium cyanoborohydride. Then heat the reaction vessel to 28 °C and keep it at this temperature for 10 h with stirring. After the reaction is complete, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3000 Da and dialyze with deionized water for 36 h. Then freeze dry for 8 h to obtain histidine-grafted pullulan.

[0036] Step III: Preparation of histidine-phosphorylated pullulan

[0037] Weigh out 6.0 g of histidine-grafted pullulan, 180.0 mL of deionized water, and 1.6 g of sodium carbonate and add them to the reaction vessel. Stir and mix thoroughly. Then add 2.0 g of 10 wt% sodium trimetaphosphate aqueous solution. Heat the reaction vessel to 42 °C and keep it at that temperature for 5 h with stirring. After the reaction is complete, adjust the pH of the reaction system to 6.8 with 10 wt% hydrochloric acid aqueous solution. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3000 Da and dialyze with deionized water for 36 h. Then freeze-dry for 8 h to obtain histidine-phosphorylated pullulan.

[0038] The reaction principle for preparing histidine-phosphorylated pullulan is as follows:

[0039] Sodium periodate selectively oxidizes and breaks down some of the vicinal diol structures on the pullulan molecular chain, forming a certain number of aldehyde sites on the polysaccharide backbone, thus achieving chemical activation while maintaining the basic continuity of the main polysaccharide structure. Subsequently, the amino group in the L-histidine molecule condenses with the aforementioned aldehyde group and is converted into a more stable covalently linked structure under the action of sodium cyanoborohydride, thereby introducing an amino acid unit containing an imidazole side group into the pullulan chain segment. Further, under the alkaline conditions provided by sodium carbonate, sodium trimetaphosphate reacts with the hydroxyl group in the histidine-grafted pullulan molecule to undergo a phosphorylation reaction, forming a phosphorylated structural unit in the product, ultimately yielding a histidine-phosphorylated pullulan derivative that combines a polysaccharide backbone, nitrogen-containing side groups, and phosphorus-containing groups.

[0040] The mechanism of action of histidine-phosphorylated pullulan in the disintegration stabilization additive of double-locked belladonna extract is as follows:

[0041] In this process, step I introduces aldehyde sites on the pullulan backbone through sodium periodate oxidation, transforming the polysaccharide, which was originally dominated by a hydrophilic backbone, into an activated precursor that can be further chemically edited. Step II utilizes the reaction of L-histidine with aldehydes and subsequent reduction stabilization to covalently graft amino acid units containing imidazole side groups onto the pullulan chain, giving the polysaccharide phase stronger interfacial participation and intermolecular interaction capabilities. Step III further introduces phosphorus-containing structural units through sodium trimetaphosphate phosphorylation, so that the resulting histidine-phosphorylated pullulan simultaneously possesses the multi-site characteristics of a polysaccharide backbone, nitrogen-containing side groups, and phosphorus-containing groups. The resulting functional phase, when constructing a dual-locked belladonna extract disintegration stabilization additive, no longer exists merely as a general hydrophilic carrier, but can participate in the internal interfacial organization, structure transfer, and media response of particles, thereby affecting the microscopic binding state of the final product and its overall operation during tableting, liquid disintegration, drug release, and humid heat storage.

[0042] Example 2

[0043] This embodiment provides a method for preparing histidine-phosphorylated pullulan, including the following steps:

[0044] Step I: Preparation of pullulan dialdehyde

[0045] Weigh 12.0 g pullulan polysaccharide and 580.0 mL deionized water and add them to the reaction vessel. Stir and mix well. Then add 3.8 g of 9 wt% sodium periodate aqueous solution. Keep the reaction vessel at 25 °C and keep it in the dark for 7 h with stirring. After the reaction is completed, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 5000 Da and dialyze with deionized water for 48 h. Then freeze dry for 10 h to obtain dialdehyde pullulan.

[0046] Step II: Preparation of histidine-grafted pullulan

[0047] Weigh out 10.0 g of pullulan dialdehyde and 360.0 mL of deionized water and add them to the reaction vessel. Stir and mix well. Then add 5.8 g of L-histidine and stir well. Adjust the pH of the reaction system to 6.5 with 10 wt% hydrochloric acid aqueous solution. Then add 1.8 g of sodium cyanoborohydride. Then heat the reaction vessel to 32 °C and keep it at this temperature for 14 h with stirring. After the reaction is complete, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 5000 Da and dialyze with deionized water for 48 h. Then freeze dry for 12 h to obtain histidine-grafted pullulan.

[0048] Step III: Preparation of histidine-phosphorylated pullulan

[0049] Weigh out 7.0 g of histidine-grafted pullulan, 230.0 mL of deionized water, and 2.4 g of sodium carbonate and add them to the reaction vessel. Stir and mix thoroughly. Then add 2.8 g of 10 wt% sodium trimetaphosphate aqueous solution. Heat the reaction vessel to 48 °C and keep it at this temperature for 7 h with stirring. After the reaction is complete, adjust the pH of the reaction system to 7.2 with 10 wt% hydrochloric acid aqueous solution. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 5000 Da and dialyze with deionized water for 48 h. Then freeze-dry for 12 h to obtain histidine-phosphorylated pullulan.

[0050] Example 3

[0051] This embodiment provides a method for preparing histidine-phosphorylated pullulan, including the following steps:

[0052] Step I: Preparation of pullulan dialdehyde

[0053] Weigh 11.0 g pullulan polysaccharide and 520.0 mL deionized water and add them to the reaction vessel. Stir and mix well. Then add 3.2 g of 8 wt% sodium periodate aqueous solution. Keep the reaction vessel at 25 °C and keep it in the dark for 6 h with stirring. After the reaction is complete, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 4000 Da and dialyze with deionized water for 42 h. Then freeze dry for 8 h to obtain dialdehyde pullulan.

[0054] Step II: Preparation of histidine-grafted pullulan

[0055] Weigh out 9.0 g of pullulan dialdehyde and 320.0 mL of deionized water and add them to the reaction vessel. Stir and mix well. Then add 5.4 g of L-histidine and stir well. Adjust the pH of the reaction system to 6.0 with 10 wt% hydrochloric acid aqueous solution. Then add 1.6 g of sodium cyanoborohydride. Then heat the reaction vessel to 30 °C and keep it at this temperature for 12 h with stirring. After the reaction is complete, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 4000 Da and dialyze with deionized water for 42 h. Then freeze dry for 10 h to obtain histidine-grafted pullulan.

[0056] Step III: Preparation of histidine-phosphorylated pullulan

[0057] Weigh out 6.4 g of histidine-grafted pullulan, 210.0 mL of deionized water, and 2.0 g of sodium carbonate and add them to the reaction vessel. Stir and mix thoroughly. Then add 2.5 g of 10 wt% sodium trimetaphosphate aqueous solution. Heat the reaction vessel to 45 °C and keep it at this temperature for 6 h with stirring. After the reaction is complete, adjust the pH of the reaction system to 7.0 with 10 wt% hydrochloric acid aqueous solution. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 4000 Da and dialyze with deionized water for 42 h. Then freeze-dry for 10 h to obtain histidine-phosphorylated pullulan.

[0058] Example 4

[0059] This embodiment provides a method for preparing guanidino-boronic acid-tyramined polyasparagine, comprising the following steps:

[0060] Step ①: Preparation of polysuccinimide

[0061] Weigh out 18.0 g of L-aspartic acid and 0.5 mL of 85 wt% phosphoric acid aqueous solution and add them to the reaction vessel. Mix them evenly and heat the reaction vessel to 155 °C under nitrogen protection. Keep the temperature for 0.8 h and then heat the reaction vessel to 205 °C and keep it for 2.5 h. After the reaction is completed, cool the solid obtained from the reaction, crush it, and pass it through a 40 mesh sieve to obtain polysuccinimide.

[0062] Step ②: Preparation of guanidino-boronic acid-tyramined polyasparagine

[0063] Weigh out 10.0 g of polysuccinimide and 160.0 mL of dimethylformamide and add them to the reaction vessel. Stir and disperse the mixture. After mixing evenly, add 4.0 g of guanidine, 2.6 g of 4-aminophenylboronic acid and 3.8 g of tyramine in sequence. Under nitrogen protection, heat the reaction vessel to 55 °C and keep it at this temperature for 16 h. After the reaction is completed, evaporate the solvent under reduced pressure and disperse the remaining material in deionized water to form a 2 wt% dispersion. Transfer the dispersion to a dialysis bag with a molecular weight cutoff of 5000 Da and dialyze with deionized water for 48 h. Then freeze dry for 10 h to obtain guanidine-boronic acid-tyramined polyasparagine.

[0064] The reaction principle for preparing guanidino-boronic acid-tyramined polyasparagine is as follows:

[0065] L-Aspartic acid undergoes intermolecular dehydration condensation and intramolecular cyclization under phosphoric acid-promoted and heated conditions, gradually forming a polymeric structure dominated by succinimide repeating units. The resulting polysuccinimide backbone contains a high density of imide rings, which can serve as active sites for subsequent nucleophilic ring-opening reactions. Subsequently, in a dimethylformamide medium, the amino groups in guanidine, 4-aminophenylboronic acid, and tyramine molecules respectively launch nucleophilic attacks on the imide rings, accompanied by ring opening of the imide structure and conversion into the corresponding amidated polyasparagine segments. This covalently introduces guanidine, arylboronic acid, and tyramine groups into the same polymer backbone. The final product is essentially a multi-substituted polyasparagine derivative, whose molecular structure consists of a polyamide backbone and side groups containing guanidine, boronic acid, and aromatic hydroxyl groups.

[0066] The mechanism of action of guanidino-boronic acid-tyramined polyasparagine as a disintegration stabilizer in double-locked belladonna extract is as follows:

[0067] In this process, step ① firstly, L-aspartic acid undergoes dehydration condensation and cyclization to form polysuccinimide, giving the material a polymer backbone with a high density of imide active sites, providing a unified reaction platform for subsequent multi-component grafting; step ② then utilizes the nucleophilic ring-opening reaction of guanidine, 4-aminophenylboronic acid and tyramine on the imide ring to covalently introduce guanidine, arylboronic acid and tyramine side groups into the same polyasparagine segment, so that the resulting polymer simultaneously possesses the structural characteristics of polyamide backbone support, multi-site polar recognition and aromatic side group participation. The functional phase formed in this way, when constructing the disintegration steady-state additive of double-locked belladonna extract, no longer exists only as a general polymer excipient, but can form richer interfacial interactions and local organizational relationships with other components in the system through multiple types of side groups, and affect the binding state, structural transfer and response mode after medium entry of particles, thereby participating in regulating the overall operation state of the final product during tableting, liquid disintegration, release and unfolding and humid heat storage.

[0068] Example 5

[0069] This embodiment provides a method for preparing guanidino-boronic acid-tyramined polyasparagine, comprising the following steps:

[0070] Step ①: Preparation of polysuccinimide

[0071] Weigh out 22.0 g of L-aspartic acid and 0.8 mL of 85 wt% phosphoric acid aqueous solution and add them to the reaction vessel. Mix them evenly and heat the reaction vessel to 165 °C under nitrogen protection. Keep the temperature for 1.2 h and then heat the reaction vessel to 220 °C. Keep the temperature for 3.5 h. After the reaction is completed, cool the solid obtained from the reaction, crush it, and pass it through a 60 mesh sieve to obtain polysuccinimide.

[0072] Step ②: Preparation of guanidino-boronic acid-tyramined polyasparagine

[0073] Weigh 12.0 g of polysuccinimide and 220.0 mL of dimethylformamide and add them to the reaction vessel. Stir and disperse the mixture. After mixing evenly, add 4.0 g of guanidine, 3.8 g of 4-aminophenylboronic acid and 5.2 g of tyramine in sequence. Under nitrogen protection, heat the reaction vessel to 60 °C and keep it at this temperature for 20 h. After the reaction is completed, evaporate the solvent under reduced pressure and disperse the remaining material in deionized water to form a 4 wt% dispersion. Transfer the dispersion to a dialysis bag with a molecular weight cutoff of 8000 Da and dialyze with deionized water for 72 h. Then freeze dry for 14 h to obtain guanidine-boronic acid-tyramined polyasparagine.

[0074] Example 6

[0075] This embodiment provides a method for preparing guanidino-boronic acid-tyramined polyasparagine, comprising the following steps:

[0076] Step ①: Preparation of polysuccinimide

[0077] Weigh out 20.0 g of L-aspartic acid and 0.7 mL of 85 wt% phosphoric acid aqueous solution and add them to the reaction vessel. Mix them evenly and heat the reaction vessel to 160 °C under nitrogen protection. Keep the temperature for 1.0 h and then heat the reaction vessel to 210 °C. Keep the temperature for 3.0 h. After the reaction is completed, cool the solid obtained from the reaction, crush it, and pass it through a 50 mesh sieve to obtain polysuccinimide.

[0078] Step ②: Preparation of guanidino-boronic acid-tyramined polyasparagine

[0079] Weigh out 11.0 g of polysuccinimide and 200.0 mL of dimethylformamide and add them to the reaction vessel. Stir and disperse the mixture. After mixing evenly, add 4.0 g of guanidine, 3.2 g of 4-aminophenylboronic acid and 5.0 g of tyramine in sequence. Under nitrogen protection, heat the reaction vessel to 58 °C and keep it at this temperature for 18 h. After the reaction is completed, evaporate the solvent under reduced pressure and disperse the remaining material in deionized water to form a 3 wt% dispersion. Transfer the dispersion to a dialysis bag with a molecular weight cutoff of 6000 Da and dialyze with deionized water for 56 h. Then freeze dry for 12 h to obtain guanidine-boronic acid-tyramined polyasparagine.

[0080] Example 7

[0081] This embodiment provides a method for preparing a dual-locked belladonna extract disintegration steady-state additive, comprising the following steps:

[0082] Step 1: Preparation of borate ester pre-complex

[0083] Weigh out 5.0 g of histidine-phosphorylated pullulan prepared in Example 1, 5.0 g of guanidino-boronic acid-tyramine polyasparagine prepared in Example 4, 100.0 mL of deionized water and 70.0 mL of anhydrous ethanol and add them to the reaction vessel. Stir and mix evenly. Adjust the pH of the reaction system to 8.4 with sodium carbonate. Then heat the reaction vessel to 28°C and keep it at that temperature for 3 h. After the reaction is completed, remove the solvent under reduced pressure and freeze-dry the obtained material for 5 h to obtain the borate ester pre-complex.

[0084] Step 2: Preparation of a dual-locked belladonna extract disintegration stabilizing additive

[0085] Weigh out 8.0g of borate ester pre-complex and 140.0mL of deionized water and add them to the reaction vessel. Stir and mix evenly. Then add 1.0g of gluconate-δ-lactone. Keep the reaction vessel at 25℃ and stir for 5h. After the reaction is completed, spray dry the resulting slurry to obtain the double-locked belladonna extract disintegration stabilizer additive.

[0086] The reaction principle for preparing the disintegration-stabilizing additive for double-locked belladonna extract is as follows:

[0087] In a weakly alkaline ethanol-water mixture, the arylboronic acid groups on the guanidinyl-boronic acid-tyramine polyasparagine chain undergo reversible condensation with the abundant vicinal diol hydroxyl groups on the histidine-phosphorylated pullulan molecular chain to form a borate ester-type intermolecular linkage structure, thus obtaining an initial pre-complexed state. Subsequently, gluconate-δ-lactone is slowly hydrolyzed in the aqueous phase, gradually adjusting the acid-base environment of the system, so that the aforementioned dynamic covalent bonds reach a new equilibrium under the new medium conditions. At the same time, it promotes the establishment of multi-point ion association between the positively charged guanidinyl and negatively charged phosphate groups on the polymer chain. The final system is essentially a composite polymer network composed of dynamic borate ester linkages and guanidinyl / phosphate electrostatic association.

[0088] Example 8

[0089] This embodiment provides a method for preparing a dual-locked belladonna extract disintegration steady-state additive, comprising the following steps:

[0090] Step 1: Preparation of borate ester pre-complex

[0091] Weigh out 6.0 g of histidine-phosphorylated pullulan prepared in Example 2, 6.0 g of guanidino-boronic acid-tyramine polyasparagine prepared in Example 5, 140.0 mL of deionized water and 95.0 mL of anhydrous ethanol and add them to the reaction vessel. Stir and mix evenly. Adjust the pH of the reaction system to 8.9 with sodium carbonate. Then heat the reaction vessel to 32°C and keep it at that temperature for 5 h. After the reaction is completed, remove the solvent under reduced pressure and freeze-dry the obtained material for 6 h to obtain the borate ester pre-complex.

[0092] Step 2: Preparation of a dual-locked belladonna extract disintegration stabilizing additive

[0093] Weigh 10.0g of borate ester pre-complex and 190.0mL of deionized water and add them to the reaction vessel. Stir and mix evenly. Then add 1.4g of gluconate-δ-lactone. The reaction vessel is then kept at 30℃ and stirred for 7h. After the reaction is completed, the resulting slurry is spray-dried to obtain a double-locked belladonna extract disintegration stabilizer additive.

[0094] Example 9

[0095] This embodiment provides a method for preparing a dual-locked belladonna extract disintegration steady-state additive, comprising the following steps:

[0096] Step 1: Preparation of borate ester pre-complex

[0097] Weigh out 5.5g of histidine-phosphorylated pullulan prepared in Example 3, 5.5g of guanidino-boronic acid-tyramine polyasparagine prepared in Example 6, 120.0mL of deionized water and 80.0mL of anhydrous ethanol and add them to the reaction vessel. Stir and mix evenly. Adjust the pH of the reaction system to 8.6 with sodium carbonate. Then heat the reaction vessel to 30°C and keep it at that temperature for 4 hours. After the reaction is completed, remove the solvent under reduced pressure and freeze-dry the obtained material for 6 hours to obtain the borate ester pre-complex.

[0098] Step 2: Preparation of a dual-locked belladonna extract disintegration stabilizing additive

[0099] Weigh out 9.0g of borate ester pre-complex and 150.0mL of deionized water and add them to the reaction vessel. Stir and mix evenly. Then add 1.2g of gluconate-δ-lactone. The reaction vessel is then kept at 28℃ and stirred for 6 hours. After the reaction is completed, the resulting slurry is spray-dried to obtain a double-locked belladonna extract disintegration stabilizer additive.

[0100] Comparative Example 1

[0101] The difference between this comparative example and Example 9 is that step III is omitted in the preparation process of the histidine-phosphorylated pullulan used in step one.

[0102] Comparative Example 2

[0103] The difference between this comparative example and Example 9 is that the guanidino-boronic acid-tyroamined polyasparagine used in step one is replaced by the omission of 4-aminophenylboronic acid in preparation step ②.

[0104] Comparative Example 3

[0105] The difference between this comparative example and Example 9 is that step one is omitted, and the histidine-phosphorylated pullulan and guanidino-boronic acid-tyramine polyasparagine used in step one are mixed in equal amounts to replace the borate ester pre-complex and participate in the experimental process in step two.

[0106] Performance testing:

[0107] Weigh out the following by weight: 20.0 parts belladonna extract, 14.0 parts double-locked belladonna extract disintegration stabilizer additive prepared in Examples 7-9 and Comparative Examples 1-3, 90.0 parts microcrystalline cellulose, 73.0 parts mannitol, 1.0 part colloidal silica and 2.0 parts magnesium stearate for later use.

[0108] Belladonna extract, double-locked belladonna extract disintegration stabilizer, microcrystalline cellulose and mannitol were pulverized separately and passed through an 80-mesh sieve. Colloidal silica and magnesium stearate were then passed through a 100-mesh sieve for later use.

[0109] First, add belladonna extract and microcrystalline cellulose to a mixer and premix for 10 minutes; then add double-locked belladonna extract disintegration stabilizer and mannitol, and mix for 15 minutes; then add colloidal silica and continue mixing for 5 minutes; finally add magnesium stearate and mix for 3 minutes to obtain the tablet premix.

[0110] The obtained total mixture was compressed into tablets using a rotary tablet press. An 8mm shallow arc die was selected, the tablet weight was controlled at 200mg, and the compression pressure was controlled at 9kN. The tablets were compressed into tablets to obtain belladonna extract tablet blanks. After tableting, the obtained tablets were placed in a dry environment at 25℃ for 24h to obtain belladonna extract tablets. The belladonna extract tablets directly prepared using the double-locking belladonna extract disintegration stabilization additive were excluded as blank controls.

[0111] Six tablets of belladonna extract prepared in Examples 7-9, Comparative Examples 1-3, and the blank control group were placed in the paddle device of a dissolution tester. 900 mL of pH 6.8 phosphate buffer (containing 0.10% sodium dodecyl sulfate) was added to each chamber as the dissolution medium. The water bath temperature was controlled at 37.0℃±0.5℃, and the paddle speed was 50 rpm. After running for 30 min, 10 mL of each tablet was taken, filtered through a 0.45 μm filter membrane, and the concentration of the active ingredient was determined by ultraviolet spectrophotometer at a wavelength of 360 nm. The dissolution rate of each tablet at 30 min was calculated and the average dissolution rate was obtained.

[0112] Six tablets of belladonna extract prepared in Examples 7-9, Comparative Examples 1-3, and the blank control group were placed in the basket of a disintegration time tester. The instrument was started at 37℃±0.5℃ with 900mL of pH=6.8 phosphate buffer as the medium. The time required for each tablet to completely disintegrate was recorded and the average disintegration time was calculated.

[0113] Six tablets of belladonna extract prepared in Examples 7-9, Comparative Examples 1-3 and blank control group were placed in a tablet hardness tester to measure the force required for the tablet to break and record the average hardness of the six tablets as a molding performance index.

[0114] Six tablets of belladonna extract prepared in Examples 7-9, Comparative Examples 1-3, and the blank control group were sealed and packaged and stored at 40℃±2℃ / 75%±5%RH for 6 months. After the storage period, the samples were taken out and tested for dissolution rate, disintegration time, hardness and other indicators after equilibration at room temperature to evaluate the stability of belladonna extract tablets under high temperature and high humidity conditions. The specific time is shown in Table 1.

[0115] Table 1 - Performance Test Data for Each Sample

[0116]

[0117] Data Analysis:

[0118] Comparative analysis of the data in Table 1 reveals that the belladonna extract tablets prepared in this invention exhibit an average dissolution rate of 91.2% over 30 minutes, an average disintegration time of 252 seconds, and a tablet hardness of 74.8 N. Furthermore, after hydrothermal treatment, the dissolution rate remains at 87.0%, the disintegration rate at 93.2%, and the tablet hardness at 95.7%. All these data are superior to the comparative example, indicating that…

[0119] In Comparative Example 1, because the polysaccharide component used for subsequent construction did not undergo step III, the system lost the further structural constraints originally formed around the polysaccharide phase. This resulted in the incomplete coordination basis between the two functional phases within the dual-locked belladonna extract disintegration stabilization additive. Consequently, during tableting, the degree of organization at the particle contact interface decreased, and the force transmission path within the tablet core was more prone to discontinuity, affecting the structural consistency after tableting. After entering the medium, it was also difficult to maintain a continuous connection between wetting propulsion, structural loosening, and content release within the tablet, easily leading to asynchronous disintegration propulsion and drug release. Under humid and hot conditions, the tablet core's microstructure's ability to withstand external disturbances weakened, resulting in a decrease in the overall stability of its mechanical state, disintegration behavior, and dissolution performance.

[0120] In Comparative Example 2, the omission of 4-aminophenylboronic acid in step ② resulted in the loss of a crucial reaction basis for the formation of pre-correlated structures in the subsequent system. This made it difficult to establish the original ordered connection between the two functional phases within the dual-locked belladonna extract disintegration steady-state additive. As a result, although the obtained additive could still enter the tablet system, the internal synergistic relationship tended to be loose, and the interparticle connections were more inclined to exist in a dispersed rather than continuous structure, thus reducing the integrity of the tablet core skeleton formed during tableting. Furthermore, after the tablet came into contact with the medium, the internal pathway development lacked a coherent structural response, easily leading to the coexistence of localized pre-loosening and localized lag, making it difficult for disintegration and drug release to proceed along the same evolutionary path. After hydrothermal treatment, this structural dispersion was more easily amplified, ultimately resulting in an overall decline in composite performance.

[0121] In Comparative Example 3, although both types of precursor components were retained, the elimination of step one resulted in the system losing the crucial process of pre-organization and synergistic construction before entering the final formulation. This caused the two functional phases to simply coexist in a direct mixed state without forming a more stable internal correlation basis. Consequently, in subsequent step two and tablet preparation, the spatial distribution between materials was more likely to exhibit random contact, making it difficult to establish the relatively continuous interfacial organization and structural transfer relationship as in the original scheme. This difference was further reflected in the overall performance of the sample, namely, the uniformity of the tablet core decreased after compaction, the coupling degree between the disintegration path and the drug release path was insufficient after the medium entered, and localized structural shifts were more likely to occur under storage disturbances, thus causing a simultaneous decrease in comprehensive indicators such as molding, disintegration, dissolution, and retention.

[0122] After the double-locking belladonna extract disintegration stabilizing additive was removed during the preparation of belladonna extract tablets in the blank control group, the system effectively lost its internal buffering mechanism that uniformly regulated the viscosity, compression behavior, liquid entry process, and storage disturbances of the extract. As a result, the tablet structure could only be maintained by the simple contact relationship between conventional excipients. Affected by this, local aggregation and uneven stress are more likely to occur at the particle interface during tableting, and it is difficult to form an orderly structure inside the tablet core that takes into account both mechanical support and subsequent disintegration requirements. After entering the medium, there is a lack of synergistic connection between wetting expansion, disintegration propulsion, and release unfolding, which easily leads to local stagnation, disintegration imbalance, or uneven release. Under high temperature and high humidity conditions, the buffering capacity of the tablet core to temperature and humidity fluctuations is further insufficient, ultimately resulting in a more significant decline in the sample's molding quality, disintegration behavior, dissolution state, and storage retention.

[0123] Comparative Examples 1-3 and the blank control group were progressively decomposed into the material configuration relationship of this scheme from three levels: functional phase pre-construction, introduction of key structural units, and two-phase organization sequence. The results show that when the construction foundation at any level is missing, the interface organization, structural transfer, and media response relationship maintained by the two types of functional phases within the system are difficult to maintain continuity. Consequently, the continuity of the tablet's state under compaction, liquid release, release and unfolding, and humid heat disturbance is weakened to varying degrees. This change is not manifested as an isolated fluctuation of a single index, but rather as a loosening of the original coupling relationship between the preparation process and the use process. Thus, this scheme does not reflect the parallel superposition of individual components, but rather the overall system characteristics based on the mutual adaptation of specific material configuration, construction sequence, and operation path.

[0124] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing an additive to improve the disintegration stability of belladonna extract, characterized in that, Includes the following steps: S1. Histidine-phosphorylated pullulan, guanidino-boronic acid-tyramined polyasparagine, deionized water and anhydrous ethanol are added to the reaction vessel and stirred. After mixing evenly, the pH of the reaction system is adjusted to 8.4-8.9 with sodium carbonate. The reaction vessel is then heated to 28-32℃ and stirred for 3-5 hours. The borate ester pre-complex is obtained after post-treatment. S2. Add the borate ester pre-complex and deionized water to the reactor and stir. After mixing evenly, add gluconate-δ-lactone. Then, keep the reactor at 25-30℃ and stir for 5-7 hours. After the reaction is completed, spray dry the resulting slurry to obtain the double-locked belladonna extract disintegration stabilizer additive.

2. The method for preparing an additive for improving the disintegration stability of belladonna extract according to claim 1, characterized in that, In step S1, the ratio of histidine-phosphorylated pullulan, guanidino-boronic acid-tyramine-modified polyasparagine, anhydrous ethanol, and deionized water is 5-6 g: 5-6 g: 100-140 mL: 70-95 mL.

3. The method for preparing an additive for improving the disintegration stability of belladonna extract according to claim 1, characterized in that, In step S2, the ratio of borate ester pre-complex, deionized water and gluconate-δ-lactone is 8-10g:140-190mL:1.0-1.4g.

4. A method for preparing an additive for improving the disintegration stability of belladonna extract according to claim 1, characterized in that, The preparation method of histidine-phosphorylated pullulan is as follows: histidine-grafted pullulan, deionized water and sodium carbonate are added to a reaction vessel and stirred. After mixing evenly, 10wt% sodium trimetaphosphate aqueous solution is added. The reaction vessel is heated to 42-48℃ and stirred for 5-7 hours. The result is obtained by post-treatment.

5. A method for preparing an additive for improving the disintegration stability of belladonna extract according to claim 4, characterized in that, In the preparation of histidine-phosphorylated pullulan substrate, the ratio of histidine-grafted pullulan, deionized water, sodium carbonate and 10wt% sodium trimetaphosphate aqueous solution is 6-7g:180-230mL:1.6-2.4g:2.0-2.8g.

6. A method for preparing an additive for improving the disintegration stability of belladonna extract according to claim 1, characterized in that, The histidine-grafted pullulan was prepared by the following method: A1. Add pullulan polysaccharide and deionized water to the reaction vessel and stir. After mixing evenly, add oxidant. Control the reaction vessel at 20-25℃ and keep it in the dark for 5-7 hours while stirring. Post-treatment yields dialdehyde pullulan. A2. Add pullulan dialdehyde and deionized water to the reaction vessel and stir. After mixing evenly, add L-histidine and stir evenly. Adjust the pH of the reaction system to 5.8-6.5 with 10wt% hydrochloric acid aqueous solution. Then add sodium cyanoborohydride. Subsequently, heat the reaction vessel to 28-32℃ and keep it at this temperature for 10-14 hours. The post-treatment yields histidine-grafted pullulan.

7. A method for preparing an additive for improving the disintegration stability of belladonna extract according to claim 6, characterized in that, In step A1, the ratio of pullulan polysaccharide, deionized water, and oxidant is 10-12g:480-580mL:2.8-3.8g, and the oxidant is a 7-9wt% sodium periodate aqueous solution; in step A2, the ratio of pullulan dialdehyde, deionized water, L-histidine, and sodium cyanoborohydride is 8-10g:280-360mL:4.2-5.8g:1.2-1.8g.

8. A method for preparing an additive for improving the disintegration stability of belladonna extract according to claim 1, characterized in that, The guanidino-boronic acid-tyramine-modified polyasparagine was prepared by the following method: B1. Add L-aspartic acid and 85wt% phosphoric acid aqueous solution to the reactor and mix evenly. Under nitrogen protection, heat the reactor to 155-165℃ and keep it at this temperature for 0.8-1.2h. Then heat the reactor to 205-220℃ and keep it at this temperature for 2.5-3.5h. Post-treatment yields polysuccinimide. B2. Add polysuccinimide and dimethylformamide to the reaction vessel and stir to disperse. After mixing evenly, add guanidine, 4-aminophenylboronic acid and tyramine in sequence. Under nitrogen protection, heat the reaction vessel to 55-60℃ and keep it at this temperature for 16-20 hours. Post-treatment yields guanidine-boronic acid-tyramine-modified polyasparagine.

9. A method for preparing an additive for improving the disintegration stability of belladonna extract according to claim 8, characterized in that, In step B1, the ratio of L-aspartic acid to 85wt% phosphoric acid aqueous solution is 18-22g:0.5-0.8mL; in step B2, the ratio of polysuccinimide, dimethylformamide, guanidine, 4-aminophenylboronic acid and tyramine is 10-12g:160-220mL:4g:2.6-3.8g:3.8-5.2g.

10. An additive for improving the disintegration stability of belladonna extract, characterized in that, The additive for improving the disintegration stability of belladonna extract is prepared by the method for preparing an additive for improving the disintegration stability of belladonna extract as described in any one of claims 1-9.

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