A product for evaluating dissolution of a poorly soluble solid dispersion

Abstract

The present application provides a product for evaluating the dissolution of a poorly soluble solid dispersion, which is composed of FaSSIF buffer solution with pH 4.0-8.0 of dissolution medium, 0.1%-2% w / v of mucin. Mucin inhibits the crystallization process of drug supersaturated solution in a single molecule state. Mucin prolongs the supersaturation of poorly soluble drugs with different crystallization behaviors by inhibiting drug crystallization or forming mucin-drug interaction without changing solubility. Under in vivo conditions, this effect of mucin is widely present in poorly soluble drugs with different crystallization mechanisms. The addition of small intestinal mucin in the dissolution medium affects the "spring-parachute" of the solid dispersion. It is suggested to improve the dissolution evaluation method of the preparation, and add a new investigation factor-mucin in the dissolution medium to more objectively simulate the in vivo characteristics.

Description

TECHNICAL FIELD

[0001] The present invention is in the field of pharmaceutical research, and more specifically, to a product for evaluating the dissolution of a poorly soluble solid dispersion. BACKGROUND

[0002] The Biopharmaceutics Classification System (BCS) provides a reference for predicting the dissolution and absorption of a drug. Many poorly soluble drugs belong to BCS class II or IV. Poorly soluble drugs are classified into three categories according to their crystallization behavior: class I (Rep. naproxen) is fast crystallization; class II (Rep. nifedipine) is medium crystallization; and class III (Rep. itraconazole, ritonavir) is slow crystallization. During the process of drug discovery, many poorly soluble drugs have been discovered, but their application is limited by low absorption and bioavailability. In the past decade, many formulation methods such as liposomes, solid dispersions, or nanocrystals, etc. techniques produce and stabilize the supersaturation effect of drugs through some polymers in a "spring-parachute" mode, enhance absorption and bioavailability. In particular, solid dispersion formulation technology is gradually being widely used. The preparation methods mainly include hot melt extrusion and spray drying, which can be selected according to the characteristics of the polymer and the drug. Hot melt extrusion can transfer, mix, and fuse the drug and polymer to prepare a solid dispersion. The solid dispersion can produce and maintain the supersaturation state of the drug during the dissolution process by inhibiting the nucleation or growth of drug crystallization, thereby promoting absorption and bioavailability, reducing side effects, and optimizing the effect of the drug in the body.

[0003] Mucus is a viscoelastic protective layer of the mucosal surface, synthesized by goblet cells. It is present on all organs of the body exposed to the external environment, such as the eye, respiratory system, digestive system and vagina, but its properties (composition, structure, thickness) are not the same. Mucus has many physiological functions: natural barrier, lubrication of the lumen, maintenance of the water layer of epithelial cells, permeable gel layer for the exchange of gases and nutrients, colonization site and attachment point for the bacterial flora, and transduction of cell signals. Mucus contains 90-95% water, 2-5% glycoproteins, lipids, proteins, electrolytes and DNA, but the main component is mucin. Mucin belongs to the family of high molecular weight (200 kDa-200 MDa) and heavily glycosylated (up to 90%) proteins, being a natural polymer. Its protein core is called "apomucin" and the glycosylation is present around the protein core, in the form of O-oligosaccharides and N-glycans chains bound to the protein core. There are many genetic subtypes of mucin: MUC1, MUC2, MUC3A, MUC3B, MUC4, MUC5AC, MUC5B, MUC6, MUC7, MUC12, MUC13, MUC15, MUC16, MUC17, MUC19, MUC20, etc. These subtypes are divided into two categories: secreted mucins and membrane-bound mucins. Secreted mucins can form a huge polymer network, expressed throughout the lumen; membrane-bound mucins are bound to the epithelial cell membrane surface and are the anchor of the secreted network. Mucins can interact with each other, having a tendency to aggregate and gel, undergoing a change in the molecular state from monomer to polymer; mucins can also interact with other components due to their high viscosity and hydrophobic / electrostatic interactions.

[0004] Caron, G. et al. found that mucin, as a polymer, has electrostatic and hydrophobic interactions with drugs. Yeap, Y. et al. found that intestinal mucus slows down the precipitation of poorly soluble drugs - carvedilol and piroxicam, stabilizing their supersaturation. However, there is no study on whether the dissolution medium containing mucin affects the dissolution characteristics of poorly soluble solid dispersions. Therefore, it is necessary to add a new investigation factor - mucin to the dissolution medium and optimize and screen its key parameters (mucin concentration, pH of the buffer solution) in order to more objectively simulate the in vivo characteristics and effectively evaluate the preparation. SUMMARY

[0005] The object of the present application is to provide a product for evaluating the dissolution of poorly soluble solid dispersions. Mucin is added to the dissolution medium, affecting the "spring-parachute" of the solid dispersion of poorly soluble drugs by prolonging their supersaturation.

[0006] In order to achieve the above technical problems, the technical scheme adopted by the present application is as follows:

[0007] A product for evaluating the dissolution of a poorly soluble solid dispersion, a FaSSIF buffer solution with pH 4.0-8.0 is prepared, 0.1%-2% w / v mucin (mucin mass, unit g, ratio to FaSSIF buffer solution volume, buffer solution volume unit mL) is added, stirring at 35-38 degrees Celsius, preferably 37 degrees Celsius until complete dissolution, the resulting solution is used to evaluate the dissolution characteristics of the poorly soluble solid dispersion.

[0008] The solid dispersion is prepared by hot melt extrusion.

[0009] The drug for preparing the solid dispersion is a BCS II or IV class poorly soluble drug with different crystallization behaviors, selected from fast crystallization type, medium crystallization type, and slow crystallization type poorly soluble drugs.

[0010] Preferably, the poorly soluble drug includes naproxen, nifedipine, itraconazole, ritonavir.

[0011] Preferably, the dissolution method is a small cup method.

[0012] The FaSSIF buffer solution is prepared according to the product specification ( https: / / biorelevant.com / fassif-fessif-fassgf / buy ).

[0013] Preferably, the pH of the FaSSIF buffer solution is 6.5.

[0014] The mucin is various secretory gastrointestinal mucins, selected from pig gastric mucin II.

[0015] Preferably, the concentration of the mucin is 0.2% w / v.

[0016] The present application first discovers that mucin is a natural supersaturation stabilizer, which prolongs the "parachute" of the solid dispersion. Mucin prolongs the supersaturation of nifedipine and delays its precipitation, showing concentration dependence and pH dependence without changing the solubility. The mechanism is that mucin in a single molecule state inhibits the crystallization process of the drug supersaturated solution. When the concentration of mucin is 0.2% w / v and the pH of the dissolution medium is 6.5, the curve characteristics are optimal, so this condition is selected. Mucin prolongs the supersaturation of poorly soluble drugs with different crystallization behaviors by inhibiting drug crystallization or forming mucin-drug interactions, without changing the solubility. Under in vivo conditions, this effect of mucin is widely present in poorly soluble drugs with different crystallization mechanisms. Mucin prolongs the "parachute" of each solid dispersion. It is suggested to improve the dissolution evaluation method of the preparation, add a new investigation factor-mucin in the dissolution medium, to more objectively simulate the in vivo characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1Figure 1 is a graph of supersaturation ratio (SSR) vs. concentration of nifedipine in mucin solutions at different concentrations (n = 3), where SSR represents supersaturation ratio.

[0018] Figure 2 Figure 2 is a photomicrograph of crystallization in FaSSIF and FaSSIF Containing 0.2% Mucin, where A represents 0 min; B represents 80 min; C represents 130 min.

[0019] Figure 3 Figure 3 is a graph of supersaturation ratio (SSR) vs. concentration of nifedipine in mucin solutions at different pH values (n = 3), where SSR represents supersaturation ratio; A represents pH 4.0; B represents pH 6.5; C represents pH 8.0.

[0020] Figure 4 Figure 4 is a graph of supersaturation ratio (SSR) vs. concentration of different poorly soluble drugs in FaSSIF vs. in FaSSIF Containing 0.2% Mucin (n = 3), where SSR represents supersaturation ratio; A represents naproxen; B represents nifedipine; C represents itraconazole; D represents ritonavir.

[0021] Figure 5 Figure 5 is a photomicrograph of crystallization in FaSSIF and FaSSIF Containing 0.2% Mucin, where SSR represents supersaturation ratio; A represents naproxen; B represents nifedipine; C represents itraconazole.

[0022] Figure 6 Figure 6 is a graph of plasma concentration vs. time after oral administration of poorly soluble drugs in rats (n = 3), where SSR represents supersaturation ratio; A represents naproxen; B represents nifedipine; C represents itraconazole.

[0023] Figure 7 Figure 7 is a graph of supersaturation ratio (SSR) vs. concentration of solid dispersions in dissolution media FaSSIF and FaSSIF Containing 0.2% Mucin (n = 3), where SSR represents supersaturation ratio; A represents naproxen; B represents nifedipine; C represents itraconazole. DETAILED DESCRIPTION

[0024] The present application is described in detail below with reference to specific embodiments. Those skilled in the art will appreciate that these embodiments are illustrative only and that the scope of the present application is not limited in any way by them. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those of a person of ordinary skill in the art. The procedures and compounds described herein are illustrative only and are not intended to be limiting. The following examples are presented to further illustrate the application. The examples are not intended to be limiting in any way. The experimental methods used in the following examples are routine methods unless otherwise specified. The raw materials, reagents and the like used in the following examples are commercially available unless otherwise specified. The embodiments of the present application will be described in detail with reference to the drawings.

[0025] Example 1 Effect of mucin on nifedipine supersaturated solution and screening of optimal parameters

[0026] Materials and instruments:

[0027] Nifedipine was purchased from Letco Medical; FaSSIF / FeSSIF / FaSSGF was purchased from Biorelevant.com; Porcine gastric mucin II was purchased from Sigma; DMSO was purchased from Sigma; Chromatographically pure methanol and acetonitrile were purchased from Fisher Chemical; Ultrapure water was prepared by a water purification system.

[0028] Lab-Line constant temperature shaker; Waters HPLC; Olympus BX53 polarizing microscope; Mettler Toledo pH meter.

[0029] Experimental methods

[0030] 1. Solubility determination

[0031] Nifedipine is susceptible to light decomposition, so all experiments must be carried out in the dark. Nifedipine was weighed and added to FaSSIF with and without mucin or different pH buffers, respectively, and dissolved to supersaturation in a constant temperature shaker at 37°C and 100 rpm. The solution was centrifuged and determined by HPLC.

[0032] 2. Preparation of supersaturated solution

[0033] Nifedipine supersaturated solution was prepared by the Solvent-shift method. Nifedipine was pre-dissolved in methanol. FaSSIF with and without mucin or different pH buffers were placed in a constant temperature shaker at 37°C and 100 rpm, and nifedipine pre-solution was gradually added to supersaturation.

[0034] 3. Supersaturation stability experiment

[0035] This experiment was designed to test the stability of supersaturation and precipitation. The supersaturated solution was placed in a constant temperature shaker at 37°C and 100 rpm. At different time points, 600 μL of sample was taken and immediately centrifuged at 14000 r / min for 10 min. 300 μL of supernatant was taken and an equal volume of DMSO was added to terminate the subsequent precipitation. HPLC detection.

[0036] 4. Polarizing microscope analysis

[0037] Over-saturated solution samples were analyzed using an Olympus BX53 polarized light microscope with 20x magnification. Temperature was controlled at 37°C using a Linkam T95 Hostage reactor with Linksys 32 software package (Olympus Co., Tokyo, Japan). After sample addition, the cover glass was sealed with nail polish to prevent solution evaporation. Images were collected at different time points to observe crystallization behavior.

[0038] 5. HPLC analysis

[0039] A C18 column (4 μm, 3.9 mm x 75 mm, Waters, USA) and a C18 guard column (4 μm, 4 mm x 3.0 mm, Waters, USA) were used to maintain the column temperature at 37°C. The mobile phase was 0.1% trifluoroacetic acid in water and 0.1% trifluoroacetic acid in acetonitrile (70:30). The flow rate was 1 mL / min. The injection volume was 10 μL. The detection wavelength was 237 nm.

[0040] 6. Data analysis

[0041] Saturation ratio (SSR)

[0042]

[0043] where C t : concentration at time point t; C max : maximum concentration; SSR: experimental saturation ratio.

[0044] Time after burst (T ss )

[0045] T ss is the length of time when the concentration is maintained above 90% of the maximum concentration. It is a method to measure the stability of drug over-saturation.

[0046] Area under curve (AUC)

[0047] AUC is the area under the curve from time point 0 to time point t, calculated by the trapezoidal method. It is also a method to measure the stability of drug over-saturation.

[0048] 7. Statistical analysis

[0049] Results are expressed as mean ± SD. Independent sample t-test was used to compare the differences between different groups. p < 0.05 indicates that the difference is statistically significant. All statistical analysis methods were processed using SPSS software.

[0050] Experimental results

[0051] 1. Effect of mucin on the solubility of nifedipine

[0052] As shown in Table 1, there was no significant difference in the solubility of nifedipine in FaSSIF solutions containing and without mucin, or in buffers with different pH values. This indicates that mucin does not affect solubility.

[0053] Table 1. Solubility of nifedipine (n=3)

[0054]

[0055]

[0056] 2. Effects of different concentrations of mucin on nifedipine supersaturation

[0057] from Figure 1 As can be seen from Table 2, T ss Or the AUC increases significantly with increasing mucin concentration. Nifedipine's T... ss Or, the AUC showed no significant difference between FaSSIF containing 0.1% mucin and FaSSIF. ss Or the AUC showed a significant difference between FaSSIF containing 0.2% mucin and FaSSIF (p<0.05). Although T ss There was no significant difference in the concentration of mucin (2% glutinin) between FaSSIF and FaSSIF, but there was a significant difference in AUC (p < 0.05). This indicates that mucin prolongs the supersaturation of nifedipine in a concentration-dependent manner. According to the statistical analysis of the parameters, a mucin concentration of 0.2% w / v is sufficient to delay the precipitation of nifedipine and best reflects the curve characteristics, thus representing the optimal condition.

[0058] Table 2. Parameters of nifedipine in mucin solutions of different concentrations (n=3)

[0059] T ss (min)]]> AUC FaSSIF 80±17.32 1913.89±146.37 FaSSIF Containing 0.1% Mucin 90±30.00 2156.61±179.62 FaSSIF Containing 0.2% Mucin 130 ± 17.32 * ]] 2313.82 ± 60.66 * ]] FaSSIF Containing 2% Mucin 80±45.83 2565.04 ± 226.65 * ]]

[0060] *vs FaSSIF, p<0.05.

[0061] 3. Effect of mucin on nifedipine crystallization

[0062] from Figure 2 As can be seen, in FaSSIF, nifedipine crystallizes at 80 min and the crystals grow at 130 min. However, in 0.2% mucin, the crystallization time is extended to 130 min. This indicates that mucin inhibits the crystallization of nifedipine in a supersaturated solution.

[0063] 4. Effects of pH on mucin function

[0064] The effect of pH on the function of mucin was tested using different pH buffers without FaSSIF. Nifedipine is considered as a weak acid (pKa = 3.93). The pH range was chosen from 4 to 8 in view of the pKa. The turbidity of the mucin solution decreased gradually as the pH increased. From Figure 3 As can be seen in Table 3, the T ss There was no significant difference between T ss There was a significant difference between T ss There was a significant difference between T

[0065] Table 3. Parameters of nifedipine in different pH mucin solutions (n = 3)

[0066] T ss (min)]]> AUC Base Buffer pH 4.0 30±0.00 2027.07±198.51 Base Buffer pH 4.0 Containing 0.2% Mucin 30±0.00 2445.43±184.18 Base Buffer pH 6.5 30±0.00 1237.41±27.46 Base Buffer pH 6.5 Containing 0.2% Mucin 90 ± 30.00 * ]] 2464.35 ± 31.18 ** ]] Base Buffer pH 8.0 30±0.00 1244.69±108.79 Base Buffer pH 8.0 Containing 0.2% Mucin 90 ± 30.00 * ]] 2040.22 ± 131.77 ** ]]

[0067] *vs Base Buffer, p < 0.05; **vs Base Buffer, p < 0.01.

[0068] Experimental Conclusion

[0069] Mucin prolonged the supersaturation of nifedipine, delayed its precipitation, and showed concentration dependence and pH dependence, without changing the solubility. The mechanism is that mucin in a monomolecular state inhibits the crystallization process of a drug supersaturated solution. Mucin is a natural supersaturation stabilizer. The curve characteristics were optimal when the concentration of mucin was 0.2% w / v and the pH of the dissolution medium was 6.5, so this condition was selected.

[0070] Example 2 Effect of Mucin on Supersaturated Solutions of Poorly Soluble Drugs with Different Crystallization Behaviors and Correlation of in Vitro and in Vivo Studies

[0071] Experimental Materials and Instruments:

[0072] Naproxen, itraconazole, ritonavir were purchased from Nexconn Pharmatechs; Nifedipine was purchased from Letco Medical; Diazepam was purchased from Sigma; FaSSIF / FeSSIF / FaSSGF were purchased from Biorelevant.com; Porcine gastric mucin II was purchased from Sigma; DMSO was purchased from Sigma; Chromatographically pure methanol, acetonitrile were purchased from Fisher Chemical; Ultrapure water was prepared by a water purification system.

[0073] Lab-Line constant temperature shaker; Waters HPLC; Olympus BX53 polarizing microscope; Organomation nitrogen blowing instrument; Mettler Toledo pH meter.

[0074] Animals: Male SD rats (body weight: 210-230 g; age: 2 months) were purchased from Beijing Huafukang Biotechnology Co., Ltd. The rats were kept in a 12-hour light-dark cycle. The rats were fasted for 12 hours before the experiment. The animal experiment has passed the ethical review (No. NKYY-DWLL-2020-004).

[0075] Experimental method

[0076] 1. Solubility determination

[0077] Different crystallization behaviors of poorly soluble drugs were weighed and added to FaSSIF and mucin-containing FaSSIF solutions, respectively, and dissolved to supersaturation at 37°C on a constant temperature shaker at 100 rpm. The solution was centrifuged, and HPLC was used for determination.

[0078] 2. Preparation of supersaturated solution

[0079] The Solvent-shift method was used to prepare supersaturated solutions of poorly soluble drugs with different crystallization behaviors. Naproxen, nifedipine, and ritonavir were pre-dissolved in methanol; itraconazole was pre-dissolved in DMSO. FaSSIF with and without mucin was placed in a constant temperature shaker at 37°C and 100 rpm, and the drug pre-solution was gradually added to supersaturation.

[0080] 3. Supersaturation stability experiment

[0081] This experiment was designed to test the stability of supersaturation and precipitation. The supersaturated solution was placed in a constant temperature shaker at 37°C and 100 rpm. At different time points, 600 μL of sample was taken and immediately centrifuged at 14000 r / min for 10 min. 300 μL of supernatant was taken and an equal volume of DMSO was added to terminate the subsequent precipitation. HPLC detection was performed.

[0082] 4. Polarizing microscope analysis

[0083] Over-saturated solution samples were analyzed using an Olympus BX53 polarized light microscope with 20x magnification. Temperature was controlled at 37°C using a Linkam T95 Hostage reactor with Linksys 32 software package (Olympus Co., Tokyo, Japan). After sample addition, the cover glass was sealed using nail polish to prevent solution evaporation. Images were taken at different time points to observe crystallization behavior.

[0084] 5. Pharmacokinetic study

[0085] Naproxen, nifedipine, itraconazole, ritonavir were pre-dissolved in DMSO. FaSSIF was placed in a constant temperature shaker at 37°C and 100 rpm, and drug pre-solution was gradually added to reach over-saturation. Rats were orally administered with over-saturated solution. At different time points, 250 μL of blood was collected from the eye socket, centrifuged at 4000 r / min for 10 min, and stored at -20°C for later use. Diazepam was added to the plasma sample as an internal standard. After vortexing for 30 s, 1 mL of methanol was added, and vortexed for 10 min to precipitate the protein. The suspension was centrifuged at 15000 r / min for 10 min, and the supernatant was collected and dried under nitrogen at 40°C. It was re-dissolved in 50 μL of methanol, centrifuged, and detected by HPLC.

[0086] 6. HPLC analysis

[0087] In vitro samples

[0088] A C18 column (4 μm, 3.9 mm x 75 mm, Waters, USA) and a C18 guard column (4 μm, 4 mm x 3.0 mm, Waters, USA) were used, and the column temperature was maintained at 37°C. The mobile phase was 0.1% trifluoroacetic acid in water and 0.1% trifluoroacetic acid in acetonitrile: naproxen 70:30; nifedipine 70:30; itraconazole 60:40; ritonavir 60:40. The flow rate was 1 mL / min. The injection volume was 10 μL. The detection wavelength was 245 nm for naproxen; 237 nm for nifedipine; 258 nm for itraconazole; and 240 nm for ritonavir.

[0089] In vivo samples

[0090] A C18 column (4 μm, 3.9 mm x 75 mm, Waters, USA) and a C18 guard column (4 μm, 4 mm x 3.0 mm, Waters, USA) were used, and the column temperature was maintained at 37°C. The mobile phase was 0.1% trifluoroacetic acid in water and 0.1% trifluoroacetic acid in acetonitrile: naproxen 65:35; nifedipine 63:37; itraconazole 50:50; ritonavir 57:43. The flow rate was 1 mL / min. The injection volume was 10 μL. The detection wavelength was 250 nm.

[0091] 7. Data analysis

[0092] Supersaturation ratio (SSR)

[0093]

[0094] Where, C t : concentration at time point t; C max : maximum concentration; SSR: experimental supersaturation ratio.

[0095] Time after burst (T ss )

[0096] T ss is the length of time when the concentration is maintained above 90% of the maximum concentration. It is a method to measure the stability of drug supersaturation.

[0097] Area under curve (AUC)

[0098] AUC is the area under the curve from time point 0 to time point t, calculated by trapezoidal method. It is also a method to measure the stability of drug supersaturation.

[0099] In vitro-in vivo correlation (IVIVC)

[0100] FDA defines IVIVC as a predictive mathematical model that describes the relationship between in vitro properties and the associated in vivo response. Class A IVIVC is the highest correlation class, representing a point-to-point relationship between in vitro and in vivo data. Linear regression analysis is performed on C in vitro and C in vivo .

[0101] 8. Statistical analysis

[0102] Results are expressed as mean ± SD. Independent sample t-test was used to compare the differences between different groups. p < 0.05 indicates a significant difference. All statistical analysis methods were processed using SPSS software.

[0103] Experimental results

[0104] 1. Effect of mucin on solubility of different crystallization behavior of poorly soluble drugs

[0105] There was no significant difference in the solubility of naproxen, nifedipine, itraconazole, and ritonavir in FaSSIF with and without mucin (Table 4). This indicates that mucin does not change the solubility of different crystallization behavior of poorly soluble drugs.

[0106] Table 4 Solubility of different crystallization behavior of poorly soluble drugs (n = 3)

[0107]

[0108] 2. Effect of mucin on supersaturation of different crystallization behavior of poorly soluble drugs

[0109] As Figure 4 and Table 5, T ss or AUC were significantly different between FaSSIF Containing 0.2% Mucin and FaSSIF (p<0.05). This indicates that mucin prolongs the supersaturation of naproxen. T ss or AUC were significantly different between FaSSIF Containing 0.2% Mucin and FaSSIF (p<0.05). This indicates that mucin prolongs the supersaturation of nifedipine. T ss or AUC were significantly different between FaSSIF Containing 0.2% Mucin and FaSSIF (p<0.05). This indicates that mucin prolongs the supersaturation of itraconazole. Although T ss There was no significant difference in T

[0110] Table 5. Parameters of poorly soluble drugs in FaSSIF vs in FaSSIF Containing 0.2% Mucin (n=3).

[0111]

[0112] *vs FaSSIF, p<0.05.

[0113] 3. Effect of mucin on crystallization of different crystallization behavior of poorly soluble drugs

[0114] As Figure 5In FaSSIF, naproxen crystallized at 15 min and the crystals grew at 60 min. However, in 0.2% mucin, the crystallization time was extended to 60 min. This indicates that mucin inhibits the crystallization of naproxen in a supersaturated solution. Similarly, in FaSSIF, nifedipine crystallized at 80 min and the crystals grew at 130 min. However, in 0.2% mucin, the crystallization time was extended to 130 min. This indicates that mucin inhibits the crystallization of nifedipine in a supersaturated solution. In FaSSIF, itraconazole crystallized at 150 min and the crystals grew at 220 min. However, in 0.2% mucin, the crystallization time was extended to 220 min. This indicates that mucin inhibits the crystallization of itraconazole in a supersaturated solution.

[0115] 4. Pharmacokinetic characteristics

[0116] Figure 6 The plasma concentrations of naproxen, nifedipine, itraconazole, and ritonavir in rats after gavage are shown. The data were fitted to a one-compartment open system pharmacokinetic model using DAS ver 2.0. Pharmacokinetic parameters are shown in Table 6.

[0117] Table 6. Pharmacokinetic parameters of poorly soluble drugs in vivo (n=3).

[0118]

[0119]

[0120] 5. Regression characteristics

[0121] C in vitro and C in vivo The linear regression equations and correlation coefficients are shown in Table 7. Statistical comparison showed that the correlation coefficient (r) between the concentration of naproxen in FaSSIF containing 0.2% mucin and its concentration in rat plasma was [value missing]. mean (r mean =0.5868±0.0407)>r 8,0.10 (r 8,0.10 =0.5494), significantly higher than the correlation coefficient between FaSSIF and rat plasma (p<0.05). The correlation coefficient r between the concentration of nifedipine in FaSSIF-containing 0.2% mucin and its concentration in rat plasma was... mean (r mean =0.8981±0.0615)>r 6,0.01 (r 6,0.01= 0.9102 ± 0.0038) was significantly higher than that of FaSSIF vs rat plasma (p < 0.05). The correlation coefficient, r, of the concentration of itraconazole in FaSSIF Containing 0.2% Mucin vs rat plasma, r = 0.8343, was significantly higher than that of FaSSIF vs rat plasma (p < 0.05). mean (r mean = 0.9102 ± 0.0038) was significantly higher than that of FaSSIF vs rat plasma (p < 0.05). The correlation coefficient, r, of the concentration of itraconazole in FaSSIF Containing 0.2% Mucin vs rat plasma, r = 0.8343, was significantly higher than that of FaSSIF vs rat plasma (p < 0.05). 6,0.01 (r 6,0.01 = 0.9102 ± 0.0038) was significantly higher than that of FaSSIF vs rat plasma (p < 0.05). The correlation coefficient, r, of the concentration of itraconazole in FaSSIF Containing 0.2% Mucin vs rat plasma, r = 0.8343, was significantly higher than that of FaSSIF vs rat plasma (p < 0.05). mean (r mean = 0.9102 ± 0.0038) was significantly higher than that of FaSSIF vs rat plasma (p < 0.05). The correlation coefficient, r, of the concentration of itraconazole in FaSSIF Containing 0.2% Mucin vs rat plasma, r = 0.8343, was significantly higher than that of FaSSIF vs rat plasma (p < 0.05). 6,0.01 (r 6,0.01 = 0.9102 ± 0.0038) was significantly higher than that of FaSSIF vs rat plasma (p < 0.05). The correlation coefficient, r, of the concentration of itraconazole in FaSSIF Containing 0.2% Mucin vs rat plasma, r = 0.8343, was significantly higher than that of FaSSIF vs rat plasma (p < 0.05).

[0122] Table 7 Regression comparison (n = 3).

[0123]

[0124]

[0125] *vs FaSSIF vs Rat, p < 0.05.

[0126] Experimental conclusion

[0127] Mucin prolonged the supersaturation of poorly soluble drugs with different crystallization behaviors by inhibiting drug crystallization or forming mucin-drug interactions without changing the solubility. This effect of mucin was widely present in poorly soluble drugs with different crystallization mechanisms under in vivo conditions.

[0128] Example 3 Effect of mucin on "spring-parachute" of solid dispersion of poorly soluble drugs

[0129] Experimental materials and instruments:

[0130] Naproxen, Itraconazole were purchased from Nexconn Pharmatechs; Nifedipine was purchased from Letco Medical; FaSSIF / FeSSIF / FaSSGF were purchased from Biorelevant.com; Porcine gastric mucin II was purchased from Sigma; DMSO was purchased from Sigma; Chromatographically pure methanol, acetonitrile were purchased from Fisher Chemical; Ultrapure water was prepared from a water purification system.

[0131] Naproxen, Nifedipine, Itraconazole solid dispersions were provided by Professor Feng Zhang's lab at the College of Pharmacy, University of Texas at Austin.

[0132] Waters HPLC; Mettler Toledo pH meter; Varian dissolution apparatus.

[0133] Experimental methods

[0134] 1. Dissolution test

[0135] Solid dispersions were prepared by hot melt extrusion method, dried, crushed, sieved, and tableted by Professor Feng Zhang's lab at the College of Pharmacy, University of Texas at Austin. The small cup method was chosen, with FaSSIF and FaSSIF Containing 0.2% Mucin as dissolution media, temperature 37°C, rotation speed 120 r / min, at different time points, 600 μL was sampled, immediately centrifuged at 14000 r / min for 10 min. 300 μL supernatant was taken, and an equal volume of DMSO was added to terminate the subsequent precipitation. HPLC detection.

[0136] 2. HPLC analysis

[0137] A C18 column (4 μm, 3.9 mm x 75 mm, Waters, USA) and a C18 guard column (4 μm, 4 mm x 3.0 mm, Waters, USA) were used, and the column temperature was maintained at 37°C. The mobile phase was 0.1% trifluoroacetic acid in water and 0.1% trifluoroacetic acid in acetonitrile: naproxen 70:30; nifedipine 70:30; itraconazole 60:40; ritonavir 60:40. The flow rate was 1 mL / min. The injection volume was 10 μL. The detection wavelength was: naproxen 245 nm; nifedipine 237 nm; itraconazole 258 nm.

[0138] 3. Data analysis

[0139] Supersaturation ratio (SSR)

[0140]

[0141] Where, C t: Concentration at time point t; C max : Maximum concentration; SSR: Experimental supersaturation ratio.

[0142] Time after burst (T ss )

[0143] T ss : Time length when the concentration is maintained above 90% of the maximum concentration. It is a method to measure the stability of drug supersaturation.

[0144] Area under curve (AUC)

[0145] AUC is the area under curve from time point 0 to time point t, calculated by trapezoidal method. It is also a method to measure the stability of drug supersaturation.

[0146] 4. Statistical analysis

[0147] Results were expressed as mean ± SD. Independent sample t test was used to compare the difference between different groups. p < 0.05 indicated significant difference. All statistical analysis was performed by SPSS software.

[0148] Results

[0149] From Figure 7 As shown in Table 8, naproxen solid dispersion started to release at 15 min and reached the peak at 90 min. The T ss or AUC was significantly different between FaSSIF Containing 0.2% Mucin and FaSSIF (p < 0.05). This indicated that mucin prolonged the "parachute" of naproxen solid dispersion. Nifedipine solid dispersion started to release at 15 min and reached the peak at 150 min. The T ss or AUC was significantly different between FaSSIF Containing 0.2% Mucin and FaSSIF (p < 0.05). This indicated that mucin prolonged the "parachute" of nifedipine solid dispersion. Itraconazole solid dispersion started to release at 15 min and reached the peak at 150 min. The T ss or AUC was significantly different between FaSSIF Containing 0.2% Mucin and FaSSIF (p < 0.01, or p < 0.05). This indicated that mucin prolonged the "parachute" of itraconazole solid dispersion.

[0150] Table 8 Parameters of solid dispersions in dissolution media FaSSIF and FaSSIF Containing 0.2% Mucin (n = 3)

[0151]

[0152] * vs FaSSIF, p<0.05.

[0153] Experimental conclusion: mucin prolongs the "parachute" of each solid dispersion (the solid dispersion itself also prolongs the "parachute"). It is suggested to improve the dissolution evaluation method, and add a new investigation factor-mucin in the dissolution medium, so as to more objectively simulate the in vivo.

[0154] The above description of the specific embodiments of the present application is not intended to limit the present application, and various changes or modifications can be made to the present application by those skilled in the art without departing from the spirit of the present application, and all such changes or modifications shall fall within the scope of the appended claims of the present application.

Claims

1. Use of a product in the evaluation of the dissolution characteristics of a poorly soluble solid dispersion, characterized in that, The product consists of FaSSIF buffer solution pH 6.5 of dissolution medium and 0.2% w / v mucin, applied to dissolution evaluation of BCS II or IV class of poorly soluble drug dispersions with different crystallization behavior, affecting the "spring-parachute" of the solid dispersions of the poorly soluble drug by prolonging its supersaturation.

2. Use of a product according to claim 1 for evaluating the dissolution profile of a poorly soluble solid dispersion, characterized in that, The mucin is porcine gastric mucin II.

3. Use of a product according to claim 1 or 2 for the evaluation of the dissolution characteristics of a poorly soluble solid dispersion, characterized in that, The poorly soluble drug is naproxen, nifedipine, itraconazole or ritonavir.

Images