Celecoxib nanocrystal, process for producing celecoxib nanocrystal, pharmaceutical composition, use of a celecoxib nanocrystal, and method of treatment for relief of pain- and inflammation-related conditions

Abstract

The present invention relates to a technology that aims to optimise the onset of action of a molecule having analgesic and anti-inflammatory properties, specifically celecoxib or derivatives thereof. The approach involves the production of nanocrystals of celecoxib or derivatives thereof stabilised with a low-viscosity polymer for a faster onset of action of the active ingredient, as well as the production process therefor, pharmaceutical compositions, uses and treatment methods comprising same.

Description

Title: “CELECOXIB NANOCRYSTAL, PROCESS FOR PRODUCING CELECOXIB NANOCRYSTAL, PHARMACEUTICAL COMPOSITION, USE OF A CELECOXIB NANOCRYSTAL, AND METHOD OF TREATMENT FOR ALLEVIATING CONDITIONS ASSOCIATED WITH PAIN AND INFLAMMATION” Field of the Invention

[0001] The present invention relates to celecoxib nanocrystals or derivatives thereof stabilized with low-viscosity polymers to provide a more rapid onset of action of this anti-inflammatory drug, as well as to a process for producing such nanocrystals, pharmaceutical compositions comprising them, uses thereof, and methods of treatment involving the same. Background of the Invention

[0002] Celecoxib (CLX) is a nonsteroidal anti-inflammatory drug (NSAID) and a COX-2 inhibitor whose mechanism of action involves reducing the production of substances associated with pain and inflammation in the human body. Accordingly, it is indicated for alleviating pain, tenderness, swelling, and stiffness caused by osteoarthritis (arthritis caused by breakdown of the lining of the joints) and rheumatoid arthritis (arthritis caused by swelling of the lining of the joints), as well as for the treatment of juvenile rheumatoid arthritis (a type of arthritis that affects children) in children 2 years of age or older.

[0003] In many cases, faster pharmacological action may be desirable to reduce patient suffering and improve patient adherence to treatment (Baryakova, T.H., Pogostin, B.H., Langer, R. et al. Overcoming barriers to patient adherence: the case for developing innovative drug delivery systems. Nat Rev Drug Discov 22, 387-409 (2023)). Considering the different routes of administration, the intravenous route affords 100% bioavailability and an immediate onset of action and would therefore be the most efficient route for treatments requiring rapid pharmacological action.

[0004] However, the most widely used route of administration is the oral route, since it does not require sterility, is safer, is more convenient, and allows selfadministration (Alqahtani MS, Kazi M, Alsenaidy MA and Ahmad MZ (2021) Advances in Oral Drug Delivery. Front. Pharmacol. 12:618411.).

[0005] In the prior art, when a rapid onset of action via the oral route is desired, solution-based liquid dosage forms are commonly used because they eliminate the dissolution step and are readily absorbed, as in the case of syrups and drops. However, solution dosage forms require the active ingredient to be readily soluble in an aqueous medium, as is the case for molecules in the Biopharmaceutics Classification System (BCS) Class I or III. This does not apply to BCS Class II molecules, which are poorly soluble in aqueous media, as is the case for CLX, which exhibits poor solubility and high permeability, with variable bioavailability due to its in vivo dissolution. CLX is also a weak acid with a pKa of 11.1.

[0006] Numerous alternatives have been investigated to improve drug delivery, including the use of nanocrystals.

[0007] Nanocrystals are non-matrix particulate drug systems on the nanoscale that are stabilized by surfactants, polymers, or a mixture thereof. In general, these particles are less than 1000 nm in size, typically between 100 and 500 nm. The term nanocrystal refers to a stable nanoscale structure of the active ingredient and may be present in either a liquid or solid external phase. In liquid form, the terms nanosuspension or nanodispersion may also be used.

[0008] The most widely used technology for producing nanocrystals is the ‘top-down’ approach, which involves starting with larger particles and applying high energy to fracture their structure and produce smaller particles. This technique is widely used mainly because it does not involve organic solvents. The most commonly used forms are wet milling and high-pressure homogenization (Raida Al-Kassas, Mahima Bansal, John Shaw, Nanosizing techniques for improving bioavailability of drugs, Journal of Controlled Release, Volume 260, 2017, Pages 202-212, ISSN 0168-3659), although other solid-fragmentation methods may also be used, such as sonication, cavitation, shear, compression, impact, and cutting.

[0009] According to the present invention, the ‘top-down’ method includes wet or dry ball milling, high-energy milling, high-pressure homogenization, and similar comminution processes. In the case of high-pressure homogenization, homogenization is carried out at a pressure of 100-2000 bar for 1 to 20 cycles.

[0010] For the production of nanocrystals by wet ball milling, the celecoxib-to-milling-bead ratio ranges from 1:1 to 1:10 (active ingredient:beads), the rotational speed from 1000 to 1800 rpm, and the processing time from 60 to 240 minutes.

[0011] In contrast, another technology, referred to as the ‘bottom-up’ approach, starts from the molecular (soluble) form and progressively forms particles in the medium in situ. Both technologies produce nanoscale particles and favor increased solubility and improved dissolution rate, absorption, and action of the active ingredient. In addition, the following advantages and distinctions of the top-down technique over the bottom-up technique in the production of nanocrystals may be highlighted: Size Control

[0012] Top-down: Offers precise control over the size of the nanocrystals, allowing specific adjustments and the production of crystals of uniform size.

[0013] Bottom-up: May result in variations in nanocrystal size due to the complexity of synthesizing particles from molecules or atoms. Efficiency in Mass Production

[0014] Top-down: Is often more efficient for the mass production of nanocrystals because it involves reducing larger materials to the desired size.

[0015] Bottom-up: May be challenging and less efficient for producing large volumes of nanocrystals because it involves the synthesis of individual molecules. Scale and Reproducibility

[0016] Top-down: Is easier to scale up for large-scale production, and the approach generally provides good reproducibility of nanocrystal properties.

[0017] Bottom-up: May be more difficult to scale up, and reproducibility may be challenging because of sensitivity to synthesis conditions. Standardization and Uniformity

[0018] Top-down: Allows greater standardization and uniformity of the nanocrystals produced, which is crucial in many applications.

[0019] Bottom-up: Uniformity may be a challenge, especially when the synthesis involves the self-assembly of molecules. Versatility in Starting Materials

[0020] Top-down: May be applied to a variety of starting materials, allowing nanocrystals to be produced from different sources.

[0021] Bottom-up: May be more limited by the availability of specific precursors and optimal synthesis conditions. Less Material Waste

[0022] Top-down: Generally involves less material waste because it starts with larger materials that can be processed efficiently.

[0023] Bottom-up: May generate undesirable by-products, resulting in greater waste of materials during the synthesis process.

[0024] The prior art discloses certain nanoscale systems for poorly soluble drugs. International application WO2013057518, filed by M. W. Encap, for example, discloses processes for the manufacture of suspensions comprising nanocrystals of one or more water-soluble or water-insoluble pharmaceutical or nutraceutical active ingredients with a particle size in the range of 0.01 to 10 microns. More specifically, the suspensions prepared by this process may be used to formulate pharmaceutical compositions, especially in liquid fill capsules.

[0025] International application WO2017072774, filed by Solubest, discloses a pharmaceutical composition for transmucosal administration of an active lipophilic compound through the oral mucosa, comprising a lipophilic active compound, a polymeric matrix formed by two or more water-soluble polymers, and a rapid dissolution agent. At least one of the water-soluble polymers is an amphiphilic polymer and at least one is either a hydrophilic polymer or an amphiphilic polymer with a hydrophobic-hydrophilic balance different from the first amphiphilic polymer. In addition, the polymeric matrix is not crosslinked and no covalent interaction occurs between the two or more polymers or between the polymers and the lipophilic active compound, which is interwoven within the aforesaid polymeric matrix. Said lipophilic active compound is selected from a group that includes anti-inflammatory agents. The specification provides examples in which the active ingredient is in nanocrystal form.

[0026] International application WO0018374, filed by Elan Pharma International, discloses controlled-release nanoparticulate formulations comprising a nanoparticulate agent to be administered and a rate-controlling polymer which functions to prolong the release of the agent after administration. The claimed compositions release the agent following administration for a time period ranging from about two to about twenty-four hours or longer. The specification states that the drug may be selected from anti-inflammatory agents, anthelmintic agents, antiarrhythmic agents, and antiasthmatic agents.

[0027] International application WO2018187728, filed by Maa Laboratories, discloses methods of preparing nanotherapeutic compounds and compositions comprising nanotherapeutic compounds. The nanotherapeutic compounds prepared according to the described methods are useful for treating diseases, such as cancer, in a subject in need thereof. It is claimed that the therapeutic agent is selected from a group that includes anti-inflammatory agents.

[0028] International application WO2013132457, filed by National Institute of Pharmaceutical Education & Research, discloses nanocrystalline solid dispersion compositions having discrete particles, wherein each discrete particle comprises crystals of at least one pharmaceutical active ingredient, veterinary active ingredient, or nutraceutical active ingredient dispersed in a matrix of at least one crystallization inducer and / or coexisting with crystals of a crystallization inducer, optionally along with pharmaceutically acceptable excipients. That application also encompasses a novel one-step process for the generation of nanocrystalline solid dispersions. Said active ingredient is selected from a group that includes nonsteroidal anti-inflammatory agents.

[0029] Patent document CN108542886, filed by Liaocheng University, discloses a method for preparing celecoxib nanocrystals from the following components, in percentage by weight: 60-85 percent of celecoxib, 10-30 percent of a steric stabilizer, and 1-10 percent of an ionic stabilizer. According to the description, a celecoxib nanocrystal suspension is prepared by wet media milling and is then lyophilized or spray-dried to obtain a solid powder.

[0030] Patent document BR 0210665, filed by Pharmacia Corporation, discloses a method for systemically administering a hydrophobic substance to a mammal, comprising delivering the hydrophobic substance to the mammalian dermis, wherein the substance has a molecular mass of 1000 daltons or less, which would include valdecoxib, celecoxib, or parecoxib.

[0031] Patent document CN114917188, filed by Shenyang Pharmaceutical University, discloses a long-acting nanosuspension of celecoxib prepared by mixing celecoxib, a steric stabilizer, a small-molecule suspending agent, and water by wet media grinding method. The celecoxib nanocrystal exhibits a rod-like morphology.

[0032] International application WO2009 / 114695, filed by Elan Pharma International, discloses a nanoparticulate angiogenesis inhibitor composition comprising particles of an angiogenesis inhibitor or a salt thereof having an average particle size of less than about 2000 nm and at least one surface stabilizer associated with the surface thereof, wherein the angiogenesis inhibitor may be celecoxib.

[0033] Patent document CN113402463, filed by Jiangnan University, discloses a preparation of celecoxib crystallites and a stabilizer for treating osteoarthritis or rheumatoid arthritis. The preparation comprises dissolving the stabilizer in water and celecoxib in absolute ethyl alcohol.

[0034] Thus, it can be seen that the preparation of celecoxib microcrystals or nanocrystals has not been directed toward achieving a faster pharmacological action. Summary of the Invention

[0035] The object of the present invention is to provide celecoxib nanocrystals or derivatives thereof that are stabilized so as to achieve a faster pharmacological action than conventional formulations containing this active ingredient.

[0036] The celecoxib nanocrystals or derivatives thereof according to the present invention are stabilized with uncharged polymers, particularly low-viscosity polymers, to provide a more rapid onset of action of this anti-inflammatory drug.

[0037] In other embodiments, the low-viscosity polymer may be based on polyvinyl alcohol, low-molecular-weight polyethylene glycol (PEG), methacrylic acid-methyl methacrylate copolymers, ethylene oxide-propylene oxide copolymers, polyacrylic acid (carbomers), hydroxypropyl cellulose (HPC), hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), carboxymethylcellulose (CMC), polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), and copolymers thereof.

[0038] According to a particular object of the present invention, the celecoxib nanocrystals or derivatives thereof are nanosized and stabilized with a low-viscosity polymer by wet milling using a ball mill, through collisions with zirconia (ZrO2) beads.

[0039] Further objects of the present invention include pharmaceutical compositions, uses, and methods of treatment associated with the celecoxib nanocrystals or derivatives thereof according to the present invention. Brief Description of the Drawings

[0040] To better define and clarify the content of the present patent application, the following figures are provided:

[0041] [Fig. 1] Figure 1 shows the particle size distribution profile of the formulations obtained with low-viscosity PVA (NCR-CLX-PVA_4-88), medium-viscosity PVA (NCR-CLX-PVA_20-88), and high-viscosity PVA (NCR-CLX-PVA_40-88).

[0042] [Fig. 2] Figure 2 shows the celecoxib nanosuspension (NCR-CLX-SUSP) obtained using the DeltaVita 1.

[0043] [Fig. 3] Figure 3 presents the results of the stability study of the CLX+PVA nanosuspension over 180 days at 4, 25, and 40 °C, with particle diameter and polydispersity index analyzed.

[0044] [Fig. 4] Figure 4 presents the dissolution profile of the celecoxib nanocrystal suspension (NCR-CLX-SUSP), evaluated in 900 mL of phosphate buffer at pH 6.8 using USP Apparatus II operated at 75 rpm for 60 minutes.

[0045] [Fig. 5] Figure 5 shows scanning electron microscopy (SEM) images of dried formulations containing celecoxib, wherein (A) is a low-magnification micrograph of the commercial formulation, scale bar 2 mm; (B) is a low-magnification micrograph of the NCR-CLX-LF formulation, scale bar 2 mm; (C) is a low-magnification micrograph of the NCR-CLX-SDSE formulation, scale bar 500 pm; (D) is a high-magnification micrograph of the commercial formulation, scale bar 100 pm; (E) is a high-magnification micrograph of the NCR-CLX-LF formulation, scale bar 100 pm; and (F) is a high-magnification micrograph of the NCR-CLX-SDSE formulation, scale bar 100 pm.

[0046] [Fig. 6] Figure 6 shows laser-diffraction results for the formulations before drying (NCR-CLX-SUSP), after spray drying (NCR-CLX-SDSE), and after fluid-bed drying (NCR-CLX-LF).

[0047] [Fig. 7] Figure 7 shows mean celecoxib concentrations in mg / mL, quantified after 48 hours of contact with stirring, for the commercially available formulation (CLX-Line), the spray-dried formulation (NCR-CLX-SDSE), and the fluid-bed-dried formulation (NCR-CLX-LF).

[0048] [Fig. 8] Figure 8 shows the mean percentage of celecoxib released into a medium at pH 6.8 over 24 hours with stirring at 75 rpm for the commercial formulation (CLX-FOXIS), the spray-dried formulation without excipient (NCR-CLX-SDSE), the spray-dried formulation with excipient (NCR-CLX-SDCE), and the fluid-bed-dried formulation (NCR-CLX-LF).

[0049] [Fig. 9] Figure 9 presents the pharmacokinetic study in rats, showing the plasma concentration of celecoxib as a function of time over 24 hours after oral administration (n=4), with a detailed view of the plasma concentration during the first 2 hours after administration of the formulations.

[0050] [Fig. 10] Figure 10 presents a panel of the pharmacokinetic results for the commercial celecoxib formulation (FOXIS - Blue) and the celecoxib nanocrystals obtained by spray drying in the presence of drying excipients (NCR-CLX-SDCE -Red).

[0051] [Fig. 11] Figure 11 presents a panel of the analgesic efficacy results for the celecoxib physical mixture (CLX-RM) and celecoxib nanocrystals (NCR-CLX), administered 1 hour and 15 minutes before the paw withdrawal latency (PWL) assay, which was performed 0.5, 1, and 2 hours after carrageenan administration.

[0052] [Fig. 12] Figure 12 presents paw thickness after carrageenan injection, with paw thickness measured at 30 minutes and 1, 2, 3, and 5 hours for the celecoxib nanocrystal suspension (NCR-CLX), physical mixture (RM), and control (Vehicle) formulations. All formulations were administered 15 minutes before carrageenan injection. Data are expressed as mean ± SEM, n=8. *p<0.05, **p<0.01, ***p<0.001 compared with the vehicle group using two-way ANOVA followed by Dunnett's multiple comparisons test. Detailed Description of the Invention

[0053] Celecoxib is a selective COX-2 inhibitor with poor water solubility and high permeability across biological membranes (Biopharmaceutics Classification System (BCS) Class II - Dolenc, A., Kristl, J., Baumgartner, S., & Planinsek, O. (2009). Advantages of celecoxib nanosuspension formulation and transformation into tablets. International Journal of Pharmaceutics, 376(1-2), 204-212; Mart^nez, L. M., Cruz-Angeles, J., Vazquez-Davila, M., Mart^nez, E., Cabada, P., Navarrete-Bernal, C., & Cortez, F. (2022). Mechanical Activation by Ball Milling as a Strategy to Prepare Highly Soluble Pharmaceutical Formulations in the Form of Co-Amorphous, Co-Crystals, or Polymorphs. In Pharmaceutics (Vol. 14, Issue 10). MDPI).

[0054] It was observed that nanosizing celecoxib promoted faster solubility and absorption, and increased the efficacy of the drug.

[0055] The mean particle size of the celecoxib nanocrystal according to the present invention may range from 10 to 1000 nm, preferably from 200 to 503 nm.

[0056] The nanocrystals according to the present invention additionally exhibit (i) a polydispersity index (PDI) ranging from 0.1 to 0.5, preferably 0.2; (ii) a zeta potential of -30 to +30 mV; and (iii) maintenance of the crystallinity of the material after the comminution process, with the main X-ray diffraction (XRD) peaks and crystal morphology as determined by electron microscopy preferably maintained.

[0057] Thus, in a first embodiment, the present invention relates to celecoxib nanocrystals or derivatives thereof stabilized with polymers, preferably polyvinyl alcohol (PVA), particularly low-viscosity PVA, to provide a more rapid onset of action of this anti-inflammatory drug. According to the present invention, a low-viscosity polymer is understood to be a polymer having a viscosity of 1.0-21.9 mPa^s, particularly 3.4-4.6 mPa^s, at a concentration of 40 g / L in water. In a preferred, non-limiting embodiment, the PVA is PVA 4-88.

[0058] Further characteristics of the polymer according to the present invention are (1) a degree of hydrolysis (USP) ranging from 70 to 95%, preferably 85-89%; (2) a molecular weight ranging from 10,000 to 100,000 Da, preferably 13,000-23,000 Da; (3) a pH, measured in a 4% solution in H2O, of 3-8, preferably 5.0-6.5; and (4) a linear or branched structure, preferably linear.

[0059] The nanocrystal according to the present invention may be in liquid form as a nanosuspension / nanodispersion or in solid form.

[0060] Celecoxib derivatives encompassed by the present invention are understood to include any molecular forms of celecoxib known in the prior art.

[0061] The influence of PVA viscosity on the formation, interaction, and stabilization of the nanocrystals obtained according to the present invention was observed. It may be inferred that collisions between the zirconia beads and the crystals become more effective as the viscosity of the PVA solution decreases, resulting in more efficient nanosizing. In addition, the shorter polymer chains promote more effective polymer-nanocrystal interactions.

[0062] PVA is a polymer traditionally used for tablet coating and powder granulation, as well as for increasing viscosity in liquid formulations and forming a matrix in semisolid formulations. The use of PVA for steric stabilization of a nanocrystal formulation, with the PVA positioned at the interface between the nanocrystals and the aqueous medium (nanosuspension), has not been described in the prior art.

[0063] Another important factor in selecting the formulation containing low-viscosity PVA was the absence of surfactants in its composition, since such surfactants may represent a risk when administered to biological systems by solubilizing the plasma membrane or forming pores that destabilize the ionic balance of cells. Due to its chemical structure, low-viscosity PVA has a high degree of hydrolysis and lacks well-defined hydrophilic and hydrophobic regions, and therefore has a reduced capacity to form micelles compared with less hydrolyzed PVAs. Consequently, its ability to form pores in cell plasma membranes is reduced. (Umemoto, Y., Uchida, S., Yoshida, T., Shimada, K., Kojima, H., Takagi, A., Tanaka, S., Kashiwagura, Y., & Namiki, N. (2020). An effective polyvinyl alcohol for the solubilization of poorly water-soluble drugs in solid dispersion formulations. Journal of Drug Delivery Science and Technology, 55.).

[0064] In general, the prior art teaches formulations containing nanocrystals stabilized by polymers and surfactants so as to keep the system stable in liquid form and redispersible in solid form. The formulation that is the object of the present invention satisfies both requirements without surfactants or charged polymers.

[0065] Anionic and cationic polymers are subject to ionization effects, which can alter dissolution rate and absorption along the gastrointestinal tract (e.g., carboxymethylcellulose (CMC) and acrylates). The few nonionic polymers, such as HPMC, PVP, and PVPVA, do not exhibit adjustable ratios of hydrogen-bond donors and acceptors.

[0066] PVA has an adjustable density of hydrogen-bond-donating hydroxyl groups and hydrogen-bond acceptors along its polymer structure while retaining pH-independent solubility. In theory, this would allow PVA to act as an effective solubility enhancer like anionic polymers while also exhibiting the low variability of nonionic polymers.

[0067] The use of low-viscosity PVA as a stabilizer according to the present invention provides a surfactant-free, pH-independent system for solubility enhancement, yielding improved particle size, polydispersity index, and stability over 6 months at 25 °C.

[0068] The nanocrystal according to the present invention provides at least a 2-fold increase in the aqueous solubility of the active ingredient. In addition, it provides a rapid onset of anti-inflammatory and analgesic action observable as early as 30 minutes after administration.

[0069] In another embodiment, the present invention also relates to the process for preparing the celecoxib nanocrystals or derivatives thereof, which employs a topdown approach based on wet milling, particularly ball milling through collisions with zirconia (ZrO2) beads. This process preserves most of the crystallinity of the active ingredient and reduces the formation of amorphous particles that may undergo structural alteration during storage. (Malamatari, Maria, et al. “Nanoparticle agglomerates of indomethacin: the role of poloxamers and matrix former on their dissolution and aerosolisation efficiency.” International Journal of Pharmaceutics 495.1 (2015): 516-526; Colombo, M., Orthmann, S., Bellini, M. et al. Influence of Drug Brittleness, Nanomilling Time, and Freeze-Drying on the Crystallinity of Poorly Water-Soluble Drugs and Its Implications for Solubility Enhancement. AAPS PharmSciTech 18, 2437-2445 (2017).).

[0070] In a particular embodiment, the active-ingredient powder and the low-viscosity PVA solution in water were subjected to collisions with zirconia (ZrO2) beads in a dual centrifuge for about 4 hours, through rotational and translational movements, under cooling. This process was optimized using a design of experiments to obtain the optimal parameters; the input variables analyzed were CLX concentration (10% to 20%), PVA solution concentration (5% to 10%), and the amount of zirconia beads (500 mg to 900 mg).

[0071] The optimal formulation selected according to the process of the present invention contained about 15% celecoxib, about 5% to 10% PVA, and about 500 to 900 mg of zirconia, and was maintained in the milling process for about 240 minutes at about 1500 rpm.

[0072] The process according to the present invention may include a drying step carried out by lyophilization (freeze-drying), vacuum evaporation / drying, air drying, spray drying, fluid-bed drying, convection drying (ovens), rotary evaporation, or adsorption.

[0073] In another embodiment, the present invention relates to pharmaceutical compositions comprising the celecoxib nanocrystals or derivatives thereof according to the present invention in admixture with pharmaceutically acceptable excipients.

[0074] Suitable excipients according to the present invention may include, but are not limited to, lactose and variations thereof, cellulose and variations thereof, maltitol, sucrose and variations thereof, sorbitol, maltose and variations thereof, starch and variations thereof, magnesium carbonate and variations thereof, magnesium oxide and variations thereof, dextrose and variations thereof, acrylates and variations thereof, alginates and variations thereof, dextrins and variations thereof, erythritol, fructose, talc and variations thereof, trehalose and variations thereof, xylitol and variations thereof, glycine and variations thereof, carbonate, phosphate, silicate, calcium sulfate, alginic acid, alginate and variations thereof, cellulose and variations thereof, chitosan and variations thereof, colloidal silicon dioxide, starch and variations thereof, croscarmellose and variations thereof, crospovidone and variations thereof, docusate sodium, glycine, guar gum, xanthan gum and variations thereof, sodium lauryl sulfate and variations thereof, benzethonium chloride and variations thereof, benzalkonium chloride and variations thereof, cetylpyridinium chloride and variations thereof, phospholipids and variations thereof, docusate sodium, hypromellose and variations thereof, poloxamer and variations thereof, polyoxyethylene and variations thereof, sorbitan esters, tricaprylin, vitamin E and variations thereof. Binders may include povidone, alginate and variations thereof, chitosan, chlorpheniramine maleate, copovidone, phthalates and variations thereof, dibutyl sebacate, lactate and variations thereof, cellulose and variations thereof, gelatin and variations thereof, hypromellose and variations thereof, maleic acid and variations thereof, maltodextrin, dextrose and variations thereof, polyethylene glycol, polyethylene and variations thereof, acrylate and variations thereof, or mixtures thereof.

[0075] In another embodiment, the present invention also relates to the use of the celecoxib nanocrystals or derivatives thereof according to the present invention.

[0076] Further objects of the present invention include uses and methods of treatment associated with the celecoxib nanocrystals or derivatives thereof according to the present invention. Without limitation, the celecoxib nanocrystals or derivatives thereof according to the present invention are suitable for alleviating pain, tenderness, swelling, and stiffness caused by osteoarthritis, rheumatoid arthritis, or juvenile rheumatoid arthritis in children 2 years of age or older. Examples

[0077] The examples provided herein are intended to illustrate some of the numerous ways of carrying out the invention without limiting the scope thereof, and to assist in demonstrating the technical effect in a direct and comparative manner. Example 1 - Comparative formulations

[0078] Comparative formulations containing different proportions of celecoxib and stabilizers were developed. The responses evaluated were particle diameter and polydispersity index (Table 1).

[0079] These nanocrystals were prepared by wet milling through collisions with zirconia (ZrO2) beads. Briefly, the active-ingredient powder and an aqueous PVA solution were subjected to collisions with ZrO2 beads in a dual centrifuge for 4 hours using rotational and translational movements under refrigeration. The resulting nanosuspension was recovered using a sieve with a 100-pm cut-off, transferred to a vial, and kept under refrigeration.

[0080] [Table 1] Compositions of the nanocrystals. % Responses evaluated Celecoxib* Soluplus** PVA 4-88** Tween 80** Povacoat** Eudragit RS 30D** PVP** Kollicoat MAE** PVA 26-88** PVA 40-88** Diameter PDI F1a 5 2.25 337.2 6.5 F2 5 1.84 1.23 NA NA F3 5 1.84 1.23 343.3 20.1 F4 5 1.84 1.23 NA NA F5 5 1.84 837.8 27.4 F6 5 1.25 1.84 NA NA F7a 8.5 1.84 1.23 348.5 19 F8a 8.5 1.23 1.84 718.1 18.3 F9a 8.5 1.84 1.23 587.2 18.8 F10 10 1.84 1.23 463.3 16.7 % Responses evaluated Celecoxib* Soluplus** PVA 4-88** Tween 80** Povacoat** Eudragit RS 30D** PVP** Kollicoat MAE** PVA 26-88** co °? o < sz Diameter PDI F11 10 3.07 378.1 15.4 F12 10 3.07 849.1 25.4 F13a 10 2.5 352.6 2.3 F14 15 1.84 1.23 381.2 21.7 F15 15 1.23 1.84 787.1 19.1 F16 15 3.07 375.7 20.5 F17 15 3.07 558.4 22.2 F18 15 3.07 NA NA F19 15 3.07 913.3 68.2 F20 15 3.07 611.8 28.2 *active ingredient **stabilizers (Soluplus - polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer; PVA 4-88 - polyvinyl alcohol with a mean viscosity of 4 mPa^s and 88% hydrolysis; PVA 26-88 - polyvinyl alcohol with a mean viscosity of 26 mPa^s and 88% hydrolysis; PVA 40-88 -polyvinyl alcohol with a mean viscosity of 40 mPa^s and 88% hydrolysis; Tween 80 - polysorbate 80; Povacoat - polyvinyl alcohol / acrylic acid / methyl methacrylate copolymer; Eudragit RS 30 D -ethyl acrylate-methyl methacrylate copolymer; PVP - polyvinylpyrrolidone; Kollicoat MAE -methacrylic acid-ethyl acrylate copolymer dispersion). a Unstable within 1 month of storage at 25 °C. NA - Not applicable; refers to the formulations for which it was not possible to obtain a response, whether due to gelation, foaming, or failure to form a suspension.

[0081] As shown by the results in Table 1, various types of polymers and surfactants were used to identify the most suitable stabilizer for developing a formulation with the highest possible drug loading, the smallest possible particle size, the lowest PDI, and the longest possible stability.

[0082] As shown by the comparative tests, low-viscosity PVA, namely PVA 4-88, was the stabilizer that best met these criteria because it has an optimal viscosity of 3.4 - 4.6 mPa^s at a concentration of 40 g / L in water.

[0083] The optimal viscosity has a strong impact on nanocrystal formation because it allows more effective collisions between the milling beads and the drug crystals, resulting in more efficient and homogeneous nanosizing of the API, as reflected by the particle size and PDI of the samples. The same effect may be observed when the polymer concentration in the medium is increased, thereby increasing viscosity.

[0084] Tests with PVAs of different viscosities showed their strong impact on the nanosizing of the crystals, as seen for the formulations containing PVA 20-88 (F19) and PVA 40-88 (F20). The particle size results showed that the formulations containing PVA of intermediate viscosity (20 mPa^s) and high viscosity (40 mPa^s) exhibited a larger diameter and were more polydisperse. The three formulations obtained using PVAs of the three different viscosities were as follows: NCR-CLX-PVA_4-88 (low viscosity), NCR-CLX-PVA_20-88 (medium viscosity), and NCR-CLX-PVA_40-88 (high viscosity), and their particle size distribution profiles after 21 days of stability testing are shown in Figure 1.

[0085] Figure 1 shows the influence of PVA viscosity on the formation, interaction, and stabilization of the nanocrystals obtained. It may be inferred that, as the viscosity of the PVA solution decreases, collisions between the zirconia beads and the crystals become more effective, resulting in more efficient nanosizing; in addition, the shorter polymer chains promote more effective polymer-nanocrystal interactions. Example 2 - Characterization of the NCR

[0086] Particle size and zeta potential of the NCR-CLX-SUSP suspensions were analyzed.

[0087] To investigate the influence of PVA on the desired formulation responses (size, appearance, and PDI), a three-factor, three-level Box-Behnken design (BBD) was initially performed according to Table 1, with the range of variation of each excipient determined on the basis of previously developed formulations. The experimental groups resulting from combinations of the independent variables are shown in Table 2.

[0088] [Table 2] Variables and levels in the Box-Behnken design for the preparation of CLX nanocrystals. Independent variables Levels Low (-1) Medium (0) High (+1) PVA (Xi) (% w / w) 5.00 7.50 10.00 CLX (X2) (% w / w) 10.00 15.00 20.00 ZIR (X3) (mg) 500.00 650.00 900.00 Dependent variable HD: hydrodynamic diameter (z-average) of the nanocrystals CLX: celecoxib; ZIR: zirconia beads; PVA: polyvinyl alcohol.

[0089] The hydrodynamic diameter, reported as z-average, and the polydispersity index (PDI) of the nanosuspensions were determined by dynamic light scattering. Appearance was determined subjectively by visual analysis (Table 3).

[0090] [Table 3] Compositions of the NCR-CLX-SUSP suspensions tested in the BBD model, with variations in the amounts of celecoxib (CLX), polyvinyl alcohol (PVA), and zirconia (ZrO2) beads. Formulation / Components (%) CLX PVA ZrO2 Size (nm) PDI Appearance 1 10 5 650 397.90 20.70 OK 2 10 10 650 503.90 11.30 OK 3 20 5 650 325.40 24.40 Gelled 4 20 10 650 325.90 18.20 Partially gelled 5 15 5 500 330.60 16.30 OK 6 15 10 500 435.60 10.40 OK 7 15 5 800 315.60 11.40 OK 8 15 10 800 355.00 12.70 OK 9 10 7.5 500 448.90 21.20 OK Formulation / Components (%) CLX PVA ZrO2 Size (nm) PDI Appearance 10 20 7.5 500 312.00 21.50 Partially gelled 11 10 7.5 800 386.80 15.20 OK 12 20 7.5 800 317.70 22.20 Gelled 13 15 7.5 650 380.35 16.30 OK 14 15 7.5 650 397.45 15.00 OK 15 15 7.5 650 393.85 17.80 OK

[0091] Formulation 7 (Table 3) exhibited the most satisfactory results and was therefore selected for experimental optimization of the process for obtaining the nanodispersions in a dual centrifuge, with processing time, rotational speed (rpm), and bead mass varied in a new BBD assay (Table 4).

[0092] On the basis of the results obtained during formulation development and process optimization, the selected formulation contained 15% celecoxib, 5% PVA, and 900 mg of zirconia and was milled for 150 minutes at 1500 rpm (Table 5); an example of the nanosuspension is shown in Figure 2.

[0093] [Table 4] Mean hydrodynamic diameter (HD) and polydispersity index (PDI) of the celecoxib nanocrystals in the response-surface design-of-experiments matrix for the variables of test duration (min), rotational speed (rpm), and bead mass (mg). Std Time (min) RPM BEADS (mg) Mean HD Mean PDI 1 120 1200 900 312.90 18.90 2 180 1200 900 285.50 16.40 3 120 1800 900 256.50 15.20 4 180 1800 900 226.50 18.20 5 120 1500 800 276.40 17.10 6 180 1500 800 246.90 21.80 7 120 1500 1000 260.10 16.70 8 180 1500 1000 234.00 12.30 9 150 1200 800 293.10 21.60 10 150 1800 800 268.30 16.40 Std Time (min) RPM BEADS (mg) Mean HD Mean PDI 11 150 1200 1000 250.50 18.60 12 150 1800 1000 243.80 16.00 13 150 1500 900 250.00 18.60 14 150 1500 900 251.90 20.40 15 150 1500 900 255.60 20.00

[0094] [Table 5] Composition of the nanosuspension and production process parameters. F % CLX % PVA ZIR (mg) Time (min) RPM NCR-CLX-SUSP 15.00 5.00 900 150 1500 Example 3 - Stability

[0095] The optimized celecoxib nanosuspension stabilized with PVA was evaluated for stability at three different temperatures (4 °C, 25 °C, and 40 °C). The parameters analyzed were particle diameter and polydispersity index (Figure 3).

[0096] Figure 3 shows that nanocrystal size and homogeneity, expressed as polydispersity, remained constant throughout the 180-day study when the nanosuspension was stored at different temperatures (4, 25, and 40 °C), indicating that this drug delivery system exhibits high stability. Example 4 - Dissolution profile

[0097] The dissolution profile of the NCR-CLX nanosuspension was compared with that of the celecoxib+PVA physical-mixture suspension (PM). After particle-size reduction, CLX could be quantified in phosphate buffer at pH 6.8. The nanocrystals exhibited up to 27.78% drug release after 60 minutes, compared with less than 2% for the physical mixture (PM) after 60 minutes (Figure 4). Example 5 - Drying of the NCR-CLX-SUSP nanosuspensions

[0098] The nanocrystals obtained by wet milling were dried using two different techniques. The first involved spraying the suspension onto excipients of the commercial formulation (lactose monohydrate, croscarmellose sodium, sodium lauryl sulfate, and povidone) in a fluidized bed (NCR-CLX-LF). The second technique was spray drying, which was used to obtain a dry powder from the nanocrystal suspension. Two formulations were tested using this second technique: one without excipients during drying (NCR-CLX-SDSE) and one with mannitol and sodium lauryl sulfate as drying excipients (NCR-CLX-SDCE).

[0099] In addition to spray drying and fluid-bed drying, other possible techniques for obtaining a powder formulation from a liquid include convection drying (ovens), rotary evaporation, lyophilization, and liquid adsorption. Example 6 - Characterization of the powders obtained

[0100] Particle size and morphology of the NCR-CLX powders were characterized by scanning electron microscopy (SEM) in Figure 4 (A-F) and laser diffraction (LD). SEM was carried out on the spray-dried powder, whereas LD measurements were performed in aqueous medium using the refractive index of the outermost layer (PVA), as shown in Figure 6 and Table 6. Solubility was determined by dispersing an excess of celecoxib in phosphate buffer at pH 6.8 for 48 hours on an orbital shaker, followed by filtration through a 0.45-pm PTFE filter and quantification by HPLC-UV / Vis (Figure 7). Dissolution testing was performed using USP Apparatus II in phosphate buffer at pH 6.8 containing 0.1% sodium lauryl sulfate, with sampling at 15, 30, 60, 120, 240, 480, and 1440 minutes; aliquots were filtered through a 0.45-pm PTFE filter and quantified by HPLC-UV / Vis (Figure 8).

[0101] [Table 6] Mean particle size and particle-size dispersity (Span) values obtained by laser diffraction for the formulations before drying (NCR-CLX-SUSP), after spray drying (NCR-CLX-SDSE), and after fluid-bed drying (NCR-CLX-LF). Group Size - LD (mm) Span NCR-CLX-SUSP 6.06 4.73 NCR-CLX-SDSE 11.3 1.94 Group Size - LD (mm) Span NCR-CLX-LF 79.2 4.55

[0102] Powder characterization showed that the spray-dried nanoparticle agglomerates had higher solubility and faster dissolution than the other groups analyzed. They were therefore selected for the subsequent in vivo pharmacokinetic assays in dogs. Example 7 - Pharmacokinetic study in rats

[0103] The oral bioavailability of the celecoxib nanosuspension was evaluated in rats. The animals received either the physical mixture (non-nanosized CLX+PVA) or CLX nanocrystals.

[0104] The objective of this study was to evaluate the increase in active-ingredient bioavailability afforded by the technology. After administration of the samples by oral gavage, plasma samples were collected at 0.25, 0.5, 1, 2, 4, 8, 12, and 24 h, and the mean plasma concentration of celecoxib as a function of time is shown in Figure 9.

[0105] Pharmacokinetic parameters including Cmax, Tmax, T1 / 2, AUClast, MRT0last, and bioavailability are presented in Table 7. Oral absorption of CLX from the nanosuspension increased compared with the physical mixture (Figure 9). The Cmax value for the nanosuspension was 4.868 ± 0.807 pg / mL, compared with 2.697 ± 0.679 pg / mL for the physical mixture, demonstrating increased bioavailability and a more rapid onset of action afforded by the technology.

[0106] [Table 7] Pharmacokinetic parameters of the celecoxib physical mixture (MF-CLX) and nanocrystal suspension (NCR-CLX-SUSP) after oral administration in rats (n=4, mean ± SD). MF-CLX NCR-CLX- SUSP Cmax (pg / mL) 2.697 0.679 ± 4.868 ± 0.807 tmax (h) 2.000 ± 1.380 ± 0.750 0.967 T1 / 2 (h) 4.530      ± 1.250 4.190 ± 0.955 AUCO-last (pg.h.mL-1) 18.259 ± 5.660 26.125 ± 6.786 MRT0-last (h) 6.550      ± 1.220 4.990 ± 0.869 Bioavailability (%) 71.900 101.000 Example 8 - Pharmacokinetic study in dogs

[0107] The oral bioavailability of spray-dried nanosized CLX was evaluated in dogs. The animals received either the commercial product (FOXIS 200 mg) or spray-dried CLX nanocrystals.

[0108] The objective of this study was to evaluate the increase in active-ingredient bioavailability afforded by the technology after spray drying. After administration of the samples, plasma samples were collected at 0.25, 0.5, 1, 2, 4, 8, 12, and 24 h, and the mean plasma concentration of celecoxib as a function of time is shown in Figure 10. Pharmacokinetic parameters including Cmax, Tmax, T1 / 2, AUClast, MRT0last, and bioavailability are presented in Table 8.

[0109] [Table 8] Pharmacokinetic parameters of celecoxib after oral administration in dogs(n=4, mean ± SD). Celecoxib Oral 200 mg FOXIS Oral 200 mg NCR-CLX-SDCE Cmax (ng / mL) 1685 4713 Tmax (h) 6.75 2.75 T1 / 2 13.1 7.61 AUC0-Last (ng.h.mL-1) 18.395 48.146 Relative bioavail. (%) - Test / FOXIS - 261.73%

[0110] Pharmacokinetic studies in Beagle dogs showed that the capsule formulation containing dry celecoxib nanocrystal powder obtained by spray drying in the presence of drying excipients (NCR-CLX-SDCE) had significantly higher absorption and consequent higher bioavailability than the commercial celecoxib formulation (FOXIS). Comparison of Cmax values showed a surprising 2.8-fold increase afforded by the technology (4713 ng / mL versus 1685 ng / mL) (Table 8 and Figure 10). Example 9 - Efficacy study in rats

[0111] After higher oral bioavailability of celecoxib had been demonstrated in both rats and dogs, an efficacy study was carried out to assess a possible increase in the analgesic and anti-inflammatory efficacy of nanosized celecoxib (NCR-CLX). A carrageenan-induced inflammation model was used, and paw thickness (swelling) and paw withdrawal latency after a thermal stimulus (thermal hyperalgesia) were evaluated.

[0112] Formulations containing celecoxib nanocrystals (NCR-CLX) and a physical mixture of celecoxib and PVA (CLX-RM) were tested. The formulations were administered 1 hour or 15 minutes (0.25 h) before the carrageenan inflammatory stimulus. Figure 11 presents the results after the thermal stimulus, with paw withdrawal latency on a hot plate measured at 0.5, 1, and 2 hours.

[0113] In parallel with the thermal-stimulus assay, paw swelling was assessed by measuring paw thickness over 5 hours to evaluate the anti-inflammatory activity of each formulation (Figure 12).

[0114] The NCR-CLX formulation exhibited greater anti-inflammatory activity, significantly reducing paw swelling at all time points compared with the physical mixture (CLX-RM) and vehicle control groups. This assay was carried out only in groups that received the formulations 15 minutes before carrageenan injection.

[0115] The NCR-CLX formulation produced a more favorable paw-withdrawal latency profile in the hot-plate test (nociception assay), with the animals keeping their paws on the plate for a longer period (indicating lower sensitivity / pain). A statistically significant difference was observed exclusively for the NCR-CLX group 0.5 h after carrageenan administration, demonstrating a superior and unexpected effect and a rapid onset of action.

[0116] The comparative tests showed that the formulations were obtained using a reproducible scientific methodology and exhibited pharmaceutical formulation advantages over products currently available on the market.

[0117] Reducing the size of the celecoxib crystals increased dissolution of the active ingredient at physiological pH (6.8) by an average of 2,5-fold and increased Cmax in the pharmacokinetic study in dogs by 2,8-fold.

[0118] In addition, the nanosuspensions could be dried using fluid-bed drying and spray drying.

[0119] The developed CLX nanosuspension formulation showed a more rapid onset of action than the physical mixture of celecoxib (active ingredient+PVA) when administered at the same concentration.

[0120] The CLX nanocrystals increased the oral bioavailability, Cmax, and Tmax of CLX compared with the product currently available on the market, FOXIS, demonstrating superior efficacy.

[0121] Those skilled in the art will appreciate that the disclosure herein enables the invention to be reproduced in the embodiments described and in other variants falling within the scope of the appended claims.

Claims

1. A celecoxib nanocrystal, wherein the celecoxib nanocrystal is stabilized with low-viscosity polymers.

2. The nanocrystal according to claim 1, wherein the low-viscosity polymer has a viscosity ranging from 1.0 to 21.9 mPa^s at a concentration of 40 g / L in water.

3. The nanocrystal according to claim 2, wherein the low-viscosity polymer has a viscosity ranging from 3.4 to 4.6 mPa^s at a concentration of 40 g / L in water.

4. The nanocrystal according to claim 1, wherein the polymer exhibits (1) a degree of hydrolysis (USP) ranging from 70 to 95%, (2) a molecular weight ranging from 10,000 to 100,000 Da, (3) a pH, measured in a 4% solution in H2O, of 3 to 8, and (4) a linear or branched structure.

5. The nanocrystal according to claim 4, wherein the polymer exhibits (1) a degree of hydrolysis (USP) ranging from 85 to 89%, (2) a molecular weight ranging from 13,000 to 23,000 Da, (3) a pH, measured in a 4% solution in H2O, of 5.0 to 6.5, and (4) a linear structure.

6. The nanocrystal according to any one of claims 1 to 5, wherein the low-viscosity polymer is based on polyvinyl alcohol (PVA), low-molecular-weight polyethylene glycol (PEG), methacrylic acid-methyl methacrylate copolymers, ethylene oxidepropylene oxide copolymers, polyacrylic acid (carbomers), hydroxypropyl cellulose (HPC), hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), carboxymethylcellulose (CMC), polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), and copolymers thereof.

7. The nanocrystal according to claim 1, wherein the nanocrystal is in liquid form as a nanosuspension / nanodispersion or in solid form.

8. The nanocrystal according to claim 1, wherein the particle size of the celecoxib nanocrystal ranges from 10 to 1000 nm.

9. The nanocrystal according to claim 8, wherein the mean particle size of the celecoxib nanocrystal ranges from 100 to 500 nm.

10. The nanocrystal according to claim 1, wherein (i) the polydispersity index (PDI) ranges from 0.1 to 0.5, (ii) the zeta potential ranges from -30 to +30 mV, and (iii) the crystallinity of the material is maintained after the comminution process.

11. The nanocrystal according to claim 1, wherein (i) the polydispersity index (PDI) ranges from 0.1 to 0.3 and (iii) the main XRD diffraction peaks and the crystal morphology as determined by electron microscopy are maintained.

12. The nanocrystal according to claim 1, wherein the nanocrystal comprises celecoxib derivatives.

13. A process for producing celecoxib nanocrystal, as defined in any one of claims 1 to 12, wherein the process employs a top-down method.

14. The process according to claim 13, wherein the top-down method comprises wet or dry ball milling, high-energy milling, high-pressure homogenization, and similar comminution processes.

15. The process according to claim 14, wherein high-pressure homogenization is carried out at a pressure of 100 to 2000 bar for 1 to 20 cycles.

16. The process according to claim 14, wherein the ball mill uses a bead filling of 75% to 90%, an agitator speed of 2000 rpm to 3600 rpm, and a pump flow rate of 30 to 185 rpm.

17. The process according to claim 13, wherein, to obtain a nanocrystal powder, one or more of lyophilization (freeze-drying), vacuum evaporation / drying, air drying, spray drying, fluid-bed drying, convection drying (ovens), rotary evaporation, solid fragmentation techniques, and a liquid adsorption technique are used.

18. A pharmaceutical composition comprising a celecoxib nanocrystal, as defined in any one of claims 1 to 12, and pharmaceutically acceptable excipients.

19. The composition according to claim 18, wherein the pharmaceutically acceptable excipients are selected from the group comprising lactose and variations thereof, cellulose and variations thereof, maltitol, sucrose and variations thereof, sorbitol, maltose and variations thereof, starch and variations thereof, magnesiumcarbonate and variations thereof, magnesium oxide and variations thereof, dextrose and variations thereof, acrylates and variations thereof, alginates and variations thereof, dextrins and variations thereof, erythritol, fructose, talc and variations thereof, trehalose and variations thereof, xylitol and variations thereof, glycine and variations thereof, carbonate, phosphate, silicate, calcium sulfate, alginic acid, alginate and variations thereof, cellulose and variations thereof, chitosan and variations thereof, colloidal silicon dioxide, starch and variations thereof, croscarmellose and variations thereof, crospovidone and variations thereof, docusate sodium, glycine, guar gum, xanthan gum and variations thereof, sodium lauryl sulfate and variations thereof, benzethonium chloride and variations thereof, benzalkonium chloride and variations thereof, cetylpyridinium chloride and variations thereof, phospholipids and variations thereof, docusate sodium, hypromellose and variations thereof, poloxamer and variations thereof, polyoxyethylene and variations thereof, sorbitan esters, tricaprylin, vitamin E and variations thereof; and wherein the binders are selected from the group comprising povidone, alginate and variations thereof, chitosan, chlorpheniramine maleate, copovidone, phthalates and variations thereof, dibutyl sebacate, lactate and variations thereof, cellulose and variations thereof, gelatin and variations thereof, hypromellose and variations thereof, maleic acid and variations thereof, maltodextrin, dextrose and variations thereof, polyethylene glycol, polyethylene and variations thereof, acrylate and variations thereof, mannitol, or mixtures thereof.

20. A use of a celecoxib nanocrystal, as defined in any one of claims 1 to 12, for the treatment of conditions associated with pain and inflammation.

21. A method of treatment for alleviating of conditions associated with pain and inflammation, comprising administering, to a patient in need thereof, a celecoxib nanocrystal as defined in any one of claims 1 to 12.

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