Clofazimine mini tablet for treating pediatric tuberculosis

Abstract

Clofazimine (CFZ) is an important component of a full oral pharmaceutical regimen recommended by the World Health Organization (WHO) for the treatment of multidrug resistant tuberculosis (MDR-TB). However, the lack of the divisible oral dosage form has limited the use of the medicament in pediatric populations that may require reduced doses to reduce the likelihood of adverse drug events. Pediatric friendly CFZ mini-tablets prepared from micronized powder via direct compression at relatively high drug loading provide suitable dosage forms for 6-month-old children as well as patients with whole capsules or difficult tablet swallowing.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 433,438, filed on December 17, 2022, entitled “Low-Cost, Shelf-Stable, Patient-Adaptable Clofazimine Mini-Tablets for Treatment of Tuberculosis in Pediatrics,” the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] Embodiments of the presently disclosed subject matter generally relate to dosage forms and formulations of the pharmaceutical agent clofazimine, and more particularly to mini-tablet formulations of clofazimine for the treatment of pediatric tuberculosis. Background Art

[0003] Tuberculosis (TB) killed over 200,000 children in 2018. Increasing resistance of Mycobacterium tuberculosis strains to first-line antibiotics has necessitated the inclusion of older, second-line antibiotics, which often exhibit more toxic adverse effect profiles, in treatment regimens. As part of efforts to develop all-oral regimens for multidrug-resistant (MDR-TB) and extensively drug-resistant (XRD-TB) strains, the World Health Organization (WHO) now recommends the inclusion of the generic drug clofazimine (CFZ) in the regimen (WHO, 2019).

[0004] Clofazimine, marketed under the trade name Lamprene, is an anti-infective drug most commonly used to treat leprosy. Clofazimine has also been used clinically to treat nontuberculous mycobacterial (NTM) infections in pediatric patients, including infections with Mycobacterium avium complex (Field et al., 2003; Jarand et al., 2016) and Mycobacterium abscessus (Yang et al., 2017; Jarand et al., 2011), including (Martiniano et al., 2017; Adler-Shohet et al., 2019). In a small cohort study published by Adler-Shohet et al. in 2019, patients with a mean age of 5.8 years were given 1 mg / kg CFZ daily for a mean duration of 105.6 days to treat odontogenic Mycobacterium abscessus (M. abscessus) infections. Adverse events were limited to skin discoloration and gastrointestinal symptoms; however, these adverse events did not lead to discontinuation of treatment. In addition, the inclusion of CFZ in the treatment regimen allowed for a reduction in the dose of amikacin, which was associated with severe toxicity.

[0005] Clofazimine was approved by the FDA in 1986 as a product For oral administration, however, this product has now been withdrawn from the market, and no commercially available CFZ formulation is currently available in the United States. Existing CFZ formulations elsewhere are capsule-based and consist of micronized drug suspended in a waxy lipid matrix. This formulation cannot be accurately dispensed to allow for the dose adjustments required for treating pediatric patients. An additional complication is the known tissue accumulation and slow clearance of CFZ from the body (Baik et al., 2012; Swanson et al., 2015; Brunaaugh et al., 2022), which makes any toxicity caused by inadvertent overdose difficult to correct. In previously described case studies treating Mycobacterium abscessus infections, a 1 mg / kg / day dose could only be achieved by extending the dosing interval to 2-6 days / week based on patient weight. This approach is common in clinical practice and often results in undesirably complex regimens and potentially increases dosing errors. Therefore, an oral formulation of CFZ with adjustable doses would represent a major advance in the treatment of pediatric TB and NTM infections.

[0006] Developing a pediatric-friendly CFZ formulation for TB requires additional considerations. Tuberculosis is more common in countries with developing economies. In these regions, access to readily available sweeteners or clean drinking water may be limited, which can make drug management more challenging for caregivers. In addition, areas with a high incidence of pediatric TB may have significant cultural differences from North American or Western European backgrounds, which influence taste and color preferences; therefore, in drug product development, a more versatile formulation platform may be preferred to accommodate local preferences (Craig et al., 2009). Environmental factors and their impact on drug stability, such as high humidity and high temperature, must also be considered. Although many oral delivery technologies have been identified as having good acceptance in pediatric patients and are now commercially available, including solutions, syrups, suspensions, chewable tablets, orally disintegrating tablets, or films (Strickley et al., 2008), such formulations typically require higher transportation costs or refrigerated storage (in the case of liquids) or extensive moisture protection (in the case of rapidly dissolving solids), which is cost-prohibitive and impractical for high-humidity, resource-poor environments with a large percentage of pediatric TB cases. Severe red staining with long-term CFZ use also precludes the use of liquid or solid pediatric oral dosage forms requiring prolonged contact with the oral mucosa. A preferred alternative is the development of a shelf-stable solid dosage form that exhibits minimal CFZ release upon oral administration while dissolving sufficiently in gastric fluid to demonstrate bioequivalence to existing FDA-approved CFZ capsules.

[0007] The greatest barrier to commercializing TB therapy is cost. TB incidence is significantly negatively correlated with GDP per capita (WHO, 2016), and access to trained healthcare professionals in these regions is limited. Therefore, for the successful implementation of oral CFZ products for treating pediatric patients, production costs must be as low as possible, and product administration must be simple, intuitive, and robust to patient error. Brunaugh and colleagues previously utilized jet milling (a micronization technique that reduces particle size distribution through particle-particle collisions without the need for organic solvents or mobile device components) (Brunaugh et al., 2018) to develop a cost-effective inhaled formulation of clofazimine that enhances drug targeting to infected macrophages and minimizes systemic exposure (Brunaugh et al., 2022; Brunaugh et al., 2010). While this targeted treatment approach may benefit adult patients, a significant proportion of pediatric patients develop disseminated TB infection, a risk that is increased in children under 3 years of age (Cruz, 2010).

[0008] Although the previously described jet-milled clofazimine formulations were developed for inhalation, Brunaugh demonstrated that micronized particles of polysorbate 80 suspended in saline alone exhibited adequate oral bioavailability and, once steady state was achieved, significantly reduced bacterial burdens in the lungs and spleen without the need for original The lipid excipients present in the formulation (Brunaugh, 2022). In this case, the larger surface area resulting from the reduced particle size distribution may increase the dissolution rate in the acidic gastric environment, thereby enabling absorption during transport to the small intestine. Therefore, these data demonstrate the feasibility of using particle size reduction rather than more complex dissolution enhancement methods (such as amorphous solid dispersions) to improve the oral bioavailability of poorly water-soluble CFZ.

[0009] Mini tablets are a newer dosage form and are generally defined as tablets exhibiting a diameter of approximately 1-5 mm. Their small size makes them suitable for patients as young as 6 months (Klingmann, 2017), who would otherwise be unable to swallow standard tablets, and the very small size of the tablets eliminates the need to incorporate an oral dispersion component that is susceptible to moisture into the formulation (Preis, 2015). In a randomized crossover design, 4-mm tablets were found to have increased acceptability and preference in infants and pediatric children compared to other typically used dosage forms (powders, suspensions, syrups) (van Riet-Nales et al., 2013). Several mini tablet or granular formulations are now on the market (Gerrard et al., 2019), which indicates the acceptability of this dosage form from a commercial and regulatory perspective.

[0010] Before the standard dosage form could be effectively taken by a patient of their size and age, a mini-tablet dosage form of CFZ was needed that would allow weight-adjusted dosages for treatment of children as young as 6 months of age while also avoiding tooth and oral staining with long-term use. Summary of the Invention

[0011] According to one embodiment, a pharmaceutical mini-tablet for treating tuberculosis is disclosed, comprising an amount of micronized clofazimine and at least one disintegrant to promote disintegration; at least one lubricant to prevent capping, and wherein the mini-tablet has a diameter of about 5 mm or less.

[0012] According to another embodiment, a method for treating a disease caused by Mycobacterium tuberculosis using a clofazimine mini-tablet is disclosed, wherein the method comprises: determining a therapeutically effective patient dose of clofazimine based on the patient's age, weight, and disease indication; determining the number of mini-tablets per patient dose based on the clofazimine dose per mini-tablet, and wherein each mini-tablet comprises a quantity of micronized clofazimine; at least one disintegrant to promote disintegration; and at least one lubricant to prevent capping. In a preferred embodiment, the mini-tablet has a diameter of about 5 mm or less and is administered to a patient as a plurality of mini-tablets.

[0013] According to another embodiment, a method for preparing clofazimine mini-tablets is disclosed, the method comprising the steps of determining a target therapeutic dose, typically based on patient weight, age, and indication, which in a preferred embodiment further comprises about 50% w / w clofazimine (CFZ). The CFZ drug substance is micronized, and in a preferred embodiment, the CFZ material is micronized by jet milling, and the micronized CFZ is then blended with excipients to impart the desired disintegration time and hardness to the final tablet, which in a preferred embodiment comprises a combination of disintegrants to reduce the disintegration time to about 2 minutes or less. In a preferred embodiment, the disintegrants comprise a first disintegrant and a second disintegrant. The blend may include a surfactant, such as sodium lauryl sulfate, and a lubricant for tableting, such as sodium stearyl fumarate. The approximately two (2) mm round mini-tablets are then directly compressed to the target hardness and may then be coated. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments and, together with the description, explain these embodiments. In the drawings:

[0015] Figure 1 A table showing disintegration and capping performance data for clofazimine mini-tablets produced with various excipient blends.

[0016] Figure 2 An exemplary dissolution profile of clofazimine mini-tablets is shown.

[0017] Figure 3A shows a schematic diagram describing the process of combining active mini-tablets with placebo and then coating the clofazimine mini-tablets at different coating weight increases.

[0018] FIG3B shows an exemplary simulated saliva-based disintegration test of coated mini-tablets.

[0019] Figure 4Shown are the release profiles of CFZ from the optimized coated mini-tablets evaluated in FeSSGF and FeSSIF.

[0020] Figures 5A-5E Shown are single-dose plasma concentration-time profiles of clofazimine (CFZ) administered via two different oral formulations in adults by the Sprague-Dawley route.

[0021] Figure 6 An overview of an exemplary method for preparing clofazimine (CFZ) mini-tablets is shown. DETAILED DESCRIPTION

[0022] The following description of embodiments refers to the accompanying drawings. Identical reference numbers in different drawings represent identical or similar elements. The following detailed description does not limit the invention. Rather, the scope of the invention is defined by the appended claims. For simplicity, the following embodiments are discussed with respect to dosage forms and formulations of clofazimine, and more specifically with respect to mini-tablet dosage forms and formulations of clofazimine for the therapeutic treatment of tuberculosis in pediatric patients. However, the embodiments discussed herein are not limited to such elements.

[0023] Throughout this specification, reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosed subject matter. Thus, the appearance of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification does not necessarily refer to the same embodiment. The accompanying drawings are intended to illustrate the claimed features and results and are not drawn to scale unless otherwise indicated. When dimensions of a given feature may be relevant, the detailed description will indicate one or more examples of ranges and units for such dimensions when necessary to implement the subject matter. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0024] Table 1 describes the estimated number of mini-tablets that would be needed in children to achieve a dose of 50 mg (which is equivalent to the lowest available soft gelatin capsule dose). A dose of 1 mg / kg / day (WHO, 2016) and a minimum 2.5 mg CFZ content per tablet (50% w / w for a 5 mg core tablet) are assumed. Twenty mini-tablets are generally considered the maximum number of tablets that can be taken at a single dose, reflecting the maximum number that can be given in a single instance using commercially available dose counters such as Phillip-Medisize. Therefore, the approximate minimum dose of CFZ required per mini-tablet is 2.5 mg. Table 1

[0025] In one example, a 2.5 mg CFZ drug load in a mini-tablet would have a size suitable for an older age range; a 2 mm tablet would require a micronized powder with a drug load of approximately 50% w / w. The challenge is that, due to the hydrophobic nature of poorly water-soluble drugs, the excipients required for the various formulation strategies that must be incorporated typically result in lower drug loads of approximately 5–30% w / w. Therefore, drug loading limitations need to be overcome to achieve sufficient micronized CFZ to treat a wide age range of pediatric patients.

[0026] Mini-tablet cores containing 50% w / w micronized clofazimine were developed and further coated to inhibit disintegration in a neutral pH environment while allowing drug disintegration and dissolution after the mini-tablets are transported to the gastric environment. Disintegration and dissolution measurements of the mini-tablets were further combined with side-by-side diffusion cells to determine the permeability of the released drug through porcine intestinal tissue. Pharmacokinetic studies were conducted in rats using both the CFZ suspension and the optimized CFZ mini-tablets to investigate the impact of processing on the in vivo bioavailability of CFZ. method

[0027] The degradation of clofazimine was evaluated using a high pressure liquid chromatography (HPLC) method published in the United States Pharmacopoeia monograph for drugs (USP, 2021). The mobile phase consisted of a 65:35 mixture of acetonitrile and an aqueous buffer composed of 4.5 g / L sodium lauryl sulfate, 1.7 g / L tetrabutylammonium hydrogen sulfate, and 21.8 g / L Na2HPO4, adjusted to pH 3.0. The flow rate was 1.0 mL / min, and the injection volume was 20 μL. An RP-8 100 column (250 x 4.6, 5 μm) (Millipore Sigma) was used for measurements. Measurements were performed using an Agilent 1100 HPLC with a diode array detector set to 280 nm. The accuracy, precision, specificity, filter compatibility, and linearity of the method were evaluated, and the method's ability to quantify impurity peaks as low as 0.05% of the target analyte concentration and accurately measure CFZ concentrations present in tablet excipient blends was demonstrated. Samples were filtered using a hydrophobic PTFE 0.22 μm filter prior to analysis. The method was found to be linear over a range of 70–130% of the target analyte concentration (250 μg / mL) and 0.05–2.00% for organic impurities / related substances.

[0028] In order to quantitatively determine CFZ in plasma to establish the pharmacokinetic parameters of the developed formulation, a liquid chromatography-mass spectrometry method (LC-MS / MS) was developed. Plasma samples (10 μL) were precipitated with 90 μL of 0.1% formic acid in acetonitrile and 10 μL of a 100 ng / mL diclofenac sodium solution prepared in methanol was added as an internal standard. The samples were vortexed for 1 minute and then centrifuged at 16,900 x g for 5 minutes at 4°C. The supernatant (50 μL) was diluted with 100 μL of 80:20 methanol:acetonitrile. The samples were analyzed for clofazimine precursor / product ions m / z 473 / 431 by liquid chromatography (Vanquish Flex UHPLC, ThermoScientific) and tandem mass spectrometry detector (TSQ Altis, ThermoScientific) in positive selected reaction monitoring (SRM) mode. The results were analyzed using a Hypersil Gold TM Separation was performed at 45°C using a gradient method on a 50 mm x 2.1 mm column (3 μm, ThermoScientific). Mobile phases A and B consisted of 0.1% formic acid in water and 0.1% formic acid in acetonitrile, respectively, eluting at a flow rate of 0.5 mL / min. Mobile phase B was maintained at 40% for the first 0.2 minutes, then increased to 95% over the next 0.8 minutes and maintained at 95% for 1 minute. The percentage of mobile phase B was then reduced back to 40% over the next 0.1 minute and maintained for 2.9 minutes. Preparation of micronized clofazimine

[0029] Clofazimine (CFZ) (Midas Pharma GmbH) was micronized by Lonza Group AG using a 10-inch spiral jet mill at a feed rate of 3 kg / hr and a grinding pressure of 100 psi. The particle size distribution of the milled powder was determined using a laser diffractometer (HELOS, Sympatec GmbH) with a RODOS dry powder disperser set at 4 bar dispersing pressure and 20% rotational speed. In one example, the powder exhibited an X10 diameter of 0.66 μm, an X50 diameter of 1.47 μm, and an X90 diameter of 3.50 μm. Evaluation of the compatibility of clofazimine with excipients

[0030] Micronized CFZ was stress-tested in combination with commercially available tableting excipient blends to establish potential mechanisms of drug degradation and to simplify the selection of excipients for mini-tablet preparation. Two different blends were evaluated: EasyTab SP (JRS Pharma) and (BASF). Since Ludipress does not contain a lubricant component and lubrication may be required during the tableting process, magnesium stearate (1% w / w) was also added to the samples containing Ludipress.

[0031] also, Eudragit E PO was evaluated as a potential candidate for a functional coating for mini-tablets to prevent CFZ release in saliva and subsequent oral staining. Blends of micronized CFZ with excipients and binary mixtures of micronized CFZ with Eudragit E PO were prepared in a 1:1 weight ratio. Blends of CFZ with Prosolv EasyTab SP, Ludipress, or Eudragit E PO were placed in open or sealed HPDE vials and stored at 70°C / 20% relative humidity (RH) or 70°C / 75% RH for 18 days, equivalent to 6 months of thermal storage. As controls, micronized CFZ alone and each excipient blend alone were stored open under each condition.

[0032] HPLC analysis of CFZ alone and with each excipient was performed on day 0, and the same samples were analyzed under various temperature and humidity conditions on day 18. Assay values ​​(% recovery) for all samples were determined by comparing peak areas with reference standards and correcting for sample water content determined by Karl Fischer titration, and related substances are reported by relative retention time (RRT) relative to the reference CFZ peak. Preparation of clofazimine mini tablets

[0033] Mini-tablets containing various ratios of CFZ (50% w / w) in combination with commercially available tablet excipients were directly compressed using a TDP-5 tablet press (LFA Machines Oxford LTD) using 2 mm diameter standard round punches and dies (Natoli). Excipients and excipient blends were selected to function as binders, glidants, disintegrants, lubricants, and / or wetting agents to support the direct compression process. Excipients evaluated included 90 (microcrystalline cellulose, colloidal silicon dioxide), EasyTab SP (microcrystalline cellulose, colloidal silicon dioxide, sodium starch glycolate, sodium stearyl fumarate), Starch (partially pregelatinized corn starch), 500(SPI Pharma)(fructose and starch), (Enonik)(fumed silica), (DuPont) (croscarmellose sodium), sodium stearyl fumarate (JRS Pharma) and sodium lauryl sulfate (Fisher Scientific). A Vankel friability tester was used according to USP <1216> Tablet friability was assessed using the Pharma Test PTB-M500 and tablet hardness was assessed using the Pharma Test PTB-M500.

[0034] The taste-masking coating was applied to the prepared CFZ mini-tablets and placebo mini-tablets (prepared with Prosolv EasyTab SP) using a YC-310 mini-spray coater (Pilotech). The nozzle orifice was 0.8 mm, the atomizing air pressure was 0.08 MPa, the blower frequency was 33 Hz, the inlet air temperature was 45°C, and the spray rate was 15 RPM. The active mini-tablets (5 g) were combined with 45 g of the placebo mini-tablets and Eudragit E PO ReadyMix (Evonik) was sprayed onto the mini-tablets over different time periods (10, 15, 20, and 25 minutes), corresponding to 13%, 15%, and 23% weight gains. In vitro drug release and permeation assessment

[0035] The disintegration and dissolution of CFZ mini-tablets were characterized in several simulated biological fluids. Simulated saliva (pH 6.8) containing 8.0 mg / mL sodium chloride, 0.19 mg / mL potassium dihydrogen phosphate, and 2.38 mg / mL sodium dihydrogen phosphate was prepared according to a published recipe (32) and used to evaluate the disintegration of CFZ mini-tablets coated with Eudragit E PO ReadyMix. Disintegration testing was performed in 20 mL borosilicate glass scintillation vials with 10 mL of medium. Fasting state simulated gastric fluid (FaSSGF) was obtained from a commercial supplier (Biorelevant.com Ltd, London, UK), and fed state simulated gastric fluid (FeSSGF) was prepared according to the method described by Jantratid et al. (Dissolution media simulating conditions in the proximal human gastrointestinal tract: an update. Pharm Res. 2008; 25(7): 1663-76., which is incorporated herein by reference for all purposes). The preparation utilized a combination of acetate buffer and whole milk to simulate gastric conditions after a standard breakfast according to FDA guidance (CPC, 2022). Preliminary evaluation of CFZ saturation solubility in each medium indicated a solubility of 0.092 ± 0.004 μg / mL in FaSSGF, which was close to the limit of quantification of the HPLC method; therefore, gastric dissolution of uncoated and coated mini-tablets was evaluated only in FeSSGF, where CFZ saturation solubility was 20.1 ± 1.86 μg / ml. The opacity of the FeSSGF medium prevented visual assessment of mini-tablet disintegration; therefore, the gastric phase of this test was performed in FaSSGF.

[0036] Mini tablet dissolution was also evaluated in fed state simulated intestinal fluid (FeSSIF) (Biorelevant, London, UK). For all dissolution tests involving coated tablets in FeSSIF, 5 mini tablets were first placed in a microcentrifuge tube of 1 mL of FaSSGF and gently inverted for 2 min to remove the pH-dependent coating. The uncoated tablets were then added to a 150 mL 37°C FeSSIF small sample container dissolution vessel with a paddle speed of 75 rpm (Distek, Inc., North Brunswick, USA). The concentration of clofazimine was measured using HPLC at 5, 10, 15-, 30-, 60-, and 120-min. The dissolution experiment was repeated three times.

[0037] The permeability of clofazimine across isolated porcine intestine (Animal Technologies, Tyler, USA) was evaluated for optimized mini-tablet formulations and micronized CFZ suspensions using a side-by-side diffusion cell apparatus (PermeGear, Hellertown, USA). The coated mini-tablets were first gently tumbled for 2 minutes in 0.5 mL of 0.01 N HCl to ensure dissolution of the pH-dependent taste-masking coating. A single uncoated mini-tablet was then added to the donor compartment of the side-by-side diffusion cell, which was separated from the receptor compartment by isolated porcine intestine, with the apical side of the membrane facing the donor compartment. For experiments using a micronized clofazimine suspension (6 mg / mL CFZ in 0.9% sodium chloride containing 0.2% w / w polysorbate 80), the suspension was added directly to the donor compartment. FeSSIF was then filled into the donor compartment to a total volume of 10 mL. 1-Decanol was selected as the acceptor fluid based on its previous in vitro-in vivo correlation assessment by Warnken et al. (In Vitro-In Vivo Correlations of Carbamazepine Nanodispersions for Application in Formulation Development. J Pharm Sci. 2018; 107(1), which is incorporated herein by reference for all purposes) and its ability to provide suitable sinking conditions for the poorly water-soluble CFZ. The experiment was repeated three times for 24 hours, after which the acceptor fluid was diluted and the CFZ content was quantified using HPLC. Single-dose pharmacokinetic evaluation in rats

[0038] It has been previously demonstrated that oral administration of micronized CFZ suspension (25 mg / kg) to mice with chronic tuberculosis (Mtb) infection resulted in a significant reduction in lung and spleen bacterial burden after two weeks of administration. Therefore, we sought to evaluate the bioequivalence of CFZ suspension and CFZ mini-tablets at two different dose levels (10.3 mg / kg and 20.6 mg / kg) in male and female Sprague-Dawley rats (average weight 246 g) as a surrogate marker for efficacy studies. Three males and three females were used in each treatment / dosing group. A 6.25 mg / mL micronized CFZ suspension was prepared by suspending CFZ particles in saline with 0.32 mg / mL polysorbate 80 and dispersing the particles using a rotor stator homogenizer. To achieve a 10.3 mg / kg dose, 1.65 mL / kg of suspension was administered via oral gavage, while to achieve a 20.6 mg / kg dose, 2.20 mL / kg of suspension was administered via oral gavage. The optimized mini-tablets (containing 3 mg of CFZ) were placed in the cap of a No. 9 gelatin capsule and administered orally. To achieve a 10.3 mg / kg dose, 1 mini-tablet was administered, while to achieve a 20.6 mg / kg dose, 2 mini-tablets were administered. After administering the mini-tablets, 1 mL of normal saline was rinsed. Blood samples were collected via tail vein puncture at 0.5, 1, 2, 4, 6, 24, 48, 72, and 96 hours after administration into a test tube containing an anticoagulant (sodium citrate). The test tubes were stored on wet ice and processed into plasma by centrifugation (3500 RPM, 5°C, 10 minutes) within 30 minutes of collection. Plasma samples were then transferred to new tubes and stored at -70°C until analysis.

[0039] Single-dose PK parameters for each formulation and dose level were determined using non-compartmental analysis in Phoenix WinNonLin version (Certara). Statistical analysis of the resulting PK data was performed to assess bioequivalence using software R and following FDA-mandated procedures (Statistical Approaches to Establishing Bioequivalence, 2001). The natural logarithm of the C value for each subject in each treatment group was used. max and AUC 0-last The values ​​were logarithmically transformed and subjected to Welch's (unequal variance) two-sample t-test to test the C values ​​of the test product (i.e., CFZ mini tablets) and the reference product (i.e., CFZ suspension). max or AUC 0-last The hypothesis that the true difference in means is not equal to 0. 90% confidence intervals for the mean differences of log-transformed data were determined. result

[0040] A low-cost direct compression process enables the production of pediatric-friendly, dose-adjustable clofazimine mini-tablets. Powder mixtures of micronized CFZ powder and commercially available excipient blends for tableting were stress-tested as a preliminary screen for formulation suitability. Prosolv Easytab SP and Ludipress excipient blends were selected because they are mixtures of multiple tableting excipients for direct mixing with the active pharmaceutical ingredient into product tablets and therefore provide a mechanism for rapidly screening several excipients for compatibility. Under the test conditions, little or no degradation of the drug-excipient blends was observed compared to baseline measurements and impurity peaks. Furthermore, the effects of the test excipients on drug product critical quality attributes, such as powder flowability upon tableting die filling, disintegration, and tablet breaking force, were further evaluated. Table 2 provides a summary of the compatibility of clofazimine-excipient (1:1) mixtures after 18 days of storage under accelerated conditions, illustrating the stability of the drug with the selected excipients under relatively high temperature and humidity conditions. Table 2

[0041] The dosage form and formulation of the mini-tablets are designed to achieve a CFZ loading of at least 50% w / w with rapid disintegration and dissolution in GI fluids, thereby maximizing the oral bioavailability of this poorly water-soluble drug. Initially, a proprietary tablet excipient blend was used. EasyTab SP or Direct compression was performed with magnesium stearate at 50% w / w CFZ loading; however, the resulting mini-tablets failed to disintegrate in FaSSGF and exhibited severe capping during production (see Figure 1 Addition of excipients such as colloidal silicon dioxide and hydroxypropylcellulose (data not shown), which are known to improve hardness and reduce capping without reducing disintegration, failed to resolve the capping and disintegration issues of the simulated tablet formulation.

[0042] The composition of clofazimine mini tablets and the hardness and disintegration time of the resulting tablets are summarized in Figure 1 Due to the high hydrophobicity of CFZ, 50% w / w drug loading and micron-sized drug particle size, it was unexpectedly found that the combination of incorporating a disintegrant into the formulation shortened the disintegration time to less than 2 minutes while achieving the desired disintegration time at high drug loading. In one embodiment, by adding 5% w / w croscarmellose sodium to a blend containing sodium carboxymethyl starch Achieved the shortest disintegration time (see Figure 1). Croscarmellose sodium is added to a blend containing sodium carboxymethyl starch, rather than increasing the amount of sodium carboxymethyl starch, to provide a wicking effect in addition to the swelling effect of the sodium carboxymethyl starch. Thus, the combination provides an additional benefit compared to using only a single selected disintegrant, as the wicking effect of the croscarmellose sodium can result in more rapid incorporation of water into the dosage form, where the sodium carboxymethyl starch is present for overall swelling and disintegration of the tablet.

[0043] Overcoming the mini-tablet disintegration time target by using a combination of disintegrants is only one goal in producing a pharmaceutically acceptable dosage form; tablet capping is also a critical issue. Tablet capping can be overcome by incorporating additional lubrication, using increased proportions of sodium stearyl fumarate (the lubricant in the Prosolv EasyTab SP blend), or using a combination of sodium stearyl fumarate and sodium lauryl sulfate. These formulations all maintained the target rapid disintegration without capping during the automated tableting process (see Figure 1 Considering that it would generally not be feasible to add other components while maintaining 50% w / w micronized CFZ, it was expected that the capping problem could not be solved while achieving the target disintegration time.

[0044] The improvement in CFZ dissolution rate in mini-tablets in FeSSGF (pH 5.0) was compared for embodiments of the above formulations containing sodium stearyl fumarate alone or in combination with the anionic surfactant sodium lauryl sulfate (SLS). Figure 2 The dissolution profiles of CFZ mini-tablets containing 1% SLS and mini-tablets without SLS in FeSSGF medium (pH 5.0, 37°C) are shown. Error bars represent standard deviations, n=3. C / C eq = CFZ concentration at the time point normalized to the equilibrium solubility measured in the medium.

[0045] Minitablets containing sodium lauryl sulfate (SLS) and sodium stearyl fumarate (SSF) showed enhanced dissolution compared to minitablets containing SSF alone ( Figure 2 ). Surfactants above their critical micelle concentration can solubilize the drug. If SLS forms micelles that can dissolve CFZ during the dissolution test, the measured CFZ concentration in FeSSGF at each time point is normalized to the final saturated solubility of CFZ in the dissolution medium to correct for any potential increase in the saturated solubility of the drug from SLS. The final average hardness of the mini-tablets containing SLS was measured to be 10N. The friability of the resulting mini-tablets was found to be 0.6%, which is consistent with the USP guidelines (USP <1216> Tablet friability) was considered acceptable.

[0046] CFZ exhibits intense red pigmentation, which can cause oral and dental staining if the dosage form disintegrates and dissolves in the mouth before swallowing. The bitter taste of the drug can also reduce compliance in the pediatric population. EPO was evaluated as a functional coating polymer to prevent premature disintegration and drug release from mini-tablets. Figures 3A-3B A schematic diagram is provided that describes the process of weighing the active mini-tablets, combining them with the placebo, and then coating the clofazimine mini-tablets at different coating weight increases ( FIG. 3A ). The coated mini-tablets were first subjected to disintegration testing in simulated saliva medium (pH 6.8) and then in fasting simulated gastric fluid (FaSSGF) at pH 1.6, which showed that the 13% WG mini-tablets were not able to sufficiently inhibit disintegration in the tests performed. The effect of coating thickness on the inhibition of mini-tablet disintegration in simulated saliva (pH 6.8) was determined by subjecting the mini-tablets to fluid bed coating for 10, 15, and 20 minutes to achieve weight gains of 13%, 15%, and 23%, respectively ( FIG. 3A ). Although 13% weight gain was not enough to inhibit disintegration, 15% and 23% weight gain levels inhibited disintegration in simulated saliva for at least 2 minutes. Transfer of the 15% and 23% weight gain mini-tablets to FaSSGF (pH 1.6) resulted in disintegration within 5 minutes and the formation of a fine powder dispersion using minimal stirring ( FIG. 3B ). Release of clofazimine from optimized mini-tablets and intestinal permeation in a simulated gastrointestinal environment.

[0047] The release of CFZ in the optimized coated mini tablets was evaluated in both FeSSGF and FeSSIF. In the case of the fed state intestinal dissolution test, the mini tablets were exposed to 0.1N HCl for two minutes, gently flipped to remove the coating, and then added to the intestinal medium. The dissolution of the mini tablets in FeSSGF was slower than that in FeSSIF, and the released CFZ was still below the saturated solubility (20.1 ± 1.9 μg / mL) in the medium. Alternatively, in FeSSIF containing available bile salts that contribute to the wetting of lipophilic micronized clofazimine, the released CFZ was able to reach a saturated solution (14.9 ± 1.5 μg / mL) in the medium within 2 hours, which provides the greatest opportunity for drug absorption without changing the physical form of the drug. Figure 4 The results of the two-hour dissolution test of clofazimine in each medium are illustrated. The dissolution profiles of Eudragit EPO-coated CFZ mini-tablets in FeSSGF and FeSSIF media are shown. The error bars represent the standard deviation of n=3. After administration of the mini-tablets, clofazimine concentrations in rats exceeded previously reported effective concentrations.

[0048] Figure 5A-E shows the single-dose plasma concentration-time curves of clofazimine (CFZ) administered via two different oral formulations in adults by the Sprague-Dawley route. Figure 5A ) or mini tablets ( Figure 5B ; single 2.5 mg mini tablets) and 20 mg / kg dose of CFZ suspension ( Figure 5C ) or mini tablets ( Figure 5D ; two 2.5 mg mini-tablets) and the arithmetic mean CFZ plasma concentration versus time curve was determined for each treatment group (n=6). Figure 5E The arithmetic mean CFZ concentration versus time curve for n = 6 rats per dosing group is presented. Pharmacokinetic results of 2.5 mg coated mini-tablets compared to micronized clofazimine suspension at two dose levels. The red dashed line within the magnified 0 to 8 h time point represents the C reported in previous testing using the micronized suspension in BALB / c mice. max , which was found to be effective in reducing colony forming units (CFU) of Mycobacterium tuberculosis. Error bars represent standard deviation of n=6 Sprague-Dawley rats.

[0049] Figures 5A-5E The results of the pharmacokinetic studies shown are summarized in Table 3. The pharmacokinetic parameters of each administration group of micronized clofazimine or coated mini-tablets were determined in Sprague-Dawley rats. Table 3

[0050] Overall, clofazimine plasma concentrations were similar between the two formulations (suspension and mini-tablets). Figures 5A-5E As seen in the , dose was not directly proportional, which is common for poorly water-soluble drugs and may be a result of exceeding the maximum amount of drug that can be dissolved in the gastrointestinal medium. The overall exposure in rats was found to be lower with a single mini-tablet than with the other groups due to a small number of mice rapidly clearing the drug at the early time points. The group given two mini-tablets was found to result in an AUC similar to that of an equal dose of the micronized suspension. 0-96h , and C max The values ​​are higher but the variation is greater. In all cases, C max Both exceed the C reported from pharmacokinetic studies in BALB / C mice treated at doses found to be efficacious. max , which is expected to ensure that the mini-tablets can provide sufficient bioavailability for effective treatment of Mycobacterium tuberculosis infection (Brunaugh, 2022). Preparation method

[0051] The following is an overview of an exemplary manufacturing process for producing the clofazimine mini-tablets described herein and is summarized in Figure 6 First, a therapeutic dose is determined 610, typically based on the patient's weight, age, and indication. Then, a predetermined mini-tablet target size of approximately 2-5 mm is established, which, in a preferred embodiment, also includes approximately 50% w / w clofazimine (CFZ) 620. The mini-tablet target size can also be a function of the target number of mini-tablets prescribed per dose, again dependent on the patient's weight, age, and indication. The CFZ drug substance is micronized 630, and in a preferred embodiment, the CFZ material is micronized by air jet milling.

[0052] Subsequently, micronized CFZ is blended 640A with an excipient to give the desired disintegration time and hardness of the final tablet. In a preferred embodiment, the final tablet includes a combination of disintegrants to shorten the disintegration time to about 2 minutes or less. The disintegrant in a preferred embodiment includes a first disintegrant (such as, ProsolvEasyTab SP blend containing sodium carboxymethyl starch) and a second disintegrant cross-linked sodium carboxymethyl cellulose (Ac-Di-Sol), which is blended with CFZ until uniform. In certain embodiments, the blend may include a surfactant such as sodium lauryl sulfate and a lubricant such as sodium stearyl fumarate for tableting. It should be noted that the second additional disintegrant can be blended in an optional second blending stage 640B, or can be merged into a single blending stage 640A with the first disintegrant.

[0053] Approximately two (2) mm round mini-tablets are directly compressed to a target hardness of 650. In certain embodiments, the target hardness is about 10 N. The tablets are then coated using a fluid bed coater such as The mini-tablets are coated 660 with EPO ReadyMix to provide a weight gain of about 23% in certain embodiments. Treatment

[0054] A clofazimine mini-tablet-based method for treating a disease caused by Mycobacterium tuberculosis in a patient comprises: determining a therapeutically effective dose of clofazimine based on the patient's age, weight, and disease indication; determining the number of mini-tablets per patient dose based on the clofazimine dose per mini-tablet; and administering the therapeutically effective amount of clofazimine to the patient as a plurality of mini-tablets. In this embodiment, each mini-tablet comprises the agents discussed above, including an amount of micronized clofazimine; at least one disintegrant to promote disintegration; at least one lubricant to prevent capping; and a polymer coating. In certain embodiments, each mini-tablet has a diameter of approximately 5 mm or less, and in preferred embodiments, a diameter of 4 mm or less.

[0055] The clofazimine mini-tablet-based treatment can be administered to patients with chronic or acute Mycobacterium tuberculosis (Mtb) infection, which can include multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XRD-TB) strains. Patients may include, but are not limited to, pediatric TB patients and patients diagnosed with nontuberculous mycobacterial (NTM) infection.

[0056] In one patient treatment example, a pediatric patient aged 2 to 3 years may weigh 12.5 kg. Using a weight-based clofazimine dosage of 1 mg / kg / day as part of the treatment regimen, the patient would require 12.5 mg of clofazimine daily. Giving the patient five (5) 2.5 mg clofazimine mini-tablets once daily during their treatment would result in accurate dosing based on their weight.

[0057] Clofazimine has also been used clinically to treat nontuberculous mycobacterium (NTM) infections, such as Mycobacterium avium complex and Mycobacterium abscessus, including in pediatric patients. For pediatric patient populations suffering from these conditions, the mini-tablets of the present disclosure also address the lack of suitable dosage forms for these indications.

[0058] For simplicity, the foregoing embodiments are discussed with respect to oral dosage forms and formulations for the treatment of pediatric tuberculosis; however, the embodiments discussed herein are not limited to such elements or applications. The dosage forms and formulations disclosed herein have applications for other therapeutic indications and patient populations. Furthermore, the features, structures, formulations, characteristics, and methods described herein may be combined in any suitable manner in one or more embodiments.

Claims

1. A mini-tablet of a drug for treating tuberculosis, comprising: A certain amount of micronized clofazimine; at least one disintegrant to promote disintegration; and at least one lubricant to prevent top cracking; Wherein the mini-tablets have a diameter of about 5 mm or less.

2. The mini-tablet according to claim 1, wherein the amount by weight of micronized clofazimine is about 50% or more of the total mini-tablet weight.

3. The mini-tablet according to claim 1, wherein the micronized clofazimine has an average particle size (X50) of 5 micrometers (μm) or less.

4. The mini-tablet according to claim 1, wherein the micronized clofazimine has an average particle size (X50) of 2 micrometers (μm) or less.

5. The mini-tablet according to claim 1, wherein the number of disintegrants is two, including a first dose and a different second dose.

6. The mini-tablet of claim 5, wherein one disintegrant is an agent that promotes swelling and the second agent is an agent that promotes wicking.

7. The mini-tablet of claim 6, wherein the first disintegrant comprises sodium starch glycolate and the second disintegrant comprises croscarmellose sodium.

8. The mini-tablet of claim 1, wherein the lubricant is a fumaric acid monoester.

9. The mini-tablet of claim 1, wherein the lubricant further comprises an anionic surfactant.

10. The mini-tablet according to claim 1, further wherein the lubricant is a combination of a fumaric acid monoester and an anionic surfactant.

11. The mini-tablet of claim 10, further wherein the lubricant is a combination of a fumaric acid monoester and an anionic surfactant, and further wherein the fumaric acid monoester is sodium stearyl fumarate and the anionic surfactant is sodium lauryl sulfate.

12. The mini-tablet of claim 1, wherein the mini-tablet has a diameter of about 4 mm or less.

13. The mini-tablet of claim 1, further comprising a polymer outer coating.

14. A clofazimine mini-tablet-based method for treating a disease caused by Mycobacterium tuberculosis in a patient in need thereof, the method comprising: Determine the therapeutically effective patient dose of clofazimine based on the patient's age, weight, and disease indication; The number of mini-tablets per patient dose is determined based on the clofazimine dose per mini-tablet. wherein each mini-tablet comprises an amount of micronized clofazimine; at least one disintegrant to promote disintegration; and at least one lubricant to prevent capping; and further wherein the mini-tablet has a diameter of about 5 mm or less; and A therapeutically effective amount of clofazimine is administered to the patient as a plurality of mini-tablets.

15. The clofazimine mini-tablet-based method of claim 14, wherein the amount of micronized clofazimine per mini-tablet by weight is about 50% or more of the total weight of each mini-tablet.

16. The clofazimine mini-tablet-based method of claim 14, wherein the micronized clofazimine of each mini-tablet has an average particle size (X50) of 5 micrometers (μm) or less.

17. The clofazimine mini-tablet-based method of claim 14, wherein the micronized clofazimine of each mini-tablet has an average particle size (X50) of 2 micrometers (μm) or less.

18. The clofazimine mini-tablet-based method of claim 14, wherein the number of disintegrants per mini-tablet is two, comprising a first dose and a different second dose.

19. The clofazimine mini-tablet-based method of claim 18, wherein one disintegrant is an agent that promotes swelling, and the second agent is an agent that promotes wicking.

20. The clofazimine mini-tablet-based method according to claim 14, wherein the disease caused by Mycobacterium tuberculosis is multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XRD-TB).

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