Composition and method of treatment

Abstract

Inclusion complex comprising an active pharmaceutical ingredient which is a P2X7 inhibitor receptor antagonist (e.g. lidocaine hydrochloride, articaine) and a cyclodextrin (e.g. HP beta cyclodextrin) for use in the treatment of an autoimmune disease or a condition in which an immune response caused by a disease or infection causes hyperinflammation (e.g. Long COVID) wherein the inclusion complex is presented for administration to the lymphoid system. A base (e.g. sodium bicarbonate) may be further included in the inclusion complex. Inclusion complex may be administered intra- or sub-dermal or subcutaneously, e.g. by infusion pump or pen injector. Also claimed is a formulation comprising an inclusion complex, said complex comprising lidocaine.HCl or articaine.HCl, hydroxypropylated β-CD, a pH modifier and water wherein the pH is 5-7.4 and the ratio and concentration of components is further limited. Said formulation may have a shelf life of at least 32 weeks based on accelerated testing at 60 °C.

Description

INTRODUCTION

[0001] The present invention relates to compositions for use in the treatment of hyperinflammation and to methods for the treatment of hyperinflammatory conditions, such as those experienced post an infection, particularly a viral infection, or following an autoimmune disease.

[0002] More particular the treatment is for a condition commonly referred to as Long COVID and associated conditions as set out below.

[0003] Long COVID is a term broadly defined as signs, symptoms, and conditions that continue or develop after initial SARS-CoV-2 infection. The signs, symptoms, and conditions are present four weeks or more after the initial phase of infection, may be multi-systemic, and may present with a relapsing I remitting pattern and progression or worsen over time, with the possibility of severe and life-threatening events even months or years after infection. Long COVID is not one condition. It represents many potentially overlapping entities, likely with different biological causes and different sets of risk factors and outcomes.

[0004] Post-COVID-19 conditions is equivalent to the lay term Long COVID, and is used to describe the new, returning, or ongoing health problems people can experience four or more weeks after initial infection with the SARS-CoV-2 virus, the virus that causes COVID-19.

[0005] Post-acute Sequelae of SARS CoV-2 infection is a term used in the scientific and medical communities that refers to ongoing, relapsing, or new symptoms or other health effects occurring after the acute phase of SARS-CoV-2 infection.

[0006] The term Long COVID as used herein covers all such terms.

[0007] More particularly the composition comprises a P2X7 receptor antagonist, more particularly still lidocaine or articaine, and most particularly it’s HCI salt together with a cyclodextrin, more particularly a p cyclodextrin and most particularly a hydroxy propylated P cyclodextrin (HPBCD). BACKGROUND

[0008] The use of a P2X7 receptor antagonist and more particularly lidocaine to treat COVID-19 (and long COVID) has been proposed.

[0009] WO2021 / 201680 (October 2021) teaches the use of lidocaine in the treatment of hyperinflammatory syndrome and more particularly the use of forms including microneedles and invasive administrative methods including intradermal, subdermal or subcutaneous administration.

[0010] More particularly a lidocaine infusion solution (20mg / ml) was used both intravenously and as a subdermal infusion (1mg / kg / hr) on COVID patients as was a continuous subdermal infusion (@0.5mg / kg / hr and 0.63mg / kg / hr) via a syringe pump.

[0011] WO2022 / 254363 (December 2022) discloses using Articaine to treat COVID and long COVID by sublingual administration.

[0012] Whilst both these patent applications provide patient data it is apparent that many patients continue to experience post COVID symptoms - see httpsi / / www.thelancetcom / LoiKna|s / ^

[0013] Indeed, this review states that in the UK alone approx. 1,8m people were reporting COVID-19 symptoms lasting more than 4 weeks as of May 2022 and in the US 7.5% of adults are still experiencing persistent symptoms 3 or more months after their initial COVID-19 diagnosis.

[0014] This article concludes that “It is clear given the high prevalence of persistent symptoms after 12 weeks (nearly 1 in 2 people) that healthcare services and policy need to prioritise Long COVID care, and in addition understand different sub-types of Long COVID to permit stratified healthcare and ensure services are not overwhelmed in the future.”

[0015] With this challenge Applicant sought to provide formulations better suited to treating Long COVID as well as providing treatment regimens which are more sustainable and likely to give rise to better patient compliance. In this regard a formulation that can be self-administered and avoids a need to attend a clinic or for the patient to be hospitalised would be beneficial.

[0016] Looking to improve upon the formulations described in WO2021 / 201680 and WO2022 / 254363, formulations used to target delivery to the lymphatic system, they postulated that the use of cyclodextrins, as opposed to other generic approaches, for example, nanoparticles, microspheres, liposomes, emulsifying drug delivery systems (EDDS) and variants thereof, might be particularly attractive.

[0017] Indeed, cyclodextrins were used in delivering a number of antivirals during the pandemic. See the review article. The Role of Cyclodextrins in COVID-19 Therapy—A Literature Review.

[0018] This review confirmed the premise that p cyclodextrins might increase solubility, stability and absorption and might reduce toxicity.

[0019] To their surprise, and unexpectedly as they further reviewed the art on cyclodextrins, they discovered that for their target indication there could be additional benefits based on two lesser-known properties of cyclodextrins, namely their antiviral and anti-inflammatory properties.

[0020] In particular, Bezerra (2022) https: / / p ubm ed. nebs. n I m. n i h. q o v / 35798224 / taught that Hydroxypropyl p cyclodextrin (HPBCD) has: i) an immunomodulatory effect (suppressing inflammatory cytokines) ii) is, independently, a therapeutic agent used in the treatment of Niemann pick C disease (where it acts to delete cholesterol); and iii) inhibits SARS-CoV2 replication.

[0021] More particularly still it reduced TNF-a levels, IL-6 and CCL2 expression such that these biomarkers might be used to identify Long COVID patients (those with high level expression) who might benefit from treatment.

[0022] Further evidence from Matasolli (2018) https: / / pubmed.ncbi.nlm.njh.QGv / 30404938 / showed the treatment of monocytes from HIV infected patients with p cyclodextrin decreased TNF-a and IL 10.

[0023] To Applicants surprise they determined that cyclodextrins had been used in combination with both Lidocaine and Articane, but for different reasons. This art is discussed below in chronological order.

[0024] Moraes (2006) httpsv / sc^ url?url=https: / / www.academia,edu / download / 4941871 3 / s10847-006-9179-x20161006-23191 dugeey.pdf&hi~en&sa~X&ei~vMb2ZZ2DGrfHy9Ypz.am kA8&scLsjg-AFWwaeZPoEa8LKoK0do^ discloses a lidocaine HPBCD (1:1) complex which reduces the rate of lidocaine release at a pH of 10.5.

[0025] Tatai (2007) https: / / wvw.researchgate.net / publication / 227089579 Preparation and investigation of m ixtures containing lidocaine base and b-cyciodextrin taught a lidocaine base and different cyclodextrins (CD) in different ratios. It concluded that P CD was the best of eight CD derivatives and that lidocaine HCI is better for systemic applications (orally) and lidocaine base is better for dermal applications.

[0026] Suzuki (2008) https: / / link.springer.eom / article / 10.1007 / s00540-008-0720-5 demonstrated that lidocaine formulated as a complex of the branched cyclodextrin 6 O -a D maltosyl p cyclodextrin could prolong local nerve block.

[0027] Soares da Silva (2011) https: / / pubmed.ncbi.nlm.nih.gov / 21822378 / disclosed a stable vaginal gel comprising lidocaine and chlorhexidine gluconate (a bactericide) with two cyclodextrins, B cyclodextrin and methyl-beta cyclodextrin lidocaine HCI.

[0028] Wei (2015) https: / / wvw.ncbi.nlm.nih.gov / pmc / artictes / PMC4370974 / looked to address the problem of taste masking with dental lidocaine HCI injections through the use of cyclodextrins. It utilises HP BCD, not something pertinent to a subcutaneous delivery mode. The formulation further comprised a vasoconstrictor, antioxidant, chelating agent, tonicity agent and sweetener.

[0029] Ferriera (2018) https: / / academic.oup.com / ipp / article / 70 / 7 / 874 / 6121864?login=false showed lidocaine to have antiproliferative and cytotoxicity activity on several cell types and that cyclodextrins improved the release profile.

[0030] Abou-Okeil (2018) https: / / www. scienced i reef. com / science / article / abs / pii / SOO14305718315519 looked at a comparison of lidocaine gel formulations with and without B cyclodextrin. They concluded an inclusion complex showed a greater decrease in inflammatory mediators.

[0031] Batista de Oliveira (2019) httgs^gybrnedmcmT^ looked at whether a HPBCD lidocaine inclusion complex provided more effective in treating antinociceptive pain. The indications were in certain models it did.

[0032] Whilst there are a significant number of publications in which lidocaine has been formulated with B cyclodextrins none have been designed as injectables targeting the lymphatic system (with a profile limiting exposure to blood plasma) as set out herein, particularly where the injection site is subcutaneous tissue.

[0033] It is an object of the present invention to provide a novel dosage form of a P2X7 receptor antagonist, particularly lidocaine or articaine, as an inclusion complex with a cyclodextrin, which is presented for administration to the lymphatic system.

[0034] Interestingly both lidocaine and articaine additionally provide antimicrobial benefits. BRIEF SUMMARY OF THE DISCLOSURE

[0035] In accordance with a first aspect of the present invention there is provided an inclusion complex comprising: i) an active pharmaceutical ingredient (API) which is a P2X7 receptor antagonist; and ii) a cyclodextrin; for use in the treatment of an autoimmune disease or a condition in which an immune response caused by a disease or infection causes hyperinflammation wherein the inclusion complex is presented for administration to the lymphatic system.

[0036] Example P2X7 receptor antagonists include those listed in Table 1 below: Table 1: Drug name and structure CAS number Potency Outcome Biological effect GW791343 1019779- 04-4 plC50 = 6.9-7.2 Reported in literature AZ10606120 (astrazeneca) 607378- 18-7 pKd = 8.9 = 8.7 Reported in literature Glioblastoma, antineoplastic activity Z?\ o V H AZD9056 (astrazeneca) / V\ H^S^y 345304- 65-6 plC50 = 8.0 7.89 Phase II trial terminated due to lack of efficacy in CD or COPD Inhibits il_-1B in monocytes Safe and well tolerated CE-224,535 (Pfizer) oh°^«A;n o 724424- 43-5 plC50= 8.7 7.89 Phase II Trial terminated Claimed in patent US6974812 Safe and well tolerated after 12 weeks of administration COPD, arthritis, asthma GSK1482160 (glaxosmith Kline) byj^ 1001389- 72-5 plC50 = 8.1 Failed to reach therapeutic efficacy within safety margins Efficacy in preclinical mouse models of pain JNJ-54175446 (Janssen) F 1627902- 21-9 plC50 = 8.46 Phase II clinical trials (ongoing as of 2023, NCT04116606) Mood modulatory effects in healthy patients with dexamphetamine Possible neuroinflammation treatment Antiseizure effects JNJ55308942 (Janssen) 2166558- 11-6 plC50 = 8.0 Phase II clinical trials for Bipolar disorder and Efficacy in mouse models of F Backup to JNJ-54175446 major depressive episode Last updated 31 / 01 / 24 (NCT05328297) depression JNJ54173717 (Janssen) J „4^0.? N / A plC50 = 8.38 Phase I clinical trials Radiolabelled as a marker for neuroinflammation for patients with parkinsons EVT401 (Evotec) O | Fxz / XzX / riH F F N / A plC50 = 8.03 Phase II clinical trials Oral P2X7 receptor antagonist Inflammatory conditions (rheumatoid arthritis) Cannabidiol 0H 13956- 29-1 Reported in literature Exerts anti inflammatory effects in monocytes comparable to NLRP3 inflammasome inhibitors

[0037] In one embodiment the autoimmune disease or the condition in which an immune response caused by the disease or infection causes hyperinflammation is a post viral condition. 5

[0038] More particularly the post viral condition is Long COVID.

[0039] Presentation to the lymphatic system most preferably comprises administration by way of intradermal, subdermal or sub-cutaneous delivery.

[0040] In one embodiment a unit dose is presented in a pen injector. Such a presentation is particularly advantageous as it allows the patient to self-medicate at home.

[0041] The pen injector typically comprises a dose volume of 3ml or less, and where the P2X7 receptor antagonist is lidocaine, the lidocaine is present at a concentration (wt / vol) of at least 1%, and more preferably at least 2.5%, more preferably still at least 5% and most preferably at least 7.5%.

[0042] In another embodiment a unit dose is presented in an infusion pump by way of intradermal, subdermal or sub-cutaneous delivery.

[0043] The infusion pump typically comprises 5ml to 1000ml, more typically 20ml to 500ml of a solution of the inclusion complex and where the P2X7 receptor antagonist is lidocaine, the lidocaine is present at a concentration (wt / vol) of at least 0.5% and the solution is delivered at a flow rate of, for example, 1ml / kg / hr (depending on the lidocaine or articaine concentration) such that the patient attains a daily dose from 0.5mg / Kg to 12mg / Kg over a 24 hour period. Such as dosage regime would equally apply to other administration devices targeting the lymphatic system, such as the injector pen

[0044] In the most preferred embodiments, the API is Lidocaine or a salt thereof, or Articaine or a salt thereof.

[0045] The API may be in the form of a base or a salt.

[0046] Where a salt is used, the preferred salt is the hydrochloride salt.

[0047] In a preferred embodiment the cyclodextrin is a 0 cyclodextrin.

[0048] A favoured 0 cyclodextrin is HP 0 cyclodextrin.

[0049] The inclusion complex further comprises a pH modifier.

[0050] The preferred pH modifier is an alkali.

[0051] Particularly favoured is sodium bicarbonate due to its’ mild action

[0052] In accordance with a second aspect of the present invention there is provided a formulation comprising an inclusion complex of: i) Lidocaine HCI or Articaine HCI; and ii) Hydroxypropylated 0 cyclodextrin; together with iii) a pH modifier; and iv) water wherein the pH is between 5 and 7.4, i) and ii) are present in a ratio of between 1:1 and 1:2; and the concentration of i) is between 2.5% and 20% weight / volume.

[0053] The formulation has a demonstrated shelf life of at least 64 weeks based on accelerated stability testing at 60° C.

[0054] The formulation is most preferably presented for subcutaneous delivery.

[0055] In one embodiment it is presented as a small volume injectable with a volume of 3ml or less and is delivered subcutaneously.

[0056] In an alternative embodiment it is provided as an infusion, to be delivered over from 1 to 30 days by way of an infusion pump.

[0057] The syringe or infusion pump delivers a therapeutic unit dose, of articaine or lidocaine, as described previously, to a patient, which dose results in a peak plasma level of below 4.7ug / ml for lidocaine to avoid toxicity.

[0058] According to a third aspect of the present invention there is a method of treating Long COVID comprising administering to a patient an effective amount of a formulation of the invention.

[0059] Different aspects and embodiments of the invention are further described hereinafter with reference to the detailed description. DETAILED DESCRIPTION

[0060] The invention is further described with reference to the following Figs and Examples in which. Figs 1a-c are respectively a chromatogram of lidocaine HCI titration, concentration data and calibration curve; Fig 2a-c are respectively a chromatogram of articaine HCI titration, concentration data and calibration curve; Figs 3a-c are respectively chromatograms of lidocaine HCI titration pH adjusted and, concentration data; Fig 4 a-c are respectively chromatograms of articaine HCI titration pH adjusted and, concentration data; Figs 5a-e are respectively chromatograms for lidocaine HCI with HPBCD and 25mg / ml, 50mg / ml, 100mg / ml and 200mg / ml lidocaine HCI with HPBCD, pH adjusted; Fig 6 are respectively chromatograms for articaine HCI with HPBCD and 25mg / ml, 50mg / ml, 100mg / ml and 200mg / ml articaine HCI with HPBCD, pH adjusted; Fig 7a and 7b are respectively chromatograms of lidocaine HCI and Articaine HCI during stability testing; and Figs 8a-d are respectively chromatograms for sterilised lidocaine HCL and articane HCL inclusion complexes with HPCD.

[0061] The aim of the experiments was to firstly identify formulations (particularly excipients and pH) that would allow high concentrations of lidocaine or articaine either as the freebase or salt (HCI) to be solubilised.

[0062] A further aim was to determine the stability of the identified formulations. Example 1 Solubility and pH studies of API without excipients Materials and methods

[0063] Stock solutions were made of: • Lidocaine HCI (200 mg / mL) • Articaine HCI (200 mg / mL) and • NaOH (0.5 M)

[0064] Lidocaine HCI and articaine HCI solutions were serially diluted. Solubility Results

[0065] The results are illustrated in Figs 1a-c and Figs 2a-c which respectively show: a) chromatogram overlay of lidocaine and articaine HCI titration; b) concentration tables; and c) calibration curves.

[0066] Following calibration, the pH of lidocaine and articaine HCI, at different concentrations, was determined as set out in Tables 2 and 3 below. Table 2 Drug cone (%) 25 mg / mL (2.5 %) 50 mg / mL (5 %) 100 mg / mL (10 %) 200 mg / mL (20 %) Lidocaine HCI 5.43 4.78 4.35 3.86 Articaine HCI 5.33 4.51 4.04 3.84 Table 3 Drug Original pH PH PH PH acceptable pH range Lidocaine HCI 3.86 5.2 Soluble 6.03 Soluble 6.8 Soluble 5-6.8 Articaine HCI 3.84 6.0 Soluble 6.89 Soluble 7.16 Cloudy 5.4-6.9 pH Results

[0067] The results are illustrated in Figs 3 and 4 which show: a) chromatogram overlay of lidocaine / articaine HCI titration b) concentration tables; and 10 c) calibration curves. Example 2 Solubility and pH studies of API with cyclodextrins 15 Materials

[0068] Formulations were made up from: API: • Lidocaine HCI or • Articaine HCI (2.5, 5, 10 and 20 %) Excipient • HPBCD or • Captisol™: 1:1 molar ratio Solvent: • Distilled water and sterilised. Method

[0069] A 40 % stock solution of API was made up was serially diluted to 5 mL for each of the desired concentrations. Subsequently, the relevant amount of cyclodextrin was added as a powder. The pH of the formulation was measured using a pH probe and subsequently adjusted using 0.5 M NaOH. The formulations were then stirred at 37 °C in a radley reaction tube in a reaction carousel and visually inspected after 4 hours and then 16 hours, stirring at 37 °C. Only the lidocaine HCI formulations were analysed via HPLC - the articaine HCI formulation data may be inferred from the stability studies. Results

[0070] pH of cyclodextrins at high concentrations are illustrated in Tables 4 and 5 • 2-hydroxypropyl beta cyclodextrin (480 mg / mL) = 5.65 • Captisol (700 mg / mL) = 5.11 Table 4 Lidocaine HCI Cone CD Cone Lido HCI Solubility pH pH adjustment** Solubility (HPLC) HPBCD 134 mg / mL 2.5 % Clear solution, soluble 5.56 - 267 mg / mL 5 % Clear solution, soluble 5.5 - 534 mg / mL 10% Clear solution, soluble 4.73 5.98 Soluble 1068 mg / mL 20 % Clear viscous gel, soluble 4.62 5.47 Soluble Captisol 194 mg / mL 2.5 % Clear solution, soluble 4.7 5.54 Soluble 388 mg / mL 5 % Clear solution, soluble 4.57 5.86 Soluble 776 mg / mL 10 % Clear solution, soluble 4.34 5.83 Soluble 1552 mg / mL 20% Clear viscous gel, soluble 3.98 5.58 Soluble Table 5 Articaine HCI Cone CD Cone Arti HCI Solubility pH pH adjustment** Solubility (visual inspection) HPBCD 120 mg / mL 2.5 % Clear solution, soluble 5.2 - 240 mg / mL 5% Clear solution, soluble 4.46 - - 480 mg / mL 10 % Clear solution, soluble 4.32 - - 960 mg / mL 20 % Clear viscous gel, soluble 3.96 5.45 Soluble** Captisol 175 mg / mL 2.5 % Clear solution, soluble 4.6 - 350 mg / mL 5 % Clear solution, soluble 4.39 - - 700 mg / mL 10 % Clear solution, soluble 4.3 - - 1400 mg / mL 20 % Clear viscous gel, soluble 4.13 5.78 Soluble** ** Visually inspected - chromatograms not taken however

[0071] The results are further illustrated in Figs 5 and 6. Discussion and conclusions across the lidocaine and articaine HCI studies

[0072] Initially, lidocaine and articaine HCI calibration curves were obtained up to 200 mg / mL of concentration with 2-fold serial dilutions down to 25 mg / mL. The pHs of these solutions were also assessed. From 25 - 200 mg / mL, Lidocaine HCI solutions were between the pH range 5.43 - 3.86 and the articaine HCI solutions were between pH range 5.33-3.84.

[0073] Lidocaine HCI and Articaine HCI are soluble in water at 200 mg / mL without excipients and may both be adjusted to at least pH 6.8 and 6.9 respectively without solubility issues.

[0074] Solubility studies with excipients cyclodextrins (HPBCD and Captisol™) were subsequently undertaken. Initially, serially diluted formulations of lidocaine HCI with stoichiometric amounts of the relevant CD were assessed by HPLC. The extensive HPLC studies were only done for lidocaine HCI. For Articaine HCI, visual inspection was undertaken. It was assumed that the results across lidocaine and articaine would be similar given they were already both soluble in water at the highest concentrations, and both excipients are used to solubilise drugs.

[0075] The chromatograms were compared across the original standards at the relevant concentrations and those with the cyclodextrins, and if relevant at the adjusted pH. The chromatograms of the lidocaine HCI at increasing concentrations were also compared. It was observed that the chromatograms of the original standards, the cyclodextrin formulations and the adjusted pH formulations were the same, barring changes in retention time due to changes in buffer.

[0076] Incremental increase in area under the curve were observed with increasing concentrations of API and cyclodextrin.

[0077] Significantly, these two observations taken together suggest that the compound and cyclodextrin formulations are soluble at increasing concentration even when the pH is adjusted thereby making high concentration aqueous formulations suitable for their intended purpose (lymphatic delivery avoiding plasma concentrations of 4.7pg / ml when delivered as an injectable).

[0078] Taken together this suggests that lidocaine and articaine HCI are soluble at high concentrations with 1:1 molar ratios of cyclodextrins at formulation pHs that are physiologically relevant.

[0079] Lidocaine and articaine HCI are soluble at 200 mg / mL in water with high concentrations of HPBCD (~ 1000 mg / mL) and Captisol™ (~ 1552 mg / mL) at pH range around 5 - 6.9. Example 3 Lidocaine and articaine freebase studies Solubility and pH studies without excipients Materials • Lipophilic lidocaine (500 mg) 1M HCI • Lipophilic articaine (500 mg)1M HCI Method

[0080] The relevant lipophilic API was added to a radley tube and 5 mL of distilled water was added, which formed a milky suspension. 1M HCI was added until the suspension clarified into a solution and no more precipitate was observed. Results

[0081] ~ 2.8 mL of 1 M HCI was required to solubilise the lipophilic drugs. For lipophilic lidocaine, the pH of the resultant formulation was measured to be 1.41 and for lipophilic articaine, the pH was measured to be 1.68. Solubility and pH studies with cyclodextrins Materials

[0082] API b. Lipophilic articaine (1000 mg)

[0083] Stock solutions: a. HPBCD (200 mg / mL) b. Captisol (200 mg / mL) 5 Method

[0084] To 5 mL of the relevant stock solutions was added 1000 mg of either lipophilic lidocaine or lipophilic articaine to form a 20 % suspension. Subsequently 1M HCI was titrated in to 0.75 equivalents HCI, at which point the pH was taken and the formulation was visually inspected. Subsequently 1M HCI was titrated into 1 equivalent of HCI and the 10 pH was taken and the final formulation was visually inspected. Results

[0085] The results are tabulated in Tables 6a and 6b below: Table 6a 15 Excipients Lipophilic lidocaine (20 %) Initial formulation 0.75 eq HCI 1 eq. HCI HPBCD (20 %) Insoluble pH = 6.44 pH = 2.95** Cloudy emulsion Clear solution Captisol (20 %) Insoluble pH = 6.44 pH = 6.10 Some precipitate remaining Clear solution Table 6b Excipients Lipophilic articaine (20 %) Initial formulation 0.75 eq HCI 1 eq. HCI HPBCD (20 %) Insoluble pH = 6.53 Some precipitate remaining pH = 5.82 Clear solution Captisol (20 %) Insoluble pH = 6.60 Some precipitate remaining pH = 6.44 Clear solution

[0086] ** overshot the amount of HCI to add (titration error) Discussion and conclusions

[0087] It is possible to solubilise highly concentrated lipophilic lidocaine and articaine only if you adjust the pH of the solution to ~ pH 6.1 (equimolar HCI). This means that ~3 % of the lipophilic lidocaine and ~ 4 % of the lipophilic articaine is available in the solution, 10 with the remainder being in the HCI salt form (calculated according the hendersen hasslebach equation with pH = 6.1 for lidocaine and pH = 6.44 for articaine solutions). Example 4

[0088] Formulations for stability testing were prepared as follows: 15

[0089] Materials were as set out in Table 7 below: Table 7 Reagent Quantity CAS# Lidocaine HCI monohydrate 4.24 g 6108-05-0 Articaine HCI 4g 23964-57-0 2- H y d roxy I propyl- betacyclodextrin 16g 128446-35-5 Sodium hydrogen carbonate (NaHCO3) 100 mg 144-55-8 Distilled H2O 100 mL 7732-18-5

[0090] 5 mL formulations containing 2.5%, 5 %, 10 % or 20 % articaine HCI or lidocaine HCI with 2.5 %, 5 %, 10 %, 20 % and 40 % 2-Hydroxylpropyl-beta-cyclodextrin (all percentages are w / v) were prepared from stock solutions. Preparation of Stock Solutions

[0091] Lidocaine HCI (400 mg / mL) 1) Take a clean 50 mL RBF on a balance and then add 4.24 g of Lidocaine HCI monohydrate 2) Add 10 mL of distilled water 3) Allow the solution to stir at 200 rpm until all the powder dissolves

[0092] Articaine HCI (400 mg / mL) 1) Take a clean 50 mL RBF on a balance and then add 4 g of Articaine HCI 2) Add 10 mL of distilled water 3) Allow the solution to stir at 200 rpm until all the powder dissolves

[0093] 2-Hydroxylpropyl-beta-cyclodextrin (800 mg / mL) 1. Take a clean 50 mL RBF on a balance and then add 16 g of 2-Hydroxylpropyl-beta-cyclodextrin 2. Add 20 mL of distilled water 3. Allow the solution to stir at 200 rpm until all the powder dissolves Preparation of 5 mL formulations 1. In clean 5 mL volumetric flasks, pipette the following volumes of the relevant stock solutions in table 2. 2. Add distilled water to all formulations to make up a final volume of 5 mL 3. Using a calibrated pH meter, measure the pH of all the formulations. 4. Add 3 - 5 mg of NaHCO3 to each formulation where necessary to adjust the final pH.

[0094] The formulations which underwent stability testing (Example 5 below) are set out in Tables 8 and 9 below. 10 Table 8 Formulation Lidocaine HCI (400 mg / mL) HPBCD (800 mg / mL) Initial pH Final pH 2.5 % Lidocaine HCI 2.5 % HPBCD 312.5 uL 156.25 uL 4.69 5.94 2.5 % Lidocaine HCI 5 % HPBCD 312.5 uL 312.5 uL 4.52 5.86 5 % Lidocaine HCI 5 % HPBCD 625 uL 312.5 uL 4.99 6.07 5 % Lidocaine HCI 10 % HPBCD 625 uL 625 uL 4.78 5.77 10 % Lidocaine HCI 10 % HPBCD 1.25 mL 625 uL 4.44 5.70 10 % Lidocaine HCI 20 % HPBCD 1.25 mL 1.25 mL 4.20 5.72 20 % Lidocaine HCI 20 % HPBCD 2.5 mL 1.25 mL 3.86 5.50 20 % Lidocaine HCI 40 % HPBCD 2.5 mL 2.5 mL 3.90 6.19 Table 9 Formulation Articaine HCI (400 mg / mL HPBCD (800 mg / mL) Initial pH Final pH 2.5 % Articaine HCI 2.5 % HPBCD 312.5 uL 156.25 uL 4.93 5.66 2.5 % Articaine HCI 5 % HPBCD 312.5 uL 312.5 uL 4.62 6.13 5 % Articaine HCI 5 % HPBCD 625 uL 312.5 uL 4.40 5.84 5 % Articaine HCI 10 % HPBCD 625 uL 625 uL 4.51 5.74 10 % Articaine HCI 10 % HPBCD 1.25 mL 625 uL 4.51 5.74 Example 5 Lidocaine and Articaine HCI salt with hydroxypropyl beta cyclodextrin stability studies 5

[0095] This example aimed to demonstrate the stability of 2.5%, 5 %, 10 % or 20 % Articaine HCI or lidocaine HCI with 2.5 %, 5 %, 10 %, 20 % and 40 % 2-Hydroxylpropyl-beta-cyclodextrin (HPBCD) (all percentages are w / v). Materials 10

[0096] The materials are set out in the Tables 10 and 11 below: Lidocaine HCI formulations PH 2.5 % Lidocaine HCI, 2.5 % HPBCD 5.94 2.5 % Lidocaine HCI, 5 % HPBCD 5.86 5 % Lidocaine HCI, 5 % HPBCD 6.07 5 % Lidocaine HCI, 10 % HPBCD 5.77 10 % Lidocaine HCI, 10 % HPBCD 5.70 10 % Lidocaine HCI, 20 % HPBCD 5.72 20 % Lidocaine HCI, 20 % HPBCD 5.50 20 % Lidocaine HCI, 40 % HPBCD 6.19 Table 11 Articaine HCL formulations pH 2.5 % Articaine HCI, 2.5 % HPBCD 5.66 2.5 % Articaine HCI, 5 % HPBCD 6.13 5 % Articaine HCI, 5 % HPBCD 5.84 5 % Articaine HCI, 10 % HPBCD 5.74 10 % Articaine HCI, 10 % HPBCD 5.74 10 % Articaine HCI, 20 % HPBCD 5.80 20 % Articaine HCI, 20 % HPBCD 5.70 20 % Articaine HCI, 40 % HPBCD 6.14 Instruments and methods 5   

[0097] HPLC Instrument: Waters ARC HPLC with a Waters 2998 PDA detector Column: Luna 5 pm C18(2) 100 A 50 x 4.6 mm Guard Column: Phenomenex Security Guard AJO-6071 Wavelength of analysis: 220 nm

[0098] The HPLC was run using a solvent system as set out in Table 12 below and included: Solvent A: 30 mM phosphate buffer (pH = 6.2), Solvent D: 70 % MeOH + 30 % 10 mM phosphate buffer. Table 12. Time Flow %A %D 1 Initial 1.00 67.0 33.0 2 9.00 1.00 5.0 95.0 3 11.00 1.00 5.0 95.0 4 11.25 1.00 67.0 33.0 5 12.50 1.00 67.0 33.0 6 12.75 0.00 67.0 33.0 Methods

[0099] Timed aliquots of the relevant formulations at 0, 25 and 60 °C were taken at 4 days, 1 week,2 weeks and 4 weeks.

[00100] Reaction rates double for every 10 °C increase (~ x 16) therefore for the 60 °C sample, 4 days = 9 weeks (2 months), 1 week = 16 weeks (4 months), 2 weeks = 32 weeks (8 months), and 4 weeks =64 weeks (16 months). Results

[00101] The chromatograms, as exemplified by Figs 7a and 7b, across the formulations from the 2 week time point, displayed no changes when compared to time zero. Therefore, from the 60 °C samples, even at the highest concentration, the formulations are stable up to 16months. Conclusion

[00102] The formulations demonstrate the suitability of the formulations for administration by subcutaneous injection as indicated. Example 6 Lidocaine and articaine formulations autoclave stability trial

[00103] Instrumentsand methods

[00104] HPLC Instrument: Waters ARC HPLC with a Waters 2998 PDA detector Column: Luna 5 pm C18(2) 100 A 50 x 4.6 mm Guard Column: Phenomenex Security Guard AJO-6071 Wavelength of analysis: 220 nm

[00105] The HPLC was run using a solvent system as set out in Table 13 below and included: • Solvent A: 30 mM phosphate buffer (pH = 6-6.25), • Solvent D = 75 % MeOH + 25 % 10 mM phosphate Table 13 Time Flow %A %D 1 Initial 1.00 67.0 33.0 2 9.00 1.00 5.0 95.0 3 11.00 1.00 5.0 95.0 4 11.25 1.00 67.0 33.0 5 12.50 1.00 67.0 33.0 6 12.75 0.00 67.0 33.0

[00106] Autoclaving was with an Iconclave (steam sterilizer) Instrument: Iconclave steam sterilizer STE-8-D Program: Liquid Temperature: 121 °C (max temp = 124 °C) Pressure: 110 kpa Holding time: 30 min Stability criteria

[00107] If there are no additional peaks in the chromatogram, the formulation is stable.

[00108] The Formulations comprised the compounds identified in Table 14 below: Table 14 Reagent Quantity CAS# Lidocaine HCI monohydrate 1590 mg 6108-05-0 Articaine HCI 750 mg 23964-57-0 2-Hydroxylpropyl-beta-cyclodextrin 1500 mg 128446-35-5 Sodium hydrogen carbonate (NaHCOs) 20 mg 144-55-8 Distilled H2O 100 mL 7732-18-5 Method

[00109] Preparation of stock solutions Lidocaine HCI (150 mg / mL or 15 %) To a clean 10 mL volumetric flask on a balance was added 1590 mg of Lidocaine HCI monohydrate. Distilled water was added up to the mark and the flask was sonicated until all the powder dissolved. Articaine HCI (150 mg / mL or 15 %) To a clean 5 mL volumetric flask on a balance was added 1590 mg of Lidocaine HCI monohydrate. Distilled water was added up to the mark and the flask was sonicated until all the powder dissolved. 2-Hydroxylpropyl-beta-cyclodextrin (300 mg / mL or 30 %) To a clean 5 mL volumetric flask on a balance was added 1500 mg of 2-Hydroxylpropyl-beta-cyclodextrin. Distilled water was added up to the mark and the flask was sonicated until all the powder dissolved.

[00110] Preparation of sterile formulations (2 mL total) 1. In clean 3 mL vials, the following volumes of the relevant stock solutions were pipetted (table 15). 2. Where necessary, distilled water was added. 3. Using a calibrated pH meter, the pH of all the formulations was measured 4. 1 - 3 mg of NaHCO3 was added to each formulation where necessary to adjust to the final pH 5. The formulations were transferred to appropriate vials and crimped with a rubber lid and a foil lid. 6. The vials were transferred to the iconoclave steam sterilizer and were sterilized at 121 °C for 30 minutes using the liquid program 5 Table 15a Formulation Lidocaine HCI (15%) HPBCD (30 %) Distilled water Initial pH Final pH 7.5 % Lidocaine HCI 7.5 % HPBCD 1 mL 0.5 mL 0.5 mL 5.38 6.28 7.5 % Lidocaine HCI 15 % HPBCD 1 mL 1 mL 0 mL 5.02 6.64 Table 15b Formulation Articaine HCI (400 mg / mL HPBCD (800 mg / mL) Distilled water Initial pH Final pH 10 7.5 % Articaine HCI 7.5 % HPBCD 1 mL 0.5 mL 0.5 mL 5.31 6.51 7.5 % Articaine HCI 15 % HPBCD 1 mL 1 mL 0 mL 5.24 Results

[00111] The chromatograms are shown in Figs 8a-8d. Conclusions

[00112] Both Lidocaine HCL and Articaine HCI did not degrade under sterilization conditions at 5 the pH stated.

Claims

1. An inclusion complex comprising:i) an active pharmaceutical ingredient (API) which is a P2X7 receptor antagonist; andii) a cyclodextrin;for use in the treatment of an autoimmune disease or a condition in which an immune response caused by a disease or infection causes hyperinflammation wherein the inclusion complex is presented for administration to the lymphoid system.

2. An inclusion complex as claimed in claim 1 wherein the autoimmune disease or a condition in which an immune response caused by a disease or infection causes hyperinflammation is a post viral condition.

3. An inclusion complex as claimed in claim 2 wherein the post viral condition is Long COVID.

4. An inclusion complex as claimed in any of the preceding claims wherein the inclusion complex is presented for administration by way of intradermal, subdermal or subcutaneous delivery.

5. An inclusion complex as claimed in claim 4 which is presented in a pen injector.

6. An inclusion complex as claimed in claim 5 wherein the pen injector comprises from 0.5 to 3.0 ml of a solution of the inclusion complex.

7. An inclusion complex as claimed in claim 6 wherein the pen injector comprises the solution of the inclusion complex at a concentration of at least 1%.

8. An inclusion complex as claimed in claim 4 which is presented in an infusion pump.

9. An inclusion complex as claimed in claim 8 wherein the infusion pump comprises from 5 ml to 1000 ml of a solution of the inclusion complex.

10. An inclusion complex as claimed in claim 9 wherein the infusion pump comprises the solution of the inclusion complex at a concentration of at least 0.5%.

11. An inclusion complex as claimed in any of the preceding claims wherein the API is Lidocaine or a salt thereof, or Articaine or a salt thereof.

12. An inclusion complex as claimed in claim 11 which is a base.

13. An inclusion complex as claimed in claim 11 which is a salt.

14. An inclusion complex as claimed in claim 13 which is the hydrochloride salt.

15. An inclusion complex as claimed in any of the preceding claims wherein the cyclodextrin is a p cyclodextrin.

16. An inclusion complex as claimed in claim 15 which is HP p cyclodextrin.

17. An inclusion complex as claimed in any of the preceding claims further comprising a pH modifier.

18. An inclusion complex as claimed in claim 17 wherein the pH modifier is an alkali.

19. An inclusion complex as claimed in claim 18 wherein the pH modifier is sodium bicarbonate.

20. A formulation comprising an inclusion complex of:i) Lidocaine HCI or Articaine HCI; andii) Hydroxypropylated p cyclodextrin;together withii) a pH modifier; andiv) waterwhereinthe pH is between 5 and 7.4,iii) and ii) are present in a ratio of between 1:1 and 1:2; andthe concentration of i) is between 2.5% and 20% weight / volume.

21. A formulation as claimed in claim 20 with a shelf life of at least 32 weeks based on accelerated stability testing at 60° C.

22. A formulation as claimed in claim 20 or 21 which is presented for subcutaneous delivery.

23. A formulation as claimed in any of claims 22 which is presented as a small volume injectable with a volume of 3ml or less.

24. A formulation as claimed in any of claims 22 which is presented for infusion by way of a pump over 1 to 30 days.

25. A formulation as claimed in any of claims 20 to 24 which is presented to deliver a unit dose from 0.5mg / kg to 12mg / kg of articaine or lidocaine to a patient over a 24 hour period, which dose results in a peak plasma level of below 4.7pg / ml for lidocaine.

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