ZA200300364B - Enhancement of the action of central and peripheral nervous system agents. - Google Patents

Description

ENHANCEMENT OF THE ACTION OF CENTRAL AND PERIPHERAL

NERVOUS SYSTEM AGENTS

FIELD OF THE INVENTION

This invention relates to pharmaceutical preparations (which expression is herein intended to include veterinary preparations) for use in treating afflictions of the animal body (which expression is herein intended to include the human body) affecting the central and/or peripheral nervous system of an animal in need of treatment.

BACKGROUND TO THE INVENTION

In EP 93912877.3 and US patent 5,633,284 and their equivalents the applicant disclosed that dermatological or topical compositions comprising the combination of nitrous oxide [N,O] and at least one fatty acid, or lower alkyl ester thereof, in a dermatologically acceptable carrier medium, are useful in the treatment of a variety of skin, muscle and joint disorders. It further disclosed therein that such combinations may beneficially also include additional active ingredients. The following active ingredients are specifically mentioned in this regard: coal tar solution, collagen, nicotinamide, nicotinic acid, lanolin, vitamin E, methyl salicylate, arnica and H1-antagonist antihistamines of which only diphenhydramine chloride is specifically mentioned.

No agent known for having an effect on the central or peripheral nervous system, was amongst the active ingredients specifically mentioned in these patents. Mention was made therein that coal tar solution (also known as

Liquor Picis Carbonis) may be used as a supplementary active ingredient and that the resultant preparation is suitable for use in the treatment, inter alia, of psoriasis, eczemaceous conditions and dermatitis. It is also disclosed in these patents that, in addition to the coal tar solution the composition may also contain an HIl-antagonist antihistamine (e.g. diphenhydramine hydrochloride) and that such a preparation may beneficially be used in the treatment of atopic and allergic conditions manifesting in skin irritations such as eczema and dermatitis. The aforementioned conditions have since the date of the above patents come to be regarded by some writers on the topic as manifestations in the skin of underlying disorders which have or include a neurological, or immunological, or some even suggest a neuro-immunological cause. These patents however do not refer to that explanation. It further gives no hint that the effects obtained are the result of any form of systemic operation of any of the components of the formulation. Coal tar liquid is not 40 known to be an agent acting on the central nervous system. Insofar as these patents may be seen to proffer any explanation at all for the results obtained, which is not what the applicant contends for, it is suggested that such explanation would, within the context of the disclosures therein, point to a local effect of soothing irritation and of repairing of skin and associated tissue damage as a result of the conditions mentioned therein. These are psoriasis, shingles, fever blisters, chicken pox, acne, chilblains, eczema, chloasmas, alopecia, dermatitis, ringworm and burn wounds.

In WO97/17978 and US patent 6,221,377 and their corresponding applications and patents the present applicant disclosed that the action of analgesic, anti-inflammatory and anti-pyretic drugs may be enhanced by administering such drugs in conjunction with a medium which comprises nitrous oxide and at least one long chain fatty acid selected from the group consisting of oleic acid, linoleic acid, alpha-linolenic acid, gamma linolenic acid, arachidonic acid, and any of the C; to Cg alkyl esters of such long chain fatty acids, mixtures of such acids and, mixtures of such esters. The medium may comprise the mixture known as Vitamin F Ethyl Ester and may optionally further comprise eicosapentaenoic acid [C20:5w3] and decosahexaenoic acid [C22:6w3].

While these applications do disclose a systemic effect in that the formulations are, for example, topically applied or orally administered to have an effect, “ say, in an affected joint or muscle, the specification again fails to disclose the mode or route of transport of the active ingredient from its site of administration to its locus of effect, and speculation in this regard would probably be based on ex post facto hindsight.

It has now surprisingly been found that the aforesaid medium has the unexpected property that it displays a remarkable ability to enhance the action of known agents affecting the central and/or peripheral nervous system, such known agents being other than the group which consists of coal tar solution, H1 antagonist antihistamines, the analgesics, the anti- inflammatories and the antipyretics. These agents will hereinafter collectively be referred to as “"CPNS agents” which term is for purposes of this specification intended to embrace those biologically active compounds which perform their action on the central or peripheral nervous system of the human or animal body, but to exclude recognised anti-inflammatory, analgesic and antipyretic substances and also excluding coal tar solution and

H1 agonist antihistamines. Subject to these exclusions it therefore includes the compounds which fall within Class 1 of the Pharmacological Classification 40 set out as part of Regulation 5(1) of the General Regulations made under

The Medicines and Related Substances Control Act, Act 101 of 1965, and the active ingredients of all products falling within Class 1 of the pharmacological classification currently employed in the Monthly Index of Medical Specialities ("MIMS") published by Times Media in South Africa, but excluding the analgesic, anti-inflammatory and anti-pyretic compounds which falls within the above two partially overlapping classes. Examples of some of the compounds falling within the group is described in greater detail below.

The exclusion of coal tar solution and H1-antagonist antihistamines, and of anti-inflammatories, analgesics and antipyretics from the ambit of the present invention is introduced without thereby conceding that the aforementioned patents and applications contain any disclosure of any CPNS agent properties of such excluded compounds, or that such properties are obvious in the light of the disclosures in such patents or applications. Such inferences are specifically denied. The exclusion is introduced simply to avoid what is anticipated to be a potential obstacle to the grant of a patent in respect of a part of the subject matter which part in itself is not considered worth contesting during examination as it might unduly delay the implementation in practice of the significant features of the present invention. 1t is expected that the remaining bulk of the subject matter of the present invention will greatly contribute to the accessibility of medicines for the treatment of a large range of ailments.

It has been pointed out in W097/17978 referred to above that nitrous oxide

Is a natural gas which is also produced synthetically, that it is also known by the trivial name "laughing gas”, and that it has been in use for many years as an inhalation anaesthetic and analgesic, particularly in dentistry.

It was further stated that nitrous oxide has been reported to have a synergistic or potentiating effect on halothane and other gaseous anaesthetics [See Goodman & Gilman's The Pharmacological Basis of

Therapeutics 8th Ed. 1990 pp. 298-300].

Since such known synergism or potentiation is based on the use of nitrous oxide administered by inhalation, and since the use of nitrous oxide on its own as an anaesthetic and analgesic has likewise been in the form of an inhalation agent, the use of nitrous oxide for all these purposes has been confined to hospitalised patients or, at best, to treatments carried out by medical practitioners in their consulting rooms, or treatments carried out by or under supervision of a nurse in charge of a home-care patient.

Nitrous oxide is known to be soluble in water and it has been reported that at 20°C and 2 atm pressure one litre of the gas dissolves in 1,5 litres of 40 water, see The Merck Index 10th Ed. p. 6499.

Nitrous oxide is also known for its use as a propellant gas, mainly as a substitute for propellant gases such as chlorofluorocarbons, and more particularly to produce a food product mousse such as whipped cream or a » 4 chocolate mousse or quick-breaking foams for hair treatment preparations.

See in this regard U.K. Patent 1033299, U.K. Patent 1105919 and European

Patent Application EPA-0123827. None of these prior publications suggests that the nitrous oxide gas plays any other role than a physical one, i.e. to expand on being depressurised and thereby to create a mousse or a foam.

In fact it is typically regarded as an inert in these applications and useful due to the fact that it is colourless, odourless and tasteless but soluble in water and oils.

There appears to be no suggestion in the literature, other than the applicant's own prior patents and patent applications referred to above, that aqueous solutions of nitrous oxide might have any effect on man or animals.

As far as the present inventors know it has also never been suggested that nitrous oxide may be used in conjunction with the CPNS to enhance the action of such agent or to serve as a carrier for such agent.

It is known in the pharmaceutical field to formulate active ingredients in so- called liposomal formulations. Unlike the present invention which is based on formulations containing long chain fatty acids and esters thereof the liposomes are based on a clearly distinguishable group of compounds namely the phospholipids, and generally also contain cholesterol as a stabilising agent and may further contain lisolecithin. These compounds or classes form no part of the present invention and, in case it is necessary to do so, are specifically excluded from the group of long chain fatty acids and derivatives thereof incorporated in the method or formulation of the invention.

OBJECT OF THE INVENTION

It is an object of the present invention to provide a method of enhancing the action of CPNS agents and to provide pharmaceutical preparations of such agents which preparations have enhanced action compared to the action of known formulations containing the same agents.

STATEMENTS OF THE INVENTION

According to the present invention there is provided a method of enhancing the action of a pharmaceutical agent selected from the group consisting of the CPNS agents selected from the group of compounds acting on the central or peripheral nervous system, but excluding coal tar solution and Hi- antagonist antihistamines and also excluding anti-inflammatory, analgesic and antipyretic agents, comprising the step of formulating the agent with an 40 administration medium which is characterised in that it comprises a solution of nitrous oxide gas in a pharmaceutically acceptable carrier solvent . for the gas and which administration medium Includes at least one fatty acid or ester or other suitable derivative thereof selected from the group consisting of oleic acid, linoleic acid, alpha-linolenic acid, gamma-linolenic acid, arachidonic acid, eicosapentaenoic acid [C20: 5w3], decosahexaenoic acid (C22: 603]. ricinoleic acid, gnd derivatives thereof selected from the group consisting of the C1-ta C6 alkyl esters thereof, the glycerol-polyethylene 5 glycol esters rest og the reaction product of hydrogenated natural oils composed largely of ricifoleic acid based oils such as castor oil with ethylene oxide. -

According to a further aspect of the present invention there is provided a pharmaceutical preparation comprising a pharmaceutical agent which is a

CPNS agent selected from the group of compounds acting on the central or peripheral nervous system, but excluding coal tar solution and H1-antagonist antihistamines and also excluding anti-inflammatory, analgesic and antipyretic agents, comprising the step of formulating the agent with an administration medium which is characterised in that it comprises a solution of nitrous oxide gas in a pharmaceutically acceptable carrier solvent for the gas and which administration medium includes at least one fatty acid or ester or other suitable derivative thereof selected from the group consisting of oleic acid, linoleic acid, alpha-linolenic acid, gamma-linolenic acid, arachidonic acid, eicosapentaenoic acid [C20: 5w3], decosahexaenoic acid } [C22: 6w3], ricinoleic acid and derivatives thereof selected from the group consisting of the C1 to C6 alkyl esters thereof, the glycerol-polyethylene glycol esters thereof and the reaction product of hydrogenated natural oils composed largely of ricinoleic acid based oils such as castor oil with ethylene oxide. :

The administration medium may further include eicosapentaenoic acid [C20:5w3] and/or decosahexaenoic acid [C22:6w3] as additional long chain fatty acids.

The carrier solvent for the nitrous oxide gas may be water or any of the pharmaceutically acceptable alcohols, ethers, oils or polymers such as, for example a polyethylene glycol. The oil may be organic or mineral oil. The organic oil may be an essential oil based on long chain fatty acids having between 14 and 22 carbon atoms in the fatty acid. The oil may also be of either natural or synthetic origin and, if of natural origin, it may be either plant oil or animal oil. As plant oils those rich in gamma linolenic acid [GLA] are preferred and as animal oil dairy cream may be used. 40 In the preferred form of the invention the solution is an aqueous solution saturated with nitrous oxide.

The water is preferably de-ionised water and free of microbes.

When the CPNS agent to be enhanced by means of the nitrous oxide is in a liquid formulation, such formulation may incorporate as part of the administration medium water or acceptable other liquid solvent into which the nitrous oxide and fatty acid or ester thereof had been dissolved or suspended or emulsified along with the CPNS agent to be enhanced by being formulated therewith. When the formulation containing the CPNS agent to be enhanced by means of the nitrous oxide is to be in a liquid (including an encapsulated liquid) presentation for oral administration or in a nasal or bronchial or pulmonary spray or in the form of an injectable formulation, such formulation may incorporate, as part of the administration medium, water or acceptable other liquid into which the nitrous oxide is dissolved and in which the fatty acid or ester thereof is either dissolved or suspended or emulsified along with the CPNS agent to be enhanced by being formulated therewith.

Likewise, where the CPNS agent is to be administered to the patient by being applied as a topical, buccal or vaginal cream or ointment, or as a cutaneous patch, or in the form of micro-depots, or as an intravenous, intramuscular or subcutaneous injection, or as a suppository, the formulation used in making up such cream, ointment, patch, depots or injectable formulation or suppository may incorporate, along with the CPNS agent to be enhanced, a quantity of water or other liquid containing, and preferably saturated with, “Ritrous oxide, the long chain fatty acid or ester thereof and a CPNS agent conjugated therewith, and, further, such additional excipients and carriers as are conventionally used in the pharmaceutical trade in making up such dosage forms.

The carrier solvent for the nitrous oxide gas may thus be essentially non- 2qucous_and. composed. of the at least one fatty acid or ester thereof elected from the group consisting of oleic” 4€id; ifiol&ic 5¢id; alpha-linolenic acid, gamma-linolenic acid, arachidonic acid, eicosapentaenoic acid [C20: 5w3], decosahexaenocic acid [C22: 6w3], ricinoleic acid and derivatives thereof selected from the group consisting of the Ci to C6 alkyl “esters thereof, the glycerol-polyethylene glycol esters thereof and the reaction product of hydrogenated natural oils composed largely of ricinoleic acid based oils with ethylene oxide, required to be part of the formulation.

The essential fatty acid, or ester thereof, component of the composition preferably comprises a mixture of esters of the fatty acids listed above.

Thus, in the most preferred form of the invention the fatty acid component 40 of the composition is constituted by the complex known as Vitamin F and in this regard it is preferred to make use of the ester form of Vitamin F known as Vitamin F Ethyl Ester. This product is commercially available under the trade description of Vitamin F Ethyl Ester CLR 110 000 Sh.L. U./g from CLR

Chemicals Laboratorium Dr.Kurt Richter GmbH of Berlin, Germany. The typical fatty acid distribution of this product is as follows: <Ce : 0

Co : 8,3%

Cis vo. 3,5%

Cig1 21,7%

Cis : 34,8% :

Cigs . 28,0% >Cyg 1,6% unknown: 2,1%

It is further preferred to add to the formulation the long chain fatty acids known as eicosapentaenoic acid [C20:5w3] and decosahexaenoic acid [C22:6w3]. Such a product combination is available from Roche Lipid

Technology under the trade name "Ropufa '30' n-3 oil".

It has been found by microscopic studies that the formulation of active agents with a medium as herein described gives rise to the formation of minute, generally spherical bodies, in which the active ingredient is contained in a stable form and from which it is delivered at the site of action.

The CPNS agent utilised in the method or formulation according to the present invention may comprise any one or more of the vast spectrum of

CPNS agents as herein defined.

From amongst the CPNS agents falling within the scope of the definition set out above this invention is particularly concerned with the following sub- classes of compounds:

Central nervous system stimulants including central analeptics, psycho analeptics (antidepressants), respiratory stimulants, hallucinogenic medicines;

Central nervous system depressants including anaesthetics, sedatives, hypnotics, barbiturates, non-barbiturates, anticonvulsants, (including anti-epileptics), tranquillisers (including phenothiazines and their derivatives, rauwolfia, diphenylmethane and its derivatives, alkyl diols and their derivatives), centrally acting muscle relaxants;

Local anaesthetics;

Medicines affecting autonomic functions including adrenomimetics 40 (sympathomimetics), adrenolytics (sympatholytics), cholinomimetics (cholinergics), cholinolytics (anticholinergics) (including anti-Parkinsonism preparations), Ganglion blockers, anti-emetics and anti-vertigo preparations,

decongestants, -hydroxytryptamine (serotonin) and serotonin antagonists, and anti-Alzheimers agents. . The invention has not yet been demonstrated by empirical work to be applicable to all the agents or classes of agents referred to herein. However in respect of such CPNS agents which have already been formulated with the aforementioned administration medium of the invention, and evaluated by different methods for the anticipated enhancement of action, no negative result has as yet been observed despite the chemical diversity of the CPNS agents which has been investigated. The applicant thus confidently expects on the basis of these preliminary observations that the invention will find general application across the entire spectrum of CPNS agents embraced by these terms as herein defined and of which some examples are set out herein.

It is part of the applicant's present postulations by which it seeks to find an understanding of the invention and to which it does not wish to be bound at this stage, that while the administration medium of the present invention serves to transport the CPNS agent formulated therewith most efficiently through the human or animal body, that medium also plays an important role in transferring, by an as yet unexplained mechanism, the CPNS agent through the membranes of and into the cells thereby to cause an effective

CPNS intercellular and / or intracellular concentration of the agent rapidly to be achieved, and to be maintained.

It is in this respect that the applicant believes that the present invention will find general application despite the vast list of agents mentioned below. The following list sets out examples of some of the specific CPNS agents with : which this invention is concerned and which will now be identified with reference to the broad classes in which they fall and, in some cases, also with reference the respective indications for which such agents are indicated

The CPNS agents with which the invention is particularly concerned are

A. the Central Nervous System Stimulants consisting of i. the following Central Analeptics:

Amphetamine, Dextroamphetamine, Methamphetamine,

Methylphenidate, Caffeine, Caffeine citrated, Caffeine and Sodium Benzoate, Clomipramine, Desipramine,

Ephedrine, Imipramine, Pemoline, Protryptiline, 40 ii. the following Psycho Analeptics (antidepressants): a. the Tricyclic Antidepressants being: ’

Amitryptyline, Amoxapine, Clomipramine,

Desipramine, Doxepin, Imipramine, Nortriptyline,

Protriptyline, Trimipramine,

b. the Monamine Oxidase Inhibitors being:

Isocarboxazid, Phenelzine, Tranylcypromine, c. Other Antidepressants being:

Burpopion, Fluoxetine, Fluvoxamine, Maprotiline,

Mitrazapine, Moclobemide, Nefazodone,

Paroxetine, Setraline, Trazodone, Venlafaxine, iii. The following Respiratory Stimulants (Bronchodilators):

Albuterol, Ephedrine, Ethylnorepinephrine,

Fenoterol, Isoproterenol, Metaproteronol,

Terbutaline, iv. The following Hallucinogenic medicines: a. the following Indoleamine hallucinogenics:

LSD, DMT, N,N-dimethylamine, Psilocybin, b. the following Phenethylamines:

Mescaline, Dimethoxymethylamphetamine (DOM), Methylenedioxyamphetamine (MDA), MDMA,

B. the Central nervous system depressants consisting of: i. The following anaesthetics:

Halothane, Isoflurane, Enflurane, Methoxyflurane,

Sevoflurane, Desflurane, Methohexital, Thiopental,

Etomidate, Ketamine, Propofol, iil. The following Sedatives and Hypnotics:

Alprazolam, Brotizolam, Chlordiazepoxide,

Clobazam, Clonazepam, Clorazepate,

Demoxepam, Diazepam, Estazolam, Flumazenil,

Flurazepam, Halazepam, Lorazepam, Midazolam,

Nitrazepam, Nordazepam, Oxazepam, Prazepam,

Quazepam, Temazepam, Traizolam, iii. the Barbiturates being:

Amobarbital, Aprobarbital, Butabarbital, Butalbital,

Mephobarbital, ~~ Methohexital, = Pentobarbital,

Phenobarbital, Secobarbital, Thiopental, iv. the Non-barbiturates being:

Buspirone, Chloral hydrate, Chlormezanone,

Diphenhydramine, Doxylamine, Ethchlovynol,

Ethinamate, Glutethemide, Hydroxyzine, 40 Meprobamate, Methotrimeprazine, Methyprylon,

Promethazine, Propiomazine, Propofol, Zolpidem,

Zolpicione, Paraldehyde, v. The Anticonvulsants, (including anti-epileptics) being:

7 10

Acetazolamide, Amobarbital, Carbamazepine, Clobazam, Clonazepam,

Clorazepate, Corticotropin, Diazepam, Divalproex,

Ethosuximate, Ethotoin, Felbamate, Fosphytoin,

Gabapentin, Lorazepam, Magnesium sulfate,

Mephenytoin, Mephobarbital, Metharbital,

Methsuximide, Nitrazepam, Paraldehyde,

Paramethadione, Pentobarbital, Phenacemide,

Phenobarbital, Phensuximide, Phenytoin,

Primidone, Secobarbital, Trimethadione, Valproate sodium, Valproic acid, vi. The following Tranquillisers (including phenothiazines and their derivatives, rauwolfia, diphenylmethane and its derivatives, alkyl diols and their derivatives) being: a. Phenothiazines and derivatives being;

Acetophenazine, Chlorpromazine,

Chlorprothixene, Flupenthixol, Fluphenazine,

Mesoridazine, Methotrimprazine, Pericyazine,

Perphenazine, Pipotiazine, Prochlorperazine,

Promazine, Thiopropazate, Thioproperazine,

Thioridazine, Thiothixene, Trifluoperazine,

Trifluoropromazine, b. Other Antipsychotics being:

Clozapine, Fluspirilene, Haloperidol, Loxapine,

Molindone, Olanzapine, Pimozide, Risperidone,

Lithium,

C. Centrally acting muscle relaxants consisting of:

Baclofen, Carisoprodol, Chlorphenesin, Chlorzoxazone,

Cyclobenzaprine, Dantrolene, Diazepam, Lorazepam,

Metaxalone, Methocarbamol, Orphenadrine, and Orphenadrine citrate, Phenytoin,

D. Local anaesthetics consisting of:

Articaine, Benzocaine, Bupivacaine, Chloroprocaine, Cocaine,

Diphenhydramine, ~~ Efidocaine, Lidocaine, Mepivacaine,

Pramoxine, Prilocaine, Procaine, Propoxycaine, and Procaine,

Proraracain, Ropivacaine, Tetracaine,

E. Medicines Affecting Autonomic Functions consisting of:

I. The Adrenomimetics (Sympathomimetics) consisting of: 40 : Phenylethylamine, Epinephrine, Norepinephrine,

Dopamine, Dobutamine, Colterol, Ethylnorepinephrine,

Isoproterenol, Isoetharine, Metaproterenol, Terbutaline,

Metaraminol, Clonidine, Phenylephrine, Tyramine,

Hydroxyamphetamine, Ritodrine, Prenalterol,

Methoxamine, Albuterol, Amphetamine, Methamphetamine, Benzphetamine,

Ephedrine, Phenylpropanolamine, = Mephentermine,

Phentermine, Fenfluramine, Propylhexedrine,

Diethylpropion, Phenmetrazine, Phendimetrazine, iil. The Adrenolytics (sympatholytics) consisting of:

Phenoxybenzamine and related Haloalkylamines,

Phentolamine, Prazosin, Terazosin, Doxazosin,

Trimazosin, Indoramine, Labetalol, Ketanserin, Urapidil,

Alfuzosin, Bunazosin, Tamsulosin, Yohimbine,

Propanolol, Metoprolol, Nadolol, Atenolol, Timolol,

Esmolol, Pindolol, Acebutolol, Labetalol, Bopindolol,

Oxprenolol, ~~ Penbutolol, Carvedilol, Medroxalol,

Bucindolol, Levubunolol (Betagan) glaucoma,

Metipranolol, Bisoprolol,Nebivolol, Betaxolol (Betoptic)

Glaucoma, iii. The Cholinomimetics (cholinergics) consisting of:

Acetylcholine, Metacholine, Carbachol, Betanechol,

Pilocarpine, Muscarine, Arecoline, Oxotremorine,

Ambenonium, Domperidone, Edrophonium,

Edrophonium & Atropine, Metoclopramide, Neostigmine,

Physostigmine, Pyridostigmine, : iv. The Cholinolytics (anticholinergics) (including anti-Parkinsonism preparations) consisting of:

Amantadine, Anisotropine, Atropine, Scopolamine and related Belladonna alkaloids, Ipratropiuii Bromide,

Benztropine, Biperidine, Chlorpromazine, Clidinium,

Dicyclomine, Diphenhydramine, Ethopropazine,

Glycopyroliate, Homatropine, Hyoscyamine,

Mepenzolate, Methantheline, Methoctramine,

Hexahydrosiladifenidol, Himbacine, Tripitamine,

Methscopolamine, Orphenadrine HCl, Pirenzepine,

Procyclidine, Propantheline, Scopolamine, Thioridazine,

Trihexyphenidyl, Carbidopa and Levodopa, Levodopa,

Pergolide, Selegiline, v. Ganglion blockers consisting of:

Hexamethonium, Trimethaphan, Mecamylamine, vi. Anti-emetics and Antivertigo preparations consisting of: 5-HT; Antagonists as Ondansetron, Granisetron,

Tropisetron, Dolasetron, D2/5-HT; Antagonist as 40 Metoclopramide, Trimethobezamide, D2 Antagonists as

Phenotiazines namely Chlorpromazine, Perphenazine,

Prochlorperazine, Promethazine, Thiethylperazine,

Triflupromazine, D2 Antagonists as Benzimidazole derivatives namely Domperidone, D2 Antagonists as

Butyrophenones namely Haloperidol, Droperidol, Corticosteroids as

Dexamethasone, Methylprednisolone, Cannabinoids as

Dronabinol, Nabilone, H; antagonists Diphenhydramine,

Meclizine, Cyclizine, Antimuscarinic agents as

Scopolamine, ~~ Benztropiane, Benzodiazepines as

Lorazepam, Alprazolam, Hy Antagonist as =; Dimenhydrinate, vii. Decongestants consisting of:

Oxymetazoline, Phenylephrine, Xylometazoline viii. -hydroxytryptamine (serotonin) and serotonin : antagonists consisting of a. 5-HT Agonists being:

Buspirone, ipsaperone, Sumatriptan, Cisapride, b. 5-HT Antagonists being:

Methysergide, Risperidone, Ketanserin,

Ondansetron,

C. 5-HT transport inhibitors being:

Fluoxetine, Sentraline,

F. Anti-Alzheimers agents consisting of:

Physostigmine, Tacrine and Lecithin in combination with

Tacrine.

An agent of specific relevance in this application is doxepin hydrochloride.

Doxepin HCI is one of a class of psychotherapeutic agents known as dibenzoxepin tricyclic compounds. Specifically, it is an isomeric mixture of 1-

Propanamine,3-dibenz[b,e]oxepin-1,1(6H)ylidene N,N-dimethyl- hydrochloride. In oral formulation it is useful as an antidepressant to relieve symptoms of depression and anxiety such as feelings of sadness, worthlessness, or guilt; loss of interest in daily activities; changes in appetite; tiredness; sleeping too much; insomnia, and thoughts of death or suicide.

Doxepin is also sometimes used to treat certain types of pain but it is not generally regarded as an analgesic in the ordinary sense of the word and has been described as one of a group of “adjuvant analgesics” along with other anti-depressants. In a topical formulation doxepin is known to be used as an anti-pruritic to relieve itching in patients with certain types of eczema. The applicant is unaware of any prior disclosure suggesting that doxepin may beneficially be used in a topical administration form for alleviating pain.

The applicant found that a potent topical formulation may be prepared 40 according to the invention by formulating doxipen with the medium as described.

It is accordingly an aspect of the present invention to provide a topical formulation, used either as a lotion or a cutaneous patch as described above in which doxepin is the active ingredient.

PRELIMINARY HYPOTHESES OF MECHANISM OF OPERATION

The mechanism by which the enhancement of action of CPNS drugs is achieved by the present invention, is currently under investigation. Some observations in this regard have been recorded above. In addition it is recorded that preliminary observations point to some additional possible explanations. The applicant again does not wish to be bound to any of the tentative explanations it may put forward at this time. It is recorded, however, that it would appear that the long chain fatty acids used in the formulation of the preparation according to the invention, or at least some of these components, form, during the manufacturing process of the medicinal formulation, very small spherical bodies, hereinafter referred to as “nanolipid vesicles”. These nanolipid vesicles have dynamic characteristics in respect of the encapsulation and subsequent delivery of compounds at predicted areas in cells and organisms where the optimal utilisation of these compounds occur with resultant maximised modes of actions.

The present model for the understanding of the invention is that the dynamic delivery characteristics of the nanolipid vesicles are utilised efficiently to transport compounds to locations where maintenance of optimal concentrations in the organisms or cells is beneficial in combating specific infective diseases. The cells in this application most probably concern neurons. The long chain fatty acids may contribute to the maintenance of the myelin sheath of the nervous system, being precursors of the sphingomeilin molecules. 30 .

These beneficial effects are believed to be attributable to the dynamic characteristics of the nanolipid vesicles. The current hypothesis is that these characteristics include: : 1. The structural characteristics of the formulation of the preparation:

Nitrous oxide and the unsaturated long chain fatty acids forming part of the administration medium are formulated by being mixed with 40 designated CPNS agents or compounds to form the nanolipid vesicles containing the compound or CPNS agent. Two important observations have been made in this regard:

I 14 a) It was found that when the unsaturated long chain fatty acids used are 20 carbons or more, the nanolipid vesicles form spherical structures with sub-compartments similar to those seen in a sponge.

These structures are stable and it is our belief that antibodies or other ligands would fit ideally in these sub-compartments so that the nanolipid vesicles bind to specific epitopes or receptors at the target cell surface. b) When unsaturated long chain fatty acids of 16 to 20 carbons are used, the form of the nanolipid vesicles is spherical with a dynamic field of moving autofluorescent particles surrounding the vesicles.

When nitrous oxide is omitted from the process the moving particles surrounding the nanolipid vesicles move erratically and asymmetrical movements are then detected.

It is believed that nitrous oxide is essential in stabilising the moving autofluorescent particles surrounding the nanolipid- vesicles, which is an essential characteristic to efficient compound delivery. 2. Stability:

The nanolipid vesicles appear to remain structurally intact after 24 months at room temperature. Any encapsulated active compounds remain encapsulated during this time. This stability feature is believed to be of substantial significance and one of the contributing factors for the enhancement observed. 3. Absence of cytotoxicity:

The nanolipid vesicles have no apparent cytotoxicity. When applied to cells in culture, at applicable concentrations they appear rather to have a beneficial effect on normal cell growth. 4, Targeting:

It has been observed that the nanolipid vesicles with unsaturated long chain fatty acids of 16 to 20 carbons, when added to cells in culture, concentrate around the mitochondria which are in the region of the 40 nuclear membrane. Nanolipid vesicles appear to display a natural affinity towards mictochondria. Furthermore mitochondria contain a specific transport mechanism for long chain fatty acids.

. h . 15

When the unsaturated fatty acids used are longer than 20 carbons, it is thought that the nanolipid vesicles target peroxisomes. It is known : that peroxisomes metabolise fatty acids containing more than 20 carbons.

In in vivo applications, the biodisposition of nanolipid vesicle- encapsulated compounds has been found to favour the liver and spleen.

Although the transport of normally readily diffusible compounds across the blood brain barrier is inhibited by the nanolipid vesicles, the nanolipid vesicles have been shown to deliver and release active compounds through the blood brain barrier to a greater extent than current commercial preparations, as will be shown for Bupicvicaine ( see

Example). The nanolipid vesicles may furthermore contribute to the bioavailability of orally administered conjugations of an active compound and the nanolipid vesicles, as was shown for antibiotic compounds, which is the subject of a separate patent application. In addition, the nanolipid : vesicle may contribute to the protection or stabilization of the active compound in the blood, especially in the case of peptides being used as active compound, where the compound is prone to digestion by proteases. 5. Mechanism of action: 5.1 Loading efficiency:

The high loading efficiency of nanolipid vesicles has been demonstrated by achieving a high degree of encapsulation of a wide range of active drugs. 5.2 Transport:

The nanolipid vesicles behave as a transport mechanism to carry molecules such as active compounds. 5.3 Release:

It has been shown that the nanolipid vesicles have very high delivery efficiencies. The high delivery efficiency relates to tissue penetration, cell adsorption, internalisation of nanolipid vesicles by cells, parasites and 40 bacteria, intra-cellular stability, and subsequent sub-cellular organelle delivery.

The result of high delivery efficiency is the release of active compounds not only at membrane sites, but also at intracellular sites including the /

nucleus of viable cells or microorganisms. The result is an enhanced efficacy of said active compound. The nanolipid vesicles and active compound appear to act synergistically in attaining enhanced efficacy. 6. Elasticity:

Confocal laser scanning microscopy (CLSM) shows that the conformation of nanolipid vesicles can be changed while in movement.

When the vesicles move through membranes, the conformation changes so that the intracellular nanolipid vesicles may have other morphological characteristics.

While moving through membranes the nanolipid vesicles ‘feed’ the membranes with unsaturated long chain fatty acids which in its turn will have a positive effect on membrane bound processes. This process has a positive effect on the metabolism of the cell and thus the survival of the cells. 7. Dynamic inter-lipid vesicle relationships:

It has been shown that vesicle inter-lipid relationships do exist. The lipid vesicles can interchange the compounds they respectively carry.

They can also combine to resize themselves continuously without detriment to their stability. The inter-lipid relationship is also revealed when moving through the cellular membrane.

These interactive membrane characteristics make the movement of the vesicles through the cells optimal.

Although inter-relationships of the dynamic nanolipid vesicles are continuously present, it has also been shown that the particles are stable in blood and body fluids for up to 5 hours.

EXAMPLES OF THE INVENTION

Without thereby limiting the scope of the invention some examples will now be described to illustrate the invention. Two preparations which do not form 40 part of the claimed subject matter of this application, being preparations first disclosed in the applicant's own prior patents referred to above, are first restated.

PREPARATION 1

» L 17

Preparing an aqueous nitrous oxide solution

A pressure vessel is charged to its operating volume with water at 20°C [ambient temperature]. The vessel is connected to a supply of nitrous oxide via a flow control valve and pressure regulator. The closed vessel is supplied with nitrous oxide at a pressure of 2 bar for a period of 48 hours, it having been determined that at the aforementioned temperature the water is saturated with nitrous oxide over such period of time under the above- mentioned pressure.

A resultant solution is bottled as stock solution for use in the formulations and applications set out below.

PREPARATION 2

Preparation of an aqueous nitrous oxide/Vitamin F emulsion 30g Vitamin F ethyl ester as identified and described above was mixed with 10g chremaphor, 2,2g methyl paraben, 0,08g butyl hydroxyanisole, 0,23g butyl hydroxytoluene with stirring at 80°C.

Into 942,5g of the stock nitrous oxide solution was dissolved 2,5g sodium propyl paraben and 2,5g Germall 115 [Imidurea] with stirring at room temperature.

The oily composition first described was emulsified into the aqueous solution with stirring to constitute a stock nitrous oxide/Vitamin F emulsion. It is herein referred to as the “nanolipid-vesicle” formulation. eee eee

Preparation 3

Injectable solution of active in an injectable solution, containing nitrous oxide in carrier formulation.

The manufacturing process for producing an injectable formulation of an active agent according to the invention will now be described with reference to the manufacture of a medicament containing Bupivacaine as active ingredient

Preparation X was made up according to the following protocol: a Ss

Step 1. Weigh off the 5469 of Bupivicaine HCl and add to the pot. Mix 40 thoroughly with N,O-saturated water until the active compound is completely dissolved.

cT | 18

Step 2. Weigh off and add together the Poloxyl hydrogenated castor oil __ 1,023Kg, Vitamin F ethyl ester 3.012Kg, into mixing pot'Z and heat to approximately 70°C until all the oil has melted.

Step 3: Weigh off and add the Methyl paraben 214g and the Butylated hydroxytoluene 36g to mixing pot 2, in the respective order, while continuously mixing ensuring each solid is dissolved before adding the next while still maintaining the temperature at 70°C.

Step 4: Combine the contents of Step 1 and Step 3 whilst stirring during addition and continue stirring until the phases are well and truly mixed. Determine and adjust the pH to near physiological pH if necessary.

Step 5: Sonicate and check vesicle size.

Step 6: Sterilise by filtration and pack into amber glass ampoules or vials.

Preparation 4 - eo

Preparation of a typical formulation having a non-aqueous solution of nitrous oxide in carrier formulation. __

The manufacturing process for producing a non-aqueous formulation of an

CPNS agent according to the invention is based on the principles and ratios of ingredient described with reference to the manufacture of a medicament containing for example Phenythoin Na as active ingredient

Preparation Y was made up based on the following protocol:

Step 1. Weigh of the applicable weight of Phenytoin Na for the purpose required, i.e. age of patients, severity of condition. Reduce the particle size to less than 60um.

Step 2. Weigh off and add together the Poloxyl hydrogenated-easter oil to a final concentration of 11.5% (w/w) Vitamin F ethyl ester to a final concentration of 23.5% (w/w) and Polyethylene glycol 400 to a final concentration of 12% (w/w) into mixing pot 2 and heat to approximately 40°C until all the oil has melted. di-a-Tocopherol may be added depending on the physico-chemical characteristics of the active compound, the rate of 40 release and period of release needed, Eicosapentaenoic acid and/or decosahexaenoic acid may be added at this step.

Step 2. Gas the oil mixture with nitrous oxide for 3 hours at 2 bar in the

Staiticss sted pressure vest I The rac tor ours 2 2 bar in the above. :

oo 19

Step 4: Transfer the gased mixture to mixing pot 1 and heat to approximately 70°C .

Step 5: Weigh off and add the Methyl paraben to a final volume of 0.5% and the Butylated hydroxytoluene 0.05% to mixing pot 1, while continuously mixing ensuring each solid is dissolved before adding the next while still maintaining the temperature at 70°C.

Step 6: Remove from the heat and allow to cool down to approximately 40

Step 7: Add the required amount of Phenytoin Na stepwise while continuously mixing.

Step 8: Gas the mixture from step 7 with nitrous oxide at 20kPa for 30 minutes with mixing until the mixture has reached room temperature.

The Phenytoin Na Preparation prepared as set out above was encapsulated in soft gel capsules in the manner well known in the pharmaceutical trade as oral capsules for use as described below.

J I

EXAMPLE 1

PREPARATION OF TOPICAL FORMULATIONS OF DOXEPIN

HYDROCHLORIDE, LIDOCAINE HYDROCHLORIDE, AND

SCOPOLAMINE HYDROCHLORIDE IN THE NANOLIPID VESICLE

FORMULATION OF PREPARATION 2 (a) A 2% composition of doxepin in the nanolipid-vesicle composition of -

Preparation 2 above was prepared by mixing doxepin hydrochloride with the nanolipid vesicle formulation as described in Preparation 2 which had been modified by the addition of Keltrol to render a thick creamy consistency, in a mass/mass ratio of 2:98 with the aid of a high speed stirrer. The composition is designated DOXIPEX CREAM. (b) In similar manner a 1.7307% composition of Lidocaine Hydrochloride was prepared and designated LIDAREX LOTION. 40 (c) A 0.3% composition of Scopolamine HBR was also prepared in the same manner and designated MZL Scopolamine.

(d) A 0.5 nasal spray composition of Oxymetazoline HCl was also prepared in the same manner with some modification and designated Oxymetazoline

MZL. (e) A 0.5% injection formulation of Bupivicaine HCl was further prepared in the same manner but with some modification and designated Bupivicaine

MZL. : EXAMPLE 2

STUDY TO INVESTIGATE THE RELEASE CHARACTERISTICS OF

THE FORMULATIONS PREPARED IN TERMS OF EXAMPLE 1

AGAINST COMMERCIAL PREPARATIONS

1. OBJECTIVE:

The scope of the study was to establish whether the Test active agents viz.

Doxepin Hydrochloride,

Lidocaine Hydrochloride

Scopolamine Hydrobromide

Oxymetazoline HCl and : 20 Bupivicaine HCI are released from the dosage forms prepared in accordance with the invention as described in Example 1, and to determine the extent and rate of such release. It was further done to compare the rate of release of Doxipex to that of an FDA approved 5% Doxepin Hydrochloride topical formulation which is commercially available in Canada where it is indicated for the treatment of pruritis associated with eczema. That product is herein referred to as DOXEPIN COM. The test further compares the release of Lidocaine Hydrochloride from LIDAREX against a commercially available Lidocaise Hydrochloride composition herein referred to as LIDOCAINE COM . The test further compared the release of the Oxymetazoline MZL to a commercially available oxymetazoline nasal spray formulation designated oxymetazoline Com. Finally the test compares the release of the Bupivicaine MZL formulation with a commercially available Bupivicaine injection formulation designated

Bupivicaine Com. 40 The applicability of the method used to test for release out of the dosage forms is confirmed in Handbook of Dissolution

Testing, Dissolution Testing of Transdermal Delivery Systems, page 61. The small receptor volume to be used, in this case 12 ml, is confirmed in the same reference.

. oe 2. METHOD

The in vitro release from the dosage forms was determined by a Hanson Model 57-6M, Manual Start-Up, Diffusion Cell Test

System available from Hanson Research with the following main parts:

CELL DRIVE CONTROL

6-CELL DRIVE WITH CELLS

VERTICAL CELLS

3. ADDITIONAL EQUIPMENT USED 1. Diffusion cell assembly, including donor top and receptor chamber (set of 6). The donor top includes a drug dosage wafer (Teflon washer), an acrylic top plate, and a clamp to connect top to bottom. 2. Pig skin, mucous membrane or Dura mater as applicable, used within 24 hours from being slaughtered kept in Ringer Solution between 2°C — 8°C. 3. Davies Gold Series Dermatome, Simplex GS 102. 4. Application squeegee and tweezers. 5. Drug dosage form. 6. Absorbent paper towels and tissues. 4. TECHNIQUE

The technique used included the following steps: 1. Obtain skin from pig heads (jawbone skin). Use

Dermatome according to the Operation standard operating procedure for the Dermatome, setting it to size the skin to a thickness of 0.33mm. The diameter of the skin should be in excess of the drug dosage wafer

OR

For investigations using the active compound

Oxymethalzoline MZL nasal spray, obtain the nasal mucous membrane of the pig in the following manner: the snout of the pig is removed just below the eyes with a stainless steel saw blade. The snout is cut in half between the 40 nostrils. The cartilage is then gently cut and the nasal passage opened. The mucous membrane is carefully loosened and removed. Mucous membrane cells of 2.5cm by 2.5 cm are cut. The membrane thickness is monitored with a micrometer

OR

For investigations using the active compound Bupivicaine

MZL Injectable Solution, obtain the Dura mater (the tough membrane forming the barrier between the brain and cranium or blood) in the following manner: Open the cranium with a stainless steel saw blade. Divide the brain in half and remove carefully from the opened cranium without disturbing the membrane. Loosen the membrane from the cranium and measure the width of the membrane with a micrometer. The thickness of the membrane should be between 0.19 and 0.24 mm. Cut at least 6 cells of 2.5 by 2.5 cm of membrane.

Prepare receptor chamber of diffusion cells with slight overflow of medium as specified in table below with temperature controlled at 32°C. 2. Prepare each piece of skin, mucous membrane or Dura mater with the relevant products one at a time as : follows: 2.1. Lift skin, mucous membrane or Dura mater with tweezers, place on tissue and blot excess of solution, invert and blot. 3.2 Place skin, mucous membrane or Dura mater in centered position on drug dosage wafer. 3.3 3.3 Place relevant products on top of skin, mucous membrane or Dura mater in dosage wafer cavity. 3.4 Use squeegee to carefully smooth product over membrane, filling entire cavity. 3.5 Wipe excess dosage off wafer.. . 3.6 Lift loaded dosage wafer with skin, mucous membrane or Dura mater and place on top of receptor cell with skin, mucous membrane or

Dura mater side towards cell medium. Exclude bubbles during process. Place top plate on top of 40 donor cell assembly, pressing down with finger, squeezing out bubbles between top plate and dosage form. Apply clamp to lock down top donor and bottom receptor halves of diffusion cell.

. EN 23 5. OPERATION OF APPARATUS:

The apparatus must be set to 150 rpm. Samples of 150ul are withdrawn with a micropipette at 10, 20, 30, 60, 90 and 120 minutes. The samples after being withdrawn are analysed for the active compound by means of HPLC, using the parameter indicated in table below for each of the different compounds.

Doxipex | Lidarex Scopol- Oxymetaz | Bupivicain

And And amine oline HC! |e MZL and

Doxepin | Lidocaine | MZL MZL and | Bupivicain

Com Com Oxymetaz | e Com oline HCI volume

Column Zorbax Zorbax Zorbax SB | Zorbax Zorbax

C18 C18 C18 C18 C18 15cm 250mm x | 150mm x |250mm x |250mm Xx 4.6mm 4.6mm 4.6mm 4.6mm

Mobile Phase | 40% 0.2M | 50ml GAA | 70% 70% 65%

NaH.PO; | in 930 m | Phosphate | Phosphate | Acetonitril buffer H2O at pH | buffer: buffer: e: 35% with 60% | 3.4 adj | 30% 30% Phosphate

MeOH adj | with 1N | MeOH, MeOH, Buffer, pH pH to 2.5 | NaOH pH2.5 pH3.5 7.7 with

H3PO4

Receptor PH 6.8 | 40% PH6.8 PH 6.8 | PH 6.8 chamber phosphate | MeOH/ phosphate | phosphate | phosphate medium buffer 60% H,O | buffer buffer buffer

Detector HPLC at HPLC at 254nm 254 nm 240 nm 280 nm | 263 nm (22°C) (22°C) (22°C) (22°C) (22°C)

Time min min min

Solvent 80% 0.2M | MeOH/ KH2PO4 KH,PO4 KH,PO4

NaHPO4 | 60% H,O | buffer pH | buffer pH | buffer pH buffer 6.8 6.8 6.8 with 20%

’ | 24

MeOH adj pH to 6.8 with IN

NaOH

Cellsused [6 16 6 [3 [3

Time at 30 15 5 which total determined

Min 6. RESULTS

The release experiment was performed in 6 cells for each product and the mean release is reported for each analysis point. The results were tabulated and graphically presented.

The results as a percentage of the active ingredient released per label claim per cell at the different time intervals was also tabulated.

Table 1 below gives a summary of the release rates and percentage release per label claim for the products determined according to calculations, reporting the mean values at 60 minutes (1 hour) for each of these compounds.

Table 1. Release rates and percentage reiease per label claim for products tested. /product (ng/cm?/h) label claim

Oxymetazoline 0.5 0.35 0.0035

MZL

Com

MZL

. . -

Cm [TT

The Release Rate was calculated as follows: 1. pg Active Released at time (min.)

Asam x Mass Std x VolReceptor x Mass of Active Applied for Z cells x C

TE mm ee ee ee rr re ee er me te cme mm a mm ee ee me mm fe ee em mee

Astd x Vol Std x Label Claim x Mass of Product Applied for 1 cell x Z x 100

WHERE:

Asam = Area of peak of sample solution

Astd = Area of peak of standard solution

Mass Std = Mass of standard taken to prepare the standard solution expressed in ug

Vol Std = Volume to which the standard solution is made up, expressed in mi

Vol Receptor = Volume of diffusion cells system receptor chamber, expressed in ml

Label Claim = Amount of active present per 100g of product

Mass of Product

Applied for 1 cell = Specific amount of product applied for a specific cell . Mass of Active

AppliedforZcells = Amount of active applied in total for all Z cells utilised per one study

C = potency of the standard, expressed as a percentage 40 i 2. Accumulative Dose (ug) released / square cm at time (min)

= ug Active Released (Surface Area of Exposed Skin) = ug Active Released 1.767cm? 3. Release Rate = Accumulative Dose (ug) released / square cm

Time (hours) 4, Percentage of Active Released at time (min.) = ug Active Released x 100 ug Active Applied :

It was established that

A. Doxipex Cream releases Doxepin hydrochloride 2.4754 times faster than the commercially available Doxepin Com : product;

B. Lidarex releases Lidocaine HCI 1.3425 times faster than the commercially available Lidocaine Com product.

D. C. The release of Oxymetazoline HCLI from the MZL formulation compared well with that of the commercial

Oxymetazoline Com formulation, but both values were very low, due to the thickness of the mucous membrane of the : pig. The human mucous membrane is much thinner and release should accordingly be much higher in humans. The release of Bupivicaine from the MZL formulation was nevertheless shown to be 10.1% faster than that of the commercially available Bupivicaine formulation after 5 min and was about equal at all other times. : 8. CONCLUSION

It is evident from the results obtained that the percentage active ingredient released from the DOXIPEX CREAM is significantly higher than that of the comparator Doxepin Com Cream. The release of Doxepin Hydrochloride from both the products consequently results in the effective administration of approximately the same quantity of active per dose although Doxipex 40 contains 2% m/m Doxepin Hydrochloride and Doxepin Com 5% m/m

Doxepin Hydrochloride in their respective formulations.

A comparison of the release rates at 60 minutes indicate that the release of

Doxepin Hydrochloride from Doxipex Cream (2%) is at a rate 2.475 times greater than that from Doxepin Com Cream (5%). The percentage of active released from the formulation of the nanolipid vesicle formulation of

Preparation 2 for this specific time is also 2.47 times greater than for the comparator.

Example 3

CLINICAL STUDIES:

Below is described three examples of the use of the Doxepin MZL

Formulation in three patients presenting with pain due to three different clinical causes.

CASE STUDY 1. USE OF DOXEPIN FORMULATION IN

MANAGEMENT OF LOWER BACK PAIN AND DEPRESSION

The doxepin in nanolipid formulation described above (DOXIPEX) was administered to the lower back area of a post-menopausal Caucasian woman suffering from manic depression associated with severe lower backache. Her depression was at the time reasonably under control through the use of

PROZAC. She experienced substantial relief from the use of the formulation of the invention and discontinued her use of PROZAC after about 6 months on DOXIPEX. This is a most surprising result in view of the very low dose of doxepin hydrochloride administered through the topical application of the formulation of the invention.

CASE STUDY 2. USE OF DOXEPIN FORMULATION IN

MANAGEMENT OF PAIN IN REITER'S SYNDROME

The doxepin in nanolipid formulation described above (DOXIPEX) was administered to the affected limbs of an active post-menopausal Caucasian : woman diagnosed four years previously with Reiter's syndrome.

Clinical symptoms in volunteer:

Incapacitated and wasted right arm of the subject due to non-movement as a result of pain in the limb. The arm was carried in a light cast.

Previous treatment of the subject:

The subject was using intramuscular and Jor oral pain relievers and muscle relaxants on a chronic basis since her diagnosis. 40 Dosage form and usage of the MZL doxipin formula:

MZL Doxipin was applied three times daily to the affected areas.

Progress:

RY [1 28

After one month of usage, the subject no longer needed the support of the armcast. Muscle degeneration due to non-usage was reversed to some - extent.

After 4 months of usage, the subject moved and used the arm freely. The wrist remained stiff.

CASE STUDY 3: USE OF DOXEPIN FORMULATION IN MANAGEMENT

OF SEVERE BACK PAIN IN A DEGENERATIVE THORACIC AND

VERTEBRAL CONDITION.

Subject:

The subject was an 80 year old Caucasian male with severe back pain due to degeneration of his vertebrae. He was nearly completely immobilised by his condition and seldom moved outside of his home. He was on chronic therapy of intramuscular pain relievers and muscle relaxants.

Dosage form and usage of the MZL Doxepin formula:

In his case, synthetic polymer cutaneous patches were saturated with MZL

Doxepin Formulation and attached at night to areas where he experienced extreme pain for prolonged release of the active compound.

Progress:

After a year of treatment, the subject was completely mobile. He stopped taking medication for pain, either of commercial origin or the Doxepin

Formulation.

Example 4

DISSOLUTION STUDIES IN RESPECT OF FORMULATIONS MADE

ACCORDING TO THE INVENTION

Formulations of the active agents referred to below were prepared in the manner described above and were subjected to dissolution tests (2 or 3 repeats as indicated below) performed in terms of the USP 24 procedure.

The following results were obtained.

Carbamazipine MZL | NTL 75% in 30 min 123%, 112%, 114% suspension

Carbamazipine Com | NTL 75% in 30 min 111%, 112%, 112% suspension

Zolpidem Tartrate MZL | NTL 75% 92%, 98%, ND

SGC

Zolpidem Tartrate Com | NTL 75% 102% 102%

SGC

Propranolol MZL SGC NTL 75% in 30 min 124% 126% 130%

h i]

Propranolol Com SGC NTL 75% in 30 min 106% 105% 107%

Phenythion Na MZL SGC | NTL 85% in 30 min 143% 147% 155% — |! [ Phenythion Na Com SGC | NTL 85% in 30 min 53%, 46%, 46% = rn

The advantages of the MZL formulations over the commercial formulations are self-evident.

Many variations of the invention may be devised without thereby departing from the spirit of the invention.

Claims (1)

1. A method of enhancing the action of a pharmaceutical agent which is characterised in that it is a CPNS agent selected from the group of compounds acting on the central or peripheral nervous system, but excluding coal tar solution and H1-antagonist antihistamines and also excluding anti-inflammatory, analgesic and antipyretic agents, comprising the step of formulating the agent with an administration medium which is a solution of nitrous oxide gas in a pharmaceutically acceptable carrier solvent for the gas and which administration medium includes at least one fatty acid or ester or other suitable derivative thereof selected from the group consisting of oleic acid, linoleic acid, alpha-linolenic acid, gamma-linolenic acid, arachidonic acid, eicosapentaenoic acid [C20: 5w3], decosahexaenoic acid [C22: 6w3], ricinoleic acid and derivatives thereof selected from the group consisting of the C1 to C6 alkyl esters thereof, the glycerol polyethylene glycol esters thereof and the reaction product of hydrogenated natural oils composed largely of ricinoleic acid based oils such as castor oil with ethylene oxide.

2. A pharmaceutical preparation characterised in that it comprises a pharmaceutical agent which is a CPNS agent selected from the group of compounds acting on the central or peripheral nervous system, but : excluding coal tar solution and H1l-antagonist antihistamines and also excluding anti-inflammatory, analgesic and antipyretic agents, comprising the step of formulating the agent with an administration medium which is characterised in that it comprises a solution of nitrous oxide gas in a pharmaceutically acceptable carrier solvent for the gas and which administration medium includes at least one fatty acid or ester or other suitable derivative thereof selected from the group consisting of oleic acid, linoleic acid, alpha-linolenic acid, gamma-linolenic acid, arachidonic acid, eicosapentaenoic acid [C20: 5w3], decosahexaenoic acid [C22: 6w3], ricinoleic acid and derivatives thereof selected from the group consisting of the C1 to C6 alkyl esters thereof, the glycerol-polyethylene glycol esters thereof and the reaction product of hydrogenated natural oils_composed largely _of ricinoleic acid based oils such as castor oil with ethylene oxide.

3. The method of claim 1 or the preparation of claim 2 wherein the 40 essential fatty acid or ester thereof, component of the composition comprises a mixture of esters of the fatty acids listed above and is preferably constituted by the complex known as Vitamin F Ethyl Ester having a typical fatty acid distribution as follows:

< Cis: 0 Ci60:8,3% Ciso : 3,5 % Cis1 . 21,7 % Cis : 34,8 % Ciga : 28,0 % >Ci5:1,6% unknown: 2,1 %.

4. The method or the preparation of claim 3 wherein the administration medium further includes eicosapentaenoic acid [C20: 5w3] and/or decosahexaenoic acid [C22: 6w3] as additional long chain fatty acids.

5. The method of claim 1 or the preparation of claim 2 wherein the carrier solvent is water (preferably deionised water) or any of the pharmaceutically acceptable alcohols, ethers, polymers such as a polyethyleneglycol or the like or an oil which is preferably an organic oil which organic oil is further preferably an essential oil based on long chain fatty acids having between 14 and 22 carbon atoms in the fatty acid and is preferably of natural origin and most preferably a plant oil rich in gamma linolenic acid [GLA].

6. The method of claim 1 or the preparation of claim 2 wherein the CPNS agent is formulated in a liquid presentation and wherein the formulation incorporate, as part of the administration medium, water or acceptable other liquid solvent into which the nitrous oxide is dissolved, preferably to saturation, and wherein the fatty acid or ester thereof is dissolved or suspended or emulsified along with the CPNS agent.

7. The method of claim 1 or the preparation of claim 2 wherein the CPNS agent is formulated to be applied as a topical, buccal or vaginal cream or ointment or as a cutaneous patch, or as an intravenous, intramuscular or subcutaneous injection, or as a suppository, and wherein the formulation used in making up such cream, ointment, injectable formulation or suppository incorporates, along with the CPNS agent to be enhanced, a quantity of water containing, and 40 preferably saturated with, nitrous oxide, the long chain fatty acid or ester thereof and the anti-infective agent formulated therewith, and, optionally further incorporates such additional excipients and carriers as are conventionally used in the pharmaceutical trade in making up such dosage forms.

vo 32

8. A method of claim 1 or a composition of claim 2 wherein the CPNS agent is selected from the group consisting of the following classes of compounds: Central nervous system stimulants including central analeptics, psycho analeptics (antidepressants), respiratory stimulants, hallucinogenic medicines; Central nervous system depressants including anaesthetics, sedatives, hypnotics, barbiturates, non-barbiturates, anticonvulsants, (including anti-epileptics), tranquillisers (including phenothiazines and their derivatives, rauwolfia, diphenylmethane and its derivatives, alkyl diols and their derivatives), centrally acting muscle relaxants; Local anaesthetics; and Medicines affecting autonomic functions including adrenomimetics (sympathomimetics), adrenolytics (sympatholytics), cholinomimetics (cholinergics), cholinolytics (anticholinergics) (including anti-Parkinsonism preparations), Ganglion blockers, anti-emetics and anti-vertigo preparations, decongestants, -hydroxytryptamine (serotonin) and serotonin antagonists, and anti-Alzheimers agents.

9. The method of claim 1 or the preparation of claim 2 wherein the active agent is selected from the group consisting of :

A. the Central Nervous System Stimulants consisting of i. the following Central Analeptics: Amphetamine, Dextroamphetamine, Methamphetamine, Methylphenidate, Caffeine, Caffeine citrated, Caffeine and Sodium Benzoate, Clomipramine, Desipramine, Ephedrine, Imipramine, Pemoline, Protryptiline,

ii. the following Psycho Analeptics (antidepressants):

a. the Tricyclic Antidepressants being: Amitryptyline, Amoxapine, Clomipramine, Desipramine, Doxepin, Imipramine, Nortriptyline, Protriptyline, Trimipramine,

b. the Monamine Oxidase Inhibitors being: Isocarboxazid, Phenelzine, Tranylcypromine,

C. Other Antidepressants being:

Burpopion, Fluoxetine, Fluvoxamine, Maprotiline, Mitrazapine, Moclobemide, i Nefazodone, Paroxetine, Setraline, Trazodone, Venlafaxine,

iii. The following Respiratory Stimulants : (Bronchodilators): Albuterol, Ephedrine, Ethylnorepinephrine, Fenoterol, Isoproterenol, Metaproteronol, Terbutaline,

iv. The following Hallucinogenic medicines:

a. the following Indoleamine hallucinogenics: LSD, DMT, N,N-dimethylamine, Psilocybin,

b. the following Phenethylamines: Mescaline, Dimethoxymethylamphetamine (DOM), Methylenedioxyamphetamine (MDA), MDMA,

B. the Central nervous system depressants consisting of: i The following anaesthetics: Halothane, Isoflurane, Enflurane, Methoxyflurane, Sevoflurane, Desflurane, Methohexital, Thiopental, Etomidate, Ketamine, Propofol, ii The following Sedatives and Hypnotics: Alprazolam, Brotizolam, Chlordiazepoxide, Clobazam, Clonazepam, Clorazepate, Demoxepam, Diazepam, Estazolam, Flumazenil, Flurazepam, Halazepam, Lorazepam, Midazolam, Nitrazepam, Nordazepam, Oxazepam, Prazepam, Quazepam, Temazepam, Traizolam, ii the Barbiturates being: Amobarbital, Aprobarbital, Butabarbital, Butalbital, Mephobarbital, = Methohexital, = Pentobarbital, Phenobarbital, Secobarbital, Thiopental, iv the Non-barbiturates being: Buspirone, Chloral hydrate, Chlormezanone, Diphenhydramine, Doxylamine, Ethchlovynol, Ethinamate, Glutethemide, Hydroxyzine, Meprobamate, Methotrimeprazine, Methyprylon, Promethazine, Propiomazine, Propofol, Zolpidem, 40 Zolpiclone, Paraldehyde,

V. The Anticonvulsants, (including anti-epileptics) being:

Acetazolamide, Amobarbital, Carbamazepine, Clobazam, Clonazepam, Clorazepate, Corticotropin, Diazepam, Divalproex, Ethosuximate, Ethotoin, Felbamate, Fosphytoin, Gabapentin, Lorazepam, Magnesium sulfate, | Mephenytoin, Mephobarbital, Metharbital, Methsuximide, Nitrazepam, Paraldehyde, Paramethadione, Pentobarbital, Phenacemide, Phenobarbital, Phensuximide, Phenytoin, Primidone, Secobarbital, Trimethadione, Valproate sodium, Valproic acid,

vi. The following Tranquillisers (including : phenothiazines and their derivatives, rauwolfia, diphenylmethane and its derivatives, alkyl diols and their derivatives) being:

a. Phenothiazines and derivatives being; Acetophenazine, Chlorpromazine, Chlorprothixene, Flupenthixol, Fluphenazine, Mesoridazine, Methotrimprazine, Pericyazine, Perphenazine, Pipotiazine, Prochlorperazine, Promazine, Thiopropazate, Thioproperazine, Thioridazine, Thiothixene, Trifluoperazine, Trifluoropromazine, :

b. Other Antipsychotics being: Clozapine, Fluspirilene, Haloperidol, Loxapine, Molindone, Olanzapine, Pimozide, Risperidone, Lithium, C Centrally acting muscle relaxants consisting of: Baclofen, Carisoprodol, Chiorphenesin, Chlorzoxazone, Cyclobenzaprine, Dantrolene, Diazepam, Lorazepam, Metaxalone, Methocarbamol, Orphenadrine, and Orphenadrine citrate, Phenytoin, D Local anaesthetics consisting of: Articaine, Benzocaine, Bupivacaine, Chloroprocaine, Cocaine, Diphenhydramine, ~~ Efidocaine, Lidocaine, ~~ Mepivacaine, Pramoxine, Prilocaine, Procaine, Propoxycaine, and Procaine, Proraracain, Ropivacaine, Tetracaine, E Medicines Affecting Autonomic Functions consisting of: 40 i The Adrenomimetics {Sympathomimetics) consisting of: Phenylethylamine, Epinephrine, Norepinephrine, Dopamine, Dobutamine, Colterol, Ethylnorepinephrine, Isoproterenol, Isoetharine, Metaproterenol, Terbutaline,

Metaraminol, Clonidine, Phenylephrine, Tyramine, Hydroxyamphetamine, Ritodrine, Prenalterol, = Methoxamine, Albuterol, Amphetamine, Methamphetamine, Benzphetamine, Ephedrine, Phenylpropanolamine, Mephentermine, Phentermine, Fenfluramine, Propylhexedrine, Diethylpropion, Phenmetrazine, Phendimetrazine, ii The Adrenolytics (sympatholytics) consisting of: Phenoxybenzamine and related Haloalkylamines, Phentolamine, Prazosin, Terazosin, Doxazosin, Trimazosin, Indoramine, Labetalol, Ketanserin, Urapidil, Alfuzosin, Bunazosin, Tamsulosin, Yohimbine, Propanolol, Metoprolol, Nadolol, Atenolol, Timolol, Esmolol, Pindolol, Acebutolol, Labetalol, Bopindolol, Oxprenolol, Penbutolol, Carvedilol, Medroxalol, Bucindolol, Levubunolol (Betagan) glaucoma, Metipranolol, Bisoprolol, Nebivolol, Betaxolol (Betoptic) Glaucoma, iii The Cholinomimetics (cholinergics) consisting of: Acetylcholine, Metacholine, Carbachol, Betanechol, Pilocarpine, Muscarine, Arecoline, Oxotremoring, Ambenonium, Domperidone, Edrophonium, Edrophonium & Atropine, Metoclopramide, Neostigmine, Physostigmine, Pyridostigmine, iv The Cholinolytics (anticholinergics) (including anti-Parkinsonism preparations) consisting of: Amantadine, Anisotropine, Atropine, Scopolamine and related Belladonna alkaloids, Ipratfopium bromide, Benztropine, Biperidine, Chlorpromazine, Clidinium, Dicyciomine, Diphenhydramine, Ethopropazine, Glycopyrollate, Homatropine, Hyoscyamine, Mepenzolate, Methantheline, Methoctramine, Hexahydrosiladifenidol, Himbacine, Tripitamine, Methscopolamine, Orphenadrine HCl, Pirenzepine, Procyclidine, Propantheline, Scopolamine, Thioridazine, Trihexyphenidyl, Carbidopa and Levodopa, Levodopa, Pergolide, Selegiline, v Ganglion blockers consisting of: Hexamethonium, Trimethaphan, Mecamylamine, 40 vi Histamine and antihistaminic agents consisting of: : 2(m-F-phenylhistamine), Dimaprit, R-a-Me-histamine, . Ethanolamines as Carbinoxamine maleate, Clemastinefumurate, Diphenhydramine HCI,

Dimenhydrinate, Ethylenediamines as Pyrilamine maleate, Tripelennamine ~ HCl, Tripelennamine citrate, Alkylamines as Chlorpheniramine maleate, Brompheniramine maleate, Piperazines as Hydroxyzine HCl, Hydroxyzine pamoate, Cyclizine HCl, Cyclizine lactate, Meclizine HC, Phenotiazines as Promethazine HCl, Second generation Alkylamines as Acrivastine, Second generation Piperazines as Cetrizine HC, Piperidines as Astemizole, Levocabastine HCl, Loratadine, Terfenadine,

vii. Anti-emetics and Antivertigo preparations consisting of: 5-HTs Antagonists as Ondansetron, Granisetron, Tropisetron, Dolasetron, D2/5-HT3; Antagonist as Metoclopramide, Trimethobezamide, D2 Antagonists as Phenotiazines namely Chlorpromazine, Perphenazine, Prochlorperazineg, Promethazine, Thiethylperazine, Triflupromazine, D2 Antagonists as Benzimidazole derivatives namely Domperidone, D2 Antagonists as Butyrophenones namely Haloperidol, Droperidol, Corticosteroids as Dexamethasone, Methylprednisolone, Cannabinoids as Dronabinol, Nabilone, Hi antagonists Diphenhydramine, Meclizine, Cyclizine, Antimuscarinic agents as Scopolamine, Benztropiane, Benzodiazepines : as Lorazepam, Alprazolam, Hi Antagonist as Dimenhydrinate, viii. Decongestants consisting of: Oxymetazoline, Phenylephrine, Xylometazoline ix. -hydroxytryptamine (serotonin) and serotonin antagonists consisting of a. 5-HT Agonists being: Buspirone, ipsaperone, Sumatriptan, Cisapride,

b. 5-HT Antagonists being: Methysergide, Risperidone, Ketanserin, Ondansetron,

35. Cc. 5-HT transport inhibitors being: Fluoxetine, Sentraline, and F Anti-Alzheimers agents consisting of: Physostigmine, Tacrine and Lecithin in combination with Tacrine. 40 mmmeemm——m—n———