WO2012176155A1

WO2012176155A1 - Pharmaceutical composition for use against inflammation and pain

Info

Publication number: WO2012176155A1
Application number: PCT/IB2012/053157
Authority: WO
Inventors: María Angélica ARZOLA PANIAGUA; Enrique Raúl GARCÍA SALGADO LÓPEZ; Juan Pablo SENOSIAIN PELÁEZ
Original assignee: Laboratorios Senosiain S.A. De C.V.
Priority date: 2011-06-22
Filing date: 2012-06-21
Publication date: 2012-12-27
Also published as: CO6831987A2; ES2441917A2; PE20141530A1; RU2604149C2; AR086733A1; ES2441917B1; CL2013003671A1; CR20130687A; NI201300142A; DOP2013000309A; RU2013157013A; MX357376B; GT201300318A; MX2011006758A; ES2441917R1; BR112013033007A2

Abstract

The invention relates to a pharmaceutical combination and composition, and in particular to a combination of an analgesic and an anti-inflammatory selected from Ketorolac and Meloxicam or Piroxicam, and pharmaceutically suitable vehicles or excipients. The invention also relates to a method for manufacturing a pharmaceutical composition and to the use of said composition in preparing a medication that can be used to treat pain and inflammation.

Description

PHARMACEUTICAL COMPOSITION FOR USE IN INFLAMMATION AND PAIN

FIELD OF THE INVENTION

The present invention relates to a combination and pharmaceutical composition and particularly to a combination of an analgesic and an anti-inflammatory selected from ketorolac and meloxicam or piroxicam and pharmaceutically acceptable carriers or excipients; It also refers to a manufacturing process of a pharmaceutical composition and the use of said composition to treat pain and inflammation.

BACKGROUND OF THE INVENTION

In the therapeutic administration of medicines, achieving effective and efficient local effects with less adverse effects is one of the main objectives of the development of pharmaceutical formulations. Localized pain and inflammation conditions are among the most frequent conditions in the general population by up to 80%, with muscle injuries being the most frequent.

Robert Raffa (USA 2005) indicated that the analgesic therapeutic alternatives available to doctors are limited, mainly for the treatment of long-term pain, therefore, it is optimal that the Treatment is also combined to ensure continuous long-term efficacy.

For the treatment of pain and inflammation, drugs can be administered locally or systemically, which will depend on each patient and the doctor's criteria.

The local administration is directed specifically to the place where pain occurs quickly and effectively. Few topically applied medications easily penetrate intact skin, absorption depends on the skin and the properties of the pharmaceutical formulation. The absorption of drugs is regulated by the characteristics of the skin and the liposolubility of the drugs.

The skin is formed by three main layers of overlapping tissues: the first is superficial (epidermis), the second sub-epidermal, (dermis) and the third deep sub-dermal (hypodermis). In the skin the epidermis contains water in addition to fat, it is a hydrolipidic layer. The cutaneous pH varies between 4.2 and 5.9 depending on the body areas, 5.5 being the average.

Skin coming into contact with alkaline pH substances between 7.1 and 13 increases permeability, which facilitates the absorption of drugs contained in forms Topical pharmaceuticals. Therefore, the present invention was designed to have an alkaline pH between 7.0 and 10.

There is a large group of forms of chronic muscle pain and aponeurosis (reinforcement of the tendon attachment to the bones), characterized by presenting painful points or trigger points (trigger points) in one or more muscles or joints in different parts of the body. It is usually accompanied by muscular contracture, limitation of the movements of the spine, neck, waist, limbs and even in some cases alteration of the anatomical shape of muscles (swelling) and joints. The specialists define them as musculoskeletal pain or myofacial pain, and these painful muscle points constitute the most common complaint when the patient attends the consultation of the pain specialist.

Other conditions include localized pain caused by bumps, sprains, muscle or tendon tearing, bad postures, which are the most frequent pains that most affect the quality of life of people.

For the treatment of systemic and localized musculoskeletal pain, there are several types of medications of which non-spheroid anti-inflammatory analgesics (NSAIDs) are among the most commonly used. Ketorolac is a NSAID derived from carboxylic and pyrrole pyrrole, it is highly soluble in water. It is a powerful and effective analgesic very effective in the treatment of moderate to severe pain. When administered in combination with another active substance, it usually presents stability problems, in laboratory tests it has been shown that its stability decreases significantly in the presence of acidic substances, this makes the formulation of a pharmaceutical composition where ketorolac and other or other coexists coexist active ingredients without affecting the stability of each of them.

Ketorolac depending on the condition can be administered from 2. Omg up to 120mg per day. Doses greater than 120mg per day can be toxic.

Meloxicam is an NSAID derived from oxicam, it is insoluble in water and its solubility increases with increasing pH. Meloxicam has a good tolerability profile, it is indicated for the treatment of acute and chronic rheumatoid arthritis, osteoarthritis (degenerative joint disease), shoulder and hip periarthritis, among other conditions.

Meloxicam depending on the condition can be administered from 0.2mg to 30mg per day. Doses greater than 50mg can be toxic. Piroxicam is a non-steroidal anti-inflammatory, analgesic and antirheumatic agent, it inhibits the synthesis of prostaglandins and their release through the reversible inhibition of the enzyme cyclooxygenase. It reduces the production of toxic superoxide anion by neutrophils and reduces the production of rheumatoid factor; which translates into pain relief in moving joints, reduction in morning stiffness, swelling, less limitation of movement, increased pressure force and decreased time required to walk.

Piroxicam is indicated for a variety of conditions characterized by pain and inflammation such as extra-articular rheumatic diseases: fibrositis, scapulo-humeral periarthritis (painful shoulder), periarthritis, tendinitis, tendosynovitis, musculoskeletal, traumatic and sports conditions: bruises, sprains, dislocations , fractures, muscle tears, sprains, sprains or lower back pain.

Piroxicam depending on the condition can be administered from 2.5mg to 60mg per day. Doses greater than 60mg can be toxic.

The combination of the present invention can be administered in systemic or local administration compositions. In the case of topical compositions, these can be gel, cream, ointment, paste or other. Of the Proposed formulations gel composition is preferred because it is a well tolerated and easily washable formulation. With a gel the sensation of freshness is produced since it is not a formulation that generates cold or heat, its topical action is located on the surface of the skin, that is only in the area of application, without the sufferings of adverse effects caused by the administration of systemically absorbed drugs.

In the state of the art, US Patent 5, 091, 182, presents a pharmaceutical composition of ketorolac of topical application which is presented in the form of a transdermal patch or collapsible aluminum tube. Said composition has a pH stability between 3.8 and 4.6. The collapsible tube formulation includes a chelating agent such as EDTA since the formulation comes into contact with aluminum in addition to an antioxidant such as BHT and a pH adjusting agent such as tromethamine.

Unlike the formulation, described in US 5,091,182, the present invention, in its preferred embodiment, comprises a topical formulation that is presented in a plastic container, lacks a chelating agent such as EDTA, is stable at a different pH and its Physicochemical stability is regulated with triethanolamine. This composition includes two active principles of marked physicochemical incompatibility with each other, which prevents their coexistence at an acidic pH, as in the invention of US Patent 5,091,182.

The application WO 2007/010584 A3, refers to a controlled release system of the type of transdermal patch containing a polymeric matrix, an inorganic dispersing agent and an active ingredient that can be an NSAID; Said polymeric system may contain between 30 and 99% by weight of the polymer, between 1 and 70% of the inorganic dispersing agent and between 1 and 50% by weight of the active ingredient. Said composition is designed as a controlled release system that can range from 24 hours to 30 days. In contrast, the present invention relates, in its preferred embodiment, to a topical pharmaceutical composition without the use of a matrix, containing 1) ketorolac and 2) meloxicam or piroxicam, and is directly applied to the skin, with synergistic anti-inflammatory and analgesic therapeutic action.

Additionally, there is a topical commercial formulation containing ketorolac gel with 2g per lOOg. This composition is topical local administration, immediate action against pain, should be applied 3 or 4 times a day.

Ketorolac, despite being an NSAID, has a very rapid effect, mainly analgesic and with less anti-inflammatory effect, so it acts in a diminished manner against inflammation The present invention resolves this limitation with the inclusion of another active ingredient: meloxicam or piroxicam. In the state of the art there is no evidence of topical absorption of Meloxicam, much less there are studies that show the joint administration of the two active ingredients and their local absorption, therefore, studies were developed that show the absorption and the degree of irritability of the pharmaceutical composition, and evaluations that demonstrate the synergistic interaction of these drugs.

JUSTIFICATION OF THE INVENTION

The formulation and administration of pharmaceutical combinations is not easy, since when administering two or more principles in a single pharmaceutical form, degradation or alteration interactions can occur between the active principles, adverse reactions, side effects, as well as the technological problems that result of the physicochemical interaction of active ingredients and excipients.

The present invention surprisingly demonstrated that the combination of ketorolac and meloxicam or piroxicam is therapeutic and synergistically effective. The combination of the present invention in a preferred embodiment without limiting the use envisages using formulations containing less active ingredient than existing commercial formulations and thereby a reduction of adverse effects.

In the present invention two active NSAIDs are presented, ketorolac (a rapid-response NSAID, mainly analgesic against mild to severe pain), and meloxicam (a long-acting and slow-acting NSAID, mainly anti-inflammatory) or piroxicam (NSAIDs immediate anti-inflammatory activity). By combining these active ingredients, a rapid and prolonged effect can be achieved, in addition to a significant decrease in side effects of the type: damage to the gastric mucosa, rash, pruritus and dryness.

In a preferred embodiment, the pharmaceutical composition of the present invention can be administered orally. In another preferred embodiment, the pharmaceutical composition may be presented topically. These formulations make it easier to administer to people who do not want or cannot receive parenteral administration treatment and who suffer from localized lesions and have mild to severe inflammation and / or pain. The topical pharmaceutical composition of the present invention, in the preferred embodiment, has an alkaline pH, this is achieved by creating a buffer and stabilizer system with the use of a support vehicle, a cosolvent, a humectant and essentially an agent that dissociates the agent. gelling and stabilizing the formulation at an alkaline pH such as triethanolamine.

With this system, an increase in the permeability of the skin is allowed and, therefore, a more rapid penetration of the active ingredients, in this way the formulation of the present invention has the power to completely cross the skin and reach deep tissue. of the skin, carrying its local analgesic and anti-inflammatory therapeutic action quickly and effectively.

The topical formulation of the present invention, has good tolerance, does not irritate, is stable against environmental factors, with a consistency suitable for its extension on the skin, with pleasant organoleptic characteristics, does not dehydrate, nor degrease the skin, nor does it generate a greasy feeling

In accordance with the above, it can be observed that both the broad spectrum, as well as the brevity of treatment and the effectiveness of the synergistic combination of the active ingredients, as well as the safety of having a pharmaceutical form with all the quality criteria, are factors of great importance for patients to benefit from adequate treatment for these conditions.

SUMMARY OF THE INVENTION

The present invention is directed to a combination and to a pharmaceutical composition comprising effective amounts of 1) ketorolac and 2) meloxicam or piroxicam.

For the topical composition of the present invention, ketorolac can be formulated from 0. 1g to 10g for each 10g of topical composition. For an oral formulation, ketorolac can be included from lmg to 120mg.

For the topical composition of the present invention, meloxicam can be formulated from 0.2g to 5g for each 10g of composition. For an oral formulation, meloxicam can be included from 2mg to 30mg.

For the topical composition of the present invention, piroxicam can be formulated from 0.2g to 20g for each 10g of composition. For an oral formulation, piroxicam can be included from 2.5mg to 60mg.

BRIEF DESCRIPTION OF THE FIGURES

Figures 1A and IB are graphs showing the temporal course of ketorolac and meloxicam hyperalgesic behavior, respectively, when administered. topically in the model of thermal hyperalgesia in rats sensitized with carrageenan.

Figures 2A and 2B are graphs showing the percentage of the Maximum Effect observed for ketorolac and meloxicam, respectively, in the model of thermal hyperalgesia in rats (* p <0.5)

Figure 3 is a graph showing the temporal course of hyperalgesic behavior (withdrawal threshold) in rats treated topically with increasing doses of the ketorolac-meloxicam combination in proportion (1: 3.2). Each point represents the mean ± e.e. of at least 6 rats.

Figure 4 is a graph showing the dose-antihyperalgesic effect curve after the topical application of the combination of ketorolac and meloxicam in the model of thermal hyperalgesia in rats, measured by the response derived as a percentage of the maximum possible antihyperalgesic effect. Each point represents the mean ± e.e. of at least 6 rats (* p <0.05 vs control)

Figure 5 shows the experimental DE ₄₀ (0.70 ± 0.03 g / 100) and the theoretical DE ₅₀ (1.17 ± 0.22 g / 100), indicating that the combination of ketorolac and meloxicam produced a synergism in the antihyperalgesic effect.

Figure 6 is a graph depicting the temporal course of inflammation in rats treated topically with increasing doses of the ketorolac-meloxicam combination in proportion (1: 3.2). Each point represents the mean ± ee of 6 rats. Figure 7 shows the anti-inflammatory dose-effect curve after topical application of the ketorolac-meloxicam combination in the carrageenan edema model in rats, measured by the derived response as a percentage of the maximum possible anti-inflammatory effect. Each point represents the mean ± ee of at least 6 rats (* p <0.05 vs control).

Figure 8 shows the experimental DEi ₅ (0.12 ± 0.09 g / 100) and the theoretical DEi ₅ (0.91 ± 0.26 g / 100), indicating that the ketorolac-meloxicam combination produced a synergism in the anti-inflammatory effect in the edema model Carrageenan-induced rats.

DESCRIPTION OF THE INVENTION

According to the invention, a pharmaceutical composition is provided comprising effective amounts of 1) ketorolac and 2) meloxicam or piroxicam.

It has been found that ketorolac is an NSAID that presents synergistic interaction with meloxicam or piroxicam, when the combination of both active ingredients is co-administered, for the treatment of pain and inflammation.

In accordance with the present invention, by administering a combination of 1) ketorolac and 2) meloxicam or piroxicam equal analgesic effects are achieved with doses considerably reduced, compared to formulations with equal doses when each active ingredient is administered separately. Any administration route can be used. Topical administration has been proven to be the most effective.

The challenge faced by the development of the present invention is to obtain a stable, safe and therapeutic therapeutic pharmaceutical composition that includes drugs that are physicochemically different from each other, such as ketorolac and meloxicam, which have a marked difference in solubility. .

Ketorolac due to its physicochemical characteristics shows greater solubility in slightly acidic solutions between a pH range of 5.0 and 6.9. Meloxicam presents greater stability in slightly basic pH in a range between 7.0 and 9.0. These characteristics of the assets hinder the manufacturing process of the pharmaceutical composition since the stability of each of them can be affected. By performing a simple combination of the active ingredients in solution (ketorolac and meloxicam), physical instability and degradation of the active substances are clearly shown.

In the present invention, one way of presenting the formulation is in the form of a gel composition, wherein an agent that dissociates the gelling agent is used, this Excipient is triethanolamine, which additionally acts as a pH regulator, thereby creating a microenvironment conducive to the coexistence of the two active principles of physicochemical properties that are different and incompatible with each other and the formulation is physicochemical stable.

The present invention, in the form of topical formulation, is characterized in that it comprises ketorolac, meloxicam or piroxicam and its pharmaceutically acceptable salts and, at least, an agent that dissociates the gelling agent and that maintains the pH of 7.0 to 10.0 in said composition .

In another embodiment of the present invention an oral formulation is presented where the main challenge is to keep ketorolac and meloxicam or piroxicam physically stable.

FORMULATIONS

Because the topical formulation is one of the most accepted for its convenience of administration and ease of transport, the present invention can be presented in cream, gel, ointment, paste or other pharmaceutical form of topical administration, of which the gel is preferred .

The formulation and manufacturing process of the pharmaceutical composition of the present invention, which contains the active ingredients ketorolac and meloxicam or piroxicam and / or its salts, is described below. pharmaceutically acceptable, additionally pharmaceutically acceptable carriers or excipients. The amounts by weight of the active ingredients, vehicles and / or excipients may be used within the ranges of use mentioned below.

• Active ingredients: The formulation may contain the active ingredients meloxicam or piroxicam and ketorolac or their pharmaceutically acceptable salts thereof. The use of the active substances is not limited to those indicated since the formulation can be presented with another NSAID such as oxicam, diclofenac, triethanolamine salicylate, naproxen, among others.

Depending on the preferred embodiment, a topical or oral formulation can be manufactured, where the excipients are selected from the following list.

• Excipients: dispersing agent of the type of propylene glycol, polyethylene glycol or derivatives of glycols, liquid paraffin, polymers of vinyl acid (carbopol), among others; agent that dissociates the gelling agent and / or stabilizing agent: ethanolamines such as monoethanolamine, diethanolamine, triethanolamine, or others; Conservatives: parabens, ethylparaben, methylparaben, butylparaben, sodium benzoate, among others; gelling agent or viscous agent: polymers of vinyl acid (carbopol), lutrol, HPC, among others; alcoholic cosolvent: ethyl alcohol, isopropyl alcohol, methanol, among others; wetting agent: glycerin, sorbitol, polyethylene glycol, among others; emulsifying agent: castor oil, cremophor RH40, Novemer, soy lecithin, twens, among others; buffer regulator or modulator: organic excipients such as lactic acid, triethanolamine or others; vehicle: purified water.

Within the range of the mentioned excipients several equivalent excipients and / or mixtures thereof were tested. In the case of the gel formulation, the gelling agent or viscous agent fulfills the function of promoting gel formation with the help of the stabilizing agent (also called the agent that dissociates the gelling agent). In the case of the cream formulation, the gelling agent or viscosifying agent fulfills the function of a viscosifying agent and with the help of the stabilizing agent that stabilizes the formulation.

Below are two representative examples of topical formulations of the present invention, a formulation in the form of a translucent gel and a cream. . ₀

1st

EXAMPLE 1 . TOPICAL FORMULATION IN GEL.

In Table 1 and 2, general topical gel formulations of the combinations of meloxicam or piroxicam and ketorolac are presented.

An example of a preferred formulation comprising ketorolac and meloxicam is illustrated in Table 3, wherein the amounts by weight of the active ingredients, vehicles and / or excipients can be used within the ranges of use mentioned, without limiting their use.

Table 1. GENERAL FORMULATION OF GEL TOPICS.

COMPONENTS Range of use.

Content for each composition lOOg

Meloxicam 0.2 - 5

Ketorolac tromethamine 0.1 - 10

Dispersing agent 17 - 22

Stabilizing agent 2.5 - 3.8

Conservative 0.04 - 0.06

Viscous agent 0.8 - 1.3

Alcoholic cosolvent 11.5 - 16

Wetting agent 4 - 6

Emulsifying Agent 1.1 - 1.8

Purified water 48 - 53

Total lOOg „„

Table 2. GENERAL FORMULATION IN GEL.

Table 3. EXAMPLE OF TOPIC FORMULATIONS IN GEL

Range of use

Ingredients Content for each composition lOOg

Formulation 1 Formulation 2 Formulation 3

Meloxicam

0.2 1 5

Ketorolac

tromethamine

0.1 0.6 10

Propylene glycol

22 20 17

Triethanolamine

3.8 3.5 2.5

Methylparaben

0.06 0.05 0.04

Carbopol 940

1.3 1 0.8

Ethyl alcohol

16 15 11.5

Glycerin

6 5 4

Cremophor RH 40

1.8 1.5 1.1

Purified water

48 53 48

Total lOOg lOOg lOOg The process for preparing the pharmaceutical gel composition is described below. This process is characterized in that it comprises the stages of:

a) Mix and disperse the gelling or viscosifying agent in purified water until completely homogeneous;

b) Mix and dissolve the alcoholic cosolvent and the preservative; add the dispersing agent, the wetting agent, the emulsifying agent and meloxicam or piroxicam, or their pharmaceutically acceptable salts, until homogeneous; adjust to a pH between 8 and 8.5; stabilize with the addition of the dissociating agent to the gelling agent or stabilizing agent;

c) Combine the mixture of part b) with the dispersion of the gelling agent of part a); stir until homogeneity and gelation; Y

d) Dissolve ketorolac, or its pharmaceutically acceptable salts, in water; and slowly adding said solution to the mixture of item c).

The present invention can also be presented in other topical pharmaceutical forms such as a cream, an ointment or another.

A cream composition is described below. EXAMPLE 2 TOPICAL FORMULATION IN CREAM.

In tables 4 and 5, the general topical cream formulations of the combination of meloxicam or piroxicam and ketorolac are presented. Table 6 illustrates examples of formulations comprising meloxicam and ketorolac where the amounts by weight of the active ingredients, vehicles and / or excipients can be used within the ranges of use mentioned without limiting their use.

Table 4. TOPICAL GENERAL FORMULATION IN CREAM.

COMPONENTS Range of use.

Content for each composition lOOg

Meloxicam 0.2 - 5

Ketorolac tromethamine 0.1 - 10

Dispersing agent 1.0 - 10

Emulsifier 0.5 - 5

Stabilizer 0.5 - 1.5

0.1 - 5.0 viscous agent

Moisturizer 0.5 - 5.0

Regulator or modulator buffer

Purified water 72 - 83

Total lOOg _{^ ^}

Table 5. GENERAL FORMULATION TOPICA IN CREAM.

Table 6. EXAMPLE OF TOPICAL FORMULATIONS IN CREAM.

Range of use

Ingredients Content for each composition lOOg

Formulation Formulation Formulation 1 2 3

Meloxicam 0.2 1 5

Ketorolac tromethamine 0.1 0.6 10

Liquid paraffin 10 6 1

Novemer EC1 5 4 0.5

Triethanolamine 1.5 1 0.5

Carbopol 980 5 0.4 0.1

Glycerin 5 3.2 0.5

Triethanolamine

Purified water 72 83 82.4

Total lOOg lOOg lOOg A process for preparing the topical cream formulation is described below. The steps are:

1. Weigh the components of the formula.

2. In a container of adequate capacity, add 300g of water, adjust the pH to 8.0 with triethanolamine solution and disperse in this solution the Carbopol 980, "Mixture A".

3. In another container place the heavy amount of liquid Paraffin, glycerin.

4. Slowly add the triethanolamine stabilizer and the Novemer EC1 polymer and slowly homogenize the mixture.

5. Disperse the heavy amount of each of the assets in the following order: Ketorolac and subsequently Meloxicam or piroxicam ("Mixture B").

6. Once "Mix B" is homogeneous, add "Mix A" slowly, with vigorous stirring between 5000 and 7000r.p.m.

7. Stir until you have a homogeneous mixture.

8. Determine the final pH of the cream that will be between 7.0 and 10.0, with 7.5 to 8.5 being preferred

So the process for preparing the pharmaceutical composition in cream is characterized in that it comprises the steps of: a) Adjust the pH of water to 8.0 and disperse the gelling or viscosifying agent;

b) Place the dispersing agent and the wetting agent; slowly add the dissociating agent to the gelling or stabilizing agent and the emulsifying agent; homogenize the mixture slowly; dispersing ketorolac or its pharmaceutically acceptable salts and, subsequently, meloxicam or its pharmaceutically acceptable salts; Y

c) Add the mixture of part a) to the mixture of part b) slowly, with vigorous stirring between 5000 and 7000 rpm. until obtaining a homogeneous mixture.

Of the processes described for the manufacture of a gel or cream formulation, it is important to note that the way in which the stable environment for the formulation is stabilized and created is the use of excipient of the type of cosolvent polymer, wetting agent and mainly the use of the stabilizing agent triethanolamine.

In the embodiment of the invention relating to the oral composition, it can be produced in tablet, tablet, granulate, dragee, powder or powder to reconstitute a solution or suspension, solutions or suspensions and, where appropriate, compressibility vehicle, diluent binder, antistatic, lubricant, plasticizer, disintegrant and even present the active ingredients in separate compartments. Finally, on the outer layer, it may or may not contain a polymeric cover that gives it protection from both internal and external factors such as humidity, light, among others.

The present topical formulation was subjected to a stability study in which the formulation was challenged at various temperature and humidity conditions in order to check the stability of the pharmaceutical composition. Also, the topical formulation was subjected to a preclinical study to prove its effectiveness.

STABILITY RESULT

The result of the stability study was performed with topical formulations in Table 3. Table 7 presents the results of the stability study for a formulation without triethanolamine, which is the agent that dissociates the gelling agent.

Table 7. Result of the formulation stability study without triethanolamine.

Table 8 presents the result of the stability study for a formulation containing triethanolamine, an agent that dissociates the gelling agent.

Table 8. Result of the stability study formulation with triethanolamine,

As described in the stability study tables, it is observed that the topical formulation complies with physicochemical stability.

An analysis of the bioavailability of the topical administration formulation was performed, from this study it can be concluded that the combination of meloxicam and ketorolac has an acceptable penetration of the dermal layers into the muscle tissue and with minimal dissemination into the vascular space, which makes it an effective and safe alternative for topical use.

With the bioavailability study it was shown that the diffusion of the drugs meloxicam and ketorolac occurs from skin to muscle, observing that 0.7 to 3.0% is bioavailable in the muscle and the passage of the combination of drugs from muscle to plasma is minimal, considering that even lower percentages can be obtained by the physiological and mechanical barriers of the skin.

The present formulation shows that the microsystem developed with the formulation surprisingly achieves the absorption of meloxicam and ketorolac in addition to ensuring that the ketorolac drug (unstable in acidic medium) remains stable in a basic medium, therefore, there is a formulation Safe, effective and physicochemical stable that offers the presence of fewer adverse effects.

RESULTS OF PRECLINICAL STUDY TO EVALUATE THE ANALGESIC AND ANTI INFLAMMATORY SYNERGIC EFFECT.

Understand ED as an effective dose, KT as ketorolac tromethamine or its salts, MLX as meloxicam.

Experimental tests were carried out that showed that the combination of ketorolac and meloxicam or piroxicam, when administered simultaneously, has a synergistic analgesic and anti-inflammatory effect.

To evaluate the interaction between meloxicam (MLX) and ketorolac (KT) an isobolographic analysis was carried out. This method is based on comparing the determined doses that are equieffective. From dose-response curves of the individual agents, the respective ED ₅₀ are obtained, that is, the dose necessary to reach 50% of the maximum possible effect. In the present study, because meloxicam had a limited maximum activity (ceiling effect), the necessary doses were used to reach 15% (SD ₁₅ ) of possible anti-inflammatory effect for each drug. Meanwhile, for the antihyperalgesic effect, because both drugs had at least 40% maximum effect, ED _40s were used to construct the isobolograms.

The evaluation of the antihyperalgesic and anti-inflammatory effects of the individual and combination drugs was carried out using topical application formulations in the form of a hydrophilic gel. The doses used were similar in all animals and corresponded to 1 g of the gel applied to the plantar surface of the right leg 1 h before the administration of carrageenan.

ISOBOLOGICAL ANALYSIS

Anti-hyperalgesic and anti-inflammatory dose-effect curves were obtained, and by means of linear regression the values of the effective dose of the drugs administered individually are obtained in accordance with the aforementioned. They were subsequently applied Topical ketorolac and meloxicam combinations in doses corresponding to different dilutions of the ED ₄₀ of each drug, estimated in the thermal hyperalgesia model, and with these doses the anti-inflammatory effect of the combinations was evaluated. A fixed proportions scheme was used, according to table 9.

Table 9. Diagram of concentrations used in preclinical study with the combinations of ketorolac and meloxicam.

RESULTS

Antihyperalgesic effect of ketorolac and meloxicam

In the experimental model to evaluate thermal hyperalgesia, 100 μΐ of a 1% carrageenan suspension in saline solution (0.9%) was administered in the lower right plantar bearing of the rat and the withdrawal latency time was determined when the limb is submerged in hot water bath (45 ° C). They were made Withdrawal threshold measurements before administration of carrageenan, and subsequently every half hour to complete 4 hours.

Topical administration of placebo, without administration of carrageenan (Negative Control), did not change the natural withdrawal threshold, which on average occurred at 6 seconds. On the other hand, the administration of carrageenan (Positive Control) induced a sustained decrease in the withdrawal threshold that reaches a minimum of about 60 minutes after the injection of the proinflammatory agent (Figure 1 A-B).

Because Meloxicam does not reach the ED ₅₀ , we worked with the ED ₄₀ (Figures 2A and 2B), with ketorolac, the maximum effect (Emax) was 73.4%, while for meloxicam it is DEmax of 45.5%. For that reason, it was decided to use ED ₄₀ as a power parameter to subsequently evaluate the nature of the analgesic interaction.

Based on these estimates, different combinations of KT and MLX were designed and tested. These combinations maintained a constant proportion of each drug, that is, the proportion of the individual drug in any combination remains constant regardless of the level of total dose administered, allowing the efficacy of the combination to be the product of that proportion. The total dose of the combination, as well as the dose of each drug in each combination is shown in Table 9, in all cases the proportion of KT-MLX remained in a ratio (1: 3.2). Topical administration of KT-MLX combinations decreased hyperalgesic behavior (Figure 3). In addition, the dose-effect curve of topical administration of the KT-MLX combinations revealed a dose-dependent antihyperalgesic effect (Figure 4). From the graphs of both figures (3 and 4) it can be seen that the Emax of the combination (DE _{40 /} 0.5) was 87.3%. Subsequent analysis of the dose-response curve of the combination showed that the experimental SD ₄₀ (SD _40E ; ± ee) was 0.70 ± 0.03 g / 100, that is about 1.7 smaller than SD _40T (p <0.05; Figure 5), the above indicates that this formulation in combination of KT-MLX produces a synergistic interaction in this hyperalgesia model.

Due to the results shown, the combination of ketorolac plus meloxicam produces a hyperalgesic synergistic effect evaluated in a model of thermal hyperalgesia, this is concluded by contrasting the power indicator (DE40) obtained experimentally with respect to the theoretical DE40 of the combination. The graphs of dose-response curves in Figures 2A and 2B show a ceiling in Emax for KT = 73% and for MLX = 45%, while with the KT-MLX combination the Emax, as seen in Figure 4, shows increases up to 87%, which in itself confirms the presence of synergism.

Anti-inflammatory effect of ketorolac and meloxicam in the carrageenan edema model In the experimental model to evaluate the anti-inflammatory response, 0.1 mL of a 1% carrageenan suspension in saline (0.9%) was administered in the right lower plantar bearing. The volume of the leg was measured before the administration of carrageenan and subsequently every half hour until 4 hours were completed.

Topical administration of KT-MLX combinations in proportion (1: 3.2) prevented the formation of edema in a dose-dependent manner (Figure 6).

From the estimation of the dose effect curve (Figure 7) it can be seen that the Emax of the combination was 36.5%. Subsequent analysis of the dose-response curve of the combination showed that the experimental DEi ₅ (DEi _5E ; ± ee) was 0.12 ± 0.09 g / 100, that is about 1.7 smaller than DEi _5T (p <0.05; Figure 8), in a manner very similar to that observed in the hyperalgesia model, that is, this KT-MLX formulation also presents synergism in the anti-inflammatory effect. IRRITABILITY STUDY

A dermal irritability study was carried out that demonstrates that the administration of the present invention is neither irritating nor toxic for such study six healthy albino rabbits were used, for intact skin as eroded, the study was performed according to NOM-096-SSA1-1994 , NOM-039-SSA1- 1993 and Pharmacopoeia of the United Mexican States 8th Edition. The topical synergistic pharmaceutical composition of the combination of meloxicam and ketorolac, or its pharmaceutically acceptable salts, is a useful and effective formulation for treating conditions of mild to severe localized skeletal muscle pain.

The use of the active substances is not limited to those indicated since the formulation can be presented with or instead of meloxicam or ketorolac other NSAID drugs such as, piroxicam, oxicam, diclofenac, triethanolamine salicylate, naproxen among others.

The invention has been described sufficiently that a person with average knowledge in the field can reproduce and obtain the results mentioned in the present description. However, any skilled person in the field of the art that is in charge of the present invention may be able to make modifications not described in the present application. However, if the subject matter claimed in the following claims is required for the application of these modifications in a given composition, said compositions should be within the scope of the present invention.

Claims

1. A pharmaceutical combination characterized in that it comprises an analgesic and an anti-inflammatory, or its pharmaceutically acceptable salts, characterized in that the anti-inflammatory is selected from meloxicam and piroxicam, and the analgesic is ketorolac.

2. A pharmaceutical composition for topical administration, characterized in that it comprises 1) meloxicam or piroxicam and 2) ketorolac, or its pharmaceutically acceptable salts, and pharmaceutically acceptable carriers or excipients.

3. A pharmaceutical composition for oral administration, characterized in that it comprises 1) meloxicam or piroxicam and 2) ketorolac, or its pharmaceutically acceptable salts, and pharmaceutically acceptable carriers or excipients.

4. The pharmaceutical composition according to claim 2, characterized in that it comprises from 0.1 to 10O of ketorolac, or its pharmaceutically acceptable salts, for each 10OOg of said composition.

5. The pharmaceutical composition according to claim 2, characterized in that it comprises from 0.2g to 5g of meloxicam, or its pharmaceutically acceptable salts, for each lOOg of said composition.

6. The pharmaceutical composition according to claim 2, characterized in that it comprises 0.5ga 20g of piroxicam, or its pharmaceutically acceptable salts, for each lOOg of said composition.

7. The pharmaceutical composition according to claim 2, characterized in that it is formulated in the form of a gel, cream, ointment and paste.

8. The pharmaceutical composition according to claim 7, characterized in that it includes a gelling agent and at least one agent that dissociates the gelling agent and maintains the pH from 7.0 to 10.0 in said composition.

9. The pharmaceutical composition according to claim 8, characterized in that the agent that dissociates the gelling agent is selected from the group consisting of ethanolamines, such as monoethanolamine, diethanolamine, triethanolamine or mixture thereof, among others.

10. The pharmaceutical composition according to claim 9, characterized in that it comprises from 2.5 mg to 3.8 mg of agent that dissociates the gelling agent for each 10 mg of said composition.

11. The pharmaceutical composition according to claim 2, characterized in that it comprises 0.5 to 1.5 mg of stabilizing agent for each 10 mg of said composition.

12. The pharmaceutical composition according to claim 8, characterized in that it further comprises :: a vehicle, dispersing agent, preservative, alcoholic cosolvent, wetting agent and / or emulsifying agent.

13. The pharmaceutical composition according to claim 3, characterized in that it can be a tablet, tablet, granulate, dragee, powder or powder to reconstitute a solution or suspension.

14. The pharmaceutical composition according to claim 3, characterized in that it further comprises a compressibility vehicle, binder, diluent, antistatic, lubricant, plasticizer and disintegrant.

15. The pharmaceutical composition according to claim 11, characterized in that the tablet, granulated or dragee, has a polymeric coating on the outer layer which confers protection from both internal and external factors.

16. The pharmaceutical composition according to claim 3, characterized in that it comprises ketorolac or its pharmaceutically acceptable salts, from lmg to 120mg for each lOOg of said composition.

17. The pharmaceutical composition according to claim 3, characterized in that it comprises meloxicam or its pharmaceutically acceptable salts, from 2mg to 30mg for each lOOg of composition.

18. The pharmaceutical composition according to claim 3, characterized in that it comprises piroxicam or its pharmaceutically acceptable salts, from 2.5mg to 60mg for each lOOg of composition.

19. A pharmaceutical composition for the treatment of pain and inflammation, characterized in that it comprises at least the following components in the following doses, in a single pharmaceutical form: a) ketorolac 2mg-120mg; and b) meloxicam 0.2mg - 30mg or piroxicam 2.5mg - 60mg.

20. The pharmaceutical composition according to claim 12, characterized in that the dispersing agent is selected from propylene glycol, polyethylene glycol or glycol derivatives, liquid paraffin, vinyl acid polymers, among others.

21. The pharmaceutical composition according to claim 12, characterized in that the preservative agent is selected from: parabens, ethylparaben, methylparaben, butylparaben, sodium benzoate, among others.

22. The pharmaceutical composition according to claim 8, characterized in that the gelling agent is selected from: polymers of vinyl acid, lutrol, hydroxypropyl cellulose, among others

23. The pharmaceutical composition according to claim 12, characterized in that the cosolvent is selected from: ethyl alcohol, isopropyl alcohol, methanol, among others.

24. The pharmaceutical composition according to claim 12, characterized in that the wetting agent is selected from: glycerin, sorbitol, polyethylene glycol, among others.

25. The pharmaceutical composition according to claim 12, characterized in that the emulsifying agent is selected from: castor oil, cremophor RH40, Novemer, soy lecithin, twens, among others; buffer regulator or modulator: organic excipients such as lactic acid, triethanolamine or others.

26. The use of the pharmaceutical combination comprising 1) meloxicam or piroxicam and 2) ketorolac, to prepare a medicament useful for the treatment of inflammation and pain.

27. The use of the pharmaceutical composition according to claims 2 6 3, to prepare a medicament useful for the treatment of inflammation and pain.

28. A process for preparing the pharmaceutical composition according to claim 12, characterized in that it comprises the steps of:

a) Mix and disperse the gelling or viscosifying agent in purified water until completely homogeneous; b) Mix and dissolve the alcoholic cosolvent and the preservative; add the dispersing agent, the wetting agent, the emulsifying agent and meloxicam or piroxicam, or their pharmaceutically acceptable salts, until homogeneous; adjust to a pH between 8 and 8.5; stabilize with the addition of the dissociating agent to the gelling agent or stabilizing agent;

29. A process for preparing the pharmaceutical composition according to claim 12, characterized in that it comprises the steps of:

a) Adjust the pH of water to 8.0 and disperse the gelling or viscosifying agent;

b) Place the dispersing agent and the wetting agent; slowly add the dissociating agent to the gelling or stabilizing agent and the emulsifying agent; homogenize the mixture slowly; dispersing ketorolac or its pharmaceutically acceptable salts and, subsequently, meloxicam or piroxicam, or pharmaceutically acceptable salts thereof; Y c) Add the mixture of part a) to the mixture of part b) slowly, with vigorous stirring between 5000 and 7000 rpm until a homogeneous mixture is obtained.