OA17881A - Topical formulations of heparin. - Google Patents

Abstract

The present invention relates to advanced topical formulations of pharmaceutically acceptable salts of Heparin providing enhanced transdermal penetration. The present invention provides clear, non-sticky liquid formulations in which the drug is ready-for- absorption and which are suitable for administration in the form of a solution or a spray. The topical formulations of the present invention do not form flaky or gel-like film on skin surface upon topical application.

Description

TOPICAL FORMULATIONS OF HEPARIN

FIELD OF THE INVENTION

The présent invention relates to topical formulation of pharmaceutically acceptable salts of Heparin. The présent invention more particularly relates to advanced topical formulation of 10 heparin salts providing enhanced transdermal pénétration.

BACKGROUND OF THE INVENTION

Superficial venous thrombophlebitis (SVT) is a condition of inflammation of vein caused by a thrombus formation in a vein below the skin surface resulting from an injury to vein. It is also caused due to the use of intravenous catheterization or a surgical procedure.

Infusion related superficial venous thrombophlebitis (SVT) is cornmon in hospitalized patients who receive intravenous thérapies. This localized thrombophlebitis increases pain and suffering of patients resulting in increased cost of therapy due to frequent change of venous cathéter lines as well as treatment of complications of local venous thrombophlebitis. (Arun B and Sharmila V. Prophylactic topical heparin can prevent or postpone intravenous cannula induced superficial thrombophlebitis. Med Hypothèses 2010; 74: 857-858). Superficial venous thrombophlebitis may also complicate varicose veins. According to published literature, the incidence of this complication ranges between 5.6 and 44 %. (Katzenschlager R, Ugurluoglu A, Hirsch M. Liposomal heparin-spraygel in comparison with subcutaneous low molecular weight heparin in patients with superficial venous thrombosis. A 25 randomized, controlled, open multicentre study, J Kardiol 2003; 10(9): 375-378)

Heparin is used in the treatment of SVT topically as well as systemically. It belongs to a group of compounds that inhibit blood coagulation and/or the compounds that inhibit platelet aggregation. The topical use of such compounds is more convenient option than the systemic delivery. Apart from the avoidance of further complications due to systemic delivery, locally 30 acting anticoagulants/ antithrombotic agents hâve positive effects on the réduction in the size of thrombus (Clôt) and pain/inflanimation. Topical heparin formulations are also used for management of varicose veins bruises due to various types of external injuries, inflammable infiltrâtes and venous ulcers. (Belcaro G, Cesarone M, Dugall M, Feragalli B, Ippolito E, Corsi M et al. Topical formulation of heparin is effective in reducing the symptoms of superficial venous thrombosis: a monocenter, observer-blind, placebo-controlled randomized study. Panminerva Med 2011; 53 (Suppl. 1 toNo. 3): 3-11)

Topical formulations of heparin or its pharmaceutically acceptable salts are used for the treatment of thrombophlebitis. These formulations are available in the form of viscous gels, thixotropic sprayable gels, ointments, creams or in the form of liposomal formulations, 10 wherein the drug is incorporated in a Phospholipid bilayer. Higher dose of topical heparin formulations hâve advantageous therapeutic effects as compared to the lower dose formulations. Despite the use of high concentration of Heparin sait in the formulation inadéquate skin pénétration of the drug from the known topical formulations leads to sub-par therapeutic effects. This is évident from the longer duration of treatment required to subside 15 the symptoms such as pain and inflammation associated with thrombophlebitis.

The dose of heparin or its variants with different molecular weights such as enoxaparin or Heparin salts such as Heparin sodium, Heparin calcium or heparinoids are mentioned in terms of International Units (IU). Topical formulations of heparin with strength ranging from 50 to 2500 IU/gm are recommended.

Heparin or its salts when used by topical route of administration are intended to provide action below the superficial skin layer. To provide adéquate therapeutic benefits it is necessary that these formulations are well absorbed through the skin. Most of the topical formulations applied on the skin in the form of creams/ointments/gels/liposomes do not provide requisite pénétration of the drug from the stratum comeum barrier of the skin in requisite concentration and hence, rather than providing desired therapeutic benefit, they merely work as good as a placebo. The formulations containing various ingrédients such as thixotropy inducing agents although claim to provide sprayable formulations they resuit in the formation of a flaky film on the surface of affected area which makes such formulations unacceptable and cosmetically unpleasant for the patient.

Conventional approaches for providing topical formulations of heparin or its sait incorporate the use of lipid-like greasy ingrédients or polymers or other ingrédients that make them sticky and/or gel-like (highly viscous) in nature and therefore, require sufficient pressure for application of the same on the affected area and/or results in formation of a flaky or gel-like film on the skin surface. Some of the formulations also mandate potent/cytotoxic components such as DMSO which may further irritate the skin of the target area leading to patient discomfort.

Ail these topical formulations of Heparin or its sait use high proportion of water as the principal carrier without considering the impact of such predominantly aqueous formulations on transdermal pénétration of Heparin.

Various approaches hâve been adopted to provide enhanced pénétration of different pharmaceutically active agents especially polar active agents such as the salts of a 10 pharmaceutically active agent. One of them is the incorporation of lipophilie pénétration enhancers in the oily phase and the drug in the aqueous phase by way of formulating emul sions/mi croemul sions.

Further, various emulsifiers/surfactants are employed to dissolve the highly lipophilie component by formation of micelles in a system containing water or by preparing oil in water 15 (o/w) émulsions. However, such émulsion formulations, unless well formulated, are highly unstable in nature and tend to cream due to the coalescence of lipid globules upon storage resulting in non-uniform dose distribution in a formulation. It is also important to control the globule size of the dispersed phase in such a formulation to ensure dose uniformity and stability. These émulsions are available in the form of opaque creams, lotions or translucent 20 formulations.

Another approach is the incoiporation of a phospholipid component in the formulation as an essential ingrédient which engulfs the drug in solubilized state to form vesicles filled with aqueous solution of the drug, known as liposomes. However, apart from the inhérent stability issues, formulation of such system is complex, highly time consuming and non-reproducible.

Further, some to the formulations also suggest the use of predominantly aqueous Systems which mandates the use of spécifie excipients in the form of a polymer or a surfactant or one or more pénétration enhancers. None of these focus on arriving at an improved carrier system which in itself is capable of providing optimum transdermal pénétration even in absence of the ingrédients such as surfactants or use of high proportion of pénétration enhancers.

Therefore, there is an unmet need for stable topical formulations capable of providing pharmaceutically acceptable salts of heparin in a therapeutically effective amount that provide enhanced pénétration of the drug and at the same time provide excellent patient compliance with pleasant feel on the skin surface as well as reduced untoward effects.

W002083086A1 discloses topical pharmaceutical formulations used in the treatment of skin and/or mucous membrane injuries more specifîcally injuries related to burns. These formulations contain atleast one osmolarity correcting agents.

WO2011138262 discloses topical solutions of Heparin & atleast one polyoxyalkylene ester of hydroxy fatty acid in water and atleast one alcohol or mixture thereof.

EP0733357B1 discloses thixotropic topical formulation with gel-like consistency containing colloïdal silicates as gelifying agents which are nebulizable by a mechanical pump.

US5958379 discloses pharmaceutical composition of topically applicable substance which upon spraying on affected area forms a concentrated gel-like préparation on the skin/mucous mucous membrane surface wherein the composition contains easily evaporable alcohol(s) in 15 the range of 5 to 40 % by weight and water in the range of 50 to 90% by weight.

US2002032171 discloses pharmaceutical composition of therapeutic agents in a carrier, wherein the carrier is formed from a combination of triglycéride and atleast two surfactants, at least one of which is hydrophilic. Upon dilution with an aqueous medium these formulations resuit in a clear aqueous dispersion of triglycéride and surfactants.

There is a need for the topical formulations of pharmaceutically acceptable salts of Heparin capable of providing safe, stable, reproducible dosage forms for a requisite amount of drug using optimum amount of water which at the same time provide enhanced transdermal pénétration and are administered with ease leading to better patient compliance.

OBJECT OF THE INVENTION

The main object of the présent invention is to provide formulations of pharmaceutically acceptable salts of Heparin with excellent transdermal pénétration and enhanced therapeutic effectiveness when applied topically in conditions such as Superficial Venous thrombophlebitis (SVT).

Another object of the invention is to provide stable topical formulations of pharmaceutically 30 acceptable salts of heparin in the form of a clear, non-sticky, water washable liquid formulation which is suitable for administration preferably in the form of a solution or a spray and which does not resuit in the formation of a flaky/gel-like fdm after application to the skin surface.

Another object of the invention is to provide topical formulations of pharmaceutically acceptable salts of Heparin that provide enhanced patient compliance and reduced adverse effects.

It is another object of the présent invention is to provide clear, transparent, reproducible topical formulation of pharmaceutically acceptable salts of Heparin with the dose ranging 10 from 50 to 2500 IU/ml by using optimum amount of water.

The homogeneous topical formulations of the présent invention provide pharmaceutically acceptable salts of heparin in a homogeneous “ready-for-absorption” composition which does not require partitioning of the drug from one phase to the other phase of the formulation and provides rapid pénétration of the drug through the skin.

The présent invention provides topical formulation of pharmaceutically acceptable salts of heparin in the form of a clear transparent solution that is not only easily administered on the affected area but also provides quick and enhanced pénétration of drug through skin without leaving any sticky/gel-like or flaky residues on the skin.

SUMMARY OF INVENTION

According to an aspect of the présent invention there is provided topical formulations of pharmaceutically acceptable salts of Heparin comprising:

to 2500 IU/ml of pharmaceutically acceptable salts of Heparin;

less than or equal to 30% v/v of water;

to 30 % v/v of a lower chain alcohol; and a water miscible vehicle selected from a group comprising propylene glycol, glycerol, glycofurol, polyethylene glycols or any mixtures thereof.

DESCRIPTION OF FIGURES

Figure 1: Comparison of length of the venous lésion on day 3

Figure 2: Change in the grade of venous lésion at baseline (a) and at day 3 (b)

Figure 3: Proportion of patients with complété healing on day 7

Figure 4: Patients (a) and Physicians (b) global assessment for Heparin formulations of présent invention (Example 13) and marketed Heparin gel

DETAILED DESCRIPTION OF THE INVENTION

The présent invention meets the above mentioned and other needs by providing topical formulations of pharmaceutically acceptable salts of heparin in the form of a homogeneous liquid formulation with an advanced carrier system.

The inventors of the présent invention surprisingly found that it is possible to préparé a clear 10 transparent formulation of pharmaceutically acceptable salts of Heparin in an amount ranging from 50 IU/ml to 2500 IU/ml in an advanced carrier system wherein, the drug is incorporated in a formulation comprising optimum amount of water in combination with sufficient amount of water-miscible/non-aqueous carrier system and yet provide enhanced pénétration of the drug across the skin.

The homogeneous formulations of présent invention are in the form of clear transparent solutions which are more stable upon storage as compared to the formulations containing a dispersed phase such as vesicles, micelles or thixotropic gels which has the tendency of creaming or cracking. At the same time, the formulations of the présent invention are capable of providing excellent pénétration of the requisite dose of drug incorporated in the 20 formulations.

Formulations in accordance with the présent invention not only provide stable formulations of Heparin salts but also surprisingly results in the enhanced transdermal pénétration and thereby provide drastic improvement in the therapeutic effect of the drug. The topical formulations of the présent invention are in the form of clear homogenous solution which 25 inay be used in the form of a spray.

In the formulations of présent invention, the drug is available in a uniformly solubilized state in the homogeneous formulation and the absorption of drug from the formulation is instantaneous and reproducible. These formulations advantageously are in the from of a clear transparent solution which can be applied easily to the affected area without providing 30 pressure or leaving a sticky/gel-like or flaky residue on the skin surface and at the same time resulting in improved patient compliance when compared to relatively viscous formulations such as viscous-gels, creams, ointments, etc.

The desired viscosity of the formulation in the présent invention is not more than 50 mPa-s (when measured at 25°C by using Ostvvald viscometer.). Preferably the viscosity of the formulations in the présent invention is in the range to 10 to 50 mPas. More preferably the viscosity of the présent invention is in the range of 25 to 40 mPas.

It was surprising that the formulations of présent invention provide the abovementioned and other benefits by using an advanced carrier system with optimum amount of water and by using a sélection of ingrédients in proportion that are safe when applied topically and therefore minimise the adverse reactions and in turn contribute positively to the health of the patients.

The formulations in accordance with the présent invention provide dose of Heparin sait in a therapeutically effective amount which can elicit desired transdermal pénétration and at the same time are safe when applied topically. Preferably, the amount of pharmaceutically 15 acceptable salts of Heparin is in the range of 50 to 2500 IU/ml.

Most surprisingly, the formulations of the présent invention are capable of providing heparin sait in an amount ranging from 50 to 2500 HJ/ml by using optimum amount of water in combination with a water-miscible canier(s) as the principal vehicle and yet provide enhanced transdermal pénétration.

The formulation in accordance with the présent invention incorporâtes water in a optimum amount in combination with a carrier system or the “base” of the formulation that augmente the transdermal pénétration of the drug. Preferably, the amount of water incorporated in the présent formulation is less than or equal to 30% v/v and more preferably less than or equal to 25% v/v. The amount of water used in the formulation of présent invention is in the range of 25 2% to 30% v/v of the formulation. More preferably, the amount of water in the formulation of the présent invention ranges from 2 to 25% v/v of the formulation. In a preferred embodiment, the amount of water used in the formulation of the présent invention is less than or equal to 10 % v/v of the formulation.

The pénétration enhancer(s) used in accordance with the présent invention are lower chain alcohol(s) with a carbon chain length ranging from Cl to C5 or mixtures thereof. Preferably, the pénétration enhancers of the présent invention are selected from a group comprising éthanol, isopropanol and their like, or mixtures thereof. The formulations of the présent invention avoid the use of such pénétration enhancers in high proportion and thereby avoid adverse effects on the skin such as déhydration and irritation of skin in case of alcohols. The said pénétration enhancer(s) of the présent invention is used in the range of 10 to 30% v/v of the formulation. In the preferred embodiments, the pénétration enhancer of the présent invention is used in the range of 10 to 20% v/v. Most preferably the pénétration enhancer(s) is used in the amount of 10% v/v of the formulation.

The formulations of présent invention use one or more water-miscible vehicle(s) as the principal vehicle of the topical formulations. The said water-miscible vehicle used for the 10 formulations of the présent invention can be selected from a group comprising Propylene

Glycol, Glycerol, Glycofurol, Poly Ethylene Glycols (e.g. PEG400, PEG600 an the like) or mixtures thereof. The said vehicle for the topical formulations of the présent invention is incorporated in an amount not less than 45% v/v preferably not less than 50% v/v of the formulation.

The formulations of the présent invention use a carrier system wherein the amount of the said water-miscible vehicle (either single component or combination of multi-components) is incorporated in a proportion always higher than the proportion of water used in the présent formulation.

In one of the embodiments of the présent invention, the water-miscible vehicle used for the formulations of the présent invention is propylene glycol either alone or in combination with one or more of Glycerol, Glycofurol, Poly Ethylene Glycols (e.g. PEG400, PEG600 an the like). Preferably, the water-miscible vehicle used in the formulations of the présent invention comprises a combination of propylene glycol and Glycerol. Most preferably, the watermiscible vehicle of the formulation of the présent invention comprises a combination of propylene glycol and Glycerol wherein the Glycerol is used in an amount ranging from 10 to 20% v/v of the formulation.

It is surprising to note that unlike the formulations known in the art, by use of such a carrier system in combination with the pénétration enhancer the formulation of the présent invention are highly stable and surprisingly provide enhanced transdermal pénétration of Heparin Sait.

The formulations of the présent invention may further comprise additional pénétration enhancer(s). The additional pénétration enhancer(s) of the présent formulation can be selected from a non-limiting group of pénétration enhancers known in the art such as fatty acids or fatty acid dérivatives, Surfactants (Anionic, cationic or non-ionic surfactants), Azones (such as Lauracapram), Amides (such as Urea and its dérivatives), Esters (such as Ethyl acetate,

Octyl salicylate), Ethers (such as Dimethyl-isosorbide), Bile salts (such as sodium deoxycholate, sodium taurocholate or sodium glycocholate), Polyols or Glycol dérivatives (such as Dipropylene glycol, Monoethyl ether of diethylene glycol) or complex forming agents such as (cyclodextrin or dérivatives thereof) etc. The said additional pénétration enhancer(s) can be used in an amount ranging from 0% to 30% v/v of the formulation.

Additionally, the formulations of the présent invention may comprise ingrédients known in the art to further improve or impact the acceptability/stability of the topical formulation of the présent invention. Such ingrédients known in the art may be selected from but are not limited to a group comprising, preservatives, stabilizers, anti-oxidants, humectants, colouring agents, pH-modifîers, buffers or perfumes or mixtures thereof.

It was observed that the formulations of présent invention provide superior pénétration of Heparin sait, as compared to the comparative formulations comprising water as the principal carrier and non-polar solvents such as Propylene Glycol in a relatively lower amount. Further, the présent formulations also provide enhanced pénétration of Heparin sait as compared to the formulations available in the market (Thrombophob® Gel 200 IU).

Non-limiting examples of the formulations of the présent invention in the form of a clear transparent solution are as provided below.

EXAMPLE 1

INGREDIENTS	QUANTITY
Heparin Sodium	lOOOIU/ml
Ethyl alcohol	10% v/v
Water	3.5% v/v
Propylene Glycol	Qs to 100 %

Viscosity of the formulation is 23 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 2

INGREDIENTS	QUANTITY
Heparin Sodium	1000 IU/ml
Ethyl alcohol	10% v/v
Water	3.5 % v/v
PEG 400	30% v/v

Propylene Glycol

Qs to100 %

Viscosity of the formulation is 35 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 3

INGREDIENTS	QUANTITY
Heparin Sodium	1000 RJ/ml
Ethyl alcohol	10% v/v
Water	3.5% v/v
Glycofurol	35% v/v
Propylene Glycol	Qs to 100 %

Viscosity of the formulation is 30 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 4

INGREDIENTS	QUANTITY
Heparin Sodium	1000 IU/ml
Ethyl alcohol	10.0% v/v
Water	3.5% v/v
Glycerol	10 % w/v
Propylene Glycol	Qs to 100 %

Viscosity of the formulation is 32 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 5 .

INGREDIENTS	QUANTITY
Heparin Sodium	1000 IU/ml
Ethyl alcohol	10.0% v/v
Water	12.5% v/v
Glycerol	10 % w/v
PEG400	Qs to 100 %

Viscosity of the formulation is 47.76 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 6

INGREDIENTS	QUANTITY
Heparin Sodium	1000 IU/ml
Ethyl alcohol	10.0% v/v
Water	20 % v/v
Glycerol	10 % w/v
PEG400	Qs to 100 %

Viscosity of the formulation is 37.45 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 7

INGREDIENTS	QUANTITY
Heparin Sodium	1000 IU/ml
Ethyl alcohol	10.0% v/v
Water	3.5% v/v
Glycerol	15 % w/v
Propylene Glycol	Qs to 100 %

Viscosity of the formulation is 35 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 8

INGREDIENTS	QUANTITY
Heparin Sodium	1000 IU/ml
Ethyl alcohol	12.5 % v/v
Water	16 % v/v
Transcutol	3 %
Glycerol	20 % w/v
Propylene Glycol	Qs to 100 %

Viscosity of the formulation is 20 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 9

INGREDIENTS	QUANTITY
Heparin Sodium	1000 IU/ml
Ethyl alcohol	10.0 %v/v
Water	25 % v/v
Glycerol	10 % w/v
PEG 400	Qs to 100 %

Viscosity of the formulation is 34.3 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 10

INGREDIENTS	QUANTITY
Heparin Sodium	2500 IU/ml
Ethanol	10% v/v
Water	6.5 % v/v
Glycerol	10 % w/v
Propylene Glycol	Qs to 100 %

Viscosity of the formulation is 27 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 11

INGREDIENTS	QUANTITY
Heparin Sodium	2500 IU/ml
Ethanol	10% v/v
Water	20.0 % v/v
Tween 80	0.5 % w/v
Glycerol	20 % w/v
Propylene glycol	Qs to 100 %

Viscosity of the formulation is 21 mPa-s when measured at 25°C by using Ostwald viscometer.

EXAMPLE 12

INGREDIENTS	QÜANTITY
Heparin Sodium	2500 IU/ml
Ethanol	15% v/v
Water	25.0 % v/v
Glycerol	15 % w/v
PEG400	20 % v/v
Glycofurol	Qs to 100 %

Viscosity of the formulation is 30 mPa-s when measured at 25°C by using Ostwald viscometer.

The viscosity of the formulations in the présent invention is in the desired range of 10 to 50 mPas and the pH of the formulations is maintained nearly neutral similar to the physiological pH of the skin surface (pH 6 to 7) to avoid any irritation to the skin. If required, in order to maintain the pH of the formulations in the desired range, pH adjusting agents or buffers known in the art may also be included in the formulation. The formulations of the présent 15 invention were found to be stable on storage for duration of complété shelf life of the formulations.

Non-limiting examples of the présent invention, detailed above can be prepared by the formulation processes known in the art. An outline of the process steps employed to préparé the formulations of the présent invention comprises:

1. Desired amount of Heparin sait and other hydrophilic excipients (if used) are dissolved iii water.

2. The solution resulting from step 1 is mixed with a part of water-miscible carrier system.

3. Hydrophobie ingrédients such as preservatives etc. (if used) are solubilised in the pénétration enhancer of présent invention.

4. The solution resulting from step 2 above is mixed with the solution resulting from the step above.

5. Auxiliary ingrédients such as the pH modifiers (if any) are added to the mixture obtained at

Step 4 above.

6. The final volume of the formulation is made-up using sufficient quantity of the watermiscible carrier System.

Further, in order to study the effect of the change in the proportion of water used in the 10 présent formulations and compare the same with the formulations containing water in a proportion higher than the water-miscible vehicle, formulations with the following formula were prepared and tested for in vitro transdermal pénétration of Heparin Sait.

Table 1: Formulations for In Vitro Transdermal pénétration studies:

INGREDIENTS	QUANTITY
Example 13	Example 14	Example 15	Example 16 (Comparative Example)	Example 17 (Comparative Example)	Example 18 (Comparative Example)
Heparin Sodium	1000 IU/ml	1000 IU/ml	1000 IU/ml	1000 IU/ml	1000 IU/ml	1000 IU/ml
Ethyl alcohol	10% v/v	10 % v/v	10% v/v	10% v/v	10% v/v	10% v/v
Glycerol	15% w/v	15% w/v	15% w/v	15 % w/v	15 % w/v	15 % w/v
Methyl Paraben	0.15% w/v	0.15% w/v	0.15 % w/v	0.15 % w/v	0.15 % w/v	0.15 % w/v
Propyl Paraben	0.05 % w/v	0.05 % w/v	0.05 % w/v	0.05 % w/v	0.05 % w/v	0.05 % w/v
Water	3.5 % v/v	10% v/v	25 % v/v	35% v/v	50% v/v	Qs to 100 %
Propyl ene Glycol	Qs to 100%	Qs to 100 %	Qs to 100%	Qs to 100 %	Qs to 100 %	10% v/v

The in vitro transdermal pénétration of Heparin Sait was compared in the formulations of the 15 présent invention (Example 13, 14, 15), with the comparative formulations (Example 16, 17,

18) and the formulations available in the market (Thrombophob gel, Zydus) through Franzdiffusion studies.

APPARATUS: Franz Diffusion Cell Assembly (PermeGear, USA) containing six station vertical cell stirrer and a black anodized aluminum cell holder with the spécification of 9 mm 20 inside diameter of receptor chamber, 5 ml volume of receptor chamber and 0.64 cm² of membrane surface area was used for the présent study.

PERMEABILITY STUDY: Permeability study was carried out with Nylon membrane placed between donor and receptor chambers of Franz diffusion cell. HPLC grade water was filled in receptor chamber and continuously stirred at 500 rpm throughout the experiment using built in magnetic stirrer. The température of HPLC grade water in receptor chamber was maintained at 37°C by circulating water in the jacket around it. Measured quantity of Heparin 10 formulations were placed in donor chamber in duplicate, as given below in the table, after the température of HPLC grade water in receptor chamber reached equilibrium (37°C). The samples (0.5mL aliquots) were withdrawn at predefined intervals up to 6 hours from the sampling port of receptor chamber. Equal volume of HPLC grade water, maintained at 37°C was used to replace the loss in volume of the receptor chamber immediately after sampling.

Collected samples were analyzed within 24 hours by HPLC.

RESULTS: The levels of Heparin sait in receptor chamber was measured with time and the average values (n=2) were used to détermine Flux, Permeability coefficient and other parameters as mentioned in the table below (Table 2):

Table 2: In vitro Permeability results

Formulation	Permeability Parameters
Flux (ug/cm2/hr)	Permeability Coefficient (Kp)	% Dose Penetrated At 6 Hour
Example 13	127.3	0.1273	93.71
Example 14	135	0.135	92%
Example 15	141.3	0.1413	90.19
Example 16	102.4	0.1024	72.97
Example 17	97	0.097	66.08
Example 18	79.51	0.07951	58.84
Thrombophob Gel	0	-	-
(The amount of Heparin sodium in the sample was below the détection limit)

The results of Franz-diffusion studies clearly show that the pénétration (flux) of Heparin Sodium is signifîcantly higher from the formulations of the présent invention as compared to the formulation using relatively higher amount of water (Example 16, 17, 18). It was surprising that when the amount of water used in the topical formulation of Heparin sodium 25 is increased beyond a range, the pénétration of Heparin sodium reduces drastically. This is further established from the fact that the pénétration of Heparin Sodium from the présent formulations (Example 13 to 15) is drastically higher than the marketed Heparin Sodium formulation (Thrombophob Gel) which uses water as the principal carrier system.

In order to validate the above outcome of the in vitro studies, a randomized, open label, comparative clinical study was conducted to compare the safety and efficacy of topical 10 solutions of the présent invention (Example 13), with Heparin gel formulations available in the market (Thrombophob Gel) for the management of post infusion superficial thrombophlebitis.

This prospective, randomized, two arm, open label, active controlled phase ΙΠ clinical study was conducted at six different hospitals across India. Patients of either sex aged between 1815 60 years, having early Grade 2-4 phlebitis (medium or advanced stage of superficial thrombophlebitis) based on phlebitis scale as per “Standards for Infusion Therapy” by Royal College of Nursing IV Therapy Forum July 2003; were included in the study. Total 202 patients were enrolled and randomized to either receive Heparin formulations of the présent invention (Example 13) (n=100) or the Heparin gel (n=102). The study médications were 20 applied in sufficient amount to cover the phlebitis lésion 3 times daily (moming, noon and evening) until healing or for maximum of 7 consecutive days.

Primary efficacy endpoints were, change in length of the venous lésion on day 3, change in the grade of the lésion on day 3, proportion of patients with complété healing on day 3 and 7; while secondary efficacy endpoints included local symptoms on day 3, and global assessment 25 by patients and investigator at the end of study. Safety endpoints included occurrence of local or systemic adverse events with study treatments. Length of venous lésion in millimeter was measured using pre calibrated stainless steel scale and grade of the lésion was noted using Phlebitis Scale before the start of study (at baseline) and on day 3 after initiation of the treatment. Phlebitis scale was assessed on a 5 grade scale detailed below: (Table 3)

Table 3 : Phlebitis scale as per standard for infusion therapy

Grades of phlebitis	Indications
Grade 0	No sign of phlebitis
Grade 1	Possibly the first sign of phlebitis
Grade 2	Early sign of phlebitis

Grade 3	Medium stage phlebitis
Grade 4	Advance stage of phlebitis or stage of thrombophlebitis
Grade 5	Advanced stage of thrombophlebitis
Note: Grades are defined as per the Phlebitis scale according to the Standards for Infusion Therapy, by Royal College of Nursing IV Therapy Forum, July 2003

On the basis of this scale, proportion of patients with complété healing (Grade 0 as per phlebitis scale) was noted on day 3 and 7. Local symptoms like pain, tenderness, redness, raised local température and venous indurations were assessed on 4 point severity scale (0None, 1- Light, 2- Moderate, 3- Severe) at baseline and on day 3.

The data was obtained from a total of 202 patients and were subjected to statistical analysis.

Demography (âge, gender, height and weight) and baseline characteristics (mean length of the venous lésion, local symptoms, and grade of phlebitis) were comparable between both the treatment groups (Table 4). Ail the enrolled patients had unilatéral superficial thrombophlebitis on upper limb.

Table 4: Démographie and baseline characteristics

Characteristics	Heparin formulations of présent invention (Example 13) (N=100)	Heparin Gel (N=102)	p value
Age (Years) [mean ± SD]	41.45 ±12.29	38.22 + 13.59	0.079
Weight (kg) [mean ± SD]	64.20 ±12.41	63.24 ± 13.47	0.601
Height (cm) [mean ± SD]	161.47 ±07.39	160.33 + 08.15	0.302
Gender
Male (n)	60	57	0.553
Female (n)	40	45
Length of the venous lésion (mm) [mean ± SD1	31.95 ± 14.98	32.67+ 17.16	0.7509
Local symptoms [mean ± SD]
Pain	01.88 ±00.57	01.88 ±00.69	1.000
Tenderness	01.90 ±00.59	01.87 + 00.71	0.744
Redness	01.06 ±00.69	01.12 ±00.69	0.537
Local température	00.91 ±00.67	00.80 ±00.70	0.255
Venous induration	00.71 ±00.81	00.75 ± 00.74	0.715
Grade of phlebitis (N)

Early stage (Grade 2)	56	52	0.7634
Medium stage (Grade 3)	35	39
Advanced stage (Grade 4)	09	11
Values are expressed in Mean ± SD for âge, weight, height, length of venous lésion and local symptoms; and absolute numbers for gender and grade of phlebitis, N = number of patients.

Primary Efficacy end-points:

1. Change in length of the venons lésion: A significantly higher réduction in length of venous lésion from baseline was observed in patients treated with the Heparin formulations of présent invention (Example 13) on day 3, as compared to patients treated with heparin gel (p = 0.0144). (See Figure 1)

2. Change in the grade of venous lésion: Grade of venous lésion was comparable between both the treatment groups at baseline (p = 0.7634), however a significant fall in percentage of patients with grade 2 & 3 was reported in patients treated with Heparin formulations of présent invention (example 13) as compared to heparin gel (p = 0.0133) (See Figure 2 (a) & (b)).

3. Proportion of patients with complété healing: In the Heparin formulations of présent invention (example 13) treatment group, 90% of the patient achieved complété resolution of the lésion on day 7, this was significantly higher as compared to 65.7% of the patients treated with heparin gel. (p < 0.00001) (Figure 3)

Secondary efficacy end points:

1. Changes in local symptoms from baseline: The local symptoms were comparable at baseline in both the treatment groups. There was significant fall in tendemess and raised local température as compared to baseline in patients treated with Heparin formulations 25 of présent invention (Example 13) as compared to heparin gel (Table 5).

Table 5: Changes in local symptoms score from baseline on day 3

Symptoms	Heparin formulations of présent invention (example 13) (N=T00)	Heparin gel (N= 102)	P value
Baseline score	Day 3 score	Change in the score	Baseline score	Day 3 score	Change in score
Pain	1.88±0.57	1.11+0.67	0.77 + 00.68	1.88+0.69	1.27+0.75	0.61 ± 00.62	0.082

Tendemess	1.90±0.59	0.99±0.59	0.91 ± 00.65	1.87±0.71	1.18±0.79	0.69 ± 00.67	0.019#
Redness	1.06±0.69	0.40±0.491	0.66 ± 00.71	1.12±0.69	0.52±0.56	0.60 ± 00.69	0.543
Raised Local température	0.91±0.67	0.27±0.45	0.64 ± 00.66	0.80±0.70	0.38±0.55	0.42 ± 00.60	0.014#
Venous induration	0.71±0.81	0.29±0.46	0.42 ± 00.65	0.75±0.74	0.35±0.54	0.40 ± 00.68	0.831
Values are expressed in Mean ± SD, N = num # Statistically significant	1er of patients.

2. Patient’s and Physician’s global assessment

Heparin formulations of présent invention (example 13) was rated Excellent - Good in most of the cases by patients (p < 0.00001) and physicians (p < 0.00001) (See Figure 4 (a) and (b)).

Safety endpoints: No cases of any expected or unexpected, local as well as systemic adverse 10 events were reported/observed during study. No case of any abnormality in the vital data as well as in physical examination was found during study.

Discussion: The study revealed that the formulation of the présent invention was found to be more effective than heparin gel as the said formulations significantly reduced the length of venous lésion. Also présent formulation was found to hâve an excellent clinical response in 15 term of healing as 90% of the patients experienced complété resolution of the lésion and local symptoms compared to 65.7% of the patients treated with heparin gel. These favourable results may be attributed to the higher pénétration of heparin through the skin achieved by the formulations of the présent invention. Further, more number of patients who were treated with the formulations of the présent invention experienced significantly better improvement 20 in grades of venous lésion from baseline phlebitis as compared to Heparin gel.

In our study, no case of any adverse events was recorded which suggests that, while improving the efficacy of heparin through quick penetrating solutions of the présent invention, safety of the patients was not vitiated.

Based upon the overall efficacy and safety of both the study drugs, patients and investigator 25 global assessment was more favourable towards heparin formulations of présent invention (example 13) than heparin gel. Further, greater improvement in efficacy of heparin with similar safety profile may hâve contributed to the higher preference of heparin formulations of présent invention (example 13).

Conclusion: The Heparin formulation of présent invention (Example 13) was found to be more effective in treatment of post infusion superficial thrombophlebitis with similar safety profile to marketed heparin gel. Hands free usage of Heparin formulations of présent invention (example 13) would facilitate ease of application and improve compliance of patients as well as nursing staff. Therefore, heparin formulations of présent invention 10 (example 13) can be a better and more convenient alternative in the management of post infusion superficial thrombophlebitis.

The results of the clinical study show that formulations of the présent invention provide quick and comprehensive pénétration through the stratum comeum to deliver higher amounts of heparin sodium in the underlying tissue. These formulations achieve higher pénétration with 15 minimal systemic exposure. Formulations of the présent invention are safe and effective for the management of Infusion related thrombophlebitis. The formulations of présent invention provide better improvement in pain at the affected site and réduction of lésion size and grade. Moreover the formulations can be provided in metered dose spray container, which is convenient to use, hence further improving the patient compliance.

In the above disclosure, it is understood that terms such as “a”, “an”, “the”, and like are words used for convenience and are not to be constructed as limiting terms. Although the présent invention has been described in considérable detail with reference to certain preferred embodiments thereof, other versions are possible. Moreover, it will be understood that the illustrations are for the purpose describing exemplary embodiment of the invention and the 25 same do not limit the scope of the présent invention.

Claims (12)

1. Topical formulations of pharmaceutically acceptable salts of Heparin comprising:

50 to 2500 IU/ml of pharmaceutically acceptable salts of Heparin;

less than or equal to 30% v/v of water;

2. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in claim 1 wherein the amount of water preferably is less than or equal to 25 % v/v of

15 the formulation.

3. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in claim 1 wherein the amount of lower chain alcohol is in the range of 10 to 20 % v/v of the formulation.

4. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in claim 3 wherein the lower chain alcohol is selected from alcohol(s) with a carbon chain length ranging from Cl to C5 or mixtures thereof.

25 5. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in claim 1 wherein the water miscible vehicle is propylene glycol.

5 to 50 mPas, more preferably in the range of 25 to 40 mPa s when measured at 25°C by using Ostwald viscometer.

5 We claim:

6. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in claim 1 wherein the water miscible vehicle is combination of propylene glycol and

30 glycerol.

7. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in any one of claims 1 to 6 wherein the amount of water is less than the amount of water miscible vehicle of the formulation.

8. Topical fonnulations of pharmaceutically acceptable salts of Heparin as claimed in any one of claims 1 to 7 wherein the viscosity of the formulations is in the range of 10

9. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in any one of claims 1 to 8 further comprising one or more additional pénétration

10. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in claim 9 wherein the additional pénétration enhancer(s) is selected from fatty acids or fatty acid dérivatives, surfactants, azones, amides, esters, ethers, bile salts, polyols or

15 glycol dérivatives, or complex forming agents and mixtures thereof.

10 enhancers.

10 a water miscible vehicle selected from a group comprising propylene glycol, glycerol, glycofurol, polyethylene glycol or mixtures thereof.

10 to 30 % v/v of a lower chain alcohol; and

11. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in any one of claims 1 to 10 further comprising pharmaceutically acceptable excipients selected from preservatives, stabilizers, anti-oxidants, humectants, colouring agents or

20 perfumes or mixtures thereof.

12. Topical formulations of pharmaceutically acceptable salts of Heparin as claimed in any one of claims 1 to 11 wherein the formulations are in the form of solution.