EP0538418A1

EP0538418A1 - Improvements relating to seaweed-derived preparations

Info

Publication number: EP0538418A1
Application number: EP19920901162
Authority: EP
Inventors: Jean Vilain
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-12-20
Filing date: 1991-12-17
Publication date: 1993-04-28
Also published as: WO1992011020A1; GB9027643D0

Abstract

Gel comportant un mélange de grains d'algues appartenant à l'espèce Lithothamnion calcareum ou Phymatolithon calcareum ainsi que de grains d'une algue appartenant à la branche des phéophycées, ledit gel étant utilisable lors de la fabrication d'un médicament destiné au traitement des affections dues aux virus herpétiques des types 1 et 2. On a également prévu un procédé de traitement des affections dues aux virus herpétiques par l'application locale dudit gel.Gel comprising a mixture of algae grains belonging to the species Lithothamnion calcareum or Phymatolithon calcareum as well as grains of an algae belonging to the branch of pheophyceae, said gel being usable during the manufacture of a medicament intended for the treatment of conditions due to herpes virus types 1 and 2. A method of treating conditions due to herpes virus is also provided for by local application of said gel.

Description

Title: Improvements relating to seaweed-derived preparations

Field of Invention

This invention concerns seaweed-derived preparations and their use for manufacture of a medicament and for therapeutic purposes.

Background to the Invention

It is known to use seaweed-derived preparations for certain cosmetic and medical applications.

One known seaweed-derived preparation comprises a gel based on the mixture of three different types of seaweed: Fucus vesiculosus, Laminaria digitata and Lithothamnion calcareum. These three types of seaweed are harvested at sea, dried on wattles, cut into large lumps and crushed to obtain a coarse powder. This powder is then converted into a very fine grained form (micronized) , to produce a fine grained powder with grain sizes in the range 0.1 to 35 microns, usually with 70% of the grains having sizes in the range 30 to 35 microns. Micronization of the grains makes available, in suspension and in solution, the large number of substances such a trace elements and a ino acids which have been absorbed by the seaweeds during their life cycle.

The fine grained powder is made into a colloidal suspension in purified water with added alginates. A preservative agent is added to provide protection against bacterial attack, and a gelling agent is added to produce either a semi-runny gel or material of stiffer consistency in the form of wafers, pads or slabs, which may optionally be supplied on a gauze-type dressing.

It is known to use the resulting gel for various cosmetic applications and also for certain medical purposes, particularly in treatment of haemorrhoids, rheumatism, arthritis and skin allergies.

It has now surprisingly been discovered that this and similar gel preparations can be used for the treatment of conditions produced., by the herpes simplex virus.

Summary of the Invention

In one aspect, the present invention concerns use of a gel comprising a mixture of grains of seaweed of the species Lithothamnion calcareum or Phymatolithon calcareum together with grains of a seaweed of the brown algae branch, for the manufacture of a medicament for treatment of conditions produced by herpes simplex viruses types 1 and 2.

In another aspect, the invention provides a method of treating conditions produced by herpes simplex virues, comprising topical application of a gel comprising a mixture of grains of seaweed of the species Lithothamnion calcareum or Phymatolithon calcareum together with grains of a seaweed of the brown algae branch.

The herpes simplex viruses are widespread and highly contagious viruses, which are transmitted by contact and produce unpleasant symptoms. Possibly as soon as about 2 to 14 days after the virus has entered the body, small blisters or vesicles appear in affected areas. The blisters are generally painful or itchy. The blisters fill up with a clear and then yellowish liquid. The tops of the blisters come off to reveal painful small ulcers which dry, scab over and heal, typically in two to three weeks. The duration of the "crisis" depends on the physiology of the affected areas and on the condition of the immunological defences of the affected person.

The virus remains in the body in dormant condition, in nerve roots beneath the skin, but can reactivate blisters and sores periodically. "Crises" can appear with varying regularity, and typically appear at intervals of a few months. As a result, it is not uncommon for affected people to have three or four crises per year.

The virus is most contagious during periods of crisis, although there is still some risk of contagion in the intervals between crises.

One form of the herpes simplex virus (type 1) generally causes sores around the mouth and nose area. Another form of the herpes simplex virus (type 2) generally causes sores in the genital and anal area. This type is highly contagious and produces very painful and unpleasant symptoms.

Small scale clinical trials of gel comprising a mixture of seaweeds as specified above have given very good results in treatment of conditions produced by both herpes simplex virus type 1 and herpes simplex virus type 2. In particular, such treatments have substantially reduced th duration of crises, and have alleviated itching and pain and have increased the intervals between crises. The gel of the invention is found to be efficacious even when treatment was started several days after the beginning of a crises. These results represent a substantial improvement over those obtained with existing known treatments.

The brown algae component of the gel preferably comprises Laminaria digitata and/or Fucus vesiculosus. There are many other known brown algae which may additionally or alternatively be used.

One currently preferred formulation comprises a mixture of grains of the following three seaweed species:

Lithothamnion calcareum Fucus vesiculosus Laminaria digitata

The proportions of the different seaweeds present are not critical. Typically more than 50% of the weight of seaweeds will be represented by the brown algae component, with this generally being in the range 80 to 90% by weight.

The seaweed is preferably in the form of finely divided grains, conveniently having a grain size of less than 35 microns, eg in the range 0.1 to 35 microns, with^'70% of the grains having a grain size in the range 30 to 35 microns. Micronization techniques for producing such finely divided grains are known to those skilled in the art, and are conveniently carried out at low temperatures. As explained above, the micronization process makes available, in suspension and in solution, the various trace elements, amino acids and other substances absorbed by the seaweeds during their life cycle.

In order to produce the gel, the mixture of seaweed grains are typically put into colloidal suspension in purified water. Alginates, such as calcium alginate, are conveniently added.

A gelling agent, e.g. xanthan gum, or locust bean gum or gellam gum is added in sufficient quantity to obtain either a semi-runny gel or other desired forms suitable for application, such as wafer, pad or slab forms; these three latter forms may be presented on a gauze-type dressing.

The gel conveniently includes a preservative to prevent against bacterial attack. Suitable preservatives are well known and include methylhydroxybenzoate.

A gel in semi-runny form is conveniently used by being applied sparingly with fingers or with a spout to affected areas. Gels in the form of wafers, pads or slabs are applied directly on the affected area as a dressing. The gel is suitably applied twice daily during periods of crisis.

A gel in semi-runny form is conveniently supplied in sealed containers, e.g. bottles, tubes or sachets. The wafer, pad or slab forms can be supplied in individual packs, either on their own or pre-applied to a gauze-type dressing. The invention will be further described, by way of illustration, in the following example.

Example

A gel formulation having the following composition was produced:

Purified water 1 litre

Laminaria digitata 20 grams

Fucus vesiculosus 20 grams

Lithothamnion calcareum 10 grams

Sodium iodide 3 grams

Alginate 10% by weight of water

Preservative 1% by weight of water

Gelling agent 1% by weight of water

In order to produce the gel, the three types of seaweed were harvested at sea, dried on wattles, cut into large lumps and crushed to obtain a coarse powder. The coarse powder was then "micronized" at low temperature to produce a powder with grain sizes in the range 0.1 to 35 microns, with 70% of the grains having a size in the range 30 to 35 microns. The micronization makes available, in suspension and in solution, the trace elements, amino acids and other substances absorbed by the seaweeds during their life cycle.

The resulting micronized powder is put into colloidal suspension with purified water, with added alginate and sodium iodide. The preservative is added to ensure against bacterial attack, and the gelling agent is added to obtain a semi-runny gel. The resulting gel is packaged in sealed containers, eg bottles, tubes or sachets.

The resulting gel was used in small scale clinical trials on patients affected by herpes simplex type 1 or by herpes simplex type 2 (genital herpes).

The gel was applied sparingly with the fingers or a spout to affected areas, twice a day (morning and evening) during crisis periods. The product does not stain and can be washed off with fresh water if required.

The treatment was continued for as long as necessary, and can be repeated as many times as required.

The ge'l is such that it can be used with great ease in a clinical environment or at home, and is suitable for self- application by the patient.

In the clinical trials for the prophylaxis and suppression of herpes (including genetial herpes) in immunocompromised patients, use of the gel gave the following results:

1. The duration of the crisis, ie the period between the moment when vesicles first appear on the surface of the skin and their disappearance, is reduced from the normal time of 10 to 15 days or more to only 2 to 4 days in cases where the gel was first applied immediately at the onset of the crisis. In cases where the gel was not initially applied at the onset of the crisis but at a later stage, use of the product was nevertheless effective in reducing the duration of the crisis.

2. Immediately after application of the gel, itching ceased or were largely alleviated, therefore increasing considerably the comfort of the patient. This has the effect of preventing the tendency of patients to scratch the affected area and so contributes to the healing process.

3. The product leaves the surrounding skin intact and tends to reduce any inflamation.

4. The product was found to be very well tolerated by the patients.

5. The vesicles which constitute the superficial lesion dehydrate within 2 to 4 days, the scab falls off and the lesion disappears completely leaving virtually intact skin after another 2 to 4 days. The product thus has a suppressing effect on symptoms.

6. The product tends to accelerate the evolution of the crisis and hence to shorten it.

1. Treatment tends to increase the time intervals between crises. Further, at recurrence, the healing period is faster than when first applied.

8. The product remains efficacious even when applied several days after the crisis has started (rather than applied on the first day of the crisis).

9. The product has no contra-indications and no^'known secondary effects.

10. It is thought possible that long term use of the product may result in complete suppression of crises, but this has not yet been tested.

The product also lacks toxicity.

The results obtained with use of the gel are similar, whether the gel was applied to patients affected with herpes simplex virus type 1 or type 2 (genital herpes).

Claims

1. use of a gel comprising a mixture of grains of seaweed of the species Lithothamnion calcareum or Phymatolithon calcareum together with grains of a seaweed of the brown algae branch, for the manufacture of a medicament for treatment of conditions produced by herpes simplex viruses.

2. The invention of claim 1 , wherein the brown algae component of the gel comprises Laminaria digitata and/or Fucus vesiculosus.

3. The invention of claim 1 or 2, wherein the gel comprises a mixture of grains of the following three seaweed species:

Lithothamnion calcareum Fucus vesiculosus

Laminaria digitata.

4. The invention of claims 1, 2 or 3, wherein more than 50% of the weight of seaweeds is represented by the brown algae.

5. The invention of claim 4, wherein brown algae comprise an amount in the range 80 to 90% by weight of the total seaweed content.

6. The invention of and any one of the preceding claims, wherein the seaweed is in the form of finely divided grains, having a grain size of less than 35 microns.

7. The invention of claim 6, wherein the seaweed grains have a grain size in the range of 0.1 to 35 microns, with 70% of the grains having a grain size in the range 30 to 35 microns.

8. The invention of any one of the preceding claims, wherein the mixture of seaweed grains is put into colloidal suspension in purified water.

9. The invention of any one of the preceding claims, wherein the gel further comprises one or more alginate, such as calcium alginate.

10. The invention of any one of the preceding claims, wherein the gel is made by mixing the seaweed grains with a gelling agent.

11. The invention of claim 10 wherein the gelling agent comprises xantham gum, and/or locust bean gum and/or gellam gum.

12. The invention of any one of the preceding claims, wherein the gel includes a preservative to prevent against bacterial attack.

13. A'method of treating conditions produced by herpes simplex viruses, comprising topical application of a gel comprising a mixture of grains of seaweed of the species Lithothamnion calcareum or Phymatolithon calcareum together with grains of a seaweed of the brown algae branch.