Excipient free N-Acetyl glucosamine tablets and method of making

Abstract

The present invention is a method of making excipient free N-Acetylglucosamine tablets and also the excipient free N-Acetylglucosamine tablets in a variety of sizes, in particular 10 gram tablets. These excipient free tablets are palatable and suitable for consumption by horses, smaller animals and humans. In the method of making these tablets, of N-Acetylglucosamine powder is mixed with a specific amount of water, to bring about a moldable mass which is formed into suitably sized tablets through compression in a tablet mold. The solvent water is then allowed to evaporate leaving behind an excipient free N-Acetylglucosamine tablet.

Claims

1. A method of making excipient free N-Acetylglucosamine chewable tablets by wetting N-Acetylglucosamine powder with 4% to 15% w/w purified water to form a mix, compressing the mix into wells of a mold to form individual wet tablets in each of the wells, expressing the wet tablets, and allowing the water to evaporate from the wet tablets.

2. The method of claim 1, in which allowing the water to evaporate from the wet tablets consists of placing the wet tablets in a drying chamber.

3. The method of claim 1, in which the amount of N-Acetylglucosamine in the excipient free N-Acetylglucosamine tablets is between 200 mg to 20 grams.

4. The method of claim 1, in which the amount of N-Acetylglucosamine in the excipient free N-Acetylglucosamine tablets is 10 grams.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) These and other aspects of the present invention will be apparent from the brief description of the drawings and the following detailed description in which:

(2) FIG. 1 is excipient free 10 gram tablets of N-Acetylglucosamine of an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(3) An embodiment of the present invention is an excipient free glucosamine and an embodiment of the method of the present invention is a process for preparing an excipient free tablet by mixing glucosamine with water, compressing the resultant mass into a mold, expressing it into individual units, and placing the tablets in a drying chamber or simply in a room so that the water is permitted to evaporate. This process allows the production of glucosamine tablets free from excipients.

(4) In formulating the glucosamine tablets of the present invention, salt free N-Acetylglucosamine was chosen to develop a chewable tablet. N-Acetylglucosamine is slightly sweet and horses and most mammals enjoy a sweet taste. Using the active ingredient of N-Acetylglucosamine, it was necessary to determine the correct solvent, as well as the correct amount of the correct solvent, and the correct rate of drying and elimination of the solvent. Water was found to be an effective solvent in an embodiment of the present invention.

(5) To prepare the excipient free tablets of N-Acetylglucosamine of the present invention, N-Acetylglucosamine powder is mixed with an amount of water of 2% to 30% w/w, the resultant mixture is placed in the wells of a tablet triturate mold of the desired tablet size and compressed with a punch and die, and the resultant tablets are dried until the solvent evaporates off.

(6) In an embodiment of the present invention, excipient free 10 g tablets of N-Acetylglucosamine are prepared by mixing N-Acetylglucosamine powder with 5% w/w sterile water, compressing the mixture into a tablet triturate mold with wells for producing 10 g tablets, and drying the resultant tablets.

(7) In an embodiment of the present invention, there is a method of making a glucosamine tablet without excipients, using a specific form of glucosamine, N-Acetylglucosamine, since it has a sweet flavour. The resulting glucosamine tablet has the following characteristics: 1. Contains N-Acetylglucosamine as the sole ingredient; 2. A discrete dose (1 tablet) is deliverable which does not require skill, thinking or effort on the part of the caregiver; 3. Pleasant tasting to ensure consumption of the whole product; 4. Is not dependent on another ‘vehicle’ to encourage consumption (e.g. water/meal/gavage); 5. Does not require a coating for the tablet to maintain integrity; and 6. Guarantees animal compliance/adherence because it is easy to ensure that the whole dose is taken, and it would be obvious if the dose is not taken since the tablet or remains of the tablet would be fully observable.

(8) The excipient free tablet of the present invention is consumable by horses, other animals and humans and the size of the tablet may be determined by the size of the consumer and the dose required by the consumer and condition being treated, for example, 200 mg to 20 grams.

(9) In an embodiment of the present invention excipient free glucosamine tablets are made with a mixture of N-Acetylglucosamine and 2.5% to 15% w/w sterile water compressed in a tablet triturate mold.

(10) In a further embodiment of the present invention, 10 gram glucosamine tablets are made with a mixture of N-Acetylglucosamine and 4% to 15% w/w sterile water compressed in a tablet triturate mold.

(11) In a further embodiment of the present invention, 10 gram glucosamine tablets are made with a mixture of N-Acetylglucosamine and 5% sterile water compressed in a tablet triturate mold to a 1.5 cm thick tablet that is 3.5 cm in diameter.

(12) The following examples show the development of the excipient free tablets of N-Acetylglucosamine and methods of making same. The 10 gram tablet was developed for horses since they are large and need a bigger dose. A 0.5 to 2 gram tablet size or lozenge is more suitable for human use, or companion animal use and still has the benefit of being excipient free and edible. The excipient free tablet can be adjusted to the requirements of an animal based on the size and dose requirement of a given animal.

EXPERIMENTS

(13) The starting point of the method for preparing an excipient free tablet is to mix an active pharmaceutical ingredient with a solvent, form the resultant mass into a tablet shape and heat it so that the solvent evaporates leaving a solid tablet behind. The choice of the solvent is dependent on the pharmaceutical ingredient, since the dried mass, or tablet, of the pharmaceutical agent needs to retain its form even when packaged in a suitable container and after being removed from the container for administration. The solvent should dissolve some of the active pharmaceutical ingredient so that during shaping and subsequent evaporation the tablet so formed will have the required mechanical strength to be packaged into and removed from a container.

(14) Trials 1-3—N-Acetylglucosamine Excipient Free Tablet Trials

(15) Initial trials involved testing whether N-Acetylglucosamine without excipients could be formed into a tablet shape that retained its shape when the tablet was 1) removed from the mold; 2) during evaporation of the solvent; 3) during packaging into a container; 4) during shipping; and 5) during handling by the end user. N-Acetylglucosamine was mixed with 30% purified water to form a wet mass that was formed using a scoop and dried in an oven at 170° F. for 1 hour. This formed well defined N-Acetylglucosamine ½ spheres but they were quite friable with handling.

(16) Similar, independent trials were performed using a silicon ice-cube tray. A wet mass was formed using ˜30% w/w purified water. This forms a crumbly mixture that can be compacted by hand. When dried, they formed friable cubes that were within ±10% of target weight of 10 g, but again crumbled with handling.

(17) Trial 4-N-Acetylglucosamine Pellets using a pellet press

(18) Recognizing that N-Acetylglucosamine could be formed into solid dosage forms, further tests were performed to explore how to make the final solid dosage form less friable. The hope was that under compression the mass would form a more cohesive and solid dosage form.

(19) Using a pellet press (from Par Instruments), tests were done compressing wetted N-Acetylglucosamine with the addition of either 50% purified water or 10% purified water and as pure dry powder. Purified water concentrations were selected to bracket previous trial concentrations (30%) to explore how purified water changes how the N-Acetylglucosamine behaves once dried.

(20) With 50% w/w purified water added, N-Acetylglucosamine compressed nicely with a lot of purified water squeezing out of the mix. A pellet was formed that, once dry, formed a hard, robust, less-friable dosage form with consistency similar to chalk.

(21) With 10% w/w purified water, less purified water squeezed out yet the N-Acetylglucosamine still compressed well. Produced a good pellet similar to the 50% but observationally less friable than the same.

(22) Pure N-Acetylglucosamine without the addition of purified water did not compress at all.

(23) Trial 5—Crude Density Calculations

(24) Calculations were made regarding whether N-Acetylglucosamine tablets could be produced on a commercial tablet machine. Crude calculations were performed to get a sense of tablet dimensions that would be required for the target weight of 10 grams. Volume and density calculations were extrapolated from the results in Trial 4 and from tablet volume and weight of commercial glucose tablets, containing excipients (the largest tablets available commercially).

(25) Trial 6—200 mg Tablet

(26) Commercial manual tablet triturate molds are only available up to 200 mg tablet size (0.181 ml), which is what was used for this experiment. Further, different solvents were used to see what could work and whether ethanol could be used.

(27) In this trial, a wet mass of N-acetylglucosamine was made with 15% w/w purified water and molded using the tablet triturate mold. These tablets were allowed to dry. The final tablet was solid, held shape, hard, not very friable, and acceptable to the palate, remaining sweet.

(28) A wet mass of N-acetylglucosamine was also formed using ethanol, once dried the tablets were very friable and broke apart easily when handled. The resultant tablets were quite bitter tasting in contrast to the tablets made with water.

(29) For both samples, tablets were produced well within ±5% of target weight.

(30) Recognizing that N-Acetylglucosamine could be produced by molding a wetted mass with purified water and dried, calculations were performed to extrapolate and estimate a mold that could potentially produce a 10 g tablet. These calculations were based on density calculations from previous trials and on assumptions of upper limits of commercial automatic tablet press die dimensions.

(31) A custom made aluminum tablet mold was made by estimating well dimensions in order to achieve a 10 g tablet; the desired target dose.

(32) Trial 7—Large Tablet Mold

(33) N-Acetylglucosamine tablets were produced using the custom-made tablet mold. N-Acetylglucosamine was wetted with 10% w/w purified water. The mold was filled with the wetted mixture calculated at a theoretical fill weight of 10 g (on a dry basis). The tablets were expelled and allowed to air dry. Tablets weights were assessed and within ±10% of the mean of the tablet weight. Mean tablet weight was 5.11 grams which is below target weight.

(34) Trial 8—Applying Compression Forces to the Custom Mold

(35) The goal with this trial was much the same as in trial 6, but compression forces were applied to attempt to fill the cavities in the custom mold with more material and achieve something closer to 10 g. A mix was made with 10% w/w purified water and the wells filled with the mix. Using a hammer and punch that fits the die, N-acetylglucosamine mix was compacted into the well with repeated fillings. Once removed and dried the tablets were weighed. Mean weight was 5.62 grams ±5.7%, again below the target weight.

(36) Tablets were quite hard, non-friable, but easy to bite into. After a few days it was noticed that the surface of the tablets was discoloured, turning a yellow brown colour.

(37) Trial 9—Taste Test on Horses

(38) Establishing that a tablet could be produced, it was necessary to learn whether they would be palatable to horses. Tablets were produced as in Trial 8 (10% w/w purified water) and tested on horses, with the permission of horse owners and trainer, and the horses ate the tablets readily directly from hand. Horse owners and trainers felt that the glucosamine tablet format was unique and represented a beneficial method of administering glucosamine to a horse.

(39) Trial 10—Preparing 10 Gram N-Acetylglucosamine Tablets

(40) A machine was built with punches and dies large enough to accommodate greater volumes of N-Acetylglucosamine. N-acetylglucosamine, tablets were formed using the new machine. Sterile water at 15%, 10%, 5% concentrations was used to prepare excipient free tablets.

(41) The resulting tablets compressed to a 1.5 cm thickness and were well formed as seen in FIG. 1. Mean weight for the tablets were 10.4, 10.5, and 10.01 grams for the 15%, 10%, and 5% w/w water mixes, respectively, after evaporation of the water solvent. After solvent evaporation the tablets made with the 15% w/w water mixes were much more friable than those using only 5% water. The tablets made with the 5% w/w water mix were well defined, with clean edges and much whiter than tablets produced with higher percentage of water. It is understood that a 10 gram tablet of N-Acetylglucosamine of an embodiment of this invention includes a tablet of 9.5 grams to 10.5 grams.

(42) Trial 11—N-Acetylglucosamine Tablets Made Using a 2.5% w/w Water Mix

(43) In an effort to minimize water content, experiments were conducted to explore the minimum water content required as a % of N-Acetylglucosamine w/w. In this trial, water was added at 2.5% w/w to N-Acetylglucosamine and tablets formed as in other trials using the new custom machine. The resultant tablets were quite friable and dusty when handled. They broke apart easily when handled and are not suitable for packaging or shipping or handling. The final tablets did not meet the hardness and friability characteristics desired.

(44) Trial 12—N-Acetylglucosamine at 4% w/w Water Mixes

(45) Trial 11 produced N-Acetylglucosamine tablets using 2.5% w/w water which did not meet the characteristics sought. At that point the 5% w/w was the best tablet produced from physical characteristics, palatability and weight consistency standpoints. To explore water content between that of 2.5% and 5% this trial looked at producing tablets at 4% w/w water. The resultant tablets formed well with acceptable demarcated edges and break with ease in hand with acceptable hardness and friability but had a lot of free powder on the outside.

(46) While embodiments of the invention have been described in the detailed description, the scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

(47) All publications cited in this specification are incorporated herein by reference, as well as Canadian Patent Application No. 3,008,722. While the invention has been described with reference to particular embodiments, it will be appreciated that modifications can be made without departing from the spirit of the invention. Such modifications are intended to fall within the scope of the appended claims.