Process of Making Cough Syrup With Masked Noscapine

This invention relates to a process and the product of the process for making the taste of noscapine, a cough depressant, in a palatable cough syrup.

In the past, the benefits of noscapine have been recognized as an effective antitussive or cough depressant. The problem has been, however, that noscapine in salt form is characterized by a bitter taste, rendering it unpalatable and for the most part unused in liquid form for treating persons with severe coughing spells. In the past, the usual procedure for processing noscapine has been to either use the salt of noscapine, which is a soluble compound in aqueous solution or to acidify the noscapine alkaloid base in order to render it more soluble by conversion to the salt; however, in either event, the characteristic bad taste remains in the resulting mixture or solution.

The present invention has as a several object the provision of a method of formulation of noscapine to obtain a liquid suspension in which the noscapine is maintained in the alkaloid form, which is relatively tasteless, therefore resulting in a more palatable preparation for use in treating coughs.

The method of formulation of this invention comprises the step of adding the noscapine alkaloid base separately from the ingredients of the carrier vehicle until just prior to mixing it in the final resulting mixture; also strictly adhering to an alkaline pH, that is one over seven, to guard against an acidic condition, in which event a salt would form causing an undesirable taste characteristic of noscapine which would render the product of the process unpalatable.

In practice, a syrup vehicle is adjusted with a buffer, such as sodium citrate, to the desired pH above 7 prior to the addition of the noscapine alkaloid; and the buffer serves to maintain the pH throughout the manufacturing process of the life of the product.

(A) Preparation of Carrier:

As an example of a formulation of a carrier according to this invention, in a stainless steel tank, or first tank, a volume of about 120 liters of Sorbitol solution, 70% by volume, which is a sugar solution, and about 40 liters of a syrup, U.S.P. is mixed with constant agitation, the syrup being about 85% sucrose.

In another vessel, or second tank, 50 liters of deionized water is heated to at about boiling temperature and to this heated water about 266 Gm. of Methylparaben and 135 Gm., or thereabouts, of Propylparaben are mixed and agitated until dissolved for use as preservatives. The preservative is then added to the aforesaid syrup and sugar solution of the first tank and agitated. The resulting mixture is heated to 80.degree. C. whereupon 400 Gm. of sodium citrate is added agitating the mixture until the sodium citrate is completely dissolved to which 400 Gm. of sodium saccharin is added until dissolved and 2,080 Gm. of sodium chloride is then added and mixed until dissolved.

In a separate and third container, which is completely dry, 1,200 Gm. of carboxymethyl cellulose, such as that, known commercially as CMC-7HF, is mixed with 6 liters of glycerin, which is 96% U.S.P. which is mixed with the CMC-7HF well. This third container's content is then mixed with the heated solution of the first and second tank in the first tank or main tank until it is completely dispersed in it.

In a fourth kettle, 112 liters of deionized water is heated to a temperature just below boiling or in the range of between about 90.degree.-95.degree. C. A suspending agent is then added to the 112 liters of heated water and agitated, a suitable suspension agent, being that which is commercially available under the tradename Veegum; a complex magnesium aluminum silicate, a registered trademark of R. T. Vanderbilt Company, Inc. and a predetermined quantity in the order of about 4 kilograms is used. This is maintained at a temperature range of 90.degree.-95.degree. C. for at least 30 minutes or until the mixture has thickened.

The thickened solution of Veegum and water is added to the main tank or main solution and mixed well. A satisfactory coloring agent is then added to the solution, which may consist of 2,000 Ml. of F D & C Fast Lime Shade coloring solution (0.5 Gm./30 ml.) with agitation.

(B) Preparation of Active Ingredient

The noscapine alkaloid which is in powdered from is mixed in the quantity of 1,200 Gm. with 6 L. of glycerin 96% and 2,000 Ml. of a flavoring solution, such as PFC #8406 Lemon-Lime Blend.

(C) Preparation of Product

The resulting mixture is then mixed and poured into the main tank to the previously mixed carrier. The finished suspension is then brought to a final volume of 400,000 Ml. (400 L. by adding sufficient deionized water) and mixed and allowed to cool to room temperature and comprises the batch which is subdivided for packaging.

The composition of the drug or cough suspension includes 15 mg. noscapine per 5 ml. plus color such as lime green in an amount of about 400 liters (440,000 ml.).

It has been found that the effectiveness of the product of the process is in the range of the effectiveness of codeine as an antitussive agent while at the same time permitting reflex coughing to continue and for doses to be administered without side effects, similar to that of narcotics, the cough syrup effectively masks the characteristic bad taste of noscapine.