Antacid suspension

A Heyd, D Dhabhar. Particle shape effect on caking of coarse granulated antacid suspensions. Drug Cosmet Ind 125 42-45. 1979. 

A pharmacist dispensed 4 fluidounces of an antacid suspension with instructions that the patient take two tablespoonfuls of the medication four times a day. How long will the medication last ... 

Acid neutralizing capacity (ANC) - ANC is a consideration in selecting an antacid. It varies for commercial antacid preparations and is expressed as mEq/mL. Milliequivalents of ANC is defined by the mEq of hydrochloride required to keep an antacid suspension at pH 3.5 for 10 minutes in vitro. An antacid must neutralize at least 5 mEq/dose. Also, any ingredient must contribute at least 25% of the total ANC of a given product to be considered an antacid. 

In pharmaceutical applications, sorbitol is used as a tablet diluent in wet granulation or dry compression formulations. It is commonly used in chewable tablets because of its sweet taste, and it is also used as a plasticizer for gelatin in capsule formulations. Sorbitol is utilized in sugar-free liquid preparations and as a stabilizer for drug, vitamin, and antacid suspensions. When it is used in syrups, crystallization around bottle caps is prevented. 

Liquid dosage forms which are disperse systems (colloidal, i.e., microspheres, nanoparticles, and micelles suspensions and emulsions) often contain preservatives which are methyl, ethyl, propyl, and butyl esters of para-hydroxybenzoic acid in various combinations. A typical example is the antacid suspensions which have high pH values which make the esters of the preservatives susceptible to hydrolysis. One way to circumvent this problem is to use several preservatives in combination with the hope that some quantities of the preservatives will remain to prevent the suspension from microbial attack. A report showing the assay of the four esters and the parent acid (one of the decomposition products) in drug products in which all the preservatives were used has been given [13]. 

Herman, L.M., Kindschu, W.M., Shallash, A.J. (1998). Treatment of mace dermatitis with topical antacid suspension (letter). Am. J. Emerg. Med. 16 613-14. 

Lazaric, K. Cucek, B. Faust, G. RPTLC method for determining parabins in oral antacid suspension during stability testing. J. Planar Chromatogr.-Mod. TLC 1999,12, 86-88. 

Mannitol has also been used to prevent thickening in aqueous antacid suspensions of aluminum hydroxide (<7% w/v). It has been suggested as a plasticizer in soft-gelatin capsules, as a component of sustained-release tablet formula-tions, and as a carrier in dry powder inhalers. It is also used as a diluent in rapidly dispersing oral dosage forms. 

In liquid preparations sorbitol is used as a vehicle in sugar-free formulations and as a stabilizer for drug, vitamin, and antacid suspensions. It has also been shown to be a suitable carrier to enhance the in vitro dissolution rate of indometa-cin. In syrups it is effective in preventing crystallization around the cap of bottles. Sorbitol is additionally used in injectable and topical preparations and therapeutically as an osmotic laxative. 

The active substances that are most frequently marketed in the form of suspensions or dry syrups and instant granules for the preparation of suspensions are antibiotics, chemotherapeutics and antiacids. Table 100 gives a formulation that was developed in the laboratory for an antacid suspension with povidone K 90. 

I call magnesium the relaxer because it stimulates the relaxation phase in muscle tissue, including the heart muscle, just as calcium stimulates the contraction phase. Many people are familiar with milk of magnesia, an antacid suspension of magnesium hydroxide sometimes used as a cathartic, and with Epsom salts, a bath salt of magnesium sulfate that produces wonderful relaxation. Dr. C. Norman Shealy considers magnesium a crucial neurochemical, which I will discuss in the next few pages. 

Gontarz N, Small RE, Comstock TJ, Stalker DJ, Johnson SM, WUUs HE. Effect of antacid suspension on the pharmacokinetics of ibuprofen. ClinPharm (1987) 6, 413-16. 

Coste IF, De Bari VA Keil LB, Needle MA. In-vitro interactions of oral hematinics and antacid suspensions. Curr TherRes(1977)22,205-15. 

The pH of antacid suspensions is between 7.7 and 8.2. This pH range is very unfavourable for the stability and effectiveness of methyl parahydroxybenzoate and no other preservatives are available for that pH range. Propyl parahydroxybenzoate can be added but additional measures are needed to achieve a reasonable shelf life the use of raw materials with a low bioburden, preventing contamination during preparation, storage in the fridge, small bottles, limited usage period. 

In capsule formulations, as mentioned by Rowe (2009) and Saniocki et al. (2013), it is used as a plasticizer formulation of gelatin and film. In liquid preparations, sorbitol is used for the stabilization of drugs, vitamins, and antacid suspensions. It is also used as a vehicle in sugar-free formulations. In syrups, it is effective in preventing crystallization around the caps of bottles. 

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