Pharmaco-economic analysis of brands of antacid formulations available in Ishaka town using titrimetric method

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Kampala International University.College of Health Science
Pharmaco-economics involves comparing the cost and consequences of products and services and Cost-effectiveness is the relationship between cost and effectiveness of a given drug. ANC of an antacid is one of the ways of evaluating effectiveness of antacid brands. ANC (mEq per unit dose) is the ability of the antacid to neutralize gastric acid (Shery et al., 2013), and it should be greater or equal to 5mEq per unit dose(FDA), where a unit dose of 0.5g for tablets and 5ml for suspensions was used. Cost was evaluated using cost per unit dose. Antacid formulations (tablets/suspensions) act by neutralizing gastric acid which is mainly hydrochloric acid (]-!Cl). Normal concentration of stomach HCl is about 0.082M and a person experiences stomach acid when HCl concentration increases to about 0.1 M. Antacids are indicated for peptic ulcer disease (PUD), gastro esophageal reflux disease (GERD), acid indigestion and bloating. Antacids contain one of the following compounds as their active ingredients: Magnesium hydroxide, calcium carbonate, sodium bicarbonate, aluminum hydroxide, magnesium trisilicate or ammonium citrate. Side effects due antacid use include: milk-alkali syndrome, osteomalacia, hypophosphatemia, constipation, diarrhea, aluminum-intoxication and dose dependent rebound hyperacidity (Omotosobayomi et al., 2015). The study design was experimental and during this study, sixteen marketed brands of vanous dosage forms were purchased from pharmacies in lshaka and their details recorded. 0.5g of tablet powder or 5ml of suspension was weighed into a 250ml flask. A known volume of O. l M l !Cl (20ml for tablets and 30ml for suspensions) was added to the flask and mixture swirled, then boiled for 15 seconds and cooled to room temperature. 8 drops of bromothymol blue were added and the mixture turned yellow. If it was not yellow, more HCI could be added until it turned yellow. The volume of excess acid added was recorded. The mixture was then titrated against 0.1 M NaOH until a blue end point was reached. The data was entered into Microsoft Excel and analyzed using ST AT A version 12 in which the ANOVA was used to test for differences amongst the ANC values and the costs per unit dose of the selected antacids. A 5% level of significance was considered and a p value less than that was taken to be significant. In this study, the ANC values and costs per unit dose of different brands were significant (p<0.0001). In this study, ANC was classified into three groups; the high ANC (13.08 - 26.48), the intermediate ANC (5.09 - 5.09) and the low ANC (0.69 - 1.98). All tablets were in the low class plus a few suspensions. Most suspensions were in the intermediate and high ANC. For suspensions Maalox plus had the highest ANC value (26.48), followed by Magnesium trisilicate vi mixture (22), and Gaviscon (13 .68) whereas Stamachfit had the lowest ( I. 78), followed by Ccntacid ( 1.89) and Magnomint (5.10). Meanwhile, for tablets, Maalox plus had the highest ANC of l .52mEq and CMT the lowest of 0.85mEq. Antacids with anti-foaming agents had lower ANC values since all were in the intermediate and low ANC group. Antacids with anti-foaming agents in this study were; Acid, Relcergel, Centacid and Mucogel (all with simethicone as the anti-foaming agent). The unit price of antacid suspension was between shs 50 - 1333 .3 per 5ml dose, while that for the tablet antacids was between shs 35.7 - 666.7, thereby making tablets to be cheaper than suspensions. For suspensions Maloox plus had the highest cost per unit dose (shs 1333.33/5111]) followed by Gaviscon (shs 875/Sml) and Mucogel (shs 600/5111]) whereas Maaga, Magnant and Magnesium trisilicatc mixture (SEY) all with unit price of shs. 50/5111] had the lowest cost per unit dose. All local suspensions except Renege], had the same cost per 5ml of shs 50, however for impmied brands like Relcergel, Centacid, Alcid and Stomachfit from the same country (India) also had different cost per 5ml. Meanwhile for the chewable tablets, Maalox plus had the highest cost per unit dose ofshs 666.7/0.5g while CMTand Minto cool had the lowest ofshs 35.7/0.5g. Maalox plus suspension had the highest ANC (26.48) but was not the most cost-effective antacid brand rather it was Magnesium trisilicate mixture (SEY), followed by Maaga, one of the local brands. No positive correlation was found between cost and effectiveness of antacid since local brands of lower cost were found to be equally effective compared with the costly imported brands. Due to high J\NC, few tablet antacids can be substituted for liquid antacids. Antacids therefore, can be consumed judiciously provided ANC details are enclosed on the label of these products. Acid neutralizing capacity details of antacid brands should be incorporated on to the labels to improve good prescribing practices. Further research should be done on other brands. Other research studies like sodium content, physico-chemical parameters and heavy metal (lead) content of antacids should be carried out.
Research report submitted to the School of Pharmacy in partial fulfilment of the requirements of the award of bachelors of Pharmacy of Kampala International University
Pharmaco-economic, Brands, Antacid, Formulations