Nitrofurantoin suspension

A Delgado, V Gallardo, A Parrera, F Gonzalez-Ca-ballero. A study of the electrokinetic and stability properties of nitrofurantoin suspensions. II Flocculation and redispersion properties as compared with theoretical interaction energy curves. J Pharm Sci 79 709-718, 1990. 

Soci MM, Parrott EL. Influence of viscosity on absorption from nitrofurantoin suspensions. J Pharm Sci 1980 69(4) 403-6. 

Figure 27 Flocculation ratio of nitrofurantoin suspensions as a function of pH in the presence of 10 M of amino acid (alanine, lysine, and glutamic acid) solutions. (Taken from Ref. 107, with permission.)...

Figure 6 Extent of flocculation, p (sediment volume/sedimem volume of stable suspension), of nitrofurantoin suspensions containing 0.1 K Carbopot 934. as a function of the concentration of NaCi at pH 4 (O) and pH 7 ( ). (From Ref. 31. Reproduced with permission of the American Pharmaceutical Association.)...

Table 2 Redispersion (as Percent Optical Transmittance) of Nitrofurantoin Suspensions with 0.1% Carbopol W at Various Times After Preparation ...

By way of example. Fig. 6 and Table 2 show the effects of Carbopol 9.W (B.F. GotxJrich on the sedimentation and redispersibility of nitrofurantoin suspensions (29-.11). As ob.served. (he fact that the optimum conditions for using Carbopol as a stabilizer in pharmaceutical suspensions occur at neutral pH manifests in high sedimentation volumes (Fig. 6) and almost perfect redispersibility (Table 2) when the experiments are performed at pH 7. 

Figure 6 Photographs of nitrofurantoin suspensions. Effect of pH on the seilimentaiion volume. The pi I decreases from left (pti 9) to right (pH 3). The chemical instability ol the drug at basic pH values is appreciable.

AV Delgado. V Gallardo, J Salcedo, F Gonzalez-Caballero, A study of the elcctro-kineiic and siabilily properties of nitrofurantoin suspensions, I Elecirokineiics. J. Pharm. Set. 79 82-86, 1990. 

V Gallardo, MA Ruiz, P Vera, F Gonzalez-Caballero, AV Delgado. Effect of amino acids on the stability properties of nitrofurantoin suspensions. Flocculation and re-dispersion as compared with interaction energy curves. J. Pharm. Pharmacol, 48 450-455. 1996,... 

TR Bates, JM Young, CM Wu, HA Rosenberg. pH-dependent dissolution rate of nitrofurantoin from commercial suspensions, tablets and capsules. J Pharm Sci 63 643-645, 1974. 

Oral suspension Oral nitrofurantoin is readily absorbed. 

Macrocrystals, monohydrate/macrocrystals The absorption of nitrofurantoin macrocrystals is slower when compared with nitrofurantoin oral suspension. 

Oral suspension Nitrofurantoin oral suspension is rapidly excreted in urine. 

E. C. Juenge, M. A. Kreienbaum, and D. F. Gurka, Assay nitrofurantoin oral suspensions contaminated with 3-(5-nitrofu ideneamino) hydantoic acid, J. Pharm. Sci., 74 100(1985). 

Nicotinic Acid Tablets (200 mg) Nicotinamide see Vitamin B3 Nifedipine Tablet Cores (10 mg) Nitrendipine Tablets (25 mg) Nitrofurantoin Tablet Cores (100 mg) Nitrofurantoin Tablets (100 mg) Norephedrine Syrup (40 mg/10 g) Nystatin Suspension (100,000 i.u./ml) Nystatin Tabet Cores (200 mg) Nystatin Tablets (50 mg and 100 mg)... 

Juenge, E.C. Kreienbaum, M.A. Gurka, D.F. Assay of nitrofurantoin oral suspensions contaminated with 3-(5-nitrofurfurylideneamino)hydantoic acid. J.Pharm.Sci., 1985, 74, 100-102... 

Ideally, a pharmaceutical suspension should be stable in a wide pH range. But in some cases (e.g.. nitrofurantoin is soluble at alkaline pH and is chemically degraded at that pH range ferrous fumarate oxidizes al.so under alkaline condi-iion.s), the chemical stability of the active compound requires that the pH of the suspension be maintained within specified values. Obviously, the remaining components of the suspension must be selected in such a way that they produce their intended effects (on scabiltiy, viscosity, etc.) at precisely that specified pH range. 

V Gallardo, AV Delgado. A Parera. J Salcedo. Electrophoretic study of nitrofurantoin in aqueous suspensions. Effect of the addition of a polymeric thickener. J. Pharm. Phannacol, 42 225-229, 1990,... 

V Gallardo. MA Ruiz, A Parera, A Delgado, A DSC study of the chemical stability of nitrofurantoin in pharmaceutical suspensions. Die Pharmazic 45 633-634, 1990. BI Idson, AJ Scheer, Suspensions. In I Wallace, ed. Problem solver. Vol I. New Jersey FMC. 1984. pp 1-31. 

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