Simulated gastric fluid

Fig. 6 Dissolution of digoxin tablets containing different fillers (in simulated gastric fluid at 37°C). (From Ref. 45.)...

Fig. 10. Controlled release of insulin in vitro from P(MAA-g-EG) microparticles simulated gastric fluid (pH = 1.2) for the first two hours and phosphate buffered saline solutions (pH = 6.8) for the remaining three hours at 37°C (243).

Fig. 15 Effect of phenytoin (PHT) particle size on (a) dissolution in simulated gastric fluid, pH 1.2, 37°C and (b) bioavailability in human volunteers after oral administration of 300 mg PHT. Dark circles lot with particle size range 74-350 /u.m open circles lot with particle size range 177-350 /am. (From Ref. 64.)...

The two media typically used include Simulated Gastric Fluid (pH 1-pH 3) and Simulated Intestinal Fluid (pH 6-pH 7). The drug substance under investigation is introduced, and its uptake in the diffusion cell ( absorption ) is governed by its hydrophilic-lipophilic balance (HLB). The absorption model proposed by Strieker (26) in the early 1970s therefore effectively took into consideration (in an experimental sense) all aspects considered by the theory of the BCS, which was introduced more than 20 years later. 

Dissolution testing is carried out in United States Pharmacopeia (USP) Apparatus I (100 rpm) or Apparatus II (50 rpm) utilizing 900 ml of the following dissolution media (1) 0.1 N HC1 or simulated gastric fluid USP without enzymes (2) a pH 4.5 buffer and (3) a pH 6.8 buffer or simulated intestinal fluid USP without enzymes. When 85% of the labeled amount of... 

All chemicals were used as received. PDADMAC and PAMPS were obtained from Aldrich Chemical Co. (Milwaukee, WI). Diclofenac sodium, sodium sulfathiazole, labetalol HCl, propranolol HCl, verapamil HCl, and diltiazem HCl were purchased from Sigma Chemical (St. Louis, MO). Dextrose USP was obtained from Amend Co. (Irvinton, NJ). Water was distilled and deionized using a Nanopure purihcation system (Fischer Scientihc, Fair Lawn, NJ). Simulated intestinal fluid was prepared using a O.OIM phosphate buffer (sodium phosphate monobasic and potassium phosphate dibasic) at pH 7 and 5.5 with different amounts of NaCl to vary the ionic strength. Simulated gastric fluid (pH 1.5) was prepared with concentrated HCl with different amounts of NaCl to vary the ionic strength. 

The dose of enzyme required to treat steatorrhea may vary among individuals, and the dose should be individualized to achieve optimal therapeutic effects. In addition less-than-precise enzyme extraction and inconsistent enteric-coating procedures demand careful consideration in selecting from the array of pancreatic enzyme products now available. As much as a 30-fold difference may be seen in pancreatic enzyme activity among products after being exposed to simulated gastric fluid [19]. 

The release tests were performed using the USP dissolution method (apparatus I) and utilized 1000 ml of pH 1.2 simulated gastric fluid (USP XXI) or pH 6.8 simulated intestinal fluid (USP XXI) without enzymes, equilibrated to 37°C and stirred with the basket rotating at 50 or 150 rev/ min. Drug concentrations were assayed by UV spectrophotometry at 255 nm. The experiments were continued until 100% dissolution was achieved. The release data were analysed to zero order, calculating the slope and intercept of the line. Each data point is the average of six individual determinations. In all cases the standard deviation was less than 9%. 

On a comparative basis, Pu, Am and Cm tend to be assimilated from the G.I. tract into the internal body in the following order Pu < Am < Cm (Figure 3). When Pu-nitrate is inhaled in aerosol form by dogs (27), daughter Am-241 tends to be transported more from lung and lymph nodes to liver than does plutonium (Fig. 3). Another example of potential Am enrichment is that when the rumen contents of fistulated cattle grazing on the Nevada Nuclear Test Site were leached with simulated gastric fluids,... 

The concentration profile during the dissolution testing of melphalan tablets in water and simulated gastric fluid was determined by HPLC. A method of data analysis was developed to take into account the spontaneous drug degradation [111]. 

Diaz-Perales, A., Blanco, C., Sanchez-Monge, R., Varela, J., Carrillo, T., and Salcedo, G. 2003. Analysis of avocado allergen (Prs a 1) IgE-binding peptides generated by simulated gastric fluid digestion. J Allergy Clin Immunol 112 1002-1007. 

Each capsule was transferred to simulated gastric fluid (SGF) and placed in a shaking water bath maintained at 37 °C for 2 hours. 

Media include acidic media (e.g., 0.1 N HCl) or simulated gastric fluid, USP without enzymes, pH 4.5 buffer and pH 6.8 buffer of simulated intestinal fluid, USP without enzymes (From FDA Draff Guidance, Jan, 1999.)... 

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