Tablets extracts

In Fig. 4.39, results for spiked placebo and for the verum tablets are given for compound A (bold lines) and B all horizontal bars should be at 100%, and the vertical lines should be centered at the same height. The gray trendlines, particularly for the LO- and Hl-range A-values indicate a systematic difference in response between tbe calibration solutions and the spiked placebo tablets (extraction efficiency, interference, etc.). For same ranges, the verum-tablets assays either underestimate the content of A by 4—5%, or A is underdosed. For compound A the repeatability figures are as follows (%-of-nom-inal, see file Fig4 39.dat), see Table 4.36. 

Non-aqueous titration of tablet extracts with sodium methoxide(27) or lithium methoxide(l)(2) has been reported. 

Figure 8 shows a typical F4PLC chromatogram of the tablet extract illustrating the complexity of the sample, which contains numerous natural components, excipients and additives. During the SP method development, it was found that extraction with a neutral aqueous buffer was problematic due the loss of one of the active ingredients by hydrolysis. The use of the PTFE filter was also important because this hydrolysis product, which is highly hydrophobic, was absorbed by nylon filters under the filtration conditions. 

FIGURE 8 HPLC chromatogram of a tablet extract of an OTC product from natural material showing many natural components including active ingredient (peaks labeled A ), preservatives P and degradants D . Note that Peak A2 was found to hydrolyzed into D under neutral extraction conditions and component D was found to be retained by Nylon filters. 

M sodium hydroxide solution is added to the sample solution and the fluorescence is determined again. The addition of sodium hydroxide removes the fluorescence by ionising the phenol group of the ethinyloestradiol and thus any residual fluorescence which is due to excipients can be subtracted from the reading. In the BP assay the ethinyloestradiol content of the tablet extract is determined by comparison with the fluorescence of a solution containing a known amount of ethinyloestradiol standard analysed using the same conditions. 

Mean area of chromatographic peaks for a duplicate analysis of the tablet extract ... 

Analysis is carried out on tablets containing naproxen 100 mg and aspirin 250 mg per tablet. A narrow range calibration curve is constructed within 20% of the expected concentration of the diluted tablet extract. UV monitoring of the column effluent is carried out at 278 nm. Suggest a column and mobile phase for this analysis both aspirin and naproxen are discussed earlier in this chapter. Suggest a suitable column and mobile phase for this analysis. The following data were obtained for the analysis ... 

Lubricants are used in tablet preparation and include magnesium stearate, stearic acid and polyethylene glycol. They only comprise at most 1-2% of the tablet bulk so that their potential to interfere is slight, particularly since their chromophores are weak. The fatty acid lubricants can often be observed if analysis of a tablet extract is carried out by GC-FID. Tablet coatings are often based on modified sugar polymers such as hydroxypropylmethylcellulose. These coatings are used at about 3% of the tablet bulk, are water soluble and do not absorb UV light. 

Parimoo and Umapathi used difference spectroscopy for the simultaneous quantitative determination of the drug and tinidazole in tablets [20]. The method comprised measurement of the absorbance at 282 and 240 nm of a solution of the tablet extract in pH 2 buffer solution relative to that of an equimolar solution in pH 13 buffer. 

A general disillusionment with conventional medicines, coupled with the desire for a natural lifestyle has resulted in an increasing utilization of herbal medicinal products (HMPs) across the developed world. Sales of botanical products in the United States have increased sharply in recent years, according to industry reports. An estimated 4 billion was spent in health food stores in 2000 for botanical products in bulk, as well as capsules, tablets, extracts, and teas (1 ). A similar trend is noted for European countries (5). 

Fig. 2.12. (a) Fluorescence spectrum of sennoside A on a silica gel TLC plate after spraying with hydrazine. Detection Aminco-Bowman spectrofluorimeter, with a TLC-scanning accessory. Ex = excitation, Em = emission, (b), Scan of a TLC analysis of a Sennokot tablet extract obtained with a Zeiss chromatogram scanner. Peaks 1 3 sennoside B 2 = sennoside A 3 = sennoside C. 

In another published application, Strode et al. developed a methodology for separation of lovastatin (a hypocholestolaemic drug) from its degradation products. Most notable from this separation was the ability to introduce 5 pi of tablet extracted into 80/20 v/v acetonitrile/water into a separation system consisting of a silica column (250 x 4.6 mm, 3 pm) with 6/94 (v/v) methanol with 0.5% TFA/carbon dioxide at 2 ml/min, a back pressure of 230 bar, and a temperature of 45 °C. The compatibility of SFC with partially aqueous sample solvents potentially extends the applicability to additional sample types, although more comprehensive studies are required to fully clarify the extent of compatibility and limitations in SFC operating conditions with aqueous samples. 

Figure 3.18. Fast LC separation of an analgesic tablet extract. Reprinted with permission from reference 19.

Figure 31. Fundamental-harmonic a.c. polarograms of a methyl-testosterone standard and a tablet extract. System ...

Fundamental-harmonic a.c. polarograms of a reserpine standard and a tablet extract. System (A) 1.62 x 10"5 M reserpine standard. (B) 1.65 x lO" M reserpine extracted from a tablet, at DME, 0.01 W TEAPFB-ACN interface, 2s drop life, room temperature, 25 +2 C. Applied pseudo-random, odd-harmonic a.c. waveform,... 

Technique 29, Section 29.11). You may need to search a computerized database to get the necessary information, or you may be able to find it in the Aldrich Catalog Handbook of Fine Chemicals, issued by the Aldrich Chemical Company. Current issues of this catalogue include listings of substances by CAS number. In your report, you should also report the relative percentage of the substance in the tablet extract. Finally, your instructor may also ask you to include the "quality" parameter from the "hit list." If possible, determine which components have antihistamine activity and which ones are present for another purpose. The Merck Index may provide this information. 

Fig. 166. Chromatogram of a tablet extract for detecting small amounts of ethinyl oestradiol. See Table 121/2 for explanatory data...

Fig. 169. Influence of variation in quality of auxiliary material on the storage properties of oestrenol tablets, a—e tablet extracts with an auxiliary material from various sources R pure substance Layer silica gel H solvent heptane-acetone (80 + 40) CS detection sulphuric acid reagent (No. 241B), inspecting in UV-light quantitative evaluation through sulphuric acid reaction also possible after localisation with iodine vapour (cf p. 147)...

The mobile phase consisted of 10 mM phosphate buffer, pH 3.8, and methanol (70 30) poppy capsule, street heroine, and COD tablet extraction (EME) Analysis time 10 min Recovery 44-54% ... 

Tablet studied (CXZ + Ibuprofen) in tablet extract, mg Pure (CXZ + Ibuprofen) added, mg Total (CXZ + Ibuprofen) found, mg B.P. (LC) Pure (CXZ + Ibuprofen) recovered (PercenttRSD ) Proposed method...

M (A) GCMS chromatograph of a tablet extract (B) CE electro-pherogram of the same tablet extract Reproduced with permis- Sion from reference 3 in sources copyright2003 Elsevier Science. 

Sample preparation Powder tablet, extract 3 times with 5 mL aliquots of wat with sonication for 15 min with vortexing at 5 min intervals each tim centrifuge at 2750 g for 5 min, combine supernatants, make up to 20 mL with water. Dilute a 50 p.L aliquot to 1 mL with MeOH, filter (0.2 aM), inject a 20 ixL aliquot. 

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