Caffeine salicylate

Except for theophyllin, the solubilities are similar at a dissolution temperature (Td) and a dissolution pressure (Pd) of 65°C and 250bar, respectively, the mole fractions are of 2.5e-4 for anthracene, 5e-4 for caffeine and 6.5e-4 for salicylic acid. Theophyllin is an order of magnitude lower, with a value of 0.2e-4. The mole fractions allow one to estimate the maximum production rate for the experimental set up. Assuming a recovery of produced particles of 100%, and no dilution required for processing, the production rates are 1.0, 1.2, 0.5 and 0.04 g/h for caffeine, salicylic acid, anthracene and theophyllin, respectively (conditions Pd = 220bar, Td=65°C, capillary =1.5cm x 75pm flow rate of liquid C02=11.2ml/min)... 

To 50 mg of sublimed caffeine in a tared test tube add 38 mg of scilicyclic acid and 2.5 mL of dichloromethane. Heat the mixture to boiling and add petroleum ether (a poor solvent for the product) dropwise until the mixture just turns cloudy, indicating the solution is saturated. If too much petroleum ether is added then clarify it by adding a very small quantity of dichloromethane. Insulate the tube in order to allow it to cool slowly to room temperature, and then cool it in ice. The needle-like crystcils are isolated by removing the solvent while the reaction tube is in the ice bath. Evaporate the last traces of solvent under vacuum and determine the weight of the derivative and its melting point. Caffeine salicylate is reported to melt at 137°C. 

Noninterfering acetaminophen, caffeine, salicylic acid, theophylline... 

C7H9N402- M.p. 337 C, an alkaloid obtained from cacao seeds or prepared synthetically. Constitutionally it is similar to caffeine, and is also a weak base. It is usually administered as the sodium compound combined with either sodium ethanoate or sodium salicylate, and is employed almost entirely as a diuretic. Physiologically theobromine resembles caffeine, but its effect on the central nervous system is less, while its action on the kidneys, is more pronounced. 

Many pharmaceutical compounds are weak acids or bases that can be analyzed by an aqueous or nonaqueous acid-base titration examples include salicylic acid, phenobarbital, caffeine, and sulfanilamide. Amino acids and proteins can be analyzed in glacial acetic acid, using HCIO4 as the titrant. For example, a procedure for determining the amount of nutritionally available protein has been developed that is based on an acid-base titration of lysine residues. ... 

Examples of the application of HPLC to the analysis of (a) acetaminophen, salicylic acid, and caffeine (b) chlorinated pesticides (c) tricyclic antidepressants and (d) peptides. (Chromatograms courtesy of Alltech Associates, Inc. Deerfield, IL). 

Students determine the concentrations of caffeine, acetaminophen, acetylsalicylic acid, and salicylic acid in several analgesic preparations using both CZE (70 mM borate buffer solution, UV detection at 210 nm) and HPLC (C18 column with 3% v/v acetic acid mixed with methanol as a mobile phase, UV detection at 254 nm). 

As the solvent mixture also contained 225 mg of tetramethyl ammonium hydroxide pentahydrate per liter at a high water content (75%), the surface of the reverse phase would have been largely covered with the tetramethyl ammonium hydroxide pentahydrate. This would have acted as an adsorbed ion exchange stationary phase. It is clear that the free acids, salicylic acid, acetylsalicylic acid (aspirin) and benzoic acid were retained largely by ionic interactions with adsorbed basic ion exchanger and partly by dispersive interactions with the exposed reversed phase. The acetaminophen and the caffeine, on the other hand, being unionized substances, were retained only by dispersive interactions with the exposed reversed phase. 

Chlorogenic acid forms a 1 1 complex with caffeine, which can be crystallized from aqueous alcohol and yields very little free caffeine on extraction with chloroform. Other compounds with which caffeine will complex in this way include isoeugenol, coumarin, indole-acetic acid, and anthocyanidin. The basis for this selection was the requirement for a substituted aromatic ring and a conjugated double bond in forming such a complex. This kind of complex does modify the physiological effects of caffeine.14 Complex formation will also increase the apparent aqueous solubility of caffeine in the presence of alkali benzoates, cinnamates, citrates, and salicylates.9... 

The interfacial tensions of a number of aqueous solutions against mercury have been measured by McLewis, Patrick and others. The tension was lowered by addition of all the solutes examined, including mercurous sulphate, salicylic acid, picric acid, neofuchsin, morphine hydrochloride, caffeine, aniline, sodium glycocholate. All of these substances except mercurous sulphate lower the surface See p. 36. 

N.A. Ilex aquifolium L. I. paraguensis st. Hil. Triterpenoids, salicylic acid, caffeine, isophthalic acid.147 Relieve menstrual cramps, calm nervous stomach. 

Certain foreign compounds may cause the retention or excretion of water. Some compounds, such as the drug furosemide, are used therapeutically as diuretics. Other compounds causing diuresis are ethanol, caffeine, and certain mercury compounds such as mersalyl. Diuresis can be the result of a direct effect on the kidney, as with mercury compounds, which inhibit the reabsorption of chloride, whereas other diuretics such as ethanol influence the production of antidiuretic hormone by the pituitary. Changes in electrolyte balance may occur as a result of excessive excretion of an anion or cation. For example, salicylate-induced alkalosis leads to excretion of Na+, and ethylene glycol causes the depletion of calcium, excreted as calcium oxalate. 

Separation selectivity was demonstrated by extraction of salicylic acid from pH 2 solutions in the presence of a 60-fold excess of ethanol and sixfold excesses of barbituric acid and caffeine. No measurable interference was observed. Experiments showed that the principal selectivity is in the extraction rather than the back extraction step. This finding indicated that the polar and/or ionic nature of these interferences prevents retention by polymer. Preconcentration of analyte was examined by means of extraction from a flowing stream and back extraction into a minimum volume. The extractor tube length was 4.3 m, and the sample was 10 mL of 1 mM oxine with an extraction time of 2.0 min. The back extractant was 80 pL of 0.2 M NaOH. A sevenfold increase in concentration was observed. Enhanced preconcentration can be expected with smaller tubing diameter-to-length ratios, larger sample volumes, and repetitive use of back extractant. 

Nieminen (58) described a gas chromatographic method for simultaneous separation and quantitation of some antipyretics including salicylamide containing phenobarbital, caffeine and codeine phosphate. Codeine phosphate was first separated from the samples as the base. Although the separation was excellent for all components, yet acetyl-salicylic acid interferes with the separation of salicylamide. 

I. M. Jalal and S. I. Sa sa, Simultaneous determination of dextro-propoxyphene napsylate, caffeine, aspirin and salicylic acid in pharmaceutical preparations by reversed-phase HPLC, Talanta, 37 1015 (1984). 

Figure 6.17 The classification of 42 drugs in the (solubility-dose ratio, apparent permeability) plane of the QBCS. The intersection of the dashed lines drawn at the cutoff points form the region of the borderline drugs. Key 1 acetyl salicylic acid 2 atenolol 3 caffeine 4 carbamazepine 5 chlorpheniramine 6 chlorothiazide 7 cimetidine 8 clonidine 9 corticosterone 10 desipramine 11 dexamethasone 12 diazepam 13 digoxin 14 diltiazem 15 disopyramide 16 furosemide 17 gancidovir 18 glycine 19 grizeofulvin 20 hydrochlorothiazide 21 hydrocortisone 22 ibuprofen 23 indomethacine 24 ketoprofen 25 mannitol 26 metoprolol 27 naproxen 28 panadiplon 29 phenytoin 30 piroxicam 31 propanolol 32 quinidine 33 ranitidine 34 salicylic acid 35 saquinavir 36 scopolamine 37 sulfasalazine 38 sulpiride 39 testosterone 40 theophylline 41 verapamil HC1 42 zidovudine.

Modelling of the aerosol formation predicts that the particles produced in partial expansions are small, in the submicron range (5-6). However, experimental size are usually larger, indicating that growth or agglomeration occur within the free jet. Indeed, the temperature of the expansion chamber was found to be a sensitive parameters runs 105/140, 104/137 for anthracene, 147/149/148 for caffeine, 130/131 for salicylic acid show that the lower the temperature, the smaller are the particles. 

The effect of pressure is illustrated through runs 137/138, or 104/105, or 106/108 for anthracene, 76/78/80 or 85/147/159 for caffeine, 122/123 or 134/135 for salicylic acid. An increasing pressure leads to a decreasing size of particle, wether the solute concentration in the fluid is kept constant or varies with the pressure. In order to investigate the respective role of the pressure or the mole fraction on the particle size, further experiments and computational works are currently performed. 

Salicylates Caffeine Meprobamate Amitriptyline Lorazep am Benzodiazepines... 

In a fatality involving the intentional overdosage of a preparation containing codeine, aspirin, phenacetin and caffeine, a blood-phenacetin concentration of 136 ig/ml was reported the codeine and salicylate blood concentrations were 5.3 and 265jLig/ml respectively (J. A. Wright et al., Clin. Toxicol., 1975, 8,457-463). 

Nonnarcotic analgesic combinations usually consist of one or more of the fitUowing agents acetaminophen, salicylates, salsalate, and saUcylamide. Some of the products contain barbiturates, meprobamate, or antihistamines to produce a sedative effect, and antacids may be included to minimize gastric upset associated with the salicylates. Caffeine, a traditional adjuvant in many analgesic combinations, may be beneficial in the treatment of certain vascular headache syndromes. Some belladonna alkaloids may be incorporated for their antispasmodic properties. Pamabrom, a diuretic, and cinnamedrine, a sympathomimetic amine, are sometimes included in products for premenstrual syndrome. 

Many of the chemicals used in this course will be unfamiliar to you. Their properties can be looked up in reference books, a very useful one being the Aldrich Catalog Handbook of Fine Chemicals. It is interesting to note that 1,4-dichlorobenzene is listed as a toxic irritant and naphthalene is listed as an irritant. Both are used as moth balls. Camphor, used in vaporizers, is classified as a flammable solid irritant. Salicylic acid, which we will use to synthesize aspirin (Chapter 26) is listed as moisture-sensitive toxic. Aspirin (acetylsalicyclic acid) is classified as an irritant. Caffeine, which we will isolate from tea or cola syrup (Chapter 8), is classified as toxic. Substances not so familiar to you—1-naphthol and benzoic acid—are classified respectively as toxic irritants and irritant. To put things in some perspective, nicotine is classified as highly toxic. ... 

Higuchi, T. Zuck, D.A. Investigation of some complexes formed in solution. III. Interactions between caffeine and aspirin, p-hydroxybenzoic acid, m-hydroxybenzoic acid, salicylic acid, salicylate ion, and butyl paraben. J. Am. Pharm. Assoc. (Wash). 1953, 42, 138-145. 

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