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Tomaszewska, Chem. Sahota, Hoffmann-La Roche, Inc. Liu and C. The pH is a dominant factor in the titration of the amine with bromine. T h i s indicates t h a t it is the unionized acetazolamide which reacts w i t h e i t h e r H or OH-. It is therefore presumed, following Aguiar and Zelmer, that acetazolamide polymorphic forms do not significantly affect bioavailability. Studies using the same above methods were undertaken by Miyagi et.❿
 
 

Analytical Profiles of Drug Substances and Excipients Vol 22 1993 ISBN 0122608224 9780122608223 – Windows 10 1703 download iso itachi pfpa form

 
 

The absorbance of the dye was measured at nm A photometric determination of 4-aminobenzoic acid was reported To 1 ml of solution containing 10 mg of the drug were added 5 ml of M-HCl and 1 ml of 0. After 2 minutes, 2 ml of 0. After further 3 minutes, the solution is diluted to 50 ml with water and the extinction is measured at nm.

An assay for the measurement of urinary 4-aminobenzoic acid in the oral pancreatic-function test was reported The measurement of the acid in urine after oral acid administration of N-benzoyl-L-tyrosylaminobenzoic has been studied with 4-dimethylaminocinnamaldehyde as chromogenic reagent.

The latter reacts with 4-aminobenzoic acid in acidic solution pH 1. The calibration graph is rectilinear for up to pg m1-I of p-aminobenzoic acid in the sample. Several colorimetric and fluorometric methods were described for the quantitation of primary arylamines These include: formation of N-substituted derivatives of p 1 nitrophenylazobenzamide. Condensation with glutaconic dialdehyde to yield 3 colored Schiff’s base. Bratton-Marshall method for urinary 4-aminobenzoic acid have been evaluated Urine samples are hydrolysed with HC1 for.

Portion of the hydrolysate are diluted to 5 ml and treated with 0. The calibration graph is rectilinear for 0.

The method was intended as a test for excocrine pancreatic function after administration of bentiromide. Bando et a1 71 have reported an enzymic method for selective determination of 4-aminobenzoic acid in urine. Urine 1 ml was heated at loo0 for 2 hours with 4M-KOH, then mixed with anhydrous acetic acid and incubated at for 20 minutes with 4-aminobenzoate hydroxylase 50 miu. After addition of g 1-‘ trichloroacetic acid, 0.

A colorimetric determination of 4-aminobenzoic acid and other primary aromatic amines using N-alkyl aminophenol and iodine has also been reported The determination of urinary 4-aminobenzoic acid with fluorescamine in the pancreatic function test with bentiromide have been published An experimental procedure is described 75 whereby addition of poly acry1ic acid to solution of 4-aminobenzoic.

NH, : H,O Solvent System Cyclohexane: ethyl acetate: chloroform: acetone Cyclohexane: ethylacetate: methanol Cyclohexane: ethylacetate: chloroform and Alkaline or neutral solvent systems w m. Karnes et a1 76 reported a comparative evaluation of two substrates for urinary determination of 4-aminobenzoic acid by room-temperature phosphorimetry.

The substrates considered were: i filter paper S. In each instance, calibration graphs were rectilinear in the range 0 to 40 mg I-‘ of 4-aminobenzoic acid. Karnes et a1 77 have also determined 4-aminobenzoic acid in urine by room-temperature phosphometry, with application to the bentiromide test for pancreatic function. The drug was derivatized with fluorescamine. The optimum pH, buffer concentration and phosphorescence characteristics are discussed. Table 10 summarizes the several thin-layer chromatographic methods reported on p-aminobenzoic acid Two more TLC methods have also been reported 89, Cumpelik 9 1 described a gas liquid chromatographic system for analysis of p-aminobenzoic acid and other multiple absorber sunscreens.

The gas chromatographic retention times of different UV absorbing agents used in sunscreen preparations are compiled as an aid to identification in cosmetic samples. The temperature was programmed from to at. Table High performance liquid chromatography of p-aminobenzoic acid Support and column pBondapak C,, Mobile phase Flow rate 1. All the samples were silanized and centrifuged. Wurst et a 92 developed a gas-chromatographic 1 method for determining trimethylsilyl derivatives of 4aminobenzoic acid and other carboxylic acid in mixtures of biological materials.

The separation was performed on 1,5-bis m-phenoxypheny1 – 1,1,3,3,5,5-hexaphenyltrisiloxane as stationary phase. Its efficiency was compared with that of SE Nitrogen carrier gas, flame ionisation detection, and a temperature programming mode were used.

Harahap et a1 93 reported a gas-chromatographic method for the analysis of 4-aminobenzoic acid in the thermoplastic aromatic polyamides after alkali fusion. The sample of the thermoplastic aromatic polyamide, containing equimolar ratios of 4-aminobenzoic acid and other acid was subjected to alkali fusion at ” for 2 hours with potassium hydroxide-sodium acetate 1. The mixture was cooled and isophthalic acid was precipitated by adjusting the solution to pH 7.

The precipitate was filtered off and isophthalic acid was derivatized to its dimethyl ester with methanolic BF, reagent. The remaining aqueous layer was adjusted to pH 6 and paminobenzoic and 3-aminobenzoic acid were extracted into chloroform and derivatized to their TMS derivatives.

Separation of the three derivatives was carried out on a column 12 ft X 0. The 3 and 4-aminobenzoic acids are separated on a.

Randau and Schnell 95 have separated 4aminobenzoic acid on columns 25 cm X 1. The MP was superior, optimal separation occuring at ; on the M column, no separation was achieved at the lower temperature and only partial separation at 50 O. It is concluded that the macroporous resins permit separation only achieved with the gel resins at much smaller particle size and greater column pressure, 5.

Another method has also been published Standard solution containing 0. PABA is used topically as a sunscreen agent usually in a concentration of. Its preparations are therefore effective in preventing sun burns but ineffecitve in preventing drug-relating or other photosensitive reactions associated with UVA light; combination with a benzophenone may give some added protection against such photosynthetic disorders.

Application of this solution once daily for 30 days did not give rise to cutaneous or systemic toxic symptoms. PABA has no protective effect when given by mouth.

Some studies were reported on the improvement of the test specificity as well as comparison and combination with established or new tests Development of vitiligo in sunexposed areas following adminstration of aminobenzoic acid by mouth was reported 1 Precautions Aminobenzoate sunscreen agents should not be used by patients with previous experience of photosensitive or allergic reactions to chemically-related drugs such as sulfonamides, thiazide diuretics and certain local anesthetics, particularly benzocaine.

PABA is readily absorbed from the gastrointestinal tract after oral adminstration 2,3. The percutaneous absorption of PABA was determined in vitro through hairless guinea pig skin The absorption of PABA was greater through nonviable skin.

Illel et. Using their skin model they compared the percutaneous absorption in appendage-free skin relative to normal skin. The results confirmed that appendageal diffusion is the major bathway in hairless rat skin.

In the absence of follides, the steady state flux and the amounts diffusing in one or two days are times lower than in normal skin. PABA serum and urine concentrations were measured in patients with normal, pathologic and pharmacologically inhibited pancreatic function A maximum increase of In patients with exocrine pancrease insufficiency or those with pharmacologically inhibited exocrine pancrease resulted in a significantly reduced PABAserum concentration.

Thyroid dysfunction was found to affect the small intestinal absorption of some drugs including p-aminobenzoic acid. Thus, examination of the effect in the i siru recirculating n perfusion and everted sac methods showed that the intestinal absorption of passively absorbed drugs were depressed in hyper- and hypothyroid rats Studies using the same above methods were undertaken by Miyagi et.

The transfer of p-acetamidobenzoic acid was not influenced by C o k When PABA was orally administered in the rat treated with Con A, the plasma concentrations of PABA and of acetamidobenzoic acid increased compared with control. No influence of Con A was observed in the I. The plasma concentrations of acetamidobenzoic acid was unchanged when this PABA metabolite was orally or I. Branco and Torres determined the levels of some water-soluble vitamins in Planorbidae.

The determinations were carried out in total snail and in digestive tract extracts of Biomphalaria glubrata. While some vitamins like folk acid showed higher levels in the digestive tract extract than in the total snail extract, the concentration of other vitamins including PABA produced higher levels in the total snail extracts. Fendrich et. Greatest concentrations of PABA were noted in the kidneys, liver and intestines with almost none in the brain.

Koren et al. PABA distribution volume in CF patients was smaller, although not significantly so, than the controls. PABA is mainly metabolized in the liver 4 and kidney It is conjugated with glycine to form p-aminohippuric. Small amounts of p-aminobenzoyl glucuronide, pacetamidobenzoyl glucuronide and traces of p-acetamidohippuric, p-acetamidobenzoic acid and unchanged aminobenzoic acid are also detected in urine 2, Chan et al.

PABA may be detected in urine as a metabolite of amethocaine, benzocaine and procaine 2. The metabolism of PABA is reported to be influenced by many factors. Acetyltransferase activities in the small intestinal mucosa and the liver were increased in rats treated with cancanavalin A These results suggest that concanavalin A will facilitate the metabolism of PABA in the small intestine and liver of rat.

The effect of ethanolamine on the acetylation of PABA was studied in adult rats The results showed that ethanolamine significantly increases the acetylation capacity of tissues. Griffeth et. Moreover, the i vivo reaction of acetylation was n found to be significantly decreased by model trauma.

This effect on in vivu pharmacokinetics appeared to be correlated closely with trauma’s influence on the conjugating enzymes and relatively independent of the post-traumatic response of the necessary co-substrates.

It is thus suggested that traumatic injury appears to have wide-ranging effects on a variety of determinants of hepatic drug metabolism. In an overview on renal disease and drug metabolism, Gibson reported that in a diseased kidney the metabolism of PABA, and other drugs known to be metabolized in the kidney, is reduced. Renal disease, therefore, has its potential to alter not only the renal clearance of unchanged drug but also may substantially modify the metabolic transformation of drugs in both the liver and the kidney.

The tissue distribution of acetyltransferase with PABA as a substrate in humans was investigated by Pacifici et. All tissue specimens catalyse the acetylation of PABA at a significant rate. These results together with the detection of Nacetylating activity in the skin of other experimental animals and humans , suggest that the skin may play an important role in the metabolism of the drug and other armatic amines.

Relatively high levels of acetyl transferase activity was also found in urinary bladder cytosol of humans A number of other studies on the metabolic acetylation of PABA appeared in the literature.

These include reports on the genetic control , kinetics , and inhibition studies of the acetyltransferase enzyme. Scheme 5 lists the major metabolites of PABA. PABA is mainly excreted in urine as its conjugate, paminohippuric acid together with small amounts of paminobenzoyl glucuronide, p-acetamidobenzoyl glucuronide. Traces of p-acetamidohippuric acid, p-acetamidobenzoic acid and unchanged benzoic acid are also detected in urine 2.

The PABA clearance was similar in the control 2. Acknowledgements The authors would like to thank Mr. Tanvir A. Butt for typing this manuscript. Rizk, M. Walash and N.

Rabou, Arch. Ed 6, 26 Radhakrishnamurty and G. Rao, J. India , 56, 79 Mynka and M. Lyutaya, Farm. Kiev , 4,38 Lai and R.

Marsh, Acta Crystalloer. Killean, P. Tollin, D. Watson and D. Young, W, 19, Anulewicz, G. Haefelinger, T. Krygowski, C. Regelmann and G. Ritter, Z. Inomata and T. Moriwaki, Nippon Kaeaku Zasshi, 9, Theoret, Spectrochim. Acta, Part A, 27, 11 Lauransan and J.

Corset, Ann. Paris , 4, Churagov, D. Gambarov and Kh. Mamedov, Koord. Khim 17, Bromilov, R. Brownlee, D. Craik, P. Fiske, J. Rowe and M. Sadek, J. Perkin Trans. Sibi, E. Prince, J. LeMelle and R. Lichter, Spectrosc. Registry of Mass Spectral Data, E. Stenhogen, S. Abrahamsson and F.

Mallonee, U. Hashimoto, J. Sunakoto and H. Fujii, Japan. Sakumoto, Bull. Walsh, M. Erion, A. Walts, J. Delany and G. Berchtold, Biochemistry, 26, McLeish, P. Wookey and K. Mortimer, Biochem. Kane and H. OBrien, J. Huang and F. Gibson, J. Kaplan and B. Nichols, J. Biol, , Goncharoff and B. Yanofsky, T. Platt, I. Crawford, B. Nichols, G. Christie, H. Horowitz, M. VanCleemput and A. Wu, Nucleic Acids Res. Policastro, K.

Au, C. Walsh and G. Berchtold, Am, Chem. Teng and B. Ganem, J. Teng, B. Ganem, S. Doktor, B. Nichols, R. Bhatnagalr and L. Vining, J. Elkins and C. Ozebberger, T. Brickman and M. Mcintosh, Bacteriol. Liu, N. Quinn, G. Berchtold and C. Walsh, Biochernisa, 29, Walsh, J. Liu, F. Rusnak and M. Sakaitani, Chem. Nichols, A. Seibold and S. Doktor, J. Ye, J. Liu and C. Walsh, Proc. Keiner, R. Huettenrauch and A. Eichhorn, Zentbl. Kumar and P. Indrasenan, J. Castellano, T.

Medwick, J. Shinkai and L. Bailey, J Pharm. Arora, and C. Bhatnagar, Z. Albert, V. Cimpu, M. Valeanu and El. Radulescu-Jercan, Rev. Roumaine Chem. Shukla, S. Ahmed and R. Dwivedi, Proc. India, Sect. A, 55, Jayaram and N. Gowda, Analyst, , El-Samman and D. Amin, Microchem. Delgado, Rev. Petrov, L. Karaseva and T.

Bogoslovskaya, Zh. Zvesti 33, Laserna, E. Torres and J. Winefordner, Anal. Acta , Narayanan, J. Bello, D. Stokes and T. Vo-Dinh, Analusis, 19, Kurenman, F. Sheyanova and V. Boyarkina, Khim. Dam and L. Veinbergs, M. Pormale, N. Kashkina and E. Simsone, Latv. PSR Zinat. Akad Vestis. Liu, Yaowu Fenxi Zazhi, 2, Bertini, V. Nuti and G. Linari, Bull. Zhang, Yaoxue Tongbao, 20, Wang and X.

Li, Yaowu Fenxi Zazhi. Taniguchi, T. Yoshida, T. Kobayashi and S. Nakano, Chem, Pharm. Bull,, 29, Wisniewski, and T. Kindlik, Diss. Teodorescu, and E. Tudor, Revta Chim. Agrawal and E. Margoliash, Analvt. Sangadzhieva, K. Bagdasarov and P. Ivakhnenko, 1zv. Yamato and K. Kinoshita, Anal. Sastry, B. Rao and K. Rao, Proc. A, 53, 7 Chem 56, Imondi, Int. Bando, T, Ogawa, H. Tsuji and K. Sasaoka, Clin.

Chem, Winston-Salem, N. C , 36, Eisenwiener, F. Morger, W. Lergier and D. Gillessen, L Clin. Warren, 11, J. Avery and H.

Malmstadt, Anal. Chem 54, Senthilnathan, S. Ramasamy and R. Hurtubise, Anal. Karnes, S. Schulman and J. Acta, , Karnes, R. Bateh, J. Winefordner and S. Schulman, Clin. Winston-Salem N. Long, R. Norin and S. Su, Anal. Chughtai, Mikrochem. Burkina, I. Grindane and N. Guseva, Khim. Pormale, 1. Rosentals and N. Kashkina, Khim. Zh 10, Tomaszewska, Chem. Thielemann, Sci. Puzakov and F. Shemyakin, Farmatsiva [Moscow , 30, 41 Radulovic and Z.

Blagojevic, Arh. Schwartz and J. Sherman, J. Mei, Yaowu Fenxi Zazhi, 3, Thielemann, Fresenius 2. Cozzi, P. Desideri, L. Lepri and V. Coas, J. Gao, Yaowu Fenxi Zazhi, 3, 26 Cumpelik, Cosmet. Toiletries, 97, 67, 71 Wurst, M. Jurkova, Z. Zouchova and R. L, Chromatom. Harahap, R. Burford and J. Haken, J. Chromatoer,, , 53 Walters and N. Raghavan, J.

Heard, jun, and G. Tritz, J. Takahashi, H. Shirono, N. Takai, A. Takeuchi and H. Funakubo, Seisan Kenkvu, 33, Demian and V. Borbely, Rev. Ito, K. Maruta, Y. Imai, T. Kato, M. Ito, S. Nakajima, K. Fujita and T. Kurahashi, Clin. Berg, I. Chesner and N. Biochem,, 22, Gagliardi, A. Amato, A. Basili, G. Cavazzutti, and D. Tonelli, J. Abidi, J. Otto, and W. Wegscheider, J. Jin and H. Zhou, Yaowu Fenxi Zazhi, 6, 49 Willis and A. Kligman, k h s. Hoek, G. Sanders, A. Teunen and G. Tijtgat, Gut. Chesner, R.

Allen-Narker, B. Buckley and N. Lawson, Clin. Puntis, J. Berg, B. Buckley, I. Booth and A. McNeish, Arch. Bornschein, Z. Skopnik, J. Btendel-Ulrich and G. Heimann, Klin. Parrish et. Mathias et. Marmelzat and M. Ramport, Contact Dermatitis, 6, Horio and T.

Higuchi, Dermatoloeica,, , Rossler, H. Janisch and K. Hampel, Gastroenterol. Murata, K. Sasaki, N. Hikichi and H. Niwa, Ann. Tohoku Coll. Pharm,, 28, Miyagi;, N. Niwa, Yakuzaieaku, 45, Branco and I. Torres, Exp, Parasitol, 19, Fendrich, J. Kvetina, F. Deml and V. Grossmann, Sb. Ved, Pr.. Karlow Univ. Hradci Kralove, 11, Koren, Z. Weizmann, G. Forstner, S.

McLeod and P. Durie, Dif. Gibson, Am. Kidney Dis. Chan, J. Miners and D. Birkett, J. Tsuji, T. Orawa, N. Bando and K. Sasaoka, Biochem. Gasparyan, Tr. Griffeth, G. Rosen and E. Rauckman, Drug Metab. Pacifici, C. Bencini and A. Rane, Pharmacology, 32, Kawakubo, S.

Manabe, Y. Yamazoe, T. Nishikawa and R. Yerokun, W. Kirlin, A. Trinidad, R. Ferguson, F. Ogolla, A. Andres, P. Brady and D. Hein, Drug Metab. Glowinski and W. Weber, J. Hein, T. Smolen, R. Fox and W. Weber, Pharm. Hein, A. Trinidad, T. Yerokun, R. Ferguson, W. Kirlin and W. Weber, Drup Metab. Trinidad, W. Kirlin, F. Andrews, T. Yeroku, R.

Ferguson, P. Hein, ibid. Trinidad, D. Rustan, R. Ferguson, L. Miller, K. Bucher, W. Ogolla and A. Andrews, Cancer Res, 50, Andrws, A. Ferguson, T. Yerokun, M. Mpezo and D. Grant, M. Blum, M. Beer and U. Meyer, Mol. Sasaki, S. Ohsako and T.

New Engl. Greene, M. Larson, E. Kelley, W. Freed, S. Dickinson, G. Weiner, I. Macmillan Publishing Company Reynolds, J. United States Pharmacopeial Convention, Inc. Parasrampuria, J. Thesis, Univ. Houston, Houston, Texas Ibrahim, S.

Yalkowsky, S. Marcel Dekker, Inc. Umeda, T. Turczan, J. Analytica Chimica Acta. Abdine, H. Hayden, A. Wallace, S. Gupta, V. Hwang, P. Chapron, D. Hossie, R. Chambers, D. U , Gal, J. Current Eye Res. Fogg, A. Alexander, K. Ellis, P. Straughn, A.

Drug Dispos. Yakatan, G. Sci Kunka, R. Sweeny, K. Lz, Chapron, 0. White, G. Human Toxicol. Schoenwald, R. Drug Oevel op. Indus Pharm. Contents 1 Description 1. Adverse Effects Precautions Yharmacokinetics 9. As potassium p-aminobenzoate: Fibroderm, Pabak, Potaba. As sodium p-aminobenzoate: Epitelplast White or slightly yellow odorless or almost odorless crystals or crystalline powder 3. It forms monoclinic prisms from dilute alcohol 1.

One gram of p-aminobenzoic acid dissolves in ml water, in 90 ml boiling water, in 8 ml alcohol, in 50 ml ether. Soluble in ethyl acetate, glacial acetic acid; slightly soluble in benzene, practically insoluble in petroleum ether 1 ; slightly soluble in chloroform, freely soluble in solutions of alkali hydroxides and carbonates 2. The Merck Index 1 states that it may turn slightly yellow on prolonged exposure to light and air.

The drug, therefore, should be stored in airtight containers and protected from light. R, values and colors are reported. Detection limits in TLC ranges from 3 to pg and in solution 0. The limit of detection was 0. The ultraviolet absorption spectrum of a solution of the drug in NaOH should exhibit maxima and minima at the same wavelengths as that of a similar solution of USP Aminobenzoic acid RS 5.

Thermal analysis of p-aminobenzoic acid was done on Dupont differential scanning calorimetry Dupont TA computerlthermal analyzer. Purity of the sample was found to be Heat of fusion of the sample was found to be Divergence and receiving slits were 10 and 0. The instrument is combined with philips PM printing recorder with both analogue recorder and digital printer.

The goniometer was aligned using silica sample before use. The X-ray pattern of para aminobenzoic acid is presented in Figure 2. Table 1. X-ray Powder Diffraction Pattern of para aminobenzoic acid. Lai and Marsh 9 determined the crystal structure of a monoclinic modification of p-aminobenzoic acid from threedimensional X-ray diffraction data.

The unit cell incorporate 8 molecules and hence two in the asymmetric unit. The structure was refined by least-squares methods to an R index, for observed reflections, of 0. The dimensions of the two structurally distinct molecules are closely similar, and suggestive of a small amount of.

The amino and carboxyl groups are displaced slightly from the planes of the benzene rings, and the nitrogen atoms are nonplanar. Dimers formation takes place by linking together pairs of molecules through two 0-Ha.

Twinning and disorder are common for these crystals. In the disordered structure, which is based on an orthorhombic unit cell half as large as the monoclinic cell, the hydrogen-bonded dimers apparently remain intact but the arrangement of N-H O bonds becomes random See Tables and Figures Killean et. Apparently the same sort of twinning and disorder was observed; and after suitable axes transformation, the two dimensional structure they reported is in satisfactory agreement with that reported by Lai and Marsh 9 above.

Anulewicz et. The pattern of molecular geometry in DABA suggests a relatively strong through-resonance effect between NMe, and COOH groups and shows nonadditivity of substituent effects on valence angles and bond lengths in the ring. Mesomeric equalization of CO bond lengths in the carboxylic groups of 10 well solved p-substituted benzoic acids depends linearly on the R O – 0 distance in the H-bridged dimers.

Full ab initio STO-3G optimization of molecular geometries for monomers of DABA, p-aminobenzoic acid and benzoic acid show reasonable agreement with experimental data. Table 4. The parameters, and their standard deviations, of the hydrogen atoms 9. Values for the coordinates have been multiplied by lo3.

Table 3. The heavy-atom parameters and their standard deviations in parentheses. All values have been. Y Molecule B 1 1 2 2 2 2 2 2 1 1 2. Molecule A 1 1 2 2 2 2 2 2 1 Table 5. The best planes of the benzene rings, atoms C l -C 6 , and the deviations of the individual atoms from these planes 9. Table 6. Description of thermal ellipsoids 9. Axis i Molecule A. I60 0. Figure 4. A composite representation of the final 3-dimentional difference map of p-aminobenzoic acid, the hydrogen contributions were omitted from the Fcs contours are at interval of 0.

A-3beginning with 0. The spectrum is characterized by an absorption maxima at nm. The literature report a maxima at nm in aqueous acid and at nm in aqueous alkali 2. The characteristic bands and their assignment are presented in Table 7.

The infrared absorption spectroscopy was used for the determination of the structure of p-aminobenzoic acid in solid, solution and gas states, for study of the properties and structures of its metal and nonmetal complexes as well as for identification purposes. Inomata and Moriwaki 12 studied the IR absorption spectra of p-aminobenzoic acid and its oand m-isomers in solid and solution states.

The study indicated that the p- and o-isomers assume a nonpolar structure dimer in the solid state and in solutions, whereas the m-isomers has a polar structure in the solid state but a nonpolar structure in solutions. The absorptions were assigned to various vibrational modes with the aid of the spectra of sodium aminobenzoate, aminobenzoic acid hydrochloride, N-deuterated and compounds with similar structure. These results were explained on the basis of electron delocalization in the benzene ring and the double bond character of the C-N bond.

The molecular and zwitterion structures of the three isomeric aminobenzoic acids were also studied 13 in different crystalline forms using IR spectroscopy. This new crystal form was obtained by direct sublimation of the isomer on a KBr window precooled to C. The analysis of IR spectra of the three isomers of aminobenzoic. The structure of some aromatic carboxylic acids in the vabor phase was also examined using the IR spectra The results showed that the acids, including paminobenzoic acid, were intermolecularly hydrogen bonded in the crystal but exist as monomers in the gas phase.

A comparative infrared spectroscopic study of complexes of ammonia and aliphatic or aromatic primary amines with iodine and chloroform was reported by Lauransan and Corset The aromatic amines form weaker complexes than aliphatic amines.

However, complexation with aromatic amines caused a large shift in the NH, stretching vibration to lower frequency. These large shifts are explained by a relocalization of the lone-pair electrons on the nitrogen atom through complexation. As a result intermolecular H-bonds involving the amine function become readily detectable in the infrared spectrum. The analysis of these shifts indicated that the NH, group is not involved in complexation in the y-form of p-aminobenzoic acid due to dimer formation.

In the or-form, chains are formed by O-H NH bonds. The IR technique was also used to study the properties and structure of divalent manganese, cobalt and nickel complexes with p-derivatives of benzoic acid The complexes were prepared, characterized and their stability constants determined.

The acid dissociation constants, the dependence of the thermal stability on the nature of the metal and the p-substituent and the lattice parameter were determined for the complexes. The 0 – H stretching frequencies of p-aminobenzoic acid together with many p- and msubstituted benzoic acids were measured in dil CCl, solution The validity of the latter for substituents without.

The assignment of the chemical shifts to the different protons presented in Table 8. Table 8: Assignment of protons chemical shifts. Chemical shift 6 5. The carbon chemical shifts assigned on the basis of the theories of.

Figure 9. I Figure Table 9: Assignment carbon chemical shifts. In a study on the importance of. Thus for a series of the general formula below, the p-or m-substituent X induces changes in the 13Cchemical shifts at the a-C atom which correlate with substituent parameters via the d.

The inductive effect of X is largely. Removal of the n-electrons of the carbonyl by complexation or protonation removes the possibility of a n-polarization mechanism and results in a change in the sign of PI values. The resonance effect of X varies considerably from one series to another, and is determined by both the inductive and resonance effects of the Z group.

All compounds that are not highly hindered show systematic changes in chemical shifts that can be correlated with inductive and resonance parameters by using a dual-substituent-parameter analysis. In these cases, resonance effects play a slightly more important role than do inductive effects.

Highly hindered compounds show no systematically significant correlations although qualitative trends are discernible. The absence of correlation reflects the different extents to which steric constraints allow or inhibit lone-pair delocalization as the deman changes with substituent. Scheme 1 shows a proposed fragmentation pattern of PABA.

Svnthesis A. Mallonee 21 synthesized p-aminobenzoic acid by agitating a mixture of water, sodium hydroxide, aqueous ammonia and p-nitrobenzoic acid charged into a steel make-. The irradiation was carried for 6 hr at 8 2 O using Hg lamp Scheme 2. It was deduced that the aminating agent was the amino radical 23 Scheme 2.

Biosvnthesis p-Aminobenzoic acid is a growth factor for certain microorganisms. This moiety is incorporated in foIate conenzymes in bacterial biosynthesis Scheme 3. Genetic studies have led to the characterization of two genes, pabA and pabB The pabA gene encodes PabA, a kDa protein with high sequence homology to the TrpG component in oaminobenzoate required for anthranilate synthesis biosynthesis Each of PabA and TrpG is capable of encoding a glutaminase activity, providing nacent ammonia for the two regiospecific chorismate aminations.

The pabB gene product, SlkDa 30 is substantially homologous to the trpE. The latter protein catalyses the ammonia-dependent chorismate amination to 2-amino-2deoxy-isochorismate and its subsequent aromatization by syn elimination of the elements of pyruvate 32, The studies carried on PabB anticipated that this protein catalyses similar regiospecific amination and then aromatization of 4-amino-4deoxychorismate, which is finally converted to PABA by crude bacterial extracts Another protein has been recently reported 35,36 with substantial homoglogy to the TrpE and PabB.

The enzyme, known as isochorismate synthase, catalyses the interconversion of chorismate and its dihydroaromatic isomer isochorismate without aromatization 37 , at the start of the enterobactin biosynthesis pathway Studies by Nichols et. This activity was proposed to act on a diffusible intermediate generated by PabB action and to convert it to the aromatic amino acid product PABA and is designed as enzyme X.

This is confirmed by a recent report by Ye et. Working on the purified PabB, they confirmed that PabB needs an additional protein, enzyme X, to convert chorismate and ammonia to paminobenzoate. The enzyme X was purified to near homogeneity from E. Dissolve 0. Each ml of 0. A method is performed for the assay of 4-aminobenzoic acid 42 by titration with 0. The product is described and its solubilities and m.

Identity tests and limit tests for insoluble matter, color of solution, heavy metal, CP SO:-? The pKb value of 4-aminobenzoic acid and other bases in acetic acid ‘acetous’ pKb are reported 44 , and differentiating titrations of five pairs of bases in acetic acid medium are considered; a glass-calomel LiCIO, bridge system is used and the titrant is HCIO, in acetic acid.

It is concluded that differentiating titration of bases is possible if the difference between their pKb values exceeds 4. A bright platinum indicator electrode was used. If more dilute reagent solution are used, there is some loss of accuracy. Kumar and Indrasenan 43 have determined p-aminobenzoic acid used in pharmaceuticals and cosmetics , by a.

An indirect volumetric method for the determination of 4-aminobenzoic acid and other amines is described The method is based on the oxidizing action of NaC1O2, Under the reaction conditions, the action of NaCIO, on the amine is directly proportional to its concentration.

The amine solution is prepared by dissolving of weighed amount in HC1, and aliquot is transferred into ground-glass stoppered Erlenmeyer flasks, with addition of a measured excess of 0. KI solution is added and the solution is agitated and titrated with 0.

The NaClO, solution must be prepared sometime before use, to allow establishment of a constant concentration and it is calibrated against 0. The use of chloramine-T for the estimation of 4aminobenzoic acid has been reported The method is claimed to be simple and accurate and determines milligram amounts of the drug. Milligram amounts of the sample were allowed to react with a known excess of chloramine-T in acidic medium at room temperature for minutes.

After the completion of reaction, the unconsumed reagent was back titrated iodometrically. The accuracy of the method is k 0. Jayaram and Gowda 48 reported a method for the assay of 4-aminobenzoic acid with aromatic N-haloamines. The method involves the use of chloramine T, bromamine-T the bromo-analogue of chloramine-T or bromamine-B the demethyl analogue of bromamine T as oxidimetric reagents. An aliquot of the test solution containing 0.

A titrimetric method suitable for the determination of pg of p-aminobenzoic acid was developed The method is based on iodination of the compound. The resulting iodide, after removal of excess iodine, is oxidized with Br to iodate which is determined by the Leipert amplification procedure. Delgado 50 have reported a coulometric determination of 4-aminobenzoic acid and other aromatic amines.

The pH is a dominant factor in the titration of the amine with bromine. Displacement of certain substituent groups e. Suitable pH, and the equivalent of bromine per molecule, for 4-aminobenzoic acid are 5 and 6, respectively. The polarographic behavior of 4-aminobenzoic acid, and other substituted benzoic acids, in aprotic dipolar solvents are studied 51 by d.

The advantage of ax. There is a linear relation between the reduction peaks of the acids and their concentration with a lower detection limit of X 10JM. A direct-injection enthalpimetric method for the determination of 4-aminobenzoic and other aromatic amines has been reported The method is based on diazotisation or nitrosation of the amine, the heat of the reaction being measured.

The double injection method is used; the difference in the temperature jumps observed on making the two injections of reagent is correlated with the amine concentration. The procedure was verified by determination of 4-aminobenzoic acid and other amines. Several theories and practical aspects of the hydrosol preparation, protocols and sample preparation procedures, and their effects on the sensitivity and reproducibility of the Raman signals are discussed.

The effect of acidity on SERS signal intensity is shown to depend on the time of the observation of the Raman spectra, illustrating the relevance of time to quantitative SERS data. The identification power of SERS at trace level of closely related compounds p-nitrobenzoic acid, p-aminobenzoic acid and aniline is illustrated.

The determination of 4-aminobenzoic acid in PreSun lotion using surface-enhanced Raman analysis has been published The plates were then vacuum-coated with a nm layer of Ag. The lotion was diluted with ethanol to give two solutions expected to contain 6 and 14 ppm of p-aminobenzoic acid. Portions 1 pl of these solutions and standards were applied. For the measurement of the surface-enhanced Raman scattering, the plates were illuminated from the back with light from a Kr laser The scattered light was transmitted to the photomultiplier tube with a second optical fiber and the p-aminobenzoic acid peak at cm-‘ was measured.

In the range 4 to 16 ppm of p-aminobenzoic acid, the results were correct to within 3 ppm; no other constituents of the lotion interfered. The other hydrolysis product diethylaminoethanol did not interfere with the determination of p-aminobenzoic acid. Liu 58 determined p-aminobenzoic acid in procaine injection by UV spectrometry. Procaine injection were mixed with 60 ml potassium tartrate and water to ml. Four ml of the solution was further diluted with water to 10 ml, which was extracted with ether.

The organic phase was dried, dissolved in 10 ml water and analyzed at nm for the determination of p-aminobenzoic acid. The quantitative determination of p-aminobenzoic acid and other compounds present in a pharmaceutical preparation, antiseborrhoeic shampoo was reported The drug was determined in a 5 g sample by dilution and measurement of the absorbance of the solution at nm.

The injections were diluted with distilled water and the absorbance was measured at , The p-aminobenzoic acid concentration was inversely related to AA,,. Wang 6 1 have applied secondary chemical equilibria in reversed-phase column partition chromatography, for the determination of procaine hydrochloride injections and quality control of 4-aminobenzoic acid.

The injection solution containing 10 mg of procaine-HC1 was applied to an 8 g silanized siliceous earth support with 5 ml of hexanol as stationary phase previously percolated with 20 ml of 0. The eluate was diluted with water to 50 ml and p-aminobenzoic acid was determined by absorbance measurement at nm vs water.

Procaine was then eluted from the column with 60 ml of 0. Equations for computation of procaine and p-aminobenzoic acid concentrations are presented. To an ice-cold solution 5 ml of 4-aminobenzoic acid in 0. The fluorescence was measured at nm excitation at nm. Samples and solutions containing 0. Their extinctions were determined in a Pulfrich photometer using an S filter.

A curve of extinction values versus the content of the drug was given. The detection of a mixture of p-aminobenzoic acid and procainamide is also reported The drug was photocolorimetrically determined 64 using its color reaction in acid media with glutaconaldehyde, the product of the alkaline decomposition of Npyridylpyridinuim chloride-HC1. Thirty minutes later, the absorbance was measured at nm. The drug was also determined 65 by diazotisation with 2N-HCl 0. The optimum pH for maximum color development is in the range of 7 to The extinction of the solution was measured at nm.

The calibration graph was rectilinear in the range of 0. The absorbance of the dye was measured at nm A photometric determination of 4-aminobenzoic acid was reported To 1 ml of solution containing 10 mg of the drug were added 5 ml of M-HCl and 1 ml of 0.

After 2 minutes, 2 ml of 0. After further 3 minutes, the solution is diluted to 50 ml with water and the extinction is measured at nm. An assay for the measurement of urinary 4-aminobenzoic acid in the oral pancreatic-function test was reported The measurement of the acid in urine after oral acid administration of N-benzoyl-L-tyrosylaminobenzoic has been studied with 4-dimethylaminocinnamaldehyde as chromogenic reagent.

The latter reacts with 4-aminobenzoic acid in acidic solution pH 1. The calibration graph is rectilinear for up to pg m1-I of p-aminobenzoic acid in the sample. Several colorimetric and fluorometric methods were described for the quantitation of primary arylamines These include: formation of N-substituted derivatives of p 1 nitrophenylazobenzamide.

Condensation with glutaconic dialdehyde to yield 3 colored Schiff’s base. Bratton-Marshall method for urinary 4-aminobenzoic acid have been evaluated Urine samples are hydrolysed with HC1 for. Portion of the hydrolysate are diluted to 5 ml and treated with 0. The calibration graph is rectilinear for 0. The method was intended as a test for excocrine pancreatic function after administration of bentiromide.

Bando et a1 71 have reported an enzymic method for selective determination of 4-aminobenzoic acid in urine. Urine 1 ml was heated at loo0 for 2 hours with 4M-KOH, then mixed with anhydrous acetic acid and incubated at for 20 minutes with 4-aminobenzoate hydroxylase 50 miu. After addition of g 1-‘ trichloroacetic acid, 0.

A colorimetric determination of 4-aminobenzoic acid and other primary aromatic amines using N-alkyl aminophenol and iodine has also been reported The determination of urinary 4-aminobenzoic acid with fluorescamine in the pancreatic function test with bentiromide have been published An experimental procedure is described 75 whereby addition of poly acry1ic acid to solution of 4-aminobenzoic. NH, : H,O Solvent System Cyclohexane: ethyl acetate: chloroform: acetone Cyclohexane: ethylacetate: methanol Cyclohexane: ethylacetate: chloroform and Alkaline or neutral solvent systems w m.

Karnes et a1 76 reported a comparative evaluation of two substrates for urinary determination of 4-aminobenzoic acid by room-temperature phosphorimetry.

The substrates considered were: i filter paper S. In each instance, calibration graphs were rectilinear in the range 0 to 40 mg I-‘ of 4-aminobenzoic acid. Karnes et a1 77 have also determined 4-aminobenzoic acid in urine by room-temperature phosphometry, with application to the bentiromide test for pancreatic function. The drug was derivatized with fluorescamine. The optimum pH, buffer concentration and phosphorescence characteristics are discussed. Table 10 summarizes the several thin-layer chromatographic methods reported on p-aminobenzoic acid Two more TLC methods have also been reported 89, Cumpelik 9 1 described a gas liquid chromatographic system for analysis of p-aminobenzoic acid and other multiple absorber sunscreens.

The gas chromatographic retention times of different UV absorbing agents used in sunscreen preparations are compiled as an aid to identification in cosmetic samples. The temperature was programmed from to at.

Table High performance liquid chromatography of p-aminobenzoic acid Support and column pBondapak C,, Mobile phase Flow rate 1. All the samples were silanized and centrifuged. Wurst et a 92 developed a gas-chromatographic 1 method for determining trimethylsilyl derivatives of 4aminobenzoic acid and other carboxylic acid in mixtures of biological materials.

The separation was performed on 1,5-bis m-phenoxypheny1 – 1,1,3,3,5,5-hexaphenyltrisiloxane as stationary phase. Its efficiency was compared with that of SE Nitrogen carrier gas, flame ionisation detection, and a temperature programming mode were used.

Harahap et a1 93 reported a gas-chromatographic method for the analysis of 4-aminobenzoic acid in the thermoplastic aromatic polyamides after alkali fusion.

The sample of the thermoplastic aromatic polyamide, containing equimolar ratios of 4-aminobenzoic acid and other acid was subjected to alkali fusion at ” for 2 hours with potassium hydroxide-sodium acetate 1.

The mixture was cooled and isophthalic acid was precipitated by adjusting the solution to pH 7. The precipitate was filtered off and isophthalic acid was derivatized to its dimethyl ester with methanolic BF, reagent. The remaining aqueous layer was adjusted to pH 6 and paminobenzoic and 3-aminobenzoic acid were extracted into chloroform and derivatized to their TMS derivatives.

Separation of the three derivatives was carried out on a column 12 ft X 0. The 3 and 4-aminobenzoic acids are separated on a. Randau and Schnell 95 have separated 4aminobenzoic acid on columns 25 cm X 1. The MP was superior, optimal separation occuring at ; on the M column, no separation was achieved at the lower temperature and only partial separation at 50 O. It is concluded that the macroporous resins permit separation only achieved with the gel resins at much smaller particle size and greater column pressure, 5.

Another method has also been published Standard solution containing 0. PABA is used topically as a sunscreen agent usually in a concentration of. Its preparations are therefore effective in preventing sun burns but ineffecitve in preventing drug-relating or other photosensitive reactions associated with UVA light; combination with a benzophenone may give some added protection against such photosynthetic disorders. Application of this solution once daily for 30 days did not give rise to cutaneous or systemic toxic symptoms.

PABA has no protective effect when given by mouth. Some studies were reported on the improvement of the test specificity as well as comparison and combination with established or new tests Development of vitiligo in sunexposed areas following adminstration of aminobenzoic acid by mouth was reported 1 Precautions Aminobenzoate sunscreen agents should not be used by patients with previous experience of photosensitive or allergic reactions to chemically-related drugs such as sulfonamides, thiazide diuretics and certain local anesthetics, particularly benzocaine.

PABA is readily absorbed from the gastrointestinal tract after oral adminstration 2,3. The percutaneous absorption of PABA was determined in vitro through hairless guinea pig skin The absorption of PABA was greater through nonviable skin. Illel et. Using their skin model they compared the percutaneous absorption in appendage-free skin relative to normal skin. The results confirmed that appendageal diffusion is the major bathway in hairless rat skin. In the absence of follides, the steady state flux and the amounts diffusing in one or two days are times lower than in normal skin.

PABA serum and urine concentrations were measured in patients with normal, pathologic and pharmacologically inhibited pancreatic function A maximum increase of In patients with exocrine pancrease insufficiency or those with pharmacologically inhibited exocrine pancrease resulted in a significantly reduced PABAserum concentration.

Thyroid dysfunction was found to affect the small intestinal absorption of some drugs including p-aminobenzoic acid. Thus, examination of the effect in the i siru recirculating n perfusion and everted sac methods showed that the intestinal absorption of passively absorbed drugs were depressed in hyper- and hypothyroid rats Studies using the same above methods were undertaken by Miyagi et. The transfer of p-acetamidobenzoic acid was not influenced by C o k When PABA was orally administered in the rat treated with Con A, the plasma concentrations of PABA and of acetamidobenzoic acid increased compared with control.

No influence of Con A was observed in the I. The plasma concentrations of acetamidobenzoic acid was unchanged when this PABA metabolite was orally or I. Branco and Torres determined the levels of some water-soluble vitamins in Planorbidae. The determinations were carried out in total snail and in digestive tract extracts of Biomphalaria glubrata. While some vitamins like folk acid showed higher levels in the digestive tract extract than in the total snail extract, the concentration of other vitamins including PABA produced higher levels in the total snail extracts.

Fendrich et. Greatest concentrations of PABA were noted in the kidneys, liver and intestines with almost none in the brain.

Koren et al. PABA distribution volume in CF patients was smaller, although not significantly so, than the controls. PABA is mainly metabolized in the liver 4 and kidney It is conjugated with glycine to form p-aminohippuric.

Small amounts of p-aminobenzoyl glucuronide, pacetamidobenzoyl glucuronide and traces of p-acetamidohippuric, p-acetamidobenzoic acid and unchanged aminobenzoic acid are also detected in urine 2, Chan et al. PABA may be detected in urine as a metabolite of amethocaine, benzocaine and procaine 2. The metabolism of PABA is reported to be influenced by many factors. Acetyltransferase activities in the small intestinal mucosa and the liver were increased in rats treated with cancanavalin A These results suggest that concanavalin A will facilitate the metabolism of PABA in the small intestine and liver of rat.

The effect of ethanolamine on the acetylation of PABA was studied in adult rats The results showed that ethanolamine significantly increases the acetylation capacity of tissues.

Griffeth et. Moreover, the i vivo reaction of acetylation was n found to be significantly decreased by model trauma. This effect on in vivu pharmacokinetics appeared to be correlated closely with trauma’s influence on the conjugating enzymes and relatively independent of the post-traumatic response of the necessary co-substrates.

It is thus suggested that traumatic injury appears to have wide-ranging effects on a variety of determinants of hepatic drug metabolism.

In an overview on renal disease and drug metabolism, Gibson reported that in a diseased kidney the metabolism of PABA, and other drugs known to be metabolized in the kidney, is reduced. Renal disease, therefore, has its potential to alter not only the renal clearance of unchanged drug but also may substantially modify the metabolic transformation of drugs in both the liver and the kidney.

The tissue distribution of acetyltransferase with PABA as a substrate in humans was investigated by Pacifici et. All tissue specimens catalyse the acetylation of PABA at a significant rate. These results together with the detection of Nacetylating activity in the skin of other experimental animals and humans , suggest that the skin may play an important role in the metabolism of the drug and other armatic amines.

Relatively high levels of acetyl transferase activity was also found in urinary bladder cytosol of humans A number of other studies on the metabolic acetylation of PABA appeared in the literature.

These include reports on the genetic control , kinetics , and inhibition studies of the acetyltransferase enzyme. Scheme 5 lists the major metabolites of PABA. PABA is mainly excreted in urine as its conjugate, paminohippuric acid together with small amounts of paminobenzoyl glucuronide, p-acetamidobenzoyl glucuronide. Traces of p-acetamidohippuric acid, p-acetamidobenzoic acid and unchanged benzoic acid are also detected in urine 2. The PABA clearance was similar in the control 2.

Acknowledgements The authors would like to thank Mr. Tanvir A. Butt for typing this manuscript. Rizk, M. Walash and N. Rabou, Arch. Ed 6, 26 Radhakrishnamurty and G.

Rao, J. India , 56, 79 Mynka and M. Lyutaya, Farm. Kiev , 4,38 Lai and R. Marsh, Acta Crystalloer. Killean, P.

Tollin, D. Watson and D. Young, W, 19, Anulewicz, G. Haefelinger, T. Krygowski, C. Regelmann and G. Ritter, Z. Inomata and T. Moriwaki, Nippon Kaeaku Zasshi, 9, Theoret, Spectrochim. Acta, Part A, 27, 11 Lauransan and J. Corset, Ann.

Paris , 4, Churagov, D. Gambarov and Kh. Mamedov, Koord. Khim 17, Bromilov, R. Brownlee, D. Craik, P. Fiske, J. Rowe and M. Sadek, J. Perkin Trans. Sibi, E. Prince, J. LeMelle and R. Lichter, Spectrosc. Registry of Mass Spectral Data, E. Stenhogen, S. Abrahamsson and F. Mallonee, U. Hashimoto, J. Sunakoto and H. Fujii, Japan. Sakumoto, Bull.

Walsh, M. Erion, A. Walts, J. Delany and G. Berchtold, Biochemistry, 26, McLeish, P. Wookey and K. Mortimer, Biochem. Kane and H. OBrien, J. Huang and F. Gibson, J. Kaplan and B. Nichols, J. Biol, , Goncharoff and B. Yanofsky, T. Platt, I. Crawford, B. Nichols, G. Christie, H. Horowitz, M. VanCleemput and A. Wu, Nucleic Acids Res. Policastro, K. Au, C. Walsh and G. Berchtold, Am, Chem.

Teng and B. Ganem, J. Teng, B. Ganem, S. Doktor, B. Nichols, R. Bhatnagalr and L. Vining, J. Elkins and C. Ozebberger, T. Brickman and M. Mcintosh, Bacteriol. Liu, N. Quinn, G. Berchtold and C.

Walsh, Biochernisa, 29, Walsh, J. Liu, F. Rusnak and M. Sakaitani, Chem. Nichols, A. Seibold and S. Doktor, J. Ye, J. Liu and C. Walsh, Proc. Keiner, R. Huettenrauch and A. Eichhorn, Zentbl. Kumar and P. Indrasenan, J. Castellano, T. Medwick, J. Shinkai and L.

Bailey, J Pharm. Arora, and C. Bhatnagar, Z. Albert, V. Cimpu, M. Valeanu and El. Radulescu-Jercan, Rev. Roumaine Chem. Shukla, S. Ahmed and R. Dwivedi, Proc. India, Sect. A, 55, Jayaram and N. Gowda, Analyst, , El-Samman and D. Amin, Microchem. Delgado, Rev. Petrov, L. Karaseva and T. Bogoslovskaya, Zh. Zvesti 33, Laserna, E. Torres and J. Winefordner, Anal. Acta , Narayanan, J. Bello, D. Stokes and T. Vo-Dinh, Analusis, 19, Kurenman, F. Sheyanova and V. Boyarkina, Khim.

Dam and L. Veinbergs, M. Pormale, N. Kashkina and E. Simsone, Latv.

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