Comparative Purity Study by UV Spectrophotometric and Fourier-Transform Infrared Spectroscopic (FTIR) Techniques for the Simultaneous Determination of Amoxicillin Tri-hydrate Capsules by UV Spectrophotometric and Fourier-Transform Infrared Spectroscopic Techniques for the Simultaneous Determination of

by the introduction of amoxicillin Amoxicillin, is a congener of ampicillin, provides similar broad-spectrum antibacterial activity of ampicillin but with the advantages of better oral absorption achieving blood concentrations approximately twice as high as obtained with ampicillin ABSTRACT This studies aims to determine and compare the quality and purity of amoxicillin capsules available in local market as well as identifying the suitable analytical method for its analysis. Amoxicillin is the most commonly prescribed antibiotic in Malaysia. In this study, UV spectrophotometry and FTIR spectroscopy are the technique used for determination of amoxicillin tri-hydrate capsules. Ethanol and 0.1 N NaOH were used as solvent in UV spectrophotometric method. The absorbance was measured at λmax 272 nm for ethanol or 247 nm for 0.1 N NaOH. For FTIR technique, the analysis was conducted in absorbance and the spectra were obtained by Agilent MicroLab FTIR software. No sample preparation was required for the FTIR spectrometer. Using UV method, five out of six samples which are brand A, B, D, E and F complied with U.S.P. official limits (not less than 90.0 % and not more than 120.0 % of the labelled amount of amoxicillin) with percentage purity of 112.07 %, 111.97 %, 114.35 %, 118.02 %, and 119.20 % respectively. All FTIR spectra obtained for different samples of amoxicillin have the similar absorption bands with the FTIR spectrum of standard amoxicillin. The similarity between the spectra is a strong indicative of the identity of amoxicillin in all of the samples analysed using FTIR technique. The prominent characteristic peaks in the region 1800-1650 cm-1 was used to compare the amoxicillin standard and samples. For FTIR technique, brand A, B and E resemble the most to the standard. By comparing both methods, FTIR spectroscopy is a more accurate method as it allowed analysis of drug without being affected by the solvent. Nevertheless, UV spectroscopy is also a simple, low cost, reproducible and accurate method of analysis which is suitable for analysis of amoxicillin tri-hydrate in pharmaceutical formulations. In conclusion, UV spectrophotometry and FTIR techniques are comparable and suitable for routine analysis of amoxicillin tri-hydrate in capsules. (FTIR)

Amoxicillin has antibacterial activity against a wide range of gram-positive and a limited range of gram-negative bacteria. It has shown to be more effective against gram-positive bacteria than gram-negative bacteria. In 1972, Amoxil, the generic amoxicillin marketed by Beecham happen to become one of the most widely prescribed antibiotics in the world. Amoxil was the original brand name used by Beecham until Beecham merged with GlaxoSmithKline (GSK) [3]. When the patency of amoxicillin has expired, various brand names have come into the market around the world. In spite of this, generic amoxicillin is still widely used in all over the world.
In fact, amoxicillin and amoxicillin/clavulanic acid are listed in the access category in the 21st Model List of Essential Medicines 2019 by WHO. The access group of antibiotics are considered as first-line or second-line treatment for common infections. They are essential antibiotics that must be widely available, affordable and quality assured [4].
Amoxicillin, belongs to beta-lactam antibiotic class, is bactericidal antibiotic effective against gram-positive and some gram-negative bacteria. It has similar mechanism of action as the antibiotic class of beta-lactam. Bacterial cell wall is important to maintain cell shape and integrity as well as to prevent cell lysis due to extreme osmotic pressure. The bacterial cell wall is made up of complex and cross-linked polymer of polysaccharides and polypeptides, peptidoglycan. The peptidoglycan contains two alternating amino sugars, N-acetyl-glucosamine and N-acetylmuramic acid which are cross-linked by peptide chains [5].
Trans-peptidase is an enzyme responsible to form cross-linkage between the adjacent peptide chains of the neighbouring strands to provide stability and rigidity to the cell wall.
Amoxicillin acts against susceptible bacteria by inhibition of the important trans-peptidation process of bacterial cell wall synthesis during the bacterial multiplication. Amoxicillin, which has a similar structural analogue of penicillin, binds covalently to the active target site of Penicillin-Binding Protein (PBP) inside the cell wall, inhibiting the trans-peptidase so that cross-linking process is blocked. Besides, it also acylates the penicillin-sensitive transpeptidase C-terminal domain by opening the beta-lactam ring and thus inactivate the enzyme. This prevents the cross-linking reaction between the two linear peptidoglycan strands and subsequently inhibiting the third and last stage of bacterial cell wall synthesis, which is essential for cell division and cell shape and other basic processes. The cell lysis is then facilitated by a bacterial cell wall autolytic enzyme such as autolysins [2][3][4][5][6][7][8][9][10][11][12][13]. The disrupted cell wall synthesis causes the cell to swell and burst due to hyperosmotic interior via osmosis.

Methodology
In present studies, UV spectrophotometry and Fourier Transform Infrared spectrometry (FTIR) is used for analysis of amoxicillin tri-hydrate in capsule. UV spectroscopy is usually adopted by HPLC as a detector, giving rise to HPLC-UV method.
Nevertheless, it is also sufficient to be used alone to determine a compound quantitatively by measuring the absorbance of the compound in its specific maximum absorbance wavelength. UV spectrophotometric method is used because of it is simple, specific, sensitive, convenience, economic, reproducible and time-saving. By comparing to HPLC, this method is simple without any sophisticated instruments, expertise operation skills, and also without the need of prior separation procedure. FTIR is another analytical method used for analysis of amoxicillin in this study. It is considered as a green analytical method which allows analysis of substances without using organic solvents. Highly potential toxic solvents for the operators and environment is eliminated. Moreover, this method excludes any prior extraction procedure of the sample and thus is suitable for substances with solubility problems .    The average for third trial of brand A was 0.164 as mentioned in       NaOH as solvent failed to meet the official limit. Figures 1-7 show the FTIR spectra of amoxicillin standard and brand A, B, C, D, E and F respectively. In the region 3600-3400cm -1 , the two small bands were assigned to water of crystallisation OH stretch and amide -NH stretching. The bands in the region between 3200-3000 cm -1 represented phenol -OH stretching and aromatic -CH stretching.

Weight Uniformity of Different Brands of Amoxicillin
The peak below 3000cm -1 was assigned to methyl -CH stretching.
The prominent characteristic bands in between 1800-1650cm -1 indicates the carbonyl (-C=O) in beta-lactam ring and amide.
The sets of bands in the region around 1600cm -1 and the other around 1500cm -1 were consistent with aromatic ring, which was assigned to C=C stretching. Multiple bands in the region 1150-

Comparison of FTIR Spectrum Between Amoxicillin Standard and Samples
FTIR spectrum of pure amoxicillin tri-hydrate shows that all the characteristic peaks of Amoxicillin tri-hydrate are present.
The spectra of amoxicillin standard and amoxicillin samples were

Discussion
The objective of this study was to determine the quality and purity of amoxicillin tri-hydrate capsules brands available in local It can absorb the atmospheric moisture so rapidly that the concentration of the prepared solution is usually changes over time.
Besides, it also reacts with carbon dioxide from the air and forms water-soluble salt sodium carbonate and thus reducing the amount of sodium hydroxide. Therefore, the drug powder cannot dissolve properly in the reduced amount of sodium hydroxide. This concern is actually reflecting in the absorbance readings. The absorbances using NaOH was observed to be lower than that of using ethanol. To eliminate this problem, the solution of NaOH has to be standardized to know the exact concentration and only prepared when needed to keep it as fresh as possible. Capsule is considered as a protective layer for the drug content.
Once the drug content is removed from the capsule, it has been exposed to the atmosphere and become extremely sensitive indicating the presence of specific functional group in amoxicillin.
In the region 3600 -3400cm -1 , the two small bands were assigned to water of crystallisation OH stretch and amide -NH stretching.
The bands in the region between 3200-3000cm -1 represented phenol -OH stretching and aromatic -CH stretching. The peak below 3000cm -1 was assigned to methyl -CH stretching. The prominent characteristic bands in between 1800-1650cm -1 indicates the carbonyl (-C=O) in beta-lactam ring and amide. The sets of bands in the region around 1600cm -1 and the other around 1500cm -1 were consistent with aromatic ring, which was assigned to C=C stretching. Multiple bands in the region 1150-950cm -1 represented the typical in-plane CH bending vibrations of aromatic compounds.
The similarity between the spectra is a strong