Comparative Study of Different Brands of Amoxicillin Using UV Spectroscopy

Amoxicillin, a widely used β-lactam antibiotic, is available under numerous brand names. Despite regulatory standards, variations in drug content among brands can impact patient outcomes. UV spectrophotometry is a simple, cost-effective, and reliable method for quantifying drug content.                       

Fig: - Amoxicillin 250mg

List of Combination Brands of Amoxicillin: -

1.Amoxicillin + Clavulanic Acid Combination Brands: -

2. Amoxicillin + Clavulanic Acid (Clavulanate Potassium): -

• Most common combination to overcome β-lactamase resistance.
• Therapeutic Use: Broad-spectrum antibacterial.

3.. Amoxicillin + Cloxacillin: -

• Purpose: Dual action against gram-positive infections.
• Therapeutic Use: Skin infections, respiratory tract infections.

4. Amoxicillin + Metronidazole: -

• Therapeutic Use: Dental infections, anaerobic bacterial infections.
• Note: Usually given as separate pills, but combo packs exist.

5. Amoxicillin + Tinidazole: -

• Therapeutic Use: Amoebiasis, giardiasis, and mixed infections.

 6. Amoxicillin + Lactic Acid Bacillus (Probiotic): -

• Purpose: Prevent antibiotic-associated diarrhea.

 7. Amoxicillin + Rifampicin (Less Common): -

• Therapeutic Use: H. pylori infection (part of a triple therapy).    

MATERIALS AND METHODS: -

2.1 MATERIALS -

• Standard Amoxicillin trihydrate (purity ≥ 99%)
• Methanol or distilled water (as solvent)
• Branded Amoxicillin tablets/capsules (5–6 brands)
• UV-Visible spectrophotometer (range: 190–1100 nm)

2.2 METHODOLOGY -

1. Preparation of Standard Solution: -
   • 100 mg of standard Amoxicillin was dissolved in 100 mL of distilled water.
   • Appropriate dilutions were made to obtain a working concentration of 10 µg/ml.
2. Preparation of Sample Solutions: -
   • Tablets from different brands were weighed and powdered.
   • An equivalent of 100 mg Amoxicillin was extracted using water/methanol.
   • Filtered, diluted, and adjusted to the same concentration as standard.
3. UV Spectrophotometric Analysis: -
   • Λ max of Amoxicillin was determined (typically around 272 nm).
   • Absorbance of both standard and sample solutions was measured.
   • Concentration was calculated using Beer-Lambert’s law.

RESULTS AND DISCUSSION: -

Table 1.1: - Absorbance of different brands of amoxicillin at 200nm

Graph 1.1 – Linearity graph of amoxicillin at 200nm