International Journal of Pharmaceutical Investigation, 2023, 13, 2, 206-214.
DOI: 10.5530/ijpi.13.2.028
Published: March 2023
Type: Review Article
Authors:
Sri Nataraj Kalakonda
Department of Pharmaceutical Analysis, Shri Vishnu College of Pharmacy, Bhimavaram, Andhra Pradesh, INDIA.
Srinivasa Rao Atla
Department of Pharmaceutical Analysis, Shri Vishnu College of Pharmacy, Bhimavaram, Andhra Pradesh, INDIA.
Roja Naveena Puvvada
Department of Pharmaceutical Analysis, Shri Vishnu College of Pharmacy, Bhimavaram, Andhra Pradesh, INDIA
Prapul Kumar Nalli
Department of Pharmaceutical Analysis, Shri Vishnu College of Pharmacy, Bhimavaram, Andhra Pradesh, INDIA.
Ijaz Sheik
Department of Pharmaceutics, Shri Vishnu College of Pharmacy, Bhimavaram, Andhra Pradesh, INDIA.
Rajendra Prasad VVS
Department of Pharmaceutical Analysis, Vishnu Institute of Pharmaceutical Education and Research, Narsapur, Telangana, INDIA.
ABSTRACT
Although acid-base titrations can be done using numerous indicators which are either synthetic or semi-synthetic, the investigation was started for natural compounds as the former ones result in polluting the habitat despite their limited availability, complicated method of preparation, and expensiveness. Equivalence point determination is the point of interest in neutralization titrations. With the change in pH, the indicators which are natural, usually end up giving a sharp color change. Plant-derived pigments that are of various shades and tints generally vary in their dyeing nature by altering pH. An indicator is a substance that exhibits the property of interchangeable color of the reaction mixture when reaching the vicinity of point with the change in pH. Acid-base titration indicators are normally weak acids or bases. Hibiscus rosa-sinensis, Ipomoea biloba, Dahlia pinnata, etc. are among the typical neutralization indicators that are extracted from plants. These natural Indicators are easily available and economical. In this review, we are discussing an overview of plant extracts, and natural pH indicators, and their significance in correspondence to analytical chemistry is illustrated.
Keywords: Anthocyanins, Dyes, Flavones, Natural indicators, Pigments.