Kinetics of degradation of a cyclic lactam analog of α-melanotropin (MT-II) in aqueous solution

Sydney O. Ugwu, En Ling Lan, Shubh Sharma, Victor J Hruby, James Blanchard

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The kinetics of degradation of MT-II in aqueous buffered solution was studied in order to facilitate the formulation of a stable oral dosage form. A stability-indicating high-performance liquid Chromatographic (HPLC) assay was used to measure the concentrations of MT-II remaining at various time periods. The rate of degradation of MT-II was studied as a function of pH, phosphate buffer concentration, temperature and ionic strength. Results indicated that the degradation of MT-II followed apparent first-order kinetics. The pH-rate profile showed that MT-II was most stable at approximately pH 5.0. Data obtained from this study also indicated that the degradation rate of this peptide was directly proportional to phosphate buffer concentration and temperature. The shelf-life of MT-II in aqueous buffer solutions at 25°C was 27 h. The activation energy was 7.5 kcal/mol. The degradation rate of MT-II appeared to be independent of the ionic strength of the aqueous buffered solution.

Original languageEnglish (US)
Pages (from-to)193-199
Number of pages7
JournalInternational Journal of Pharmaceutics
Volume102
Issue number1-3
DOIs
StatePublished - Feb 7 1994

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Melanocyte-Stimulating Hormones
Lactams
Buffers
Osmolar Concentration
Phosphates
Temperature
Dosage Forms
Peptides

Keywords

  • Analog
  • Degradation
  • Kinetics
  • Peptide
  • Stability
  • α-Melanotropin

ASJC Scopus subject areas

  • Pharmaceutical Science

Cite this

Kinetics of degradation of a cyclic lactam analog of α-melanotropin (MT-II) in aqueous solution. / Ugwu, Sydney O.; Lan, En Ling; Sharma, Shubh; Hruby, Victor J; Blanchard, James.

In: International Journal of Pharmaceutics, Vol. 102, No. 1-3, 07.02.1994, p. 193-199.

Research output: Contribution to journalArticle

Ugwu, Sydney O. ; Lan, En Ling ; Sharma, Shubh ; Hruby, Victor J ; Blanchard, James. / Kinetics of degradation of a cyclic lactam analog of α-melanotropin (MT-II) in aqueous solution. In: International Journal of Pharmaceutics. 1994 ; Vol. 102, No. 1-3. pp. 193-199.
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