title: Thermal behaviour of procaine and benzocaine Part II: compatibility study with some pharmaceutical excipients used in solid dosage forms.
abstract: BACKGROUND
  The compatibility study of active substances with excipients finds an important role in the domain of pharmaceutical research, being known the fact that final formulation is the one administered to the patient. In order to evaluate the compatibility between active substance and excipients, different analytical techniques can be used, based on their accuracy, reproducibility and fastness.
  
  
  RESULTS
  Compatibility study of two well-known active substances, procaine and benzocaine, with four commonly used excipients, was carried out employing thermal analysis (TG/DTG/HF) and Fourier Transform Infrared Spectroscopy (UATR-FT-IR). The selected excipients were microcrystalline cellulose, lactose monohydrate, magnesium stearate and talc. Equal proportion of active substance and excipients (w/w) was utilized in the interaction study. The absolute value of the difference between the melting point peak of active substances and the one corresponding for the active substances in the analysed mixture, as well the absolute value of the difference between the enthalpy of the pure active ingredient melting peak and that of its melting peak in the different analysed mixtures were chosen as indexes of the drug-excipient interaction degree. All the results obtained through thermal analysis were also sustained by FT-IR spectroscopy.
  
  
  CONCLUSIONS
  The corroboration of data obtained by thermal analysis with the ones from FT-IR spectroscopy indicated that no interaction occurs between procaine and benzocaine, with microcrystalline cellulose and talc, as well for the benzocaine-lactose mixture. Interactions were confirmed between procaine and benzocaine respectively and magnesium stearate, and for procaine and lactose.
authors: Adriana
authors: A
authors: Fuliaş
authors: Ionuţ
authors: I
authors: Ledeţi
authors: Gabriela
authors: G
authors: Vlase
authors: Faculty of Pharmacy, University of Medicine and Pharmacy "Victor Babeş", Eftimie Murgu Square 2, Timişoara RO-300041, România. mcpopoiu@yahoo.com.
authors: Călin
authors: C
authors: Popoiu
authors: Alina
authors: A
authors: Hegheş
authors: Mihai
authors: M
authors: Bilanin
authors: Titus
authors: T
authors: Vlase
authors: Dorina
authors: D
authors: Gheorgheosu
authors: Marius
authors: M
authors: Craina
authors: Simona
authors: S
authors: Ardelean
authors: Dumitru
authors: D
authors: Ferechide
authors: Otilia
authors: O
authors: Mărginean
authors: Liana
authors: L
authors: Moş
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