In vitro study on the interaction of ketotifen fumarate with anhydrous theophylline

Abstract

The purpose of the present study was to investigate the interaction between ketotifen fumarate and anhydrous theophylline in aqueous media of various pH (1.2 and 6.8). Using Job's continuous-variation analysis and Ardon's spectrophotomeric measurement methods, the values of the stability constants of theophylline with ketotifen were determined at a fixed temperature (37 o C) at various pH. The stability constants, ranging between 5.66 and 9.92, were derived from Ardon's plot, indicating that comparatively stable complexes had formed as a result of an interaction between the drugs. However, following the interaction of theophylline with ketotifen, stability constants were <1 at gastric pH (1.2) and intestinal pH (6.8). Concurrent administration of ketotifen and theophylline could result in the formation of a stable complex and this is likely to reduce the therapeutic activities of both drugs.Uniterms: Stability constant. Job's method. Ardon's method. Ketotifen. Theophylline.O objetivo do presente estudo foi investigar a interação entre o fumarato de cetotifeno e a teofilina anidra em meios aquosos com vários pH (1,2 e 6,8). Utilizando a análise da variação contínua de Job e os métodos de medida espectrofotométrica de Ardon, os valores das constantes de estabilidade da teofilina com o cetotifeno foram determinados em temperatura fixa (37 oC) em vários pH. As constantes de estabilidade, variando entre 5,66 e 9,92 derivaram-se a partir do delineamento de Ardon, indicando, comparativamente, que complexos estáveis se formaram como resultado da interação entre os fármacos. Entretanto, seguindo a interação da teofilina com o cetotifeno, as constantes de estabilidade foram <1, em pH gástrico (1,2) e intestinal (8,8). A administração concomitante de cetotifeno e teofilina poderia resultar na formação de complexo estável, o que reduz a atividade terapêutica de ambos os fármacos. Uniterms: Constante de estabilidade. Método de Job. Método de Ardon. Cetotifeno. Teofilina.

Does Rabeprazole Sodium Alleviate the Anti-diabetic Activity of Linagliptin? Drug-Drug Interaction Analysis by In vitro and In vivo Methods

“…In this process, the UV absorption spectra of linagliptin, rabeprazole sodium, and their 1:1, 1:2, and 2:1 solution mixtures at various pH (1.4, 2.4, and 7.4) were compared [15]. The samples' stock solution was diluted to appropriate levels by buffer at the desired pH, and the spectra were recorded between 190 and 800 nm using the UV visible spectrophotometer.…”

Development and validation of a single HPLC method for the determination of thirteen pharmaceuticals in bulk and tablet dosage form

“…Central nervous system stimulants are a group of drugs that produce an increase in mental and motor activity. 1,3,7-Trimethylxanthine, commonly referred to as caffeine (CAF) acts as a stimulant psychotrope and as a mild diuretic [17], while theophylline (THP) displays antiinflammatory activities by inhibiting the activity of CD4 lymphocytes in vitro and through mediator release from mast cells [18].…”