ABSTRACT
This study is designed, to find out the effect of innate lipid solubility on buccal absorption of basic drugs with similar pka values. Allopurinol hydrochloride, nortriptyline hydrochloride and procainamide hydrochloride with Pka values 9.4, 9.7 and 9.2 respectively were selected for in vivo [buccal absorption test] and in vitro [I-octanol/buffer partitioning coefficient] study at pH range 6-10. Results found that the mean percentage of buccal partitioning and/I-octanol partitioning of allopurinol hydrochloride was decreased with the increase in pH from 6.0-10. On the other had mean percentage of buccal partitioning and I-octanol partitioning of procainamide hydrochloride and nortriptyline hydrochloride was increased with the increase in pH from 6.010. It is concluded that although the drugs studied have nearly similar Pka values their lipid solubility is widely variable. A good correlation between buccal and I-octanol partitioning excluded the possibility of interaction between these drugs and I-octanol. Decrease in lipid solubility of allopurinol hydrochloride with increase in pH needs further evaluation
Subject(s)
Humans , Male , Female , Solubility/drug effects , Pharmacokinetics , Allopurinol/pharmacokinetics , Procainamide/pharmacokinetics , Diffusion , Absorption , LipidsABSTRACT
O objetivo da experiencia foi determinar o efeito da hiperlipidemia experimental na farmacocinetica da procainamida (PA) e N-acetilprocainamida (NAPA), cujo nome oficial e acecainida. A experiencia foi realizada em um periodo de dois meses em 20 coelhos, machos, divididos aleatoriamente em dois grupos: controle e experimental (deixado em dieta rica em gorduras). Depois dos dois meses foram realizadas determinacoes farmacocineticas em todos os animais. Apos administracao estomacal (por sonda) de procainamida em dose de 40 mg/kg, foi coletado sangue para as determinacoes, durante um periodo de 12 horas. Para calculos, foi tomado o modelo de dois compartimentos para administracao extravascular. Foi observada diminuicao da concentracao da PA e NAPA no sangue, diminuicao do volume de distribuicao e aumento da depuracao total. A presente experiencia demonstrou o efeito da hiperlipidemia experimental na farmacocinetica de PA e NAPA, seguido de aumento da velocidade de eliminacao do farmaco do organismo