PAMPA—a drug absorption in vitro model

Amorphous Polymeric Drug Salts as Ionic Solid Dispersion Forms of Ciprofloxacin

“…Therefore, the differences in solubility described above cannot be attributed to changes in pH, but rather to the physical form of the drug and the presence of polymers. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 38 The CIP ASDs may be considered as basic salts, as they consist of an interaction between the positively charged amino group of the drug and negatively charged carboxylate groups of the polymers. According to Kramer and Flynn, the pH-solubility profile of a basic salt can be represented by two independent solubility profiles, one of which describes when the free base is the saturation species, and the other when the salt is the saturation species.…”

Acid-Base Cosolvent Method for Determining Aqueous Permeability of Amiodarone, Itraconazole, Tamoxifen, Terfenadine and Other Very Insoluble Molecules

“…19) Permeability coefficients were calculated by taking into account filter porosity and sample mass balance. 14,15) pK a flux Method of Determining Intrinsic Permeability Coefficients The permeability barrier is assumed to consist of the artificial lipid membrane (held in place by the microfilter) and the two unstirred water layers (UWL) on each side of the barrier, separating the membrane from the bulk aqueous solution. 14) Since serial resistance is additive and permeability is the inverse of resistance, 1/P e ϭ1/P u ϩ1/P m (1) where P m is the permeability of the artificial membrane, and P u is the total UWL permeability coefficient.…”

“…3, pK a flux , P u and P o , were determined by a weighted nonlinear refinement procedure, with supplied aqueous pK a values. 14,15,19,22,23) Both cosolvent and cosolvent-free parameters were determined by the same procedure.…”

“…PAMPA (parallel artificial membrane permeability assay), introduced by Kansy et al 2) to predict the oral absorption of new therapeutic agents, has undergone substantial recent development, [3][4][5][6][7][8][9][10][11][12][13][14][15] and is gaining acceptance in pharmaceutical research. [16][17][18][19] However, test compounds with very low aqueous solubility (Ͻ20 mg/ml) have been very difficult to assay with UV detection.…”

Use of voltammetry for in vitro equilibrium and transport studies of ionisable drugs

“…Supported liquid membranes (SLM) on the other hand, which typically contain a lipid solution of an organic solvent immobilised on a polymer membrane, are very stable and have intrinsic durability and are therefore suitable for use in the industrial setting and even large scale applications. SLMs were successfully applied in transfer studies of drug molecules, namely in prediction of drug absorption in humans using the artificial membrane permeability method Parallel Artificial Membrane Permeation Assay (PAMPA) [35][36][37], cellmonolayer permeability assays such as human epithelial colorectal adenocarcinoma (Caco-2) [38][39][40] or Madin-Darby canine kidney (MDCK) [41], drug lipophilicity determination [37,42,43] and extraction/removal of drugs [44,45].…”