Effect of pH on weakly acidic and basic model drugs and determination of their ex vivo transdermal permeation routes

ABSTRACT The aim of the present study was to investigate the effect of donor pH on the transdermal permeability of the model drugs across rat skin and also to determine the major route of transport of the drugs. Weakly acidic drugs (partition coefficient) ibuprofen (3.6), aceclofenac (3.9), glipizide (1.9) and weakly basic drugs olanzapine (3.6), telmisartan (6.0), and sildenafil citrate (1.9) were selected for the study. The ex vivo permeation studies of these drugs at different donor pH (pH - 1.2, 4, 5, 6.8, 7.4, and 8) using Franz diffusion cell (area, 7.54 cm2) has shown a pH-dependent permeability. Among these drugs the weakly acidic drugs has shown higher permeation rates compared to the weakly basic drugs. The permeability coefficient and the distribution coefficient of the weakly basic drugs increased on increasing the pH whereas the weakly acidic drugs showed an inverse relation. The weakly basic drugs also showed an increase in permeation with increase in the fraction of unionized species indicating dominance of transcellular route of permeation. With an exception of sildenafil citrate, a weakly basic salt form of the drug which showed a high permeation value at pH 7.4 where 57% of the drug was unionized, indicating the involvement of both paracellular and transcellular route in its permeation.

Mass spectrometry detection of basic drugs in fast chiral analyses with vancomycin stationary phases / 药物分析学报

Current trends in chiral analysis of pharmaceutical drugs are focused on faster separations and higher separation efficiencies. Core-shell or superficially porous particles (SPP) based chiral stationary phases (CSPs) provide reduced analysis times while maintaining high column efficiencies and sensitivity. In this study, mobile phase conditions suitable for chiral analyses with electrospray ionization LC-MS were systematically investigated using vancomycin as a representative CSP. The performance of a 2.7 μm SPP based vancomycin CSP (SPP-V) 10 cm × 0.21 cm column was compared to that of a corresponding 5 μm fully porous particles based analogue column. The results demonstrated that the SPP-V column provides higher efficiencies, 2–5 time greater sensitivity and shorter analysis time for a set of 22 basic pharma-ceutical drugs. The SPP-V was successfully applied for the analysis of the degradation products of racemic citalopram whose enantiomers could be selectively identified by MS.

Analysis of the effect of the basic drug system in 12 non-primary health care institutions of Lu Zhou / 中国生化药物杂志

Objective To analyze the usage of basic drugs in non-primary health care institutions in Luzhou,Sichuan,to comment on the performance of the basic drug system,and to provide reference data for relevant ministries and departments.Methods To collect and to statistically analyze the data of the categories and sales amount of the basic drugs used by three level-3A health care institutions and nine level-2 health care institutions from Jan 1,2010 to Dec 31,2012. Results The purchasing proportion of the basic drugs in the level-3A institutions for 2010,2011,and 2012 are respectively 15.62%,17.84%,20.01%;similarly,the data for the level-2A institutions are respectively 29.35%,32.16%,35.07%;the data for the level-2B institutions are respectively 34.73%,37.05%,40.02%.The sales proportion ofthe basic drugs for the years of2010,2011,and 2012 are respectively 10.43%,12.38%,15.04% for the level-3A institutions,25.08%,27.24%,30.12% for the level-2A institutions,and 29.24%,32.08%,35.03%for the level-2B institutions.Conclusion Non-primary health care institutions should firmly execute the basic drug system, enhance the propaganda of this policy,try to increase the purchasing proportion of the basic drugs,supervise the prescription behavior of the doctors, and optimize the basic drug index in order to use drugs more appropriately and efficiently.

Survey of Rational Drug Use for Twenty Diseases / 中国药房

OBJECTIVE: To understand the current situation of clinical drug use and to inspect the rationality of drug use and survey indices. METHODS: Twenty common diseases(1 530 cases ) treated in this hospital in 1995 were selected. Patierits were divided into three groups according to the sources of expenses: free of charge, self - expense, public - expense or into cases of internal medical and surgical departments. Using selected drug use indicators(SDUI) and self - designed indices, clinical drug use were surveyed and analyzed. RESULTS: There were no significant differences between each group jn main indices. It showed that irrational drug use was only different in degree. CONCLUSION: ①The indices adopted are practicable and rational for surveying and studying the rational drug use objectively. ②In any health care system and in any disease, the irrational drug use was serious.