Polymorphism, pseudopolymorphism, and amorphism of peracetylated alpha-, beta-, and gamma-cyclodextrins

Polymorphism, pseudopolymorphism, and amorphism of hexakis(2,3,6-tri-O-acetyl)-alpha-cyclodextrin (TAalphaCyD), heptakis(2,3,6-tri-O-acetyl)-beta-cyclodextrin (TAbetaCyD), and octakis(2,3,6-tri-O-acetyl)-gamma-cyclodextrin (TAgammaCyD) were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffractometry (XRPD), Fourier transform infrared spectroscopy (FTIR) and optical microscopy. An anhydrous and a bi-hydrate crystalline forms of TAalphaCyD, two monotropic anhydrous polymorphs and three pseudopolymorphs (i.e. methanolate, hydrate, and isopropanolate-hydrate) of TAbetaCyD, as well as two monotropic anhydrous polymorphs and isostructural pseudopolymorphs (e.g. hydrate and isopropanolate-hydrate) of TAgammaCyD were isolated and characterized. The amorphous forms of each TACyD were also obtained. Thermal data for desolvation of TAalphaCyD.2H2O and TAbetaCyD.CH3OH were reconciled with their crystal packing features. Melting temperatures and enthalpies of the crystalline forms of each TACyD can be referred to for possible solid-state interactions with drugs.     

Synthesis,anti-inflammatory,analgesic, and antibacterial activities of some triazole,triazolothiadiazole, and triazolothiadiazine derivatives

This study is concerned with the synthesis of new 1,2,4-triazoles, 1,3,4-thiadiazoles, and 1,3,4-thiadiazines derivatives. Derivatives 3a–i were obtained by condensation of 4-amino-3-(4-pyridine)-5-mercapto-1,2,4-triazole 1 with the appropriate aldehyde. Compounds 4a–i were synthesized in a one pot reaction involving compounds 3a–i, formaldehyde, and morpholine. Condensation of compound 1 with the appropriate acids or 4-substituted phenacyl bromide gave compounds 6a–d and 8a–f respectively. The chemical structures of the newly synthesized derivatives were elucidated using different spectral and elemental methods of analysis. All compounds were evaluated for their anti-inflammatory activity and the most potent derivatives were tested for their analgesic activity using indomethacin as a reference drug. In addition, ulcerogenicity and LD₅₀ for the most active compounds were evaluated. Moreover, the antibacterial activities of the newly synthesized derivatives were investigated.     

Storage,release, uptake,and inactivation of purines

Adenine nucleotides are released into the interstitial space during platelet thrombus formation and neurotransmission. ATP has also been reported to be released from the heart and endothelial cells in some studies. Ecto ATPase, ADPase, and 5′-nucleotidase activities capable of hydrolyzing ATP sequentially to adenosine are present in many cell types and may serve to terminate the actions of the nucleotides. The opposing effects of adenosine and ATP on the same cell types have suggested a modulatory role for adenosine of the actions of extracellular ATP and that the rates of hydrolysis of nucleotides might be regulated. Consistent with this it has been found that the balance between feedforward inhibition of 5′-nucleotidase by ADP and/or ATP and preferential delivery of AMP from ADPase to 5′-nucleotidase determines the rate of adenosine production and that this differs in different cell types. Alternatively, adenosine may be produced intracellularly as a result of an imbalance between energy demand and supply. There are at least two different cytosolic forms of 5′-nucleotidase. Degradation of ATP during increased metabolic activity results in an increase in intracellular AMP concentration. Either cytosolic enzyme has a high KM (2–5 mM) and would thus respond to this increase with a proportional rise in the rate of adenosine production. The nucleoside transporter is essential to allow the diffusion of adenosine to extracellular receptor sites. In general, adenosine must be taken up via the nucleoside transporter before it is inactivated either by phosphorylation by adenosine kinase in the micromolar range or by deamination by adenosine deaminase at higher concentrations. © 1993 Wiley-Liss, Inc.     

New synthesis of benzo-delta-carbolines, cryptolepines, and their salts: in vitro cytotoxic, antiplasmodial, and antitrypanosomal activities of delta-carbolines, benzo-delta-carbolines, and cryptolepines

The paper describes, in its first part, a new synthesis of benzo-delta-carbolines, cryptolepines, and their salts. The strategy is based on the association between halogen-dance and hetero-ring cross-coupling. It is fully convergent and regioselective with interesting overall yields from 27% to 70%. A halogen-dance mechanism in quinoline series is also proposed. The formal synthesis of potential antimalarial compounds and the first total synthesis of 11-isopropylcryptolepine are also described. In the second part, cytotoxic activity against mammalian cells and activities against Plasmodium falciparum and Trypanosoma cruzi of benzo-delta-carbolines and delta-carbolines were evaluated in vitro to study the structure-activity relationships. For benzo-delta-carbolines, methylation at N-5 increases the cytotoxic and antiparasitic activities. A further alkylation on C-11 generally increases the cytotoxic activity but not the antiparasitic activity, cryptolepine and 11-methylcryptolepine being the most active on both parasites. Taking advantage of the fluorescence of the indoloquinoline chromophore, cryptolepine was localized by fluorescence microscopy in parasite DNA-containing structures suggesting that these compounds act through interaction with parasite DNA as proposed for cryptolepine on melanoma cells. For delta-carbolines, methylation at N-1 is essential for the antimalarial activity. 1-Methyl-delta-carboline specifically accumulates in the intracellular parasite. It has weak cytotoxic activity and can be considered as a potential antimalarial compound.     

New antiretroviral drugs: a review of the efficacy,safety, pharmacokinetics,and resistance profile of tipranavir,darunavir, etravirine,rilpivirine, maraviroc,and raltegravir

Background: The introduction and approval of new antiretroviral agents in the US and Canada bring new opportunities and new challenges. Arguably, for the first time ever, clinicians have the drugs necessary to achieve the goal of suppressing HIV RNA to levels less than 50 copies/mL in even the most treatment-experienced patients and in those with extensive drug-limiting resistance mutations. However, the use of these new agents is complicated by many drug–drug interactions and – to some extent – pre-existing mutations. To derive maximum durability from the use of these newer drugs, a thorough understanding of their indications and limitations is critical. Objective: To thoroughly review the six most recently approved or soon-to-be-approved antiretroviral drugs in the US and Canada: tipranavir, darunavir, etravirine, rilpivirine, maraviroc, and raltegravir. Methods: Discussion of the indications for, and pharmacokinetics, resistance profile, activity, toxicity, and clinical trials results of, the six new agents. Results/conclusions: These six new agents have resulted in marked progress towards the goal of being able to provide HIV-infected individuals with the drugs necessary to achieve decades of durable suppression of HIV without substantial toxicity.     

Stereospecific and circadian-phase-dependent kinetic behavior of d,l-, l-, and d-propranolol in plasma, heart, and brain of light--dark-synchronized rats

In light--dark-synchronized male rats, the kinetic behavior of d,l-, l-, and d-propranolol after single (1.78 and 8.89 mg/kg) or multiple drug administration (6 X 8.89 mg/kg) was studied in plasma, heart, and brain both in the light period (L) and in the dark period (D). With either dosage regimen the kinetics of racemic propranolol displayed a temporal dependency, elimination half-lives in plasma, heart, and brain being shorter during D than during L. This was observed with the stereoisomers only after single drug application with no circadian phase dependency at steady-state concentrations. On the other hand, the kinetic behavior of l- and d-propranolol exhibited pronounced stereospecificity in that t1/2 Beta, Vdbeta, plasma clearance, and drug accumulation in heart and brain were greater for l-propranolol than for the d-isomer. Stereospecific differences in t1/2 beta and elimination rate were more pronounced during D. In the light of the flow-dependent hepatic extraction of propranolol it is unlikely that daily variations in microsomal liver enzyme activity are responsible for the chronopharmacokinetics of propranolol. It is assumed that daily variations in liver blood flow, which is more effectively reduced by beta-receptor blockade in the period of increased sympathetic tone during D, are mainly responsible for the chronopharmocokinetics of the therapeutically used d,l-propranolol.     

Thyroid hormone, glucocorticoids, and prolactin at the nexus of physiology, reproduction, and toxicology

A symposium at the 2003 Annual Meeting of the Society of Toxicology brought together an expert group of endocrinologists to review how non-reproductive hormones can affect the endocrine system. This publication captures the essence of those presentations. Paul Cooke and Denise Holsberger recapitulate the evidence of how thyroid hormones affect male and female reproduction, and reproductive development. Ray Witorsch summarizes the many effects of glucocorticoids on the reproductive system. Finally, Paul Sylvester reviews the mechanism of action of prolactin, and reminds us that this ancient hormone has many functions beyond lactation.     

HPLC法同时测定酚氨咖敏颗粒中三组分的含量

目的:建立 HPLC 法同时测定酚氨咖敏颗粒中对乙酰氨基酚、咖啡因、氨基比林的含量。方法:采用日本岛津 VP-ODS色谱柱(150 mm×4.6 mm,5μm),以甲醇-水(40:60)为流动相,流速:1.0 mL·min~(-1),检测波长273 nm,柱温:30℃,进样量:20 μL。结果:对乙酰氨基酚进样浓度在10～100μg·mL~(-1)范围内线性关系良好(r=0.9999),平均回收率(n=3)为98.8%～99.4%;咖啡因进样浓度在2.4～24μg·mL~(-1)范围内线性关系良好(r=0.9999),平均回收率(n=3)为98.2%～101.5%;氨基比林进样浓度在8～80μg·mL~(-1)范围内线性关系良好(r=0.9998),平均回收率(n=3)为98.3%～100.4%。结论:本方法灵敏度高,操作简便、可靠,适用于测定酚氨咖敏颗粒中对乙酰氨基酚、咖啡因、氨基比林的含量。     

Pharmacokinetic, pharmacodynamic, and efficacy profiles of alogliptin, a novel inhibitor of dipeptidyl peptidase-4, in rats, dogs, and monkeys

The aim of the present research was to characterize the pharmacokinetic, pharmacodynamic, and efficacy profiles of alogliptin, a novel quinazolinone-based dipeptidyl peptidase-4 (DPP-4) inhibitor. Alogliptin potently inhibited human DPP-4 in vitro (mean IC(50), ~ 6.9 nM) and exhibited > 10,000-fold selectivity for DPP-4 over the closely related serine proteases DPP-2, DPP-8, DPP-9, fibroblast activation protein/seprase, prolyl endopeptidase, and tryptase (IC(50) > 100,000 nM). Absolute oral bioavailability of alogliptin in rats, dogs, and monkeys was 45%, 86%, and 72% to 88%, respectively. After a single oral dose of alogliptin, plasma DPP-4 inhibition was observed within 15 min and maximum inhibition was > 90% in rats, dogs, and monkeys; inhibition was sustained for 12 h in rats (43%) and dogs (65%) and 24 h in monkeys (> 80%). From E(max) modeling, 50% inhibition of DPP-4 activity was observed at a mean alogliptin plasma concentration (EC(50)) of 3.4 to 5.6 ng/ml (10.0 to 16.5 nM) in rats, dogs, and monkeys. In Zucker fa/fa rats, a single dose of alogliptin (0.3, 1, 3, and 10 mg/kg) inhibited plasma DPP-4 (91% to 100% at 2 h and 20% to 66% at 24 h), increased plasma GLP-1 (2- to 3-fold increase in AUC(0-20 min)) and increased early-phase insulin secretion (1.5- to 2.6-fold increase in AUC(0-20 min)) and reduced blood glucose excursion (31%-67% decrease in AUC(0-90 min)) after oral glucose challenge. Alogliptin (30 and 100 mg/kg) had no effect on fasting plasma glucose in normoglycemic rats. In summary, these data suggest that alogliptin is a potent and highly selective DPP-4 inhibitor with demonstrated efficacy in Zucker fa/fa rats and potential for once-daily dosing in humans.     

PCP, THC, ethanol, and morphine and consumption of palatable solutions

Water-deprived rats were given daily opportunities (2.0-hr sessions) to take water or a sweet solution (20% or 24% sugar-water). After stable intakes of each fluid were achieved, the effects of phencyclidine hydrochloride (PCP), delta-9-tetrahydrocannabinol (THC), ethanol (E), and morphine (M) on intakes were tested. PCP, THC, and M all enhanced intake of the sweet solution, while E produced varying effects across doses tested. With other rats, nearly the same procedure was used except that the test solution presented with water was 0.9% sodium chloride. Doses of PCP enhanced intake of the salty solution. These data, combined with the data from similar studies of the effects of opioids and benzodiazepines, indicate that a wide variety of agents that are self-administered also modify intake of ingesta.     

Combination action of sisomicin, dibekacin and cefotetan, cefotaxime, latamoxef, and cefsulodin against Escherichia coli, Serratia marcescens, and Pseudomonas aeruginosa

The combined actions of sisomicin (SISO), dibekacin (DKB) and cefotetan (CTT), cefotaxime (CTX), latamoxef (LMOX), cefsulodin (CFS) against E coli KC-14, S. marcescens T-55 and P. aeruginosa E-2 were studied. The following results were obtained. The combination of SISO-CTT, SISO-CTX, SISO-LMOX, SISO-CFS, DKB-CTT, DKB-CTX, DKB-LMOX and DKB-CFS using the checker board dilution method on E. coli KC-14, S. marcescens T-55, P. aeruginosa E-2 were found to have a synergistic effect and the minimum FIC index values were 0.26--0.50 for SISO and 0.28--0.75 for DKB, respectively. With the killing kinetic method, all combinations tested showed a synergistic effect.     

Pharmacokinetics of Liquiritigenin in Mice,Rats, Rabbits,and Dogs,and Animal Scale-Up

Pharmacokinetics of liquiritigenin (LQ) and its two glucuronide metabolites, M1 and M2, in mice, rats, rabbits, and dogs and animal scale-up of the pharmacokinetic parameters of LQ were evaluated. After intravenous administration of LQ, the AUC (AUC_0?t) values of LQ, M1, and M2 were proportional to LQ doses in all animals studied. Animal scale-up of some pharmacokinetic parameters of LQ was performed based on the parameters after its intravenous administration (20 mg/kg; in the linear pharmacokinetic range) to the four species. Linear relationships were obtained (r > 0.968) between log CL (or CL/f_u) (L/h) and log species body weight (W) (kg) [CL (or CL/f_u) = 3.29 (34.0) W^{0.723 (0.789)}] and log V_ss (or V_ss/f_u) (L) and log W (kg) [V_ss (or V_ss/f_u) = 0.340 (3.52) W^{0.882 (0.948)}]. Interspecies scale-up of plasma concentration–time data of LQ using apolysichron (complex Dedrick plots) resulted in similar profiles, and plasma concentration–time profile of humans were predicted using the well-fitted four animal data. Our results indicate that the LQ data obtained from laboratory animals could be utilized to generate preliminary estimates of the pharmacokinetic parameters of LQ in humans. These parameters can serve as guidelines for better planning of clinical studies. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4327–4342, 2009     

Absorption,distribution, metabolism,and excretion of CKD-732, a novel antiangiogenic fumagillin derivative,in rats,mice, and dogs

The pharmacokinetics of CKD-732 (6-O-4-[dimethyl-aminoethoxy)cinnamoyl]-fumagillol x hemioxalate) was investigated in male SD rats and beagle dogs after bolus intravenous administration. The parent compound and metabolites obtained from in vitro and in vivo samples were determined by LC/MS. The main metabolite was isolated and identified as an N-oxide form of CKD-732 by NMR and LC/MS/MS. CKD-732 was metabolized into either M11 or others by rapid hydroxylation, demethylation, and hydrolysis. The blood level following the intravenous route declined in first-order kinetics with T(1/2)beta values of 0.72 to approximately 0.78 h for CKD-732 and 0.92 to approximately 1.09 h for M11 in rats at a dose of 7.5 to approximately 30 mg/kg. In dogs, T(1/2)beta values of CKD-732 and M11 were 1.54 and 1.79 h, respectively. Moreover, AUC values increased dose dependently for CKD-732 and M11 in rats and dogs. The CLtot and Vdss did not change significantly with increasing dose, indicating linear pharmacokinetic patterns. The excretion patterns through the urine, bile, and feces were also examined in the animals. The total amount excreted in urine, bile, and feces was 2.13% for CKD-732 and 1.29% for M11 in rats, and 1.58% for CKD-732 and 2.28% for M11 in dogs.     

Comparison of natriuretic, uricosuric, and antihypertensive properties of tienilic acid, bendrofluazide, and spironolactone.

The antihypertensive properties of the new diuretic tienilic acid were investigated. Thirteen previously untreated hypertensive patients took part in a double-blind crossover study in which 30 days' treatment with tienilic acid 250 mg, bendrofluazide 5 mg, and spironolactone 100 mg were compared. Bendrofluazide caused the greatest natriuresis on the first treatment day and the most rapid fall in blood pressure. The ultimate antihypertensive effect of all three drugs was similar. Tienilic acid caused a noticeable reduction in serum urate concentrations and a rise in urate clearance, in contrast to the other two agents, which caused slight urate retention. Tienilic acid and bendrofluazide caused falls and spironolactone a rise in plasma potassium concentrations. No untoward effects were seen from any of the drugs. It is concluded that tienilic acid is a moderately potent diuretic that lowers plasma urate concentrations. It may be the drug of first choice for hypertensive patients who already have gout or are likely to develop it when taking thiazide diuretics.     

Pharmacokinetics, tissue distribution, and excretion of sitafloxacin, a new fluoroquinolone antibiotic, in rats, dogs, and monkeys

The pharmacokinetics, tissue distribution and excretion of sitafloxacin (CAS 127254-12-0, DU-6859a) were investigated in rats, dogs, and monkeys following single intravenous or single oral administration of 14C-labelled sitafloxacin at a dose of 4.69 mg/kg. Following single administration of the oral dose, serum concentrations of radioactivity peaked at 0.5 h in rats, 2.3 h in dogs, and 2.5 h in monkeys. The apparent absorption ratios of 14C-sitafloxacin based on the AUC0-infinity were 31%, 51%, and 93% in rats, dogs, and monkeys, respectively. In rats, the drug-related radioactivity had been distributed to most organs and tissues 30 min after oral dosing, and had been essentially eliminated after 24 h. The highest levels of radioactivity were observed in the kidneys and liver, whereas the concentrations in the cerebrum and spinal cord were much lower than the serum value. The urinary recoveries of radioactivity after intravenous dosing were 45.5 % in rats, 32.3 % in dogs, and 77.8 % in monkeys. In bile duct-cannulated rats, 57.8 % of the orally administered radioactivity was excreted in the bile within 48 h, and at least 45 % of the sitafloxacin-related material secreted in the bile was re-absorbed from the gastrointestinal tract. These results indicate that sitafloxacin is rapidly absorbed and widely distributed into various tissues. Sitafloxacin-related material is eliminated primarily through both renal and biliary excretion in rats, and possibly in dogs, whereas renal excretion is the major route of elimination in monkeys.     

Simultaneous Estimation of Hydrochlorothiazide,Hydralazine Hydrochloride,and Reserpine Using PCA,NAS, and NAS-PCA

In this study, new and feasible UV-visible spectrophotometric and multivariate spectrophotometric methods were described for the simultaneous determination of hydrochlorothiazide (HCTZ), hydralazine hydrochloride (H.HCl), and reserpine (RES) in combined pharmaceutical tablets. Methanol was used as a solvent for analysis and the whole UV region was scanned from 200–400 nm. The resolution was obtained by using multivariate methods such as the net analyte signal method (NAS), principal component analysis (PCA), and net analyte signal-principal component analysis (NAS-PCA) applied to the UV spectra of the mixture. The results obtained from all of the three methods were compared. NAS-PCA showed a lot of resolved data as compared to NAS and PCA. Thus, the NAS-PCA technique is a combination of NAS and PCA methods which is advantageous to obtain the information from overlapping results.     

The effects of quazepam,triazolam, flunitrazepam and placebo,alone and in combination with ethanol,on day-time sleep,memory, mood and performance

Day-time sleep and residual effects of quazepam 15 mg, triazolam 0·25 mg, flunitrazepam 1 mg, and placebo, alone and in combination with ethanol, were studied using a randomized, double-blind, crossover, single-dose design. Eight healthy volunteers, four male and four female, aged 19–24 years, received each medication in the morning after a ‘normal’ sleep at home the preceding night. Quazepam and triazolam decreased the sleep onset when compared to placebo. The combination with ethanol did not change these findings. Quazepam and placebo showed less residual effects than triazolam and flunitrazepam at 4 hours after drug intake: in combination with ethanol at 4 and 6 hours. No significant differences in mood were found between the different ‘treatments’, except with regard to alertness for quazepam and placebo compared to flunitrazepam, alone and in combination with ethanol, all at 4 hours. The combination drug/ethanol showed an increase in C_max of the former and a delay in T_max when compared to drug alone. The study indicated few clinically useful correlations between clinical effect and plasma concentration.     

Cytotoxicity,antiviral and antimicrobial activities of alkaloids,flavonoids, and phenolic acids

Objective: Some natural products consisting of the alkaloids yohimbine and vincamine (indole-type), scopolamine and atropine (tropane-type), colchicine (tropolone-type), allantoin (imidazolidine-type), trigonelline (pyridine-type) as well as octopamine, synephrine, and capsaicin (exocyclic amine-type); the flavonoid derivatives quercetin, apigenin, genistein, naringin, silymarin, and silibinin; and the phenolic acids namely gallic acid, caffeic acid, chlorogenic acid, and quinic acid, were tested for their in vitro antiviral, antibacterial, and antifungal activities and cytotoxicity.

Materials and methods: Antiviral activity of the compounds was tested against DNA virus herpes simplex type 1 and RNA virus parainfluenza (type-3). Cytotoxicity of the compounds was determined using Madin-Darby bovine kidney and Vero cell lines, and their cytopathogenic effects were expressed as maximum non-toxic concentration. Antibacterial activity was assayed against following bacteria and their isolated strains: Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Enterococcus faecalis, and Bacillus subtilis, although they were screened by microdilution method against two fungi: Candida albicans and Candida parapsilosis.

Results: Atropine and gallic acid showed potent antiviral effect at the therapeutic range of 0.8–0.05 µg ml^?1, whilst all of the compounds exerted robust antibacterial effect.

Conclusion: Antiviral and antimicrobial effects of the compounds tested herein may constitute a preliminary step for further relevant studies to identify the mechanism of action.