Development and validation of analytical method by HPLC-DAD for determination of vasodilator active in pharmaceutical ophthalmic forms

The substance 4-Aminobenzamidine dihydrochloride (4-AD) is one of the degradation products of diminazene aceturate and has demonstrated antiglaucomatous potential. Glaucoma is the second leading cause of blindness worldwide; thus, new therapeutic alternatives must be studied, for example, the molecule 4-AD vehiculated into polymeric inserts for prolonged release. The present work aims to develop and validate an analytical method to quantify 4-AD in pharmaceutical ophthalmic forms. A HPLC was used with UV-Vis detector, at 290 ƞm and ACE® C18 column (125 × 4.6 mm, 5 µm), in which the mobile phase consists of phosphate buffer (pH 7.4) and triethylamine (30 mmol/L), under an isocratic flow of 1.0 mL/min. The retention time of 3.2 minutes was observed. The method was developed and validated in accordance with ANVISA recommendations and ICH guides. The linearity range was established between the concentrations 5 and 25 µg/mL (correlation coefficient r = 0.993). The accuracy, repeatability, and intermediate precision tests obtained a relative standard deviation less than or equal to 5%. In addition, the method was considered selective, exact. and robust, with pH being its critical factor. Therefore, the HPLC analysis method is robust and can be used to quantify 4-AD in pharmaceutical forms for ocular application.(AU)

Efficacy and safety of a single dose pentamidine (7mg/kg) for patients with cutaneous leishmaniasis caused by L. guyanensis: a pilot study

Abstract: BACKGROUND: There have been few studies on pentamidine in the Americas; and there is no consensus regarding the dose that should be applied. OBJECTIVES: To evaluate the use of pentamidine in a single dose to treat cutaneous leishmaniasis. METHODS: Clinical trial of phase II pilot study with 20 patients. Pentamidine was used at a dose of 7 mg/kg, in a single dose. Safety and adverse effects were also assessed. Patients were reviewed one, two, and six months after the end of treatments. RESULTS: there was no difference between the treatment groups in relation to gender, age, number or location of the lesions. Pentamidine, applied in a single dose, obtained an effectiveness of 55%. Mild adverse events were reported by 17 (85%) patients, mainly transient pain at the site of applications (85%), while nausea (5%), malaise (5%) and dizziness (5%) were reported in one patient. No patient had sterile abscess after taking medication at a single dose of 7mg/kg. CONCLUSIONS: Clinical studies with larger samples of patients would enable a better clinical response of pent amidine at a single dose of 7mg, allowing the application of more powerful statistical tests, thus providing more evidences of the decrease in the effectiveness of that medication. Hence, it is important to have larger studies with new diagrams and/or new medications.

Different Extracts of Zingiber officinale Decrease Enterococcus faecalis Infection in Galleria mellonella

Dried, fresh and glycolic extracts of Zingiber officinale were obtained to evaluate the action against G. mellonella survival assay against Enterococcus faecalis infection. Eighty larvae were divided into: 1) E. faecalis suspension (control); 2) E. faecalis + fresh extract of Z. officinale (FEO); 3) E. faecalis + dried extract of Z. officinale (DEO); 4) E. faecalis + glycolic extract of Z. officinale (GEO); 5) Phosphate buffered saline (PBS). For control group, a 5 μL inoculum of standardized suspension (107 cells/mL) of E. faecalis (ATCC 29212) was injected into the last left proleg of each larva. For the treatment groups, after E. faecalis inoculation, the extracts were also injected, but into the last right proleg. The larvae were stored at 37 °C and the number of dead larvae was recorded daily for 168 h (7 days) to analyze the survival curve. The larvae were considered dead when they did not show any movement after touching. E. faecalis infection led to the death of 85% of the larvae after 168 h. Notwithstanding, in treatment groups with association of extracts, there was an increase in the survival rates of 50% (GEO), 61% (FEO) and 66% (DEO) of the larvae. In all treatment groups, the larvae exhibited a survival increase with statistically significant difference in relation to control group (p=0.0029). There were no statistically significant differences among treatment groups with different extracts (p=0.3859). It may be concluded that the tested extracts showed antimicrobial activity against E. faecalis infection by increasing the survival of Galleria mellonella larvae.

Extratos seco, fresco e glicólico de Zingiber officinale foram obtidos para avaliar suas ações por meio de ensaio de sobrevivência em G. mellonella contra infecção por Enterococcus faecalis. Oitenta larvas foram divididas em: 1) Suspensão de E. faecalis (controle); 2) E. faecalis + extrato fresco de Z. officinale (FEO); 3) E. faecalis + extrato seco de Z. officinale (DEO); 4) E. faecalis + extrato glicólico de Z. officinale (GEO); 5) Solução tampão fosfato salina (PBS). Para o grupo de controle, 5 µL de inóculo de suspensão padronizada (107 células/mL) de E. faecalis (ATCC 29212) foi injetado na última proleg esquerda de cada lagarta. Para os grupos com tratamento, após a injeção de E. faecalis, os extratos foram injetados na última proleg direita. Após as injeções, as lagartas foram armazenadas a 37 °C e o número de animais mortos foi registrado diariamente em 168 h (7 dias) para analisar a curva de sobrevivência. As lagartas foram consideradas mortas quando elas não mostraram qualquer movimento após o toque. A infecção por E. faecalis levou à morte de 85% das lagartas após 168 h. Não obstante, nos grupos de tratamento com associação dos extratos, houve um aumento nas taxas de sobrevivência de 50% (GEO), 61% (FEO) e 66% (DEO) das lagartas. Em todos os grupos com tratamento, as lagartas apresentaram um aumento na sobrevivência, com diferença estatisticamente significativa em relação ao grupo controle (p=0,0029). Não houve diferença estatisticamente significativa entre os tratamentos com os diferentes extratos (p=0,3859). Pode concluir-se que os extratos testados mostraram atividade antimicrobiana contra a infecção por E. faecalis, aumentando a sobrevivência das lagartas de G. mellonella.

The Effect of Ultrasound-guided TAPB on Pain Management after Total Abdominal Hysterectomy

BACKGROUND: Incisional pain is particularly troublesome after hysterectomy. A method called transversus abdominis plane block (TAPB) has shown promise in managing postoperative pain. In this study, we evaluated the analgesic efficacy of ultrasound-guided TAPB after hysterectomy at different time points and at each time point separately for 48 hours. METHODS: Forty-two patients (ASA I, II) who were electively chosen to undergo total abdominal hysterectomy were divided into 2 groups, control (group C) and intervention (group I). Twenty-one patients underwent TAPB (group I) and 21 patients received only the standard treatment with a fentanyl pump (group C). Both groups received standard general anesthesia. For patients in group I, following the surgery and before emergence from anesthesia, 0.5 mg/kg of ropivacaine 0.2% (about 20 cc) was injected bilaterally between the internal oblique and transverse abdominis muscles using sonography. Pain scores using the Visual Analogue Scale (VAS) and drug consumption were measured at 2, 6, 12, 24, and 48 hours after TAPB. RESULTS: There were no significant differences in demographics between the two groups. VAS scores appeared to be lower in group I, although there was no interaction with time when we compared mean VAS measurements at different time points between group I and group C (P > 0.05). The amount of fentanyl flow was consistently higher in group C, but when we compared the two groups at each time point separately, the observed difference was not statistically significant (P < 0.053). The incidence of vomiting was 10% in group I and 28% in group C. There were no complaints of itching, and sedation score was 0 to 3. There were no complications. CONCLUSIONS: This study showed that TAPB did not result in a statistically significant decrease in VAS scores at different time points. TAPB did lead to decreased fentanyl flow, but when we compared the two groups at each time point separately, the observed difference was not statistically significant.

The analgesic effect of ultrasound-guided transverse abdominis plane block after laparoscopic totally extraperitoneal hernia repair / 대한마취과학회지

BACKGROUND: The ultrasound-guided transverse abdominis plane block (TAPB) reduces postoperative pain after laparoscopic abdominal surgery. But, its effect post laparoscopic totally extraperitoneal hernia repair (TEP) is not clear. In this study, we evaluated the analgesic effect of ultrasound-guided TAPB in TEP. METHODS: In this prospective, randomized study, forty adult patients (ASA I-II) scheduled for a TEP under general anesthesia were studied. In the TAPB group (n = 20), an ultrasound-guided bilateral TAPB was performed with 0.375% ropivacaine 15 ml on each side after the induction of general anesthesia. The control group (n = 20) did not have TAPB performed. Fentanyl 50 microg was repeatedly injected as per the patient's request in the recovery room. Pain scores at rest and on coughing were assessed postoperatively in the recovery room (20 min, at discharge) and at 4, 8, and 24 hours after surgery. RESULTS: In the recovery room, pain scores (numeric rating scale, 0-10) at postoperative 20 min were lower in the TAPB group (3.9 +/- 1.6, 4.9 +/- 1.8) than the control group (6.9 +/- 1.6, 8.0 +/- 1.6) at rest and on coughing. Also, pain scores upon discharge from the recovery room were lower in the TAPB group (3.2 +/- 1.2, 4.2 +/- 1.5) than the control group (5.3 +/- 1.6, 6.5 +/- 1.8) at rest and on coughing. CONCLUSIONS: The ultrasound-guided TAPB in patients that had undergone TEP reduced postoperative pain scores and the fentanyl requirement in the recovery room. Also, pain scores on coughing were reduced until postoperative 8 hours.

Synthesis and 5-HT reuptake inhibition activity of biarylbenzamidine derivatives / 药学学报

A series of biarylbenzamidine analogs were synthesized and tested for their biological activities of inhibiting the reuptake of 5-HT. All of them were new compounds, and their structures were confirmed by 1H NMR and HRMS. Preliminary in vitro pharmacological tests showed that all target compounds exhibited 5-HT reuptake inhibition activity. Among the tested compounds, 5i, 4a and 5m exhibited potent inhibitory activity against 5-HT reuptake in vitro. It is a chance to find a better precursor of SSRIs (selective serotonin reuptake inhibitors) for further optimization of compounds.

Thermodynamic evaluation and modeling of proton and water exchange associated with benzamidine and berenil binding to ß-trypsin

Serine-proteases are involved in vital processes in virtually all species. They are important targets for researchers studying the relationships between protein structure and activity, for the rational design of new pharmaceuticals. Trypsin was used as a model to assess a possible differential contribution of hydration water to the binding of two synthetic inhibitors. Thermodynamic parameters for the association of bovine ß-trypsin (homogeneous material, observed 23,294.4 ± 0.2 Da, theoretical 23,292.5 Da) with the inhibitors benzamidine and berenil at pH 8.0, 25°C and with 25 mM CaCl2, were determined using isothermal titration calorimetry and the osmotic stress method. The association constant for berenil was about 12 times higher compared to the one for benzamidine (binding constants are K = 596,599 ± 25,057 and 49,513 ± 2,732 M-1, respectively; the number of binding sites is the same for both ligands, N = 0.99 ± 0.05). Apparently the driving force responsible for this large difference of affinity is not due to hydrophobic interactions because the variation in heat capacity (DCp), a characteristic signature of these interactions, was similar in both systems tested (-464.7 ± 23.9 and -477.1 ± 86.8 J K-1 mol-1 for berenil and benzamidine, respectively). The results also indicated that the enzyme has a net gain of about 21 water molecules regardless of the inhibitor tested. It was shown that the difference in affinity could be due to a larger number of interactions between berenil and the enzyme based on computational modeling. The data support the view that pharmaceuticals derived from benzamidine that enable hydrogen bond formation outside the catalytic binding pocket of ß-trypsin may result in more effective inhibitors.

Chronic microsporidial stromal keratitis in an immunocompetent, non-contact lens wearer.

An 82-year-old healthy man with unilateral chronic stromal keratitis, initially diagnosed to have viral keratitis and refractory to medical therapy, showed numerous oval, microsporidial organisms, measuring 4-5 m in length in the corneal biopsy. Penetrating keratoplasty, followed by treatment with systemic albendazole and topical propamidine isethionate resulted in resolution of the infection. Electron microscopy of the keratoplasty specimen demonstrated sporoblasts with diplokaryotic nuclei and multiple coils of the filament. The light and electron microscopic features were consistent with microsporidial keratitis.

Linear competitive inhibition of human tissue kallikrein by 4-aminobenzamidine and benzamidine and linear mixed inhibition by 4-nitroaniline and aniline

Hydrolysis of D-valyl-L-leucyl-L-arginine p-nitroanilide (7.5-90.0 `M) by human tissue kallikrein (hK1) (4.58-5.27 nM) at pH 9.0 and 37ºC was studied in the absence and in the presence of increasing concentrations of 4-aminobenzamidine (96-576 `M), benzamidine (1.27-7.62 mM), 4-nitroaniline (16.5-66 `M) and aniline (20-50 mM). The kinetic parameters determined in the absence of inhibitors were: Km = 12.0 + or - 0.8 `M and k cat = 48.4 + or - 1.0 min-1. The data indicate that the inhibition of hK1 by 4-aminobenzamidine and benzamidine is linear competitive, while the inhibition by 4-nitroaniline and aniline is linear mixed, with the inhibitor being able to bind both to the free enzyme with a dissociation constant Ki yielding an EI complex, and to the ES complex with a dissociation constant Ki', yielding an ESI complex. The calculated Ki values for 4-aminobenzamidine, benzamidine, 4-nitroaniline and aniline were 146 + or - 10, 1,098 + or - 91, 38.6 + or - 5.2 and 37,340 + or - 5,400 `M, respectively. The calculated Ki' values for 4-nitroaniline and aniline were 289.3 + or - 92.8 and 310,500 + or - 38,600 `M, respectively. The fact that Ki'>Ki indicates that 4-nitroaniline and aniline bind to a second binding site in the enzyme with lower affinity than they bind to the active site. The data about the inhibition of hK1 by 4-aminobenzamidine and benzamidine help to explain previous observations that esters, anilides or chloromethyl ketone derivatives of Nalpha-substituted arginine are more sensitive substrates or inhibitors of hK1 than the corresponding lysine compounds

Competitive parabolic inhibition of bovine trypsin by benzamidines

Competitive parabolic inhibition, a rare type of inhibition of one-substrate enzymes, is described for alpha-and beta-trypsin. The enzymes were so inhibited by two bis-benzamidines 4-4' diazoamino-bis-benzamidine, Berenil (DABB) and its platinum complex, DABB-PtCl2, acting on acyl-amino acid-peptidyl nitroanilides (Nan) substrates, when inhibitor concentrations exceed 10 mM and approch the millimolar range. The type of nonlinear inhibition observed require4s ternary complex formation between one enzyme molecule and two inhibitor molecules (M. E. M), and also permits the formation of the mixed ternary complex (M. E. S.). Binding of the first DABB molecule to the active center of trypsin takes place with K1 values of ca. 1.50 uM for both alpha-and- beta-trypsin. The secondary binding site binds the inhibitor with dissociation constants K12 close to 0.25 mM for both forms of the enzyme, as determined with different substrates. The dissociation constants of the ternary mixed complexes (Ksi and Kis), however, depend on the structural features of the substrates, which are of negligible importance for Bz-Arg-Nan, but significant for Ac-Phe-Arg-Nan and D-Val-Leu-Arg-Nan, reflecting subsite interactions between S1-S3 and S'2. Pentamidine, a diamidino-4,4'-diphenoxy-alkane with a flexible chain, behaved as a strict competitive inhibitor. This implies that the triazene moiety of DABB is involved in the interaction between the inhibitor and the secondary binding site of the enzyme

A plausible identification of secondary binding site in trypsin and trypsinogen

1. The determination of the binding of 4,4'diazoamino-bis-benzamidine (DABB) to alfa-trypsin by equilibrium measurements in columns indicated a stoichiometry of 2 mol ligan/mol enzyme. One molecule binds to the secondy binding site, sith Ki2=mMat pH8,0, 25-C. 2. Bovine pancreatic trypsin inhibitor (BPTI) prevented binding of DABB to both sites, indicating that they are topographically close and within the interface of the trypsin-BPTI complex. 3. On the basis of data from the interface of the trypsin-BPTI complex, we concluded that the secondary binding site of trypsin is plausibly identified as the same site in trypsin that binds the Arg-17 reside of BPTI, i.e., Tyr-39 and Tyr-151 in bovine trypsin. This site would then correspond to subsite S'2 on the enzyme surface

The substituent effect on complex formation between alfa-trypsin and para-substituted benzamidinium ions: A thermodynamic study

Dissociation constants, Kj, were determined spectrophotometrically by measuring the absorbance at 410 nm, using N alfa-benzoyl-D,L-argomome-para-nitroanilide (Bz-D,L-Arg-Nan) as substrate. The Ki values for the complexes of alfa-trypsin with each of the para-derivatives of the benzamidinium ion -NH2, -CH3, -H, -F, -Cl, -Br, -COOEt, and -NO2 were measured at six temperatures (8,15,20,25, 29 and 33§C), in order to determine the thermodynamic parameters for complex formation. The standard enthalpy change was constant and all other parameters were also negative. The large negative values obtained for the standard heat capacity change suggest that the process occurs with a conformational adaptation in the enzyme structure. The apparent partial specife volumes of free alfa-trypsin and alfa-trypsin bound to benzamidinium ion indicated that there is a decrease of approximatelly 0.10 cm**3/g in the enzyme volume when the inhibitor binds. This contraction is consistent with the release of about 130 water molecules per enzyme molecule

Estudo comparativo entre cloridrato de benzidamina versus hexamidina associada ao cloridrato de tetracaína no tratamento tópico das amegdalites / Benzydamine versus hexamydine associated with chloridrate of tetracaine in topic treatment of tonsillitis

Sessenta e seis pacientes febris, com amigdalite aguda ou crônica reacutizada foram tratados por um período de 7 dias consecutivos com nebulizaçöes tópicas de benzidamina spray ou hexamidina + tetracaína aerosol.Ambas as medicaçöes experimentadas mostraram-se altamente efetivas, de boa tolerabilidade e palatabilidade. Observou-se tendência de melhora mais rápida com a utilizaçäo da benzidamina spray. Os resultados obtidos com o uso da benzidamina spray indicam que este potente antiinflamatório tópico deve ser incluído no arsenal terapêutico destinado ao combate das amigdalites, pelo valioso alívio sintomático que é capaz de proporcionar