Development of UV-visible spectrophotometric methods for the quantitative and in silico studies for cilazapril optimized by response surface methodology.

For cilazapril (CLZ), analytical methods based on donor-acceptor phenomenon that are simple, rapid with broad linear dynamic range for the quantification of drug are not available in the literature. Considering the requirement for the methods, in this study, two economic, potent analytical methods based on the complexation of CLZ with π-acceptors, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 2,5-dichloro-3,6-dihydroxy-p-benzoquinone (CA) were developed, validated, and studied spectrophotometrically. Various analytical data were discussed. The effects of experimental variables were optimized from the results of in silico technique, i.e. Box-Behnken design under response surface methodology. Linear dynamic range was significantly good in the range of 6-60 µg mL-1 and 20-260 µg mL-1 for DDQ and CA methods. Moreover, molecular docking studies corroborated the experimental results. Further, the methods were supplemented by the pharmaceutical and biological application for the quantitative assay of CLZ. Collectively, the results of the reported method of the analysis suggest that the developed approach is simple, sensitive, accurate and precise.

Lignin-Based Spherical Structures and Their Use for Improvement of Cilazapril Stability in Solid State.

Biopolymer-based spherical particles exhibit unique properties including narrow sizes and many functional groups on their surfaces. Therefore, they show great potential for application in many scientific and industrial processes. The main aim of this study was to prepare lignin-based spherical particles with the use of a cationic surfactant, hexadecyl(trimethyl)ammonium bromide (CTAB). In the first step, different preparation procedures were tested with varying parameters, including biopolymer and surfactant ratios, lignin filtration, and experimental time. The morphological and dispersion characteristics of the materials were determined to select the best samples with the most promising properties, which could then be tested for their acute toxicity. It was observed that almost all materials were characterized by spherical shapes in micro- and nanosizes. The sample with the best physicochemical properties was used for further analysis and then tested for medical applications: the improvement of the stability of a drug molecule, cilazapril (CIL). The formulated material (CIL@LC-2a 1:1 wt./wt.) exhibited outstanding properties and significantly improved the stability of cilazapril as tested in conditions of increased temperature and humidity. Lignin spherical particles may be employed as a promising material for shielding other active compounds from decomposition.

Multicriteria Optimization Methodology in Stability-Indicating Method Development of Cilazapril and Hydrochlorothiazide.

Multicriteria optimization methodology was applied in development of UHPLC-UV-MS method for separation of cilazapril, hydrochlorothiazide and their degradation products. This method is also applicable for analysis of cilazapril, hydrochlorothiazide and their degradation products in combined tablet formulation. Prior to method optimization forced degradation studies were conducted. Cilazapril and hydrochlorothiazide were subjected to acidic (0.1, 0.5 and 1.0 M HCl), basic (0.1, 0.5 and 1.0 M NaOH), thermal (70°C), oxidative (3-30% H2O2) degradation and photodegradation (day light). Cilazapril appeared to be unstable toward acid and base and resulted in formation of cilazaprilat. Hydrochlorothiazide significantly degraded after acid, base and thermal hydrolysis and formed degradation product was 4-amino-6-chlorobenzene-1.3-disulfonamide. For both substances, after oxidative degradation unknown products have arisen. Initial percentage of acetonitrile in mobile phase, final percentage of acetonitrile in mobile phase, time of gradient elution and column temperature were defined as variables to be optimized toward two chromatographic responses by means of central composite design and Derringer's desirability function. The satisfactory chromatographic analysis was achieved on Kinetex C18 (2.6 µm, 50 × 2.1 mm) column with temperature set at 25°C. The final mobile phase consisted of acetonitrile and 20 mM ammonium formate buffer (pH adjusted to 8.5). The flow rate of the mobile phase was 400 µL min-1 and it was pumped in a gradient elution mode.

Use of LC-MS/TOF, LC-MS(n), NMR and LC-NMR in characterization of stress degradation products: Application to cilazapril.

Forced degradation studies on cilazapril were carried out according to ICH and WHO guidelines. Significant degradation of the drug was observed in acid and base conditions, resulting primarily in cilazaprilat. In neutral condition, five degradation products were formed, while under oxidative condition, two degradation products were generated. In total, seven degradation products were formed, which were separated on an Inertsil C-18 column using a stability-indicating HPLC method. Structure elucidation of the degradation products was done by using sophisticated and hyphenated tools like, LC-MS/TOF, LC-MS(n), on-line H/D exchange, LC-NMR and NMR. Initially, comprehensive mass fragmentation pathway of the drug was laid down. Critical comparison of mass fragmentation pathways of the drug and its hydrolytic degradation products allowed structure characterization of the latter. 1D and 2D proton LC-NMR studies further confirmed the proposed structures of hydrolytic degradation products. The oxidative degradation products could not be characterized using LC-MS and LC-NMR tools. Hence, these degradation products were isolated using preparative HPLC and extensive 1D ((1)H, (13)C, DEPT) and 2D (COSY, TOCSY, HETCOR and HMBC) NMR studies were performed to ascertain their structures. Finally, degradation pathways and mechanisms of degradation of the drug were outlined.

Stability of cilazapril in pediatric oral suspensions prepared from commercially available tablet dosage forms.

Abstract: Cilazapril is a drug commonly used in management of heart failure in pediatric population. On pharmaceutical market it is available only in inconvenient for pediatric use tablet dosage forms. Until now, no oral liquid formulation containing cilazapril has been evaluated. Therefore, the aim of this study was to prepare easy to made and palatable 1 mg/mL oral liquid formulation with cilazapril (with consideration of original and generic cilazapril tablet and different packages) and subsequent investigation of physicochemical stability of these suspensions. Formulations were compounded using cilazapril obtained from original or generic cilazapril marketed tablet formulations and Ora-Blend" suspending agent. Stability of prepared suspensions stored in closed amber glass or amber plastic PET bottles in the temperature of 298 K was estimated throughout 28 day shelf-life period. Chemical stability was assessed by HPLC cilazapril stability indicating method. Physical stability was evaluated by appearance, taste, smell, pH and theological assessments. Cilazapril oral suspensions at concentration of 1 mg/mL demonstrated satisfactory stability over 28 day long storage at room temperature. Cilazapril concentrations remained within acceptable limit (+/- 10%) stored in closed amber bottles made of glass or PET material. Moreover, suspensions physical properties remained unaffected. Cilazapril - Ora-Blend* pediatric oral liquid is easy to made, palatable and stable when stored at room temperature for 28 days. Stability of cilazapril oral liquid remains unchanged while using cilazapril tablets produced by different manufacturers and bottles made of amber glass or PET material.

The aldosterone receptor antagonist spironolactone prevents peritoneal inflammation and fibrosis.

Peritoneal fibrosis is a complication of patients with long-term continuous ambulatory peritoneal dialysis (CAPD). Reports have indicated that angiotensin (Ang) II may correlate with the development of peritoneal fibrosis. However, it is unknown whether aldosterone also has a role in the development of peritoneal inflammation and fibrosis. The aim of the present study was to clarify the role of aldosterone in peritoneal inflammation and fibrosis. A rat model of peritoneal inflammation and fibrosis was established by daily intraperitoneal injection of dialysates and lipopolysaccharide in a 4-day interval over a period of 7 days. The animals were randomly assigned to five groups as follows: control (C); peritoneal dialysis (PD); peritoneal dialysis-spironolactone (PD-S); peritoneal dialysis-cilazapril (PD-C); and peritoneal dialysis-spironolactone-cilazapril (PD-SC). After 30 days, the TGF-ß1 concentration in dialysates from all treatment groups was determined by ELISA. The histopathology of the parietal peritoneum was examined, and the expression of MCP-1, c-Jun, fibronectin (FN) and TGF-ß1 in the abdominal membrane was determined by immunohistochemistry. Mineralocorticoid receptor (MR), 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2) and CYP11B2 (aldosterone synthase) were analyzed by real time-PCR. Collagen deposition was significantly higher in PD compared with the other groups. The expression of MR, 11ß-HSD2 and CYP11B2 was significantly higher in PD compared with the other groups. Spironolactone and/or cilazapril treatment partially ablated the increase in monocyte chemoattractant protein (MCP)-1, p-c-Jun, transforming growth factor (TGF)-ß1, FN, MR, 11ß-HSD2 and CYP11B2. Furthermore, treatment with spironolactone and/or cilazapril also reduced the infiltration of CD-4- and ED-1-positive cells in rat peritoneal tissues after peritoneal fibrosis. Exogenous aldosterone may have a key role in the development of peritoneal inflammation and fibrosis. Spironolactone decreased peritoneal inflammation and fibrosis, which was associated with reduced secretion from peritoneal macrophages, inactivation of the c-Jun N-terminal kinase (JNK) pathway and subsequent downregulation of the expression of TGF-ß1.

Enalapril enhances the anticonvulsant activity of lamotrigine in the test of maximal electroshock.

BACKGROUND: The aim of this study was to find out whether angiotensin-converting enzyme (ACE) inhibitors, enalapril and cilazapril, affect the anticonvulsant action of some second-generation antiepileptics, lamotrigine (LTG), topiramate (TPM) and oxcarbazepine (OXC). METHODS: The effects of ACE inhibitors on antiepileptic drugs were examined in the mouse model of maximal electroshock. RESULTS: Enalapril (30 mg/kg ip) potentiated the anticonvulsant action of LTG, decreasing its ED50 value from 5.3 to 3.6 mg/kg (p < 0.01). The anticonvulsant activity of TPM or OXC was not modified by enalapril. Cilazapril did not affect the protective activity of the studied antiepileptics. The interaction between enalapril and LTG could be pharmacodynamic in nature because enalapril did not change plasma and total brain concentrations of LTG. CONCLUSIONS: This study shows that there are no negative interactions between the studied antiepileptic drugs and enalapril or cilazapril. Enalapril even enhanced the anticonvulsant activity of LTG in the MES test in mice that is thought to be a predictive model of human generalized tonic-clonic seizures.

Cilazapril stability in the presence of hydrochlorothiazide in model mixtures and fixed dose combination.

The presented study aimed at the evaluation of hydrochlorothiazide influence on cilazapril stability in model mixture and fixed dose tablet formulation. The degradation of cilazapril in the presence of hydrochlorothiazide took place according to autocatalytic reaction kinetic mechanism, described mathematically by Prout-Tompkins equation. Hydrochlorothiazide coexistence with cilazapril in model mixture and fixed dose tablet without blister package accelerated cilazapril degradation in comparison with degradation of cilazapril substance. Values of reaction induction time shortened, while those of observed reaction rate constant increased. Increasing values of relative humidity and temperature have negative impact on cilazapril stability. Determined semi-logarithmic relationships: In k = f(RH) and Arrhenius ln k = f(1/T) are linear and are cilazapril stability predictive. The blister (OPA/Alu/PVC//Alu) package of fixed dose tablets, constitutes absolute moisture protection and prevent cilazapril--hydrochlorothiazide interaction occurrence.

Rapid and simple stability indicating HPLC method for the determination of cilazapril in pure substance and pharmaceutical formulation in comparison with classic and derivative spectrophotometric methods.

The present study describes development and subsequent validation of high performance liquid chromatographic method (HPLC) in comparison with spectrophotometric methods (classic, first, second and third order derivative) for determination of pure cilazapril in substance and pharmaceutical preparation. The main aim of this study was to find the method suitable not only for determination of cilazapril, but additionally useful in degradation kinetic study. Only the HPLC method is stability indicating. The HPLC method utilizes LiChroCART 250-4 HPLC-Cartridge, LiChrospher 100 RP-18 (5 µm) column, at ambient temperature, eluted at the flow rate 1.0 mL/min. The mobile phase consists of acetonitrile, methanol and phosphate buffer (pH 2.0) (60:10:30, v/v/v). Wavelength of detection is set at 212 nm. Benzocaine is used as an internal standard. The second and third order derivative spectrophotometric methods can be applied for the cilazapril analysis in substance and tablet, but not for stability evaluation (the lack of selectivity towards degradation product).

Common medications among dental outpatients: considerations in general dental practice.

OBJECTIVES: To provide information about the most common medications listed as being taken by dental patients presenting to an outpatient setting at a tertiary institution and to establish a list of the most common medications for review for the general dental practitioner. METHODS: A retrospective review was undertaken of 300 dental outpatient notes chosen from patients seen in the urgent dental care and exodontia clinics at the School of Dentistry in Dunedin. Data were recorded on patient age, medication list reported at the time of presentation and the number of medications. The ten most common medications encountered were listed in order of frequency, along with the ten most common prescription medications and the most common supplements or alternative remedies. A concise pharmacological synopsis for each of the ten most common medications was then presented as a review. RESULTS: The age range of patients was from 18 to 88 years, with a mean age of 43.2 years (median age 41 years). More than one-quarter were aged 20-29 years. Some 56% of patients reported taking at least one medication at the time of presentation. The greatest number of medications being taken by an individual patient was 15. Of 138 different medications identified, the most commonly reported included aspirin, paracetamol and omeprazole. A list of the ten most common medications was established for concise review, in order to outline aspects important to the general dental practitioner. CONCLUSIONS: This study provides information on the most common medications reported among dental outpatients presenting to a tertiary institution and highlights the need for general dental practitioners to be knowledgeable about them and their impact on dental treatment.

Advantages of automation in plasma sample preparation prior to HPLC/MS/MS quantification: application to the determination of cilazapril and cilazaprilat in a bioequivalence study.

An HPLC/MS/MS method characterized by complete automation and high throughput was developed for the determination of cilazapril and its active metabolite cilazaprilat in human plasma. All sample preparation and analysis steps were performed by using 2.2 mL 96 deep-well plates, while robotic liquid handling workstations were utilized for all liquid transfer steps, including liquid-liquid extraction. The whole procedure was very fast compared to a manual procedure with vials and no automation. The method also had a very short chromatographic run time of 1.5 min. Sample analysis was performed by RP-HPLC/MS/MS with positive electrospray ionization using multiple reaction monitoring. The calibration curve was linear in the range of 0.500-300 and 0.250-150 ng/mL for cilazapril and cilazaprilat, respectively. The proposed method was fully validated and proved to be selective, accurate, precise, reproducible, and suitable for the determination of cilazapril and cilazaprilat in human plasma. Therefore, it was applied to a bioequivalence study after per os administration of 2.5 mg tablet formulations of cilazapril.

Ultra-thin-layer chromatography mass spectrometry and thin-layer chromatography mass spectrometry of single peptides of angiotensin-converting enzyme inhibitors.

The separation of structurally related angiotensin-converting enzyme (ACE) inhibitors lisinopril, cilazapril, ramipril and quinapril and their corresponding active diacid forms (prilates) by conventional TLC silica gel 60 plates was contrasted with that afforded by monolithic ultra-thin-layer chromatographic (UTLC) plates. For the use of UTLC plates technical modifications of the commercially available equipments for the sample application, development and detection were made. Plates were developed in modified horizontal developing chamber using ethyl acetate-acetone-acetic acid-water (4:1:0.25:0.5, v/v). Detection of the separated compounds was performed densitometrically in absorption/reflectance mode at 220 nm and after exposure to iodine also by image analysis. The obtained results showed that monolithic layer is more efficient for the separation of structurally similar polar compounds, such as prilates than conventional silica layers. Identification of the compounds was confirmed by ESI-MS after their on-line extraction from the UTLC and TLC plates by means of Camag TLC-MS interface.

Kaposi's sarcoma in a patient with psoriasis vulgaris.

A 54-year-old woman presented with angiomatous lesions located on the upper extremities and right cruris. Histopathological findings were typical of Kaposi's sarcoma (KS). She had had mild to moderate psoriasis since she was 25 years old. She had been using cilazapril (an angiotensin-converting enzyme inhibitor) for the last 9 months. She had had similar lesions in the past while taking the same medication. Because our patient's KS lesions had developed during treatment with cilazapril, the drug was stopped. One month later, spontaneous regression of KS nodules was noted and after 4 months no KS lesions were seen.

Effects of bisoprolol and cilazapril on the central retinal artery blood flow in patients with essential hypertension--preliminary results.

BACKGROUND: A growing body of evidence suggests that effective blood pressure reduction may inhibit the progression of microvascular damage in patients with essential arterial hypertension. However, the potential influence of anti-hypertensive drugs on ocular circulation has not been studied sufficiently. PURPOSE: The aim of our study was to evaluate the effects of anti-hypertensive therapy on blood flow in the central retinal artery in patients with systemic arterial hypertension. MATERIAL AND METHODS: Twenty patients with essential arterial hypertension, aged 32-46 years, were examined with Doppler ultrasonography (10 MHz ultrasound probe). Blood flow velocities, pulsatility, and vascular resistance were determined before and 3 hours after systemic application of either bisoprolol 5 mg or cilazapril 2.5 mg. RESULTS: Administered bisoprolol significantly decreased maximum (9.8 ± 0.5 cm/s versus 8.5 ± 0.6 cm/s; P < 0.05) and minimum (2.75 ± 0.19 cm/s versus 1.75 ± 0.27 cm/s; P < 0.02) velocity, increased the Pourcellot's index (0.71 to 0.79; P < 0.05) in central retinal artery. There were no statistically significant changes in central retinal artery blood flow after administration of cilazapril. CONCLUSION: Systemic application of beta-blockers may unfavourably disturb the ocular blood flow.

Cilazapril increases plasma ghrelin concentration in obese patients with arterial hypertension.

INTRODUCTION: Ghrelin is a polypeptide hormone secreted mainly by the stomach cells, stimulating food intake and growth hormone release. Decreased plasma ghrelin concentration was found in obese subjects. Clinical and experimental data suggest that ghrelin also exerts a blood pressure lowering property. The influence of antihypertensive medication on plasma ghrelin concentration has not been studied, yet. MATERIAL AND METHODS: Plasma ghrelin concentration was estimated in 52 hypertensive obese (HA + O), 14 normotensive obese (O), and 15 lean healthy subjects in the fasting state, and after ingestion of a standard meal. HA + O patients were randomly allocated into 4 groups treated alternatively with: cilazapril, bisoprolol, amlodipine, or indapamide. After 6 weeks of antihypertensive monotherapy, the assessments were repeated. RESULTS: Similar fasting [HA + O - 780 (676-960) pg/ml; O - 751 (619-899) pg/ml] and postprandial plasma ghrelin concentrations were found in hypertensive and normotensive obese subjects. Plasma ghrelin concentrations in lean healthy subjects were significantly higher (987 (765-1366) pg/ml) in comparison to O and HA + O. Treatment with cilazapril was followed by a 28.0% increase of plasma ghrelin concentration (p = 0.04), while with bisoprolol, a 18.9% decrease (p = 0.01). No significant changes of ghrelinaemia were observed in HA + O treated with amlodipine or indapamide. No significant correlation between blood pressure and plasma ghrelin concentration before the therapy and their changes after 6 weeks of medication were found. CONCLUSIONS: 1. Our data do not support the major role of ghrelin in blood pressure regulation in obesity. 2. An increase of plasma ghrelin concentration after treatment with cilazapril was observed. (Pol J Endocrinol 2010; 61 (1): 21-27).

Blockade of the RAS increases plasma adiponectin in subjects with metabolic syndrome and enhances differentiation and adiponectin expression of human preadipocytes.

AIMS: This observational study aimed to investigate the effects of renin-angiotensin system (RAS) blockers on plasma adiponectin in subjects with metabolic syndrome (Mets) and differentiation, adiponectin expression of human omental (OM) and subcutaneous (SC) preadipocytes. METHODS: Fifty-three patients with Mets were treated with angiotensin converting enzyme inhibition (ACEI), angiotensin II receptor blocker (ARB) or nothing, lipid profile and adiponetin were measured. OM and SC preadipocytes were obtained from sixteen normal non-menopausal women undergoing elective abdominal surgery and subsequently differentiated in the presence of ACE, ARB or thiazolidinedione (TZD). Differentiation was assessed using a number of biochemical and function parameters. RESULTS: Plasma adiponectin was increased dramatically as a result of ACEI and ARB treatment. Most of the metabolic and differentiating parameters were improved significantly by RAS blockers or TZD. Compared with TZD, RAS blockers have stronger effects on omental preadipocytes in differentiation and insulin sensitivity. The improvement of adiponectin mRNA expression was significantly greater in ARB-treated omental preadipocytes compared with TZD-treated ones. CONCLUSION: These results suggest that adiponectin may serve as potential therapeutic targets of ACEI and ARB for treating the Mets and its related complications. It also suggests a potential benefit of RAS blockers on Mets with characteristic visceral obesity.

[Successful treatment of polymedicamentous poisoning with metoprolol, diltiazem and cilazapril].

INTRODUCTION: Poisoning caused by drugs with cardiodepressive effects is an urgent condition in medicine which is associated with high mortality rate regardless of modern therapeutic methods. Accidental or intentional poisoning whit these drugs produces heart activity depression and cardiovascular collapse as consequences. Current therapy for severe poisoning caused by beta-blockers and calcium channel blockers includes both unspecific and specific antidote therapy whit glucagon, as well as application of adrenergic drugs, calcium, phosphodiesterase inhibitors and hyperinsulinemia/euglycemia therapy. However, even whit the application of these drugs, prompt measures of unspecific detoxication therapy and cardiopulmonary reanimation are crucial for survival of patients with severe poisoning. CASE REPORT: A 28-year-old female patient was hospitalized for cardiogenic shock and altered state of conscioussnes (Glasgow coma score = 4), caused by acute poisoning with 2 g of metoprolol (Presolol), 1.8 g of diltiazem (Cortiazem) and 50 mg of cilazapril (Zobox). Prolonged cardiopulmonary resuscitation was applied during the first 16 hours of hospitalization, including administration of crystaline solutions (8 L), 17 mg of adrenaline, 4 mg of atropine, 4 mg of glucagone and 1.6 g of dopamine, with electro-stimulation by temporary pacemaker and mechanical ventilation. In a defined time period, normalized state of consciousness was registered, mechanical ventilation was stopped and normal heart activity and hemodynamic stability were accomplished. During hospitalization the patient was treated for mild pneumonia and after ten days, completely recovered, was released and sent to home treatment. CONCLUSION: Prompt measures of cardiopulmonary resuscitation and multidisciplinary treatment in intensive care units significantly increase the chances of complete recovery of a patient with severe poisoning caused by drugs with cardiodepressive efects.

Combination of an ACE inhibitor and indapamide improves blood pressure control, but attenuates the beneficial effects of ACE inhibition on plasma adiponectin in patients with essential hypertension.

BACKGROUND: Antihypertensive agents differentially influence the plasma adiponectin concentration and the effects of fixed-dose combination regimens remain unclear. The influence of a combination of an angiotensin-converting enzyme inhibitor (ACEI) and a thiazide-type diuretic or an ACEI alone on plasma adiponectin concentrations in patients with essential hypertension was evaluated in the present study. METHODS AND RESULTS: After a 2-week placebo run-in phase, 30 patients with essential hypertension were randomized to receive preterax (2 mg perindopril/0.625 mg indapamide) or cilazapril (2.5 mg) once daily for 12 weeks. Plasma adiponectin and insulin concentrations were measured before and after treatment. Insulin resistance was measured by homeostasis assessment index (HOMA-IR). Treatment with preterax (P=0.003) and cilazapril (P=0.031) significantly reduced systolic blood pressure (BP), but only preterax reduced diastolic BP (P=0.024). Cilazapril treatment significantly increased the plasma adiponectin concentration (P=0.025) and reduced plasma triglycerides (P=0.041), whereas preterax treatment increased the plasma insulin concentration (P=0.041) and tended to increase HOMA-IR. CONCLUSIONS: The combination of an ACEI and indapamide improved BP control, but attenuated the beneficial effects of ACE inhibition on plasma adiponectin in patients with essential hypertension. Such a combination may be best reserved for improved BP control rather than for metabolic protection in clinical hypertension.