Comparing the interactions of nitrendipine with lysozyme or human serum albumin and the effects of vitamin C and naringin on these interactions by spectroscopy and molecular docking methods

The interactions between drugs and proteins play a pivotal role in determining the pharmacological effects and disposition of drugs within the human body. This study focuses on exploring the interaction between nitrendipine and lysozyme/human serum albumin. Spectroscopic analysis indicated a compound static quenching, indicative of the formation of stable complexes between the drug and proteins. The addition of vitamin C or naringin resulted in a decrease of the binding constant between nitrendipine and lysozyme/human serum albumin. The presence of these compounds may disrupt the interactions between the drug and proteins, potentially leading to an increased concentration of free nitrendipine in the bloodstream. Nitrendipine binds more easily to human serum albumin at 310 K, and human serum albumin has an average binding site ratio with nitrendipine approximately 0.1 higher than that with lysozyme. Vitamin C has a greater impact on the binding constant of nitrendipine to human serum albumin and lysozyme. Compared to the binary system of proteins with the drug, the ternary system with the addition of vitamin C at 310 K reduces the binding constants of lysozyme and human serum albumin by 85%. In conclusion, this study explores the significance of considering drug-protein interactions in understanding drug behavior and potential drug-food interactions.

Formulation, Optimization and Evaluation of Nanoparticulate Oral Fast Dissolving Film Dosage Form of Nitrendipine

The primary objective of the present research work was to develop nanoparticles incorporating (nanoparticulate) fast dissolving (orodispersible) film evincing enhanced solubility and bioavailability of nitrendipine (NIT). An antisolvent sonoprecipitation method was employed to produce the NIT nanosuspension (NS), which was optimized using the 3² optimal response surface design and then the optimized one was evaluated for various parameters (Gandhi et al., AAPS PharmSciTech 22 (1):1-15, 2021). The NIT nanoparticulate orodispersible film (N-ODF) was prepared utilizing the nanosuspension by the solvent casting method using the Vijay film-forming instrument. The N-ODF was optimized by the 2³ full factorial design and was evaluated for several parameters. The optimized NS depicted a particle size of 505.74 ± 15.48 nm with a polydispersity index (PDI) of 0.083 ± 0.006 (Fig. 1b). The NIT nanoparticles showed a striking increment in saturation solubility (26.14 times), when compared with plain NIT (2). The developed NIT N-ODF exhibited thickness (0.148 ± 0.008 mm), folding endurance (280.33 ± 5.51 times), surface pH (6.86 ± 0.05), tensile strength (8.25 ± 0.13 kg/cm²), % elongation (63.5 ± 1.97%), and disintegration time (24.60 ± 1.31 s) to be within the standard intended limit. The in vitro dissolution study unveiled 100.28 ± 2.64% and 100.68 ± 2.50% of NIT release from lyophilized nanocrystals (in 8 min) and N-ODF (in 3.5 min), respectively, whereas the conventional NIT tablet took 30 min to release 99.94 ± 1.57% of NIT (Gandhi et al., AAPS PharmSciTech 22 (1):1-15, 2021). The in vivo pharmacokinetic study in rabbits inferred the achievement of significantly (p < 0.05) higher bioavailability of NIT on release from N-ODF in comparison to the conventional NIT tablet. Thus, the generation of N-ODF can be considered as a propitious move toward improving the efficacy of NIT to treat hypertension and angina pectoris.

Nitrendipine-Treatment Increases Cork Spot Disorder Incidence in Pear 'Akituki' (Pyrus pyrifolia Nakai.) by Altering Calcium Distribution Inside the Fruit

‘Akituki’ (Pyrus pyrifolia Nakai.) is a very popular and profitable pear cultivar in China. However, its high susceptibility to cork spot disorder has limited its expansion of cultivated area. The mechanisms of cork spot disorder have been discussed extensively, focusing on Ca²⁺ deficiency, yet no consensus has been made. In this study, we applied nitrendipine (NI) as a Ca²⁺ uptake inhibitor to explore the role of calcium in cork spot disorder occurrence. Results showed that NI treatment on the fruit remarkably increased the incidence of cork spot disorder; alteration of mineral contents happened at the early developmental stage of the fruit, especially on the outer flesh and the peel of the fruit; and this gap was filled gradually along with the expansion of the fruit. Significant differences in the expression levels of Ca²⁺ transport-related genes were found in the inner flesh, outer flesh and peel during the fruit growth period. The observation of free Ca²⁺ localization indicated the intracellular imbalance of Ca²⁺ in the NI-treated fruit. In conclusion, NI treatment reduced the calcium content in the fruit at an early developmental stage, altered the related expression of genes and influenced the cellular Ca²⁺ balance in the fruit, which prompted the occurrence of cork spot disorder. Measures for the prevention and control of cork spot disorder should be taken at the early stage of the fruit development in the field.

Development of Nanonized Nitrendipine and Its Transformation into Nanoparticulate Oral Fast Dissolving Drug Delivery System

The present research focuses on the development of a nanoparticulate (nanocrystals-loaded) rapidly dissolving (orodispersible) tablet with improved solubility and bioavailability. The nanosuspension (NS) was prepared by antisolvent sonoprecipitation technique and the optimized NS was lyophilized to obtain nanocrystals (NCs), which were evaluated for various parameters. The nitrendipine (NIT) nanoparticulate orodispersible tablet (N-ODT) was prepared by direct compression method. The optimized N-ODT was evaluated for pre and post compression characteristics, in vivo pharmacokinetic and stability profile. The optimized NS showed a particle size of 505.74 ± 15.48 nm with a polydispersity index (PDI) of 0.083 ± 0.006. The % NIT content in the NCs was found to be 78.4 ± 2.3%. The saturation solubility of NIT was increased remarkably (26.14 times) in comparison to plain NIT, post NCs development. The DSC and p-XRD analysis of NCs revealed the perseverance of the integrity and crystallinity of NIT on lyophilization. The results of micromeritic studies revealed the good flow-ability and compressibility of NCs blend. All the post-compression properties of N-ODT were observed within the standard intended limit. The dispersion, wetting, and disintegration time of the optimized batch of N-ODT was found to be 39 ± 1.13 s, 44.66 ± 1.52 s, and 33.91 ± 0.94 s respectively. The in vitro dissolution study displayed 100.28 ± 2.64% and 100.61 ± 3.3% of NIT released from NCs (in 8 min) and N-ODT (in 6 min) respectively, while conventional NIT tablet took 30 min to release 99.94 ± 1.57% of NIT. The in vivo pharmacokinetic study in rabbits demonstrated significantly (p < 0.05) higher bioavailability of NIT on release from N-ODT than the conventional NIT tablet. Thus, N-ODT could be a promising tool for improving the solubility and bioavailability of NIT and to treat cardiovascular diseases effectively.

Validated LC-MS/MS method for the simultaneous determination of enalapril maleate, nitrendipine, hydrochlorothiazide, and their major metabolites in human plasma

Hypertension is a major risk factor for atherosclerosis and ischemic heart disease. Most hypertensive patients need a combination of antihypertensive agents to achieve therapeutic goals. A rapid, sensitive, and selective liquid chromatography-tandem mass spectrometric method was developed and validated for simultaneous determination of enalapril maleate (ENA) and its major metabolite enalaprilat (ENAT), nitrendipine (NIT) and its major metabolite dehydronitrendipine (DNIT), and hydrochlorothiazide (HCT) in human plasma using felodipine as an internal standard (IS). The drugs were extracted from plasma using one-step protein precipitation. Chromatographic separation was performed on a Symmetry C₁₈ column, with water and acetonitrile (10:90, v/v) as mobile phase. The detection was carried out using multiple reaction monitoring mode and coupled with electrospray ionization source. Multiple reaction monitoring transitions were m/z 377.1 → 234.1 for ENA, m/z 349.2 → 206.1 for ENAT, m/z 361.2 → 315.1 for NIT, m/z 359 → 331 for DNIT, m/z 295.9 → 205.1 for HCT, and m/z 384.1 → 338 for felodipine (IS). The method was linear over concentration ranges of 1-200, 20-500, 5-200, 2-100, and 5-200 ng/mL for ENA, ENAT, NIT, DNIT, and HCT, respectively, with r² ≥ 0.99. Method validation was performed according to U.S. Food and Drug Administration guidelines. The validated method showed good sensitivity and selectivity and could be applied for therapeutic drug monitoring and bioequivalence studies.

Nitrendipine and Dementia: Forgotten Positive Facts?

Nowadays, there are about 50 million people suffering from dementia worldwide. In 2030, it is expected that there will be 82 million people living with dementia and in 2050, their number should reach 152 million. This increase in the number of people with dementia results in significant social and economic problems. Therefore, researchers attempt to reduce risk factors causing the development of dementia such as high blood pressure. Epidemiological studies have shown that hypertension increases the risk of dementia at an older age. It can, therefore, be assumed that hypertension therapy will reduce the risk of dementia. However, previous clinical studies have shown that the efficacy of different antihypertensive drugs differs in this respect. The drug group that appears to be the most effective in these analyses is calcium channel blockers (CCBs). The most significant preventive efficacy in terms of protection against dementia has been demonstrated with nitrendipine. Its use is, therefore, particularly advantageous in elderly patients with systolic hypertension who are at high risk of dementia. The purpose of this study is to restore the discussion on the prevention of vascular dementia and Alzheimer’s dementia with nitrendipine in indicated hypertonic patients. The authors performed a literature search of available sources describing the issue of dementia, hypertension and its treatment with nitrendipine. In addition, they made a comparison and evaluation of relevant findings. The results of the detected research studies indicate that nitrendipine is able to reduce the incidence of dementia [Alzheimer’s disease (AD), vascular and mixed] by 55%. The treatment of 1,000 patients with nitrendipine for 5 years may prevent 20 cases of dementia. However, what has not yet been explained is the temporal link between hypertension and dementia due to the long-time intervals between hypertension and the development of dementia.

Solubility and Thermodynamic Analysis of Antihypertensive Agent Nitrendipine in Different Pure Solvents at the Temperature Range of 298.15 to 318.15°K

The aim of the present study was to ascertain the solubility of nitrendipine (NP), an antihypertensive drug in six different pure solvents such as water, ethyl acetate (EA), ethanol, isopropyl alcohol (IPA), polyethylene glycol-400 (PEG-400), and Transcutol at temperature from 298.15 to 318.15 K under atmospheric pressure (p) of 0.1 MPa. Experimental solubility data of NP was fitted with Apelblat and ideal models. The mole fraction solubility of NP was found maximum in PEG-400 (6.85 × 10^-2 at 318.15 K) followed by Transcutol (4.65 × 10^-2 at 318.15 K), EA (1.68 × 10^-2 at 318.15 K), ethanol (2.83 × 10^-3 at 318.15 K), IPA (2.69 × 10^-3 at 318.15 K), and water (1.29 × 10^-7 at 318.15 K). The dissolution activity of NP was observed as an endothermic, spontaneous, and an entropy-driven in most of studied pure solvents. The solubility data of NP obtained in the present study could be useful in purification, recrystallization, and dosage forms design of NP.

Preparation of starch macrocellular foam for increasing the dissolution rate of poorly water-soluble drugs

Starch macrocellular foam (SMF), a novel natural bio-matrix material, was prepared by the hard template method in order to improve the dissolution rate and oral bioavailability of poorly water-soluble drugs. Nitrendipine (NDP) was chosen as a model drug and was loaded into SMF by the solvent evaporation method. SMF and the loaded SMF samples (NDP-SMF) were characterized by scanning electron microscopy, differential scanning calorimetry, X-ray powder diffraction and Fourier transform infrared spectroscopy. In vitro drug release studies showed that SMF significantly increased the dissolution rate of NDP. In vivo studies showed that the NDP-SMF tablets clearly increased the oral bioavailability of NDP in comparison with the reference commercial tablets. All the results obtained demonstrated that SMF was a promising carrier for the oral delivery of poor water-soluble drugs.

Formulation and evaluation of nitrendipine buccal films

A mucoadhesive drug delivery system for systemic delivery of nitrendipine, a calcium channel blocker through buccal route was formulated. Mucoadhesive polymers like hydroxypropylmethylcellulose K-100, hydroxypropylcellulose, sodium carboxymethylcellulose, sodium alginate, polyvinyl alcohol, polyvinyl pyrrolidone K-30 and carbopol-934P were used for film fabrication. The films were evaluated for their weight, thickness, percentage moisture absorbed and lost, surface pH, folding endurance, drug content uniformity, In vitro residence time, In vitro release and ex vivo permeation. Based on the evaluation of these results, it was concluded that buccal films made of hydroxylpropylcellulose and sodium carboxymethylcellulose (5±2% w/v; F-4), which showed moderate drug release (50% w/w at the end of 2 h) and satisfactory film characteristics could be selected as the best among the formulations studied.

[Theoretical model of a cost-effectiveness analysis of combined enalapril-nitrendipine therapy for treating hypertension]

OBJECTIVE

Cost-effectiveness analysis of combined enalapril-nitrendipine therapy (E/N), as second-line therapy for light or moderate hypertension.

DESIGN

Theoretical model of cost-effectiveness, based on the norms of hypertension treatment in primary care, the considered view of a panel of experts and the direct costs of health resources and purchase of medication.

SETTING

Spanish National Health system.

PARTICIPANTS

Simulation of 1000 patients with hypertension, with a time horizon of one year.

INTERVENTIONS

After a prior failure of the first-line treatment with either enalapril or nitrendipine, an evaluation was made of the possibilities of increasing dosage of the first-line treatment, changing the drug or administering the E/N combination.

MAIN MEASUREMENT

The likelihoods, in the primary care context, of controlling diastolic pressure, of abandonment and of using the two strategies or not were measured, as were the use of health resources in each situation, and costs of resource use and of medication.

RESULTS

The cost-effectiveness quotient of the combined E/N treatment was consistently more efficient than the increase in dose or change to another drug. This was so, whether the treatment was started with enalapril (301.06 euros vs 337.97 euros and 588.42 euros) or with nitrendipine (331.5 euros vs 469.88 euros and 579.76 euros).

CONCLUSIONS

Combined therapy (E/N) is, on the basis of the assumptions made in the model, an efficient therapy option. Therefore, it can be recommended for prescription.

Effect of bile acids on absorption of nitrendipine in healthy subjects

AIMS

To examine whether bile acids such as ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) can influence the absorption of nitrendipine, a highly lipophilic calcium channel blocker.

METHODS

Six healthy subjects received nitrendipine (10 mg) with and without UDCA (50 mg) and CDCA (200 and 600 mg) with an interval of 1 approximately 2 weeks between study phases.

RESULTS

Bile acids decreased the Cmax (ng ml(-1)) [control 10.9 +/- 5.8 (mean+/- s.d.), UDCA 5.0 +/- 4.7 (95% confidence interval for difference; 3.9, 7.8, P = 0.0006), CDCA (600 mg) 5.0 +/- 3.9 (2.6, 9.2, P = 0.0059)] and AUC (ng ml(-1) h) [(control; 60 +/- 36, UDCA 15 +/- 13 (20, 73, P = 0.0064), CDCA (600 mg) 19 +/- 19 (21, 63, P = 0.0038)] of nitrendipine, while elimination half-life remained unchanged.

CONCLUSIONS

These results suggest that the amount of nitrendipine absorbed was decreased when the drug was administered with UDCA and CDCA.

Differences in the actions of some blockers of the calcium-activated potassium permeability in mammalian red cells

1. The actions of some inhibitors of the Ca2+-activated K+ permeability in mammalian red cells have been compared. 2. Block of the permeability was assessed from the reduction in the net loss of K+ that followed the application of the Ca2+ ionophore A23187 (2 microM) to rabbit red cells suspended at a haematocrit of 1% in a low potassium solution ([K]0 0.12-0.17 mM) at 37 degrees C. Net movement of K+ was measured using a K+-sensitive electrode placed in the suspension. 3. The concentrations (microM +/- s.d.) of the compounds tested causing 50% inhibition of K+ loss were: quinine, 37 +/- 3; cetiedil, 26 +/- 1; the cetiedil congeners UCL 1269, UCL 1274 and UCL 1495, approximately 150, 8.2 +/- 0.1, 0.92 +/- 0.03 respectively; clotrimazole, 1.2 +/- 0.1; nitrendipine, 3.6 +/- 0.5 and charybdotoxin, 0.015 +/- 0.002. 4. The characteristics of the block suggested that compounds could be placed in two groups. For one set (quinine, cetiedil, and the UCL congeners), the concentration-inhibition curves were steeper (Hill coefficient, nH, > or = 2.7) than for the other (clotrimazole, nitrendipine, charybdotoxin) for which nH approximately 1. 5. Compounds in the first set alone became less active on raising the concentration of K+ in the external solution to 5.4 mM. 6. The rate of K+ loss induced by A23187 slowed in the presence of high concentrations of cetiedil and its analogues, suggesting a use-dependent component to the inhibitory action. This was not seen with clotrimazole. 7. The blocking action of the cetiedil analogue UCL 1274 could not be overcome by an increase in external Ca2+ and its potency was unaltered when K+ loss was induced by the application of Pb2+ (10 microM) rather than by A23187. 8. These results, taken with the findings of others, suggest that agents that block the red cell Ca2+-activated K+ permeability can be placed in two groups with different mechanisms of action. The differences can be explained by supposing that clotrimazole and charybdotoxin act at the outer face of the channel whereas cetiedil and its congeners may block within it, either at or near the K+ binding site that determines the flow of K+.

Effects of N- and L-type calcium channel antagonists and (+/-)-Bay K8644 on nerve-induced catecholamine secretion from bovine perfused adrenal glands

1. The effects of N- and L-type calcium channel antagonists and (+/-)-Bay K8644 on catecholamine release from chromaffin cells and acetylcholine release from splanchnic nerve terminals was investigated in bovine perfused adrenal glands. 2. Adrenal glands were perfused retrogradely and preloaded with [3H]-choline. Subsequent efflux of 3H-labelled compounds was taken as an index of acetylcholine release from the splanchnic nerve terminals. Noradrenaline and adrenaline release from the glands was measured by h.p.l.c. with electrochemical detection. 3. A maximally effective frequency of field stimulation of the adrenal nerves, 10 Hz, induced release of catecholamines and 3H-labelled compounds. Tetrodotoxin (1 microM) abolished release of both catecholamines and 3H-labelled compounds. A combination of mecamylamine (5 microM) and atropine (1 microM) inhibited nerve-induced catecholamine release by about 75% but did not inhibit release of 3H-labelled compounds. Reducing the concentration of extracellular calcium 5 fold to 0.5 mM inhibited nerve-induced catecholamine release by 80% and release of 3H-labelled compounds by 50%. 4. (+/-)-Bay K8644 (1 microM), nitrendipine (1 microM), omega-conotoxin-GVIA (10 nM) and the combination of nitrendipine and omega-conotoxin-GVIA each had no effect on nerve-induced release of 3H-labelled compounds. 5. (+/-)-Bay K8644 (1 microM) potentiated nerve-induced catecholamine release by 75%. Nitrendipine (1 microM) reduced release by 20% but this did not reach statistical significance, omega-Conotoxin-GVIA (10 nM) reduced nerve-induced catecholamine release by 75%, while the combination of omega-conotoxin-GVIA and nitrendipine reduced release to the same extent as omega-conotoxin-GVIA alone. 6. Exogenous acetylcholine perfusion through the glands produced a concentration-dependent increase in catecholamine release. The maximally effective concentration of acetylcholine for catecholamine release was > or = 300 microM, while 30 microM acetylcholine gave comparable catecholamine release to that obtained with 10 Hz field stimulation. 7. (+/-)-Bay K8644 (1 microM), nitrendipine (1 microM) and omega-conotoxin-GVIA (10 nM) each had no significant effect on catecholamine release evoked by perfusion of the gland with either a near maximally effective concentration of acetylcholine, 100 microM, or with the lower concentration of 30 microM. 8. The results show that the omega-conotoxin-GVIA-sensitive N-type voltage-sensitive calcium channels located on the chromaffin cells are largely responsible for catecholamine release induced by nerve stimulation in bovine adrenal glands. In contrast, N-type calcium channels are not involved in catecholamine release induced by exogenous acetylcholine. L-type voltage sensitive calcium channels do not play a major role in nerve-induced or exogenously applied acetylcholine-induced catecholamine release. However, the L-type calcium channels do have the potential to augment powerfully nerve-induced catecholamine release. N- and L-type calcium channels do not play a major role in the presynaptic release of acetylcholine.

Antihypertensive effects of nitrendipine and cilazapril alone, and in combination in hypertensive patients with chronic renal failure

1. It has been reported that calcium antagonists lower blood pressure more effectively in salt replete hypertensive patients with a low plasma renin activity (PRA), whereas angiotensin converting enzyme (ACE) inhibitors are more effective in salt depleted patients with a high level of PRA. An inverse relationship between the antihypertensive effects of these two groups of drugs might therefore be expected. 2. Since salt retention and inappropriately high levels of PRA are said to contribute to hypertension in patients with chronic renal failure (CRF), an additive antihypertensive effect with both drugs might also be expected in such patients. 3. To test these hypotheses, we investigated the acute and chronic antihypertensive effects of the calcium antagonist nitrendipine and the new ACE inhibitor cilazapril, given alone, and in combination, in a double-blind, randomized, placebo controlled study of 11 hypertensive patients with chronic renal failure who had a mean pretreatment blood pressure of 149 +/- 3/96 +/- 2 mm Hg. Patients received nitrendipine 10 mg, cilazapril 1.25 or 2.5 mg depending on creatinine clearance, or placebo once daily orally. Nitrendipine and cilazapril were also combined at the same doses. 4. Nitrendipine and cilazapril were equally effective, with a maximal acute reduction of mean arterial pressure (MAP) of 5.3 +/- 1.8% and 8.0 +/- 1.9%, and after 1 week of treatment 5.0 +/- 2.4% and 8.1 +/- 1.8%, respectively. In individual patients no inverse relationship between the blood pressure responses to the two drugs was found.(ABSTRACT TRUNCATED AT 250 WORDS)