Functional candesartan loaded lipid nanoparticles for the control of diabetes-associated stroke: In vitro and in vivo studies

Abstract

Diabetes mellitus is a metabolic disease that raises the odds of developing stroke. Candesartan has been used to prevent stroke due to its inhibitory effects on blood pressure, angiogenesis, oxidative damage, and apoptosis. However, oral candesartan has very limited bioavailability and efficacy due to its weak solubility and slow release. The study aimed to develop a nasal formulation of candesartan-loaded liposomes containing ethanol and propylene glycol (CLEP) to improve candesartan's delivery, release, permeation, and efficacy as a potential diabetes-associated stroke treatment. Using design expert software, different CLEP formulations were prepared and evaluated in vitro to identify the optimum formulation, which. The selected optimum formulation composed of 3.3% phospholipid, 10% ethanol, and 15% propylene glycol significantly increased the release and permeation of candesartan relative to free candesartan by a factor of 1.52 and 1.47, respectively. The optimum formulation significantly reduced the infarction after stroke in rats; decreased flexion, spontaneous motor activity, and time spent in the target quadrant by 70%, 64.71%, and 92.31%, respectively, and enhanced grip strength by a ratio of 2.3. Therefore, nasal administration of the CLEP formulation could be a potential diabetes-associated stroke treatment.

Keywords: Candesartan; Diabetes mellitus; Ethanol; Liposomes; Propylene glycol; Stroke.

Graphical abstract

Fig. 1

Diagnostic plot of CLEP formulations; (a) and (c) Power transforms Box–Cox plot; the value of lambda is used to select a model power transform by plotting the data in a Box-Cox plot. (b) and (d) Studentized residuals vs. predicted response plot for EE% and particle size, respectively. Residual vs. predicted response provides a visual representation of the distribution of the measured response.

Fig. 2

3D Response surface plot for the effect of L-αphosphatidylcholine concentration, ethanol concentration and propylene glycol concentration on EE% (a) and particle size (b); 3D Response surface plot help users better understand the interaction between variables and their impact on each response.

Fig. 3

a) Differential Scanning Calorimetry thermograms of optimum CLEP formulation which exhibited the disappearance of all peaks of CDT, L-α-phosphatidylcholine and cholesterol; (∆H) enthalpy fusion; b) Fourier Transform Infrared (FTIR) spectra of optimum CLEP formulation which exhibited the appearance of all peaks of CDT, L-α-phosphatidylcholine and cholesterol.

Fig. 4

a) Surface morphology of optimum CLEP formulation by TEM exhibited spherical vesicles that appeared as black dots; b) Effect of storage on the %EE and particle size of CLEP formulations at 4 °C, 25 °C and 40 °C.

Fig. 5

a) The percentage of CDT release from the optimum CLEP formulation in comparison to free CDT, in phosphate buffer (pH 6.8, mean ± S.D., n = 3); b) the percentage of CDT permeation from the optimum CLEP formulation in comparison to free CDT in phosphate buffer (pH 6.8, mean ± S.D., n = 3).

Fig. 6

a) Serum glucose, cholesterol and triglycerides levels; b) Neurological behavioral activities in rats of all treated and untreated groups; Significance: ^⁎p-value <0.05 versus control negative group, ^#p-value <0.05 versus control positive group, ^@ p-value <0.05 versus free CDT group. CDT: candesartan, CLEP: candasertan loaded liposomes containing ethanol and propylene glycol.

Fig. 7

Histopathology images of brain tissue in normal rats and rats of all treated and untreated groups. Blue arrow: dead shrunken neurons, red arrow: perivascular edoema, green arrow and arrow head: pyknotic nuclei of some neurons, and yellow arrows: normal structured neurons. CDT: candesartan, CLEP: candasertan loaded liposomes containing ethanol and propylene glycol. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 8

Haematological (a) and biochemical (b) parameters of optimum CLEP group compared to control negative group. Significance: ^# p-value <0.05 versus control negative group.