International Journal of Pharmaceutics 474 (2014) 6–13
Contents lists available at ScienceDirect
International Journal of Pharmaceutics journal homepage: www.elsevier.com/locate/ijpharm
In vivo pharmacokinetics and biodistribution of resveratrol-loaded solid lipid nanoparticles for brain delivery S. Jose a, **, S.S. Anju a , T.A. Cinu a,b , N.A. Aleykutty a , S. Thomas c , E.B. Souto d,e,f, * a
University College of Pharmacy, Mahatma Gandhi University, Cheruvandoor Campus, Ettumanoor, Kottayam 686631, Kerala, India Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka, India c Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, India d Faculty of Health Sciences, Fernando Pessoa University, Rua Carlos da Maia, 296, P-4200-150 Porto, Portugal e Centre for Research in Bimedicine (CEBIMED), Fernando Pessoa University, Praça 9 de Abril, 349, P-4249-004 Porto, Portugal f Institute of Biotechnology and Bioengineering, Centre of Genomics and Biotechnology, University of Trás-os-Montes and Alto Douro, 5001-801 Vila-Real, Portugal b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 10 April 2014 Received in revised form 31 July 2014 Accepted 2 August 2014 Available online 4 August 2014
Resveratrol is a potent anticancer. However, because of its low half-life ( F4 > F9 > F10 > F12 > F8 > F2 > F5 > F6. The results reveal that EE increases as the lipid content in the formulation increases (Fig. 1). The increase in matrix content is expected to raise the EE by providing more space to incorporate the drug. Increment of the lipid content also reduces the escaping of drug into the external phase, which accounts for an increase in EE. In a fixed drug–lipid ratio, SLN with a combination of surfactants (Tween 80 and PVA) showed higher EE than with Tween 80 alone. This difference was attributed to the increased solubilization of resveratrol in the lipid by the combination of two surfactants, namely, Tween 80 and PVA. Emulsification was found inadequate when using Tween 80 alone, which contributes to the risk of drug expulsion from the lipid matrix to the external phase. Therefore, the EE was found to be low in formulation with Tween 80 alone. Though the same concentration of surfactants was used in formulations F10–F12, it was not technological feasible to emulsify the increased lipid content. The value of drug loading capacity (LC) varied from 0.61 0.07 (formulation F1) to 3.08 0.10 (formulation F9). FTIR studies were conducted to find out any interaction between resveratrol and compritol 888 ATO. FTIR spectrum resveratrol (Fig. 2) showed absorption bands of C O stretching at 1145 cm1, CQC stretching due to aromatic ring at 1583 cm1 and 1461 cm1, O H stretching due the alcoholic group at 3166.5 cm1, C C stretching due to the olefinic group at 1633.5 cm1 and trans olefinic band at 964.5 cm1. Similarly, compritol (Fig. 2) revealed he absorption bands of O-H stretching attributed to the alcoholic group at 3243 cm1, CQO stretching due to esters at 1743 cm1, C H stretching due to alkanes at 2915.11 cm1. The physical mixture and formulation showed absorption bands corresponding to resveratrol and compritol indicating no interaction between these two components in the formulation. DSC and XRD studies were performed in order to characterize drug status inside the SLN. The DSC patterns of bulk lipid and drug loaded SLN (formulation F9) are shown in Fig. 3. The DSC thermogram of bulk lipid showed a sharp endothermic peak at 74 C. However, the enthalpy of formulation is much lower than the bulk lipid, indicating the decrease in crystallinity of lipid in the SLN formulation. These results reveal the presence of a more unstable polymorphic form of lipid with higher drug content and long term storage.
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S. Jose et al. / International Journal of Pharmaceutics 474 (2014) 6–13
Fig. 2. FTIR spectra of bulk resveratrol (A) and of bulk Compritol 888 ATO (B).
XRD pattern of the resveratrol showed the peaks at 2u value of 18.57, 21.67, 23.02 , 24.67, 27.67, 37.97, 43.77, 51.07 and compritol at 20.77 and 23.47 (Fig. 4), indicating the crystallinity both of the components. Their physical mixture revealed the peaks of components, while the formulation showed peaks neither of drug or lipid and confirming massive crystal order disturbance, which may be due to the insertion of drug between the glyceride chains of the lipid. SEM analysis revealed the spherical and smooth surface morphology of the prepared SLN (Fig. 5).
The in vitro release profiles of SLN in phosphate buffer pH 7.4 are depicted in Fig. 6. All the formulations demonstrated a sustained release pattern. The values of cumulative percentage of drug released during 24 h varies from 46.96 3.0 (F6, drug–lipid – 1:15) to 97.03 1.19 (F1, drug–lipid – 1:5). The increase in lipid concentration prolonged the release of drug from the SLN, attributed to the good solubility of resveratrol in the compritol and its homogenous distribution within the lipid matrix. The maximum percentage of drug released was obtained from the formulations with low lipid content. As the lipid content in the
S. Jose et al. / International Journal of Pharmaceutics 474 (2014) 6–13
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Temperature (oC) Fig. 3. DSC patterns of bulk Compritol 888 ATO and of SLN.
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B
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formulation increases, the release was found to slow down. All the formulations showed an initial burst release followed by a sustained release pattern. The burst release was attributed to the rapid release of drug adsorbed on to the surface of the nanoparticles. The optimum formulation was based on our set criteria of relatively high EE, drug LC and minimum particle size (
Contents lists available at ScienceDirect
International Journal of Pharmaceutics journal homepage: www.elsevier.com/locate/ijpharm
In vivo pharmacokinetics and biodistribution of resveratrol-loaded solid lipid nanoparticles for brain delivery S. Jose a, **, S.S. Anju a , T.A. Cinu a,b , N.A. Aleykutty a , S. Thomas c , E.B. Souto d,e,f, * a
University College of Pharmacy, Mahatma Gandhi University, Cheruvandoor Campus, Ettumanoor, Kottayam 686631, Kerala, India Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka, India c Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, India d Faculty of Health Sciences, Fernando Pessoa University, Rua Carlos da Maia, 296, P-4200-150 Porto, Portugal e Centre for Research in Bimedicine (CEBIMED), Fernando Pessoa University, Praça 9 de Abril, 349, P-4249-004 Porto, Portugal f Institute of Biotechnology and Bioengineering, Centre of Genomics and Biotechnology, University of Trás-os-Montes and Alto Douro, 5001-801 Vila-Real, Portugal b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 10 April 2014 Received in revised form 31 July 2014 Accepted 2 August 2014 Available online 4 August 2014
Resveratrol is a potent anticancer. However, because of its low half-life ( F4 > F9 > F10 > F12 > F8 > F2 > F5 > F6. The results reveal that EE increases as the lipid content in the formulation increases (Fig. 1). The increase in matrix content is expected to raise the EE by providing more space to incorporate the drug. Increment of the lipid content also reduces the escaping of drug into the external phase, which accounts for an increase in EE. In a fixed drug–lipid ratio, SLN with a combination of surfactants (Tween 80 and PVA) showed higher EE than with Tween 80 alone. This difference was attributed to the increased solubilization of resveratrol in the lipid by the combination of two surfactants, namely, Tween 80 and PVA. Emulsification was found inadequate when using Tween 80 alone, which contributes to the risk of drug expulsion from the lipid matrix to the external phase. Therefore, the EE was found to be low in formulation with Tween 80 alone. Though the same concentration of surfactants was used in formulations F10–F12, it was not technological feasible to emulsify the increased lipid content. The value of drug loading capacity (LC) varied from 0.61 0.07 (formulation F1) to 3.08 0.10 (formulation F9). FTIR studies were conducted to find out any interaction between resveratrol and compritol 888 ATO. FTIR spectrum resveratrol (Fig. 2) showed absorption bands of C O stretching at 1145 cm1, CQC stretching due to aromatic ring at 1583 cm1 and 1461 cm1, O H stretching due the alcoholic group at 3166.5 cm1, C C stretching due to the olefinic group at 1633.5 cm1 and trans olefinic band at 964.5 cm1. Similarly, compritol (Fig. 2) revealed he absorption bands of O-H stretching attributed to the alcoholic group at 3243 cm1, CQO stretching due to esters at 1743 cm1, C H stretching due to alkanes at 2915.11 cm1. The physical mixture and formulation showed absorption bands corresponding to resveratrol and compritol indicating no interaction between these two components in the formulation. DSC and XRD studies were performed in order to characterize drug status inside the SLN. The DSC patterns of bulk lipid and drug loaded SLN (formulation F9) are shown in Fig. 3. The DSC thermogram of bulk lipid showed a sharp endothermic peak at 74 C. However, the enthalpy of formulation is much lower than the bulk lipid, indicating the decrease in crystallinity of lipid in the SLN formulation. These results reveal the presence of a more unstable polymorphic form of lipid with higher drug content and long term storage.
10
S. Jose et al. / International Journal of Pharmaceutics 474 (2014) 6–13
Fig. 2. FTIR spectra of bulk resveratrol (A) and of bulk Compritol 888 ATO (B).
XRD pattern of the resveratrol showed the peaks at 2u value of 18.57, 21.67, 23.02 , 24.67, 27.67, 37.97, 43.77, 51.07 and compritol at 20.77 and 23.47 (Fig. 4), indicating the crystallinity both of the components. Their physical mixture revealed the peaks of components, while the formulation showed peaks neither of drug or lipid and confirming massive crystal order disturbance, which may be due to the insertion of drug between the glyceride chains of the lipid. SEM analysis revealed the spherical and smooth surface morphology of the prepared SLN (Fig. 5).
The in vitro release profiles of SLN in phosphate buffer pH 7.4 are depicted in Fig. 6. All the formulations demonstrated a sustained release pattern. The values of cumulative percentage of drug released during 24 h varies from 46.96 3.0 (F6, drug–lipid – 1:15) to 97.03 1.19 (F1, drug–lipid – 1:5). The increase in lipid concentration prolonged the release of drug from the SLN, attributed to the good solubility of resveratrol in the compritol and its homogenous distribution within the lipid matrix. The maximum percentage of drug released was obtained from the formulations with low lipid content. As the lipid content in the
S. Jose et al. / International Journal of Pharmaceutics 474 (2014) 6–13
0
50
0
100
150
200
250
11
300
-2 -4 D -6 S C -8
Compritol 888 ATO SLN
M -10 w -12 -14 -16
Temperature (oC) Fig. 3. DSC patterns of bulk Compritol 888 ATO and of SLN.
A
3000 2500 2000 1500 1000 500 0
B
0
10
20
30
40
50
60
0
10
20
30
40
50
60
3000 2500 2000 1500 1000 500
formulation increases, the release was found to slow down. All the formulations showed an initial burst release followed by a sustained release pattern. The burst release was attributed to the rapid release of drug adsorbed on to the surface of the nanoparticles. The optimum formulation was based on our set criteria of relatively high EE, drug LC and minimum particle size (
