Characterization of Nigella Sativa L. Essential Oil-Loaded Solid Lipid Nanoparticles

American Journal of Pharmacology and Toxicology 5 (1): 52-57, 2010


ISSN 1557-4962

© 2010 Science Publications

Corresponding Author: Nagi A. ALHaj, Department of Medical Microbiology, Faculty of Medicine and Health Sciences,

Sana’a University, P.O. Box 13078, Sana’a, Yemen Tel: +967-1-218889 H/S +967-714-222-561

52

Characterization of Nigella Sativa L. Essential Oil-Loaded Solid Lipid Nanoparticles

1,4Nagi A. ALHaj, 2Mariana. N. Shamsudin, 2Norfarrah. M. Alipiah, 2Hana F. Zamri,

3Ahmad Bustamam, 3Siddig Ibrahim and 4Rasedee Abdullah

1Department of Medical Microbiology, Faculty of Medicine and Health Sciences,

Sana’a University, P.O. Box 13078, Sana’a, Yemen

2Department Marine Science and Aquaculture, Institute of Bioscience,

University Putra Malaysia, 43400, Serdang, Selangor, Malaysia

3Laboratory of Cancer Research MAKNA-UPM, Institute of Biosciences,

University Putra Malaysia, Serdang, Selangor DE, Malaysia

4Department of Microbiology and Pathology, Faculty of Veterinary Medicine,

University Putra Malaysia, Serdang 43400, Selangor, Malaysia

Abstract: Problem statement: Seeds of Nigella sativa L., commonly known as black seed, have been used in traditional medicine by many Asian, Middle Eastern and Far Eastern Countries to treat headache, coughs, abdominal pain, diarrhea, asthma, rheumatism and other diseases. The seeds of this plant are the most extensively studied, both phytochemically and pharmacologically. The aqueous and

oil extracts of the seeds have been shown to possess especially nowadays in pharmaceutical antioxidant, anti-inflammatory, anticancer, analgesic, antimicrobial activities and medicinal and cosmetic applications, sanitary, cosmetic, agricultural and food industries. Approach: The aim of this study was to formulate a new delivery system for dermal and cosmetic application by the incorporation of Nigella sativa essential oil into solid lipid nanoparticles SLN. SLN formulations were prepared

following the high-pressure homogenization after starring and ultra-trax homognization techniques using hydrogenated palm oil Softisan 154 and N. sativa essential oil as lipid matrix, sorbitol and water as surfactants. The SLN formulation particle size was determined using Photon Correlation System (PCS). Results: The change of particle charge was studied by Zeta Potential (ZP) measurements, while

the melting and re-crystallization behavior was studied using Differential Scanning Calorimetry

(DSC). Data showed a high physical stability for both formulations at various storage

temperatures during 3 months of storage. In particular, average diameter of N. sativa essential oilloaded

SLN did not vary during storage and increased slightly after freeze-drying the SLN

dispersions. Conclusion: Therefore, obtained results showed that the studied SLN formulations are

suitable carriers in pharmaceutical and cosmetic fields.

Key words: Solid lipid nanoparticles, Nigella sativa, palm oil, high pressure homogenization,







INTRODUCTION

Recent advances in nanoparticulate systems for improved drug delivery display a great potential for the administration of exigent active molecules. Solid Lipid Nanoparticles (SLNs) have emerged as an alternative to other novel delivery approaches due to various advantages such as feasibility of incorporation of lipophilic and hydrophilic drugs, improved physical stability, low cost compared to liposomes and ease of scale-up and manufacturing. Moreover, the potential of SLNs in epidermal targeting, follicular delivery, controlled drug delivery, increased skin hydration due to greater occlusivity and photostability improvement of active pharmaceutical ingredients has been very well established (Shah et al., 2007; Muller et al., 2000; Mehnert and Mader, 2001). Solid lipid nanoparticles are colloidal carrier systems composed of a high

melting point lipid/s as a solid core coated by surfactants. The term lipid in a broader sense includes triglycerides, partial glycerides, fatty acids, hard fats and waxes. A clear advantage of SLNs is the fact that the lipid matrix is made from physiological lipids which decreases the danger of acute and chronic toxicity. Highly purified natural solid lipids such as stearine fractions of fruit kernel are low cost alternative to the commercial lipids used for SLN production. This specialty material is derived from indigenous source, available in abundance and supplemented with essential

bio-actives. They are completely biodegradable. High saturated fatty acid-oleic acid-saturated fatty acid (SOS) content and exceptional high oxidation resistance of these fractions (Gunstone, 2004) would be beneficial for drug encapsulation efficiency and the drug stability upon the encapsulation, respectively. The main aim of this investigation was to develop SLNs from indigenous solid lipids by using a simple method such as microemulsion technique. Furthermore, the aim was to characterize these SLNs and evaluate its potential in the topical delivery system using a lipophilic drug model. Nigella sativa is an annual herb of the Ranunculaceae family, which grows in countries bordering the Mediterranean Sea, Pakistan and India. This widely

distributed plant is native to Arab countries and other parts of the Mediterranean region. For thousands of years, this plant has been used in many Asian, Middle

Eastern and Far Eastern Countries as a spice and food preservative as well as a protective and health remedy in traditional folk medicine for the treatment of

numerous disorders. The seed of this plant is commonly known as black seed and is referred to by the prophet Mohammed as having healing powers. The seeds are

commonly eaten alone or in combination with honey and in many food preparations. The oil prepared by compressing the seeds of N. sativa is used for cooking. Black seed is also identified as the curative black cumin in the Holy Bible and is described as the Melanthion of Hippocrates and Discroides and as the Gith of Pliny. N. sativa plant is one of the most extensively studied, both phytochemically and pharmacologically. The extracts of N. sativa seeds have been used by patients to suppress coughs disintegrate renal calculi, retard the carcinogenic process (Worthen et al., 1998;

Hosseinzadeh et al., 2007) treat abdominal pain, diarrhea, flatulence and polio (Enomoto et al., 2001), exert choleretic and uricosuric activities, antiinflammatory

(Chakravarty, 1993; Houghton et al., 1995) and antioxidant effects (Mansour et al., 2002; Mansour, 2000). Besides, the essential oil was shown to have antihelminthic (Agarwal et al., 1979), antinematodal (Akhtar and Riffat, 1991), antischistosomal (Mahmoud et al., 2002), antimicrobial (Aboul-Ela et al., 1996; Hanafy and Hatem, 1991; Aboul-Ela, 2002) and antiviral (Salem and Hossain, 2000) effects. The pharmacological properties appear to be involved in the beneficial effects of N. sativa oil on headache, flatulence, blood homeostasis abnormalities, rheumatism and related inflammatory diseases (Boulos, 1983). Moreover, the seeds are believed to have

carminative, stimulatory and diaphoretic properties and are used in the treatment of bronchial asthma and eczema (Boulos, 1983). In view of this, exploring the potential of SLNs in improving the topical delivery of N. sativa oil seems worthwhile wherein; indigenous natural solid lipids were explored to offer their inherent merits to improve treatment efficacy and patient compliance. An alternative, lab-scale technique of

micro-emulsion template was utilized for production of SLNs in the preparation of topical dosage form.

MATERIALS AND METHODS

Nigella sativa seeds: The seeds were purchased from a local herbal shop in Yemen. Seeds were stored in dark at 4°C for 20 days. Immediately prior to the extraction

process, the seeds were ground in a blender to produce a powder with an approximate size of 150 g.

Supercritical Fluid Extraction (SFE): A SFE system mode (Thar, Germany) at the Food Science and Biotechnology Laboratory UPM was used for the extraction. In this study, extraction was performed by filling extraction vessel with 150.0 g of the completely crashed seeds. The plant was then extracted with SFE under 400 atm pressure and 40°C temperature for 15 min static followed by 20 min dynamic. A duraflow manual variable restrictor (Suprex) was used in the SFE system to collect the extracted analytes as shown in the (Fig. 1 and 2).The SFE flow rate through the duraflow restrictor was approximately 25 g min-1 (compressed). The extracted analyses were collected in a volumetric flask. The final volume of the extract was adjusted to 35 mL at the end of the extraction. In order to have better collection efficiency, the 35 mL volumetric flask was placed in an ice bath during the dynamic extraction stage.



RESULTS

An adequate characterization of the solid lipid particles is a necessity for the control of the quality of the product. PCS is the most powerful techniques for routine measurements of particle size. The zeta potential distribution of SLN was showed in Table 1. The mean zeta potential was -15.4 mV (n = 5). Therefore, this method had gained a relative good stability and dispersion quality. The zeta potential of SLN (3) varied in dependence of the emulsifier concentration from K14.8 mV, prior to any addition of nonionic emulsifier, to about 0 mV at an emulsifier lipid ratio of 1-2. Due to the decrease in particle size and zeta potential with increasing surfactant concentration it is supposed that the surfactant is present at least partly

close to the particle interface.



The cooling curves obtained 1 day after production showed that the formulation re-crystallized in different polymorphic forms. SLN cooling curve shows a main

peak at 55.68°C which can be attributed to the beta modification.