RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, KARNATAKA
BANGALORE
ANNEXURE – II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1. / Name of the Candidateand Address:
/ L.VYSHNAVI
D/O Murthy raju,
D.NO: 8-6-3,
Gaminivari street,
West godavari,
Tanuku-534211.
Andhra pradesh.
2. / Name of the Institution: /
Al-Ameen College of Pharmacy,
Hosur Road, Bangalore – 560 027.
3.
4. / Course of Study and Subject:
Date of Admission: / M. Pharm – Pharmaceutics
2nd November 2011
5. / Title of the Topic:
“Formulation and evaluation of Methotrexate loaded solid lipid nanoparticles for topical application of psoriasis”
6.0 / Brief resume of the intended work:
6.1 – Need for the study:
Psoriasis is a chronic autoimmune skin disease.1 It is a non contagious skin condition which mainly affects the skin of the elbows, knees, and scalp.2 It is caused by the T cells that mistakenly trigger a reaction in the skin cells resulting in being produced too quickly3. So, psoriasis is referred to as a “T cell-mediated disease. It is clinically characterized by irritated red patches on skin,yellow-brown nails, joint pain or aching, severe dandruff on the scalp,blisters containing fluid on the skin, erythematous sharply demarcated papules, rounded plaques covered by silvery micaceous scale and epidermal hyper proliferation overlying immune mediated dermal inflammation.4
Statistics state that it affects approximately 3% of people globally.3 Treatment for psoriasis depends on severity. Various topical therapies are available for the treatment of psoriasis such as Calcipotriene, Corticosteroids, tar, Anthralin phototherapy with ultraviolet B radiation (UVB) and Methoxsalen (psoralen) with ultraviolet A radiation (PUVA). The systemic treatment includes drugs like Methotrexate, Cyclosporine and Acitretin. Newer drugs called biologics such as Adalimumab, Alefacept, Etanercept, Infliximab and Stelara are also used. Treatment with topical steroids suppresses the body’s immune system when used for prolonged period of time, whereas systemic drugs like Methotrexate, Cyclosporine impair liver and kidney functioning and decrease RBCs, WBCs and Platelets counts.4,5
Methotrexate, 4-amino-4-deoxy-10-methypetroyl-L-glutamic acid6 is a folic acid antagonist with antineoplastic activity8 and belongs to BCS class IV which has low solubility and low permeability.7 Oral Methotrexate is currently indicated for the treatment of severe psoriasis. It has been shown to selectively inhibit DNA synthesis in psoriatic epidermal cells decreasing mitotic activity.8 Also it acts by inhibition ofT cell activation and suppression of intercellular adhesion moleculeexpression byT cells.9
The dose of the oral Methotrexate in the marketed formulations like Rheumatrex, Trexall is 5 mg, 7.5 mg, 10 mg and 15 mg.6 For adults with psoriasis, a typical oral Methotrexate dose is 10 to 25 mg once weekly or 2.5 mg every 12 hrs for three doses (once weekly).10 Dose of topical Methotrexate in marketed formulations like Laurocapram [Azone] gel, Rextop gel is (0.1%, 0.5%, and 1%).11
When administered orally, Methotrexate has elimination half-life of 3-10 hrs12 and low oral bioavailability of 33% only.9 The use of Methotrexate is limited by systemic side effects, teratogenicity, hepatotoxicity and GI discomforts. So topical administration of Methotrexate may lessen the risk of systemic toxicity while increasing local bioavailability in the skin.4 A major problem in topical administration of drug is that it has a high molecular weight (454.56 g/mol) and is mostly in the dissociated form at physiological pH; its capacity for passive diffusion is thus limited.13
Thus particulate carrier systems may mean an option to improve dermal penetration. Since epidermal lipids are found in high amounts within the penetration barrier, lipid carriers attaching themselves to the skin surface and allowing lipid exchange between the outermost layers of the stratum corneum and the carrier appear promising.14 Their small particle size ensures close contact to the stratum corneum and the lipid provides selective drug delivery to skin layers.4
Solid Lipid particles can be developed as an alternative colloidal carrier system for emulsion; liposome and polymeric nanoparticles for controlled drug delivery system.15 Solid lipid nanoparticles (SLN) can be prepared using solid lipids in presence of surfactant by different methods such as high pressure homogenization, microemulsion technology, solvent evaporation and solvent diffusion methods.16 The presence of lipid and surfactant in the preparation increases the solubility as well as the bioavailability of poorly water soluble drugs and can be administered by subcutaneous, oral, IM, topical or pulmonary way.15
It has been claimed that SLN combine the advantages and avoid the disadvantages of other colloidal carrier. Proposed advantages include; Possibility of controlled drug release and drug targeting, excellent biocompatibility, Increased drug stability, High drug payload, Incorporation of lipophilic and hydrophilic drugs feasible, No toxicity of the carrier, Avoidance of organic solvents, No problem with respect to large scale production and sterilization.15,17
Thus, poorly soluble drugs are very often a challenging problem in drug formulation. Lipid-based formulation has become a novel approach to formulate poorly water-soluble drugs to exhibit versatile, good and reproducible bioavailability. In the present study an attempt will be made to design, develop, and evaluate the SLN incorporated gel for topical controlled drug delivery of Methotrexate for treatment of psoriasis.
6.2 REVIEW OF LITERATURE:
· Kortig SM, et al. (2007) investigated on lipid nanoparticles for improved topical application of drugs for skin diseases besides liposomes, solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been studied intensively. Here they described the potential of these carrier systems and compared the dermal uptake from SLN and NLC to the one of alternative vehicle systems. A special focus was upon the interactions of active ingredients and the lipid matrix as well as the quantification of dermal penetration.14
· Pardeike J, et al. (2009) reviewed Lipid nanoparticles (SLN, NLC) in cosmetic and pharmaceutical dermal products. Production of lipid nanoparticles and final products containing lipid nanoparticles is feasible by well-established production methods. SLN and NLC exhibit many features for dermal application of cosmetics and pharmaceutics, i.e. controlled release of actives, drug targeting, occlusion and associated with it penetration enhancement and increase of skin hydration. Due to the production of lipid nanoparticles from physiological and/or biodegradable lipids, this carrier system exhibits an excellent tolerability and is a “nanosafe” carrier.18
· Moddaresi M, et al. (2010) investigated the role of vehicle- nanoparticle interactions in topical drug delivery. The aim of this work was to understand how the mobility of nanoparticles influenced the delivery of a model drug when the carriers were suspended in a hyaluronic acid vehicle. The phase-inversion method used here was suitable for producing monodisperesed Tocopheryl acetate (TA) lipid nanoparticles of less than 100nm in diameter. Adding purified TA nanoparticles to sodium hyaloranate led to a one step production system of a gel without any additives. Rheology measurements showed that LN interacted with the HA gel network and this reduced the LN mobility. However, reducing the mobility of the LN by increasing the HA gel viscosity did not affect the TA permeation. Drug release from lipid nanoparticles was the rate limiting step.19
.
· Amrutiya N, et al. (2009) developed Microsponges for topical delivery of Mupirocin, a topical antibiotic agent used in treatment of primary and secondary skin infections. Microsponges containing Mupirocin were prepared by an emulsion solvent diffusion method. In vitro drug release, ex vivo drug deposition, and in vivo antibacterial activity of Mupirocin-loaded formulations were studied. Drug release through cellulose dialysis membrane showed diffusion-controlled release pattern and drug deposition studies using rat abdominal skin exhibited significant retention of active in skin from microsponge based formulations by 24hr. Microsponges-based emulgel formulations showed prolonged efficacy in mouse surgical wound model infected with S.aureus.20
· Dodov MG, et al. (2002) prepared Liposomal hydrogel formulations of lidocaine HCl have been prepared and evaluated in-vitro drug release properties. Liposomes composed of Soya lecithin and cholesterol, with lidocaine HCl, entrapped in the inner water compartment, was prepared by simple hydration method. Topical liposomal gel formulations were prepared by incorporation of liposomes into a structured vehicle. This provides prolonged drug release rate. The concentration of gelling agent in a range 1.5–2.0% affected the release rate slightly. In vitro release data showed liposomes act as reservoir systems for continuous delivery of drug and release kinetic can be described as diffusion-controlled.21
· Vermeulen B, et al. (1999) studied on the formulation and stability of erythromycin-benzoyl peroxide in a topical gel: The combination of benzoyl peroxide and erythromycin is used for the local treatment of acne and available as a commercial preparation. The influence of storage temperature and non active ingredients on the stability of benzoyl peroxide and erythromycin in topical gel preparations, an extempore compounding was described. A microbiological and an HPLC method were used to determine the erythromycin and the benzoyl peroxide concentrations, respectively. For a formulation compounded with hydroxyethylcellulose no stability problems were observed. For the formulation containing Carbopol 940, the levels of erythromycin varied over a wide range due to precipitation and aggregation of the drug during compounding.22
· Agarwal Y, et al. (2010) formulated and characterized Acitretin loaded Nanostructured Lipid Carriers (ActNLCs), to understand in vitro drug release and clinically evaluated the role of the developed gel in the topical treatment of psoriasis. ActNLCs were prepared by solvent diffusion technique. ActNLCs were lyophilized and crystallinity of NLC was characterized by DSC and XRD. The NLCs were incorporated in Carbopol 934 P gel base and in vitro skin deposition studies in Human Cadaver Skin and double-blind clinical studies in psoriatic patients were conducted. Significantly higher deposition of Acitretin was found in human cadaver skin from ActNLC gel as compared to Act plain gel. Clinical studies demonstrated significant improvement in therapeutic response and reduction in local side effects with ActNLCs loaded gel indicated its effectiveness in the topical treatment of Psoriasis.4
· Urtti A, (2003) studied on microemulsions as vehicles for topical delivery of estradiol. The microemulsions were shown to increase the transdermal delivery of estradiol 200–700-fold over the control. The superior flux appears to be mainly due to the large solubilizing power of the microemulsions, which leads to larger concentration gradients towards the skin. Flux of estradiol in the skin was at adequate level for therapeutic effects.23
· Xiangliang Y, (2007) designed isotretinoin-loaded SLN (IT-SLN) formulation with skin targeting for topical delivery of isotretinoin. The various IT-SLN formulations were prepared by homogenization method for topical delivery of isotretinoin. The in vitro permeation studies showed all the formulation could avoid the systemic uptake of isotretinoin when compared with the control. IT-SLN D had high accumulative amount of isotretinoin in skins and showed a significant skin targeting effect. The entrapment efficiency and the concentrations of the ingredients of formulations influenced the uptake of drug.24
· Guangxi Z, (2009) prepared solid lipid nanoparticles (SLNs) of Penciclovir by a double (W/O/W) emulsion technique and evaluated the potential of SLNs as the carrier of Penciclovir for topical delivery. The cumulative amount of Penciclovir penetrated through excised rat skins from SLNs was more than 2-fold that of the commercial cream as a control at 12 h after administration. Compared with commercial cream, the amount of Penciclovir penetrated into dermis from SLNs increased by 130%. The interaction between SLNs and the skin surface changed the apparent morphology of stratum corneum and broke the close conjugation of corneocyte layers, which resulted in the increased permeation of Penciclovir into skin dermis. The results suggested that SLNs were valuable as a topical delivery carrier to enhance the penetration of Penciclovir.25
· Alvarez-Figueroa M.J, (2001) performed in vitro assays to know the effectiveness of transdermal administration of Methotrexate (MTX) by iontophoretic delivery from two types of hydrogel and passive delivery from two types of microemulsions. Both iontophoretic transdermal delivery of MTX from hydrogels and passive transdermal delivery from microemulsions were more effective than passive transdermal diffusion from Methotrexate aqueous solutions. The effectiveness of iontophoretic delivery from hydrogels was not affected by the type of hydrogel used, or by MTX concentration in the loading solution. The effectiveness of passive delivery from microemulsions, showed some relationship to MTX concentration, but appeared not to be affected by microemulsion composition or phase proportion. In all cases detectable amounts of MTX remained in the skin at the end. These results suggested that both hydrogels and micro emulsions may be of value for the topical administration of MTX in the treatment of psoriasis.13
· Michele Trotta, (2004) studied on deformable liposomes to investigate the effectiveness of dermal administration of Methotrexate (MTX). Liposomes size, entrapment efficiency and MTX release through dialysis membrane were determined and the interaction between MTX and liposomes was investigated using differential scanning calorimetry. The MTX amount permeated through pig skin were three- to four-fold higher using liposomes containing dipotassium glycyrrhizinate (KG) compared to those from water solution or normal liposomes. No significant differences were observed between soybean lecithin (PC)-KG liposomes and hydrogenated lecithin (HPC)-KG liposomes. At the end of the skin permeation assay using deformable liposomes, up to 50% of the administered dose was found in the skin. This capability depends on the self-regulating carrier deformability. These results suggested that liposomes containing KG may be of value for the topical administration of MTX in the treatment of psoriasis.8
· Souto E.B, (2008) suggested Cyclosporine A loaded into SLN is an improved oral formulation. The CycA seems to be incorporated in molecularly dispersed form, i.e., as solid solution. Differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) measurements were employed for the analysis of the polymorphic modifications and mode of drug incorporation. The processing of the bulk lipid into nanoparticles was accompanied by a polymorphic transformation from the ß to the α-modification. After production, the drug-free SLN dispersions converted back to ß-modification, while the drug-loaded SLN stayed primarily in α-modification. After incorporation of cyclosporine A into SLN, the peptide lost its crystalline character. It concluded that cyclosporine is molecularly dispersed in between the fatty acid chains of the liquid-crystalline a-modification fraction of the loaded SLN.16
6.3 OBJECTIVE OF STUDY
To formulate and evaluate SLN of Methotrexate followed by incorporation of these SLN into gel for topical administration.