Synthesis, characterization and in vitro studies of pegylated melphalan conjugates.

Melphalan, a drug used for the treatment of breast, ovaries and a certain type of cancer in the bone marrow, was conjugated to linear methoxy poly (ethylene glycol) (M-PEG) of 2000 and 5000, Da. An ester linkage between polymer and drug was used in the coupling to yield a polymeric prodrug. Purified esters were characterized by Maldi-Tof and IR spectroscopy methods. The modification allowed overcoming the known melphalan aqueous solubility problem (0.1 µg/ml) leading us to obtain a polymer-drug bioconjugate more suitable for oral and parental administration. It was found that molecular weight of M-PEG is critical for the conjugates stability, aqueous solubility (80 times and 123 times higher aqueous solubility for M-PEG 2000 and M-PEG 5000, respectively), and hemolytic activity. The melphalan caused 100% hemolysis above the concentration 3.5 µg/ml in 1 h. whereas conjugate of M-PEG 2000 and M-PEG 5000 shows 81.3 ± 0.5% and 48.8 ± 1.5% hemolysis, respectively at 32 µg/ml after1 h. Further In vitro anticancer activity of melphalan and its conjugates was performed with breast cancer MCF-7 cell lines. It shows that LD50 concentration was higher 1.14 and 2 µm for M-PEG 2000 and M-PEG 5000, respectively in comparison to pure melphalan (0.74 µm). Above studies revealed improved pharmacokinetics properties upon conjugation.

Pluronic F127-tailored lecithin organogel of acyclovir: preclinical evidence of antiviral activity using BALB/c murine model of cutaneous HSV-1 infection.

Herpes is a well-known contagious infection equally affecting both sexes. Among many antiviral drugs employed for its treatment, acyclovir (ACY) is the drug of choice. The currently available therapies of ACY suffer from limitations like poor oral bioavailability (10-15%) and high-dose requirement. The present scientific study aims to explore pluronic lecithin organogel (PLO) as a novel drug delivery platform for ACY to bring an improvement in its delivery through topical route. The properties of organogel like biocompatibility and amphiphilic nature which facilitates dissolution of various drugs of different solubility characteristics along with enhancing the permeation potential of active molecules make it a favorable drug delivery platform for the management of topical diseases. The developed PLO formulations were characterized for micromeritic characteristics, viz., zeta potential, percentage drug content, organogel morphology, skin permeation, retention, and stability studies. The selected topical formulation was further compared with the marketed one for its therapeutic efficacy by inducing cutaneous Herpes simplex virus type 1 infection followed by confirmation of viral load by immunofluorescence and PCR analyses. The developed formulation showed significant improvement over the marketed product as reflected in lesion scoring index and PCR analysis. Further, it proved better to the marketed formulation in t.i.d. treatment regimen in comparison to control. The improvement in overall performance leading to enhanced bioavailability and safety is attributed to the synergism between excipient properties and formulation characteristics. The drug ACY in this micro environment not only finds an improved delivery vehicle but it also offers enhanced drug-target interactions.

Novel dithranol phospholipid microemulsion for topical application: development, characterization and percutaneous absorption studies.

The objective of this study was to develop and characterize a novel dithranol-containing phospholipid microemulsion systems for enhanced skin permeation and retention. Based on the solubility of dithranol, the selected oils were isopropyl myristate (IPM) and tocopherol acetate (TA), and the surfactants were Tween 80 (T80) and Tween 20 (T20). The ratios of cosurfactants comprising of phospholipids and ethanol (1 : 10) and surfactant to co-surfactant (1 : 1 and 2.75 : 1) were fixed for the phase diagram construction. Selected microemulsions were evaluated for globule size, zeta potential, viscosity, refractive index, per cent transmittance, stability (freeze thaw and centrifugation), ex vivo skin permeation and retention. The microemulsion systems composed of IPM and T80 with mean particle diameter of 72.8 nm showed maximum skin permeation (82.23%), skin permeation flux (0.281 mg/cm²/h) along with skin retention (8.31%) vis-à-vis systems containing TA and T20. The results suggest that the developed novel lecithinized microemulsion systems have a promising potential for the improved topical delivery of dithranol.

Fabrication of acyclovir-loaded flexible membrane vesicles (FMVs): evidence of preclinical efficacy of antiviral activity in murine model of cutaneous HSV-1 infection.

The present investigation focuses on the development and evaluation of acyclovir-loaded flexible membrane vesicles (ACY-FMVs) and evaluates their targeting potential to localize the drug into skin layers. The drug-loaded FMVs were prepared by thin-film hydration method and characterized for various attributes including micromeritics, entrapment efficiency, vesicle shape, size, and degree of deformability. The values of particle size and zeta potential of the developed carrier system were found to be 453.7 nm and - 11.62 mV, respectively. The system was further incorporated into a hydrogel and evaluated for skin permeability and retention characteristics in comparison to marketed formulation. The developed formulation demonstrated enhanced retention of drug deep inside the skin layers which can probably decrease the frequency of application of the drug, thereby reducing its adverse effects. Skin irritancy studies performed on Laca mice skin proved the safety and non-irritant nature of ACY-FMVs. The pharmacodynamic studies on murine model for HSV-1 infection demonstrated immense potential and safety of topically applied ACY-FMVs. However, more intensive studies need to be pursued to explore and exploit the potential of lipid-based systems in anti-viral therapeutics. These preclinical findings provide a hope for corroborating the efficacy in clinical situations.

Microemulsions mediated effective delivery of methotrexate hydrogel: more than a tour de force in psoriasis therapeutics.

Methotrexate (MTX), a well known drug for the treatment of cancer and rheumatoid arthritis, has gained prominence in the treatment of psoriasis over the period of years. However, the present mode of systemic administration through oral or parenteral route has always proposition, full of compromises. The toxicity of drug to the vital organs and physiological environment is the major concern. Also, its poor skin penetration is one major problem. Hence novel system based on lipid carriers has been considered here to overcome the barriers. Microemulsions (MEs) were prepared using pseudo-ternary phase diagram (PTPD) and they were characterized for various parameters such as size, shape (cryo-SEM), PDI, zeta potential, etc. The chosen MEs system (optimized) was then incorporated into secondary vehicles and characterized for rheological behavior, texture profile analysis, in vitro release, ex vivo permeation and drug distribution into different layers of skin. The developed formulations were further evaluated in ex vivo and in vivo such as cell line study, imiquimod-induced psoriatic model, allergic contact dermatitis, rat tail model (% orthokeratosis) and safety test (Draize test). The MEs based MTX gel has shown its potential in locating the drug at the desired domain of stratum corneum, epidermal and dermal layers of skin and reducing systemic absorption. Our results are suggestive of MEs potential as a novel carrier for topical delivery of MTX in topical therapeutic and safety approaches. In conclusion, developed MEs-based hydrogel has shown promising results in achieving effective delivery of MTX.

Efficacy of Novel Topical Liposomal Formulation of Cyclosporine in Mild to Moderate Stable Plaque Psoriasis: A Randomized Clinical Trial.

IMPORTANCE: Attempts to use topical cyclosporine in treatment of psoriasis have failed because of unfavorable physicochemical properties and inappropriate formulation design of the conventional dosage forms. OBJECTIVE: To evaluate the efficacy of topical cyclosporine using liposomal nanocarriers (lipogel) in limited chronic plaque psoriasis. DESIGN, SETTING, AND, PARTICIPANTS: A single-center randomized clinical trial was conducted using a 3-arm parallel group, double-blind, vehicle and active comparator design and included 38 patients with chronic plaque psoriasis measuring less than or equal to 100 cm2 performed in a tertiary care hospital. INTERVENTIONS: In the first arm, a total of 24 patients were randomized to receive either cyclosporine lipogel, 2.0% weight by weight (w/w), or placebo lipogel. In the second arm, 7 patients were randomized to receive cyclosporine lipogel, 2.0%, or conventional cyclosporine cream, 2.0% w/w. The third arm comprised 7 patients randomized with cyclosporine lipogel, 2.0% or standard clobetasol propionate cream, 0.05% w/w. Patients were examined twice weekly for 14 weeks, or until total lesional clearance was observed, whichever was earlier. MAIN OUTCOMES AND MEASURES: The primary outcome measure was the dermatological sum score (DSS) assessing erythema, scaling, and plaque elevation on a 4-point scale (0, absent; 1, minimal; 2, moderate; 3, severe). RESULTS: In 38 patients (23 men and 15 women with a mean [SD] age range from 35 [8] to 40 [13] years), a 19% decrease in DSS score from a mean (SD) of 8.45 (0.67) to 6.82 (0.77) compared with baseline was observed after 2 weeks of treatment with cyclosporine lipogel, 2.0% w/w (P < .001; 95% CI, 13.77-24.51) in 59% of psoriasis lesional sites. At the end of the eighth week, a significant reduction (approximately 83%) in DSS was seen in all sites treated with cyclosporine lipogel, (P < .001; 95% CI, 77.48-88.22). At the end of the study period, complete clearance (ie, DSS = 0) was observed in 16 (41%) psoriasis lesional sites treated with cyclosporine lipogel, 85.7% of sites treated with clobetasol propionate cream, and none of the sites treated with conventional cyclosporine cream or placebo gel. CONCLUSIONS AND RELEVANCE: Topical liposomal formulation of cyclosporine, 2.0% w/w, is effective in treatment of limited chronic plaque psoriasis with a satisfactory safety profile. Future clinical trials should assess liposomal cyclosporine in larger study populations. TRIAL REGISTRATION: Clinical Trials Registry-India Identifier: CTRI/2011/12/002307.

Tamoxifen-loaded novel liposomal formulations: evaluation of anticancer activity on DMBA-TPA induced mouse skin carcinogenesis.

PURPOSE: Tamoxifen (TAM) is a non-steroidal estrogen receptor modulator known for its anticancer activity. Apart from marked breast cancer activity, this drug has also shown potential in treating other types of cancers including skin cancers. TAM is reported to be associated with serious side effects primarily due to its systemic distribution. The localized delivery of this drug in this regard would be highly beneficial with respect to safety as well as efficacy. METHODS: In the current studies, an endeavor has been made to investigate the efficacy of topically applied liposome-encapsulated TAM on skin cancer model. The drug was encapsulated in phospholipid-based vesicular systems viz. conventional liposomes and elastic liposomes. Incidence of papillomas and histopathological examination were employed to determine the efficacy of the tested formulations. RESULTS: The results demonstrated carrier-dependent strong inhibition of skin carcinogenesis with encapsulated drug vis-à-vis drug in the solution form. The encouraging findings from the current work construe immense potential of the TAM-loaded liposomal systems in the management of skin cancer.

Novel stain-free lecithinized coal tar formulation for psoriasis.

BACKGROUND: Coal tar has been a very popular traditional treatment for various types of psoriasis for over a century. It is the first-line treatment for scalp, hand, and foot psoriasis. However, the application of coal tar on hair invariably causes staining, which results in a high degree of patient non-compliance, especially in patients with non-black hair. Thus, the treatment of scalp psoriasis with a topical coal tar formulation requires that special concern be paid to product esthetics. OBJECTIVE: This study aimed to evaluate the hair-staining characteristics of a novel lecithinized coal tar (LCT) formulation on different types of mammalian hair. METHODS: Samples of hair from different mammals, including human, sheep, rabbit, and goat, were repeatedly exposed to the LCT formulation over 14 days. The color of hair samples treated with LCT was compared with that of untreated control hair samples. RESULTS: The study revealed the distinct non-staining potential of the LCT formulation. CONCLUSIONS: This LCT formulation lacks the propensity to stain hair and thus has excellent potential to be exploited in the treatment of scalp psoriasis.