Physicochemical and structural characterization of iron-sucrose formulations: a comparative study.

Intravenous polynuclear iron formulations are vital components in the treatment of iron deficiency anemia associated with chronic kidney disease as well as other diseases associated with gastro-intestinal and cardio-vascular system. Intravenous iron preparations consist of iron-carbohydrate nanoparticles with iron-oxyhydroxide as a core covered by carbohydrate shell. These preparations should be very well characterized in terms of their physicochemical properties and pharmacological profile in order to establish safety and efficacy. The present research work was aimed to physicochemically characterize a new generic iron-sucrose preparation (IS-Claris) and establish its equivalency with the reference product (Venofer®). Various analytical techniques including gel permeation chromatography (GPC), mass spectroscopy (MALDI-TOF), absorption spectroscopy, X-ray diffraction analysis (XRD), nuclear magnetic resonance spectroscopy (proton and (13)C NMR), Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA) were employed. It was observed that the specifications of IS-Claris obtained through these analyses reflect those of Venofer® and hence the two formulations were considered comparable.

In vivo performance evaluation and establishment of IVIVC for osmotic pump based extended release formulation of milnacipran HCl.

The objective of the present study was to carry out a pharmacokinetics evaluation of an oral modified release formulation [Aquarius EKX 19102 SRX-2 based osmotic pump (OP)] containing highly soluble milnacipran HCl (MH) as a model drug. It was also aimed at developing an in vitro-in vivo correlation (IVIVC) model for a developed OP. In vivo plasma concentration data were obtained from six healthy male New Zealand albino rabbits after administration of immediate-release milnacipran HCl solution (IRMHSOL) and milnacipran HCl osmotic pump (MHOP). In vitro samples were analysed using an in house developed spectrophotometry method and in vivo samples were analysed using a RP-HPLC method developed by the author. A deconvolution based Level A model was attempted through a correlation of the percent in vivo input obtained through deconvolution and the percent in vitro dissolution obtained experimentally. A good correlation between the percentages dissolved vs absorbed (R(2) = 0.978) was obtained using level A correlation. Evaluation of the internal predictability of level A correlation was calculated in terms of the percent prediction error, which was found to be below 15%. In a nutshell, the success of the present study warrants further studies in patient volunteers to assess the ability of the MHOP to provide an effective therapy for depression.

Innovation of novel 'Tab in Tab' system for release modulation of milnacipran HCl: optimization, formulation and in vitro investigations.

The study was aimed toward development of modified release oral drug delivery system for highly water soluble drug, Milnacipran HCl (MH). Novel Tablet in Tablet system (TITs) comprising immediate and extended release dose of MH in different parts was fabricated. The outer shell was composed of admixture of MH, lactose and novel herbal disintegrant obtained from seeds of Lepidium sativum. In the inner core, MH was matrixed with blend of hydrophilic (Benecel®) and hydrophobic (Compritol®) polymers. 3² full factorial design and an artificial neuron network (ANN) were employed for correlating effect of independent variables on dependent variables. The TITs were characterized for pharmacopoeial specifications, in vitro drug release, SEM, drug release kinetics and FTIR study. The release pattern of MH from batch A10 containing 25.17% w/w Benecel® and 8.21% w/w of Compritol® exhibited drug release pattern close proximal to the ideal theoretical profile (t(50%) = 5.92 h, t(75%) = 11.9 h, t(90%) = 18.11 h). The phenomenon of drug release was further explained by concept of percolation and the role of Benecel® and Compritol® in drug release retardation was studied. The normalized error obtained from ANN was less, compared with the multiple regression analysis, and exhibits the higher accuracy in prediction. The results of short-term stability study revealed stable chataracteristics of TITs. SEM study of TITs at different dissolution time points confirmed both diffusion and erosion mechanisms to be operative during drug release from the batch A10. Novel TITs can be a succesful once a day delivery system for highly water soluble drugs.

Microemulsion-based gel of terbinafine for the treatment of onychomycosis: optimization of formulation using D-optimal design.

The aim of the present investigation was to evaluate microemulsion as a vehicle for dermal drug delivery and to develop microemulsion-based gel of terbinafine for the treatment of onychomycosis. D-optimal mixture experimental design was adopted to optimize the amount of oil (X(1)), Smix (mixture of surfactant and cosurfactant; X(2)) and water (X(3)) in the microemulsion. The formulations were assessed for globule size (in nanometers; Y(1)) and solubility of drug in microemulsion (in milligrams per milliliter; Y(2)). The microemulsion containing 5.75% oil, 53.75% surfactant-cosurfactant mixture and 40.5% water was selected as the optimized batch. The globule size and solubility of the optimized batch were 18.14 nm and 43.71 mg/ml, respectively. Transmission electron microscopy showed that globules were spherical in shape. Drug containing microemulsion was converted into gel employing 0.75% w/w carbopol 934P. The optimized gel showed better penetration and retention in the human cadaver skin as compared to the commercial cream. The cumulative amount of terbinafine permeated after 12 h was 244.65 ± 18.43 µg cm(-2) which was three times more than the selected commercial cream. Terbinafine microemulsion in the gel form showed better activity against Candida albicans and Trichophyton rubrum than the commercial cream. It was concluded that drug-loaded gel could be a promising formulation for effective treatment of onychomycosis.

Topical delivery of clobetasol propionate loaded microemulsion based gel for effective treatment of vitiligo--part II: rheological characterization and in vivo assessment through dermatopharmacokinetic and pilot clinical studies.

Vitiligo is a non contagious acquired pigmentation disorder with limited treatment possibilities. Clobetasol propionate (CP) is the drug-of-choice for vitiligo which suppresses the immune system by reducing immunoglobulin action and causes the restoration of melanocytes leading to repigmentation of skin. However, despite being effective, its low and variable bioavailability prompt for development of novel carrier that could effectively target CP to site of action without producing undesirable side-effects. Low solubility of CP in subsequent poor in vivo bioavailability was overcome by formulating microemulsion based gel of CP (MBC) which would enhance the percutaneous transport of CP into and across the skin barrier. Comprehensive characterization of MBC was carried out for viscosity, gel strength and rheological behavior. In vitro studies revealed much higher drug release, skin penetration and enhanced skin accumulation as compared to control (Cream of CP). In vitro and in vivo occlusion studies demonstrated similar occlusiveness for MBC and control. MBC exhibited 3.16 times higher stratum corneum CP levels compared to control. Visualization of cutaneous uptake in vivo using laser scanning microscopy confirmed targeting of CP to epidermis and dermis. Dermatopharmacokinetic studies of MBC showed enhanced drug deposition of CP in skin layers. MBC was assessed for in vivo efficacy by single blind randomized pilot clinical study. The efficacy was assessed by vitiligo area scoring index (VASI) method. After completion of trial, repigmentation of vitiligo patches in patients were evaluated and scored. MBC was superior in terms of faster repigmentation and efficacy when compared with control (p value<0.5). Hence, it was concluded that CP loaded MBC possess enhanced skin localization as well as therapeutic activity in vitiligo patients.

Drug delivery to the nail: therapeutic options and challenges for onychomycosis.

Onychomycosis is one of the most common nail disorders. It affects 10-30% of the world population and is caused by dermatophytes, non-dermatophytes, molds, and yeasts. Present treatment methods of onychomycosis include oral therapy, topical therapy, and a combination of both; they have mild-to-moderate efficacy, with a relapse and reinfection rate of 20-25%. For oral therapy, newer antifungal compounds (azole class and allylamine class) are being investigated to increase efficacy and minimize side effects. Oral therapy with antifungal agents have severe side effects, with lesser bioavailability and longer duration of treatment. By contrast, topical therapy of onychomycosis is associated with greater patient compliance and fewer systemic side effects and drug interactions. Current topical treatment options of onychomycosis are nail lacquers, ointments, lotions, solutions, and gels, but these formulations have been unsuccessful due to poor penetration and distribution of drugs at the infected site. Therefore, novel therapeutic options are constantly being researched to improve the efficacy of onychomycosis treatment by enhancing the permeation of the drug across the nail to reach the infected site. Various physical and chemical enhancement methods have been studied to increase the permeation of drugs across the nail plate to the nail bed. Device-based therapeutic options have also been investigated to increase the antifungal drug concentration and its effects in the onychomycotic nail. Randomized clinical trials of these novel therapies have demonstrated better efficacy. The present review discusses the anatomy of the human nail, onychomycosis and its types, onycholysis, and conventional and novel therapies. We also review patents granted as well as design challenges facing optimal drug formulation for onychomycosis treatment.

Topical delivery of clobetasol propionate loaded microemulsion based gel for effective treatment of vitiligo: ex vivo permeation and skin irritation studies.

The aim of the present investigation was to evaluate microemulsion as a vehicle for dermal drug delivery and to develop microemulsion based gel (MBC) of clobetasol propionate (CP) for the effective treatment of vitiligo. D-Optimal mixture experimental design was adopted to optimize the amount of oil (X(1)), S(mix) (mixture of surfactant and cosurfactant) (X(2)) and water (X(3)) in the microemulsion. The formulations were assessed for globule size (nm) (Y(1)) and solubility of CP in microemulsion (mg/ml) (Y(2)). The microemulsion containing 3% oil, 45% S(mix) and 50% water was selected as the optimized batch (ME). The globule size and solubility of CP in ME were 18.26 nm and 36.42 mg/ml respectively. Transmission electron microscopy showed that ME globules were spherical in shape. Carbopol 934P was used to convert microemulsion containing drug into gel form without affecting its structure. Ex-vivo permeation studies showed that cumulative amount of CP permeated (Q(n)) from ME, MBC and market formulation (MFCP) at 8h after application were 53.6±2.18, 28.43±0.67 and 37.73±0.77 µg cm(-2) respectively. MBC showed greater retention of CP in to skin layers than ME and MFCP. Skin irritation studies showed MBC to be significantly less irritating than MFCP. Photomicrographs and scanning electron micrographs of skin sections treated with MBC showed significant changes in the skin structure, which was attributed to the interaction of microemulsion components with skin resulting in permeation enhancement and retention of CP into skin layers. It was concluded that CP loaded gel could be a promising formulation for effective treatment of vitiligo.

Microemulsion-based antifungal gel delivery to nail for the treatment of onychomycosis: formulation, optimization, and efficacy studies.

Onychomycosis is the most common nail disease affecting nail plate and nail bed. Onychomycosis causes onycholysis which creates cavity between the nail plate and nail bed, where drug formulations could be applied, providing a direct contact of drug with the nail bed facilitating drug delivery on the infected area. The purpose of the present study was to design and evaluate the potential of microemulsion-based gel as colloidal carrier for itraconazole for delivery into onycholytic nails for effective treatment of onychomycosis. Itraconazole-loaded microemulsions were prepared and optimized using D-optimal design. The microemulsion containing 6.24 % oil, 36 % Smix, and 57.76 % water was selected as the optimized batch (MEI). The globule size and drug loading of the optimized batch were 48.2 nm and 12.13 mg/ml, respectively. Diffused reflectance FTIR studies were performed to study drug-excipient incompatibility. Ex vivo permeation studies were carried out using bovine hoof and human cadaver skin as models for nail plate and nail bed, respectively. Microemulsion-based itraconazole gel (MBGI) showed better penetration and retention in human skin as well as bovine hoof as compared to commercial preparation (market formulation, MFI). The cumulative amount of itraconazole permeated from the MBGI after 12 h was 73.39 ± 3.55 µg cm(-2) which was 1.8 times more than MF. MBGI showed significantly higher ex vivo antifungal activity (P < 0.05) against Candida albicans and Trichophyton rubrum when compared to MFI. Stability studies showed that MBGI was stable at refrigeration and room temperature for 3 months. It was concluded that drug-loaded gel could be a promising formulation for effective treatment of onychomycosis.

Development of directly compressible metformin hydrochloride by the spray-drying technique.

Metformin hydrochloride exhibits poor compressibility during compaction, often resulting in weak and unacceptable tablets with a high tendency to cap. The purpose of this study was to develop directly compressible metformin hydrochloride by the spray-drying technique in the presence of polymer. Metformin hydrochloride was dissolved in solutions containing a polymer, namely polyvinylpyrrolidone (PVP K30), in various concentrations ranging from 0-3% (m/V). These solutions were employed for spray-drying. Spray-dried drug was evaluated for yield, flow property and compressibility profile. Metformin hydrochloride spray-dried in the presence of 2% PVP K30 showed an excellent flow property and compressibility profile. From the calculated Heckel's parameter (Py = 2.086), it was demonstrated that the treated drug showed better particle arrangement in the initial compression stage. Kawakita analysis revealed better packability of the treated drug compared to the untreated drug. Differential scanning calorimetry and Fourier transform infrared spectroscopy experiments showed that the spray-dried drug did not undergo any chemical modifications. Tablets made from the spray-dried drug (90%, m/m) were evaluated for crushing strength, friability and disintegration time and the results were found satisfactory.