Leveraging the Exploratory and Predictive Capabilities of Design of Experiments in Development of Intraarticular Injection of Imatinib Mesylate Containing Lipospheres.

An intraarticular, liposphere-based, formulation of Imatinib mesylate for weekly administration was developed. Lipospheres were prepared using double emulsion technique using dierucoyl phosphatidylcholine, 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt), cholesterol, and tricaprylin as lipid phase in dichloromethane in a four-step process. Primary emulsion, formed using a high-pressure homogenizer, was diluted using a secondary aqueous phase in an Inline mixer to form the liposomal dispersion. Nitrogen flushing was done to remove dichloromethane, and the dispersion was finally centrifuged and adjusted for potency. The amount of cholesterol and triglyceride was taken as formulation variables, and speed of homogenization was used as a process variable in the Box-Behnken design while particle size, % drug entrapment, and drug release at the end of 4 h and 5 days were taken as response variables. Multivariate data analysis grouped the variables in two latent variable sets, one based on the speed and the other on the composition of lipospheres. Multiple linear regression analysis was used to generate mathematical model for each response. Constraints were put on the values of responses, as per the requirements of the final product, and the "freedom to operate" design space was located using an overlay plot. The center point batch sufficed all the set criteria, and Monte Carlo simulations on the factor variables indicated a defect rate of 5%. The center point batch was characterized for viscosity, osmolality, pH, drug release, and lipocrit value. The dispersion was charged in a prefilled syringe and studied for stability. The product was found to be stable at 2-8°C over a period of 6 months.

QbD based development of proliposome of lopinavir for improved oral bioavailability.

Aim of present work was to apply quality by design (QbD) principles for the development of proliposome of poorly soluble lopinavir (LPV). The patient-centric quality target product profile (QTPP) was defined and critical quality attributes (CQAs) earmarked. Risk assessment studies were carried out to identify the probable risks affecting the CQAs of the product. On the basis of preliminary study, lipid:drug ratio and amount of carrier were selected as critical material attributes (CMAs) and were optimized by face centered central composite design. Liposome vesicle size, drug entrapment efficiency and % drug release after 60min were selected as CQAs and mathematical relationship between CQAs and CMAs was derived using multiple linear regression analysis. Optimum composition of CMAs, identified using numerical optimization and desirability function, demonstrated excellent entrapment efficiency (>90%), drug release characteristics (>95% in 60min) and had vesicle size of 659.7±23.1nm. Solid state characterization studies (Differential Scanning Calorimetry, scanning electron microscopy and X-ray diffraction) were performed for optimized proliposome, suggested transformation of crystalline to amorphous form. Oral bioavailability study in Wistar rats revealed that LPV proliposome exhibited 2.24 and 1.16 fold higher bioavailability than pure LPV and available commercial formulation of LPV/RTV (lopinavir+ritonavir), respectively. Stability study of the optimized LPV loaded proliposome was performed as per ICH guideline and was found to be stable for period of 6months. Overall results of the study indicate that the proliposome offers advantages of enhanced oral bioavailability for poorly soluble LPV.

Statistical modeling, optimization and characterization of solid self-nanoemulsifying drug delivery system of lopinavir using design of experiment.

OBJECTIVE: Lopinavir (LPV), an antiretroviral protease inhibitor shows poor bioavailability because of poor aqueous solubility and extensive hepatic first-pass metabolism. The aim of the present work was to investigate the potential of the solid self-nanoemulsifying drug delivery system (S-SNEDDS) in improving dissolution rate and oral bioavailability of LPV. MATERIALS AND METHODS: Liquid SNEDDS (L-SNEDDS) of LPV were prepared using Capmul MCM C8, Cremophor RH 40 and propylene glycol and their amounts were optimized by Scheffe's mixture design. L-SNEDDS formulations were evaluated for different physicochemical and in vitro drug release parameters. S-SNEDDS were prepared by adsorbing L-SNEDDS on Neusilin US2 and characterized for solid-state properties. In vivo bioavailability of S-SNEDDS, marketed Lopinavir + Ritonavir (LPV/RTV) formulation and pure LPV was studied in Wistar rats. Stability study of S-SNEDDS was performed as per ICH guidelines. RESULTS AND DISCUSSION: Optimized L-SNEDDS obtained by Scheffe design had drug loading 160 ± 1.15 mg, globule size 32.9 ± 1.45 nm and drug release >95% within 15 min. Solid state studies suggested the transformation of the crystalline drug to amorphous drug. The size and zeta potential of globules obtained on dilution S-SNEDDS remained similar to L-SNEEDS. In vivo bioavailability study revealed that S-SNEDDS has 2.97 and 1.54-folds higher bioavailability than pure LPV and LPV/RTV formulation, respectively. The optimized S-SNEDDS was found to be stable and had a shelf life of 2.85 years. CONCLUSION: The significant increase in drug dissolution and bioavailability by prepared SNEDDS suggest that the developed S-SNEDDS is a useful solid platform for improving oral bioavailability of poorly soluble LPV.

Development and Optimization of Solid Self Nanoemulsifying Drug Delivery (S-SNEDDS) Using D-Optimal Design for Improvement of Oral Bioavailability of Amiodarone Hydrochloride.

The solid-self nanoemulsifying drug delivery system (S-SNEDDS) of Amiodarone hydrochloride (AH) was prepared and evaluated. AH exhibits poor aqueous solubility (0.3-0.5 mg/ml) and therefore variable oral bioavailability. Capmul MCM, Cremophor RH-40 and Propylene glycol were identified as oil, surfactant and co-surfactant for preparing L-SNEDDS. D-optimal design was used to optimize the amount of components in liquid self nanoemulsifying drug delivery system (L-SNEDDS). Optimized AH-L-SNEDDS having 15.8 nm globule size and 99.5 %transmittance was then adsorbed on Neusilin US2 to form solid self nanoemulsifying drug delivery system (AH-SSNEDDS). AH loaded L-SNEDDS and S-SNEDDS were characterized for various physicochemical properties and solid state properties. In vitro dissolution, ex vivo drug release study and In vivo study were performed for pure AH, AH-LSNEDDS and AH-S-SNEDDS. Both AH loaded L-SNEDDS and S-SNEDDS showed more than 95% drug release in 20 min during drug release studies. In vivo study revealed that release of AH from S-SNEDDS was 2.26 times and LSNEDDS was 1.83 times higher than that from suspension when given to rabbits (p < 0.01). The optimized S-SNEDDS was found to be stable and its shelf life was found to be 2.2 years. S-SNEDDS could serve as a potential drug delivery system for AH.

Development and optimization of solid self-nanoemulsifying drug delivery system (S-SNEDDS) using Scheffe's design for improvement of oral bioavailability of nelfinavir mesylate.

The present research was aimed at development and evaluation of self-nanoemulsifying drug delivery system (SNEDDS) for improving bioavailability of nelfinavir mesylate (NFV), a protease inhibitor exhibiting pH dependent solubility and variable oral bioavailability. Maisine 35-1, Cremophor RH-40, and Labrasol were identified as oil, surfactant, and co-surfactant that had best solubility for NFV. Scheffe's mixture design was used to optimize the amount of components in liquid self-nanoemulsifying drug delivery system (L-SNEDDS) by taking their amounts as independent variable, whereas globule size, drug loading, and percent transmittance were taken as dependent variable. Optimized NFV-L-SNEDDS was then adsorbed on Neusilin US2 to form solid self-nanoemulsifying drug delivery system (S-SNEDDS). NFV loaded L-SNEDDS and S-SNEDDS were characterized for various physicochemical properties, and solid-state properties were determined through differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy studies. In vitro dissolution using simulated gastric fluid and simulated intestinal fluid, ex vivo drug release study, and in vivo study were performed for pure NFV and NFV-S-SNEDDS. NFV-S-SNEDDS showed more than 90 % drug release in 20 min during drug release studies irrespective of pH of the dissolution medium. In vivo study revealed significant difference between release of NFV from suspension and NFV-L-SNEDDS and NFV-S-SNEDDS when given to rabbits (p < 0.001). NFV-L-SNEDDS and NFV-S-SNEDDS were subjected to stability study as per ICH guidelines, and NFV-S-SNEDDS was found to be stable during the period of study. S-SNEDDS could serve as a potential drug delivery system for NFV.

Development of carbamazepine transnasal microemulsion for treatment of epilepsy.

Carbamazepine is widely preferred therapy for the treatment of epilepsy. However, oral therapy results in slower brain uptake and systemic side effects. Intranasal route can achieve faster brain uptake, but poor aqueous solubility of carbamazepine is the main obstacle for administration by nasal route. The purpose of this study was to prepare and evaluate intranasal oil in water microemulsion of carbamazepine to improve its solubility and enhance the brain uptake. Intranasal microemulsion of carbamazepine was prepared by water titration method using oleic acid as oil, Tween 80 as surfactant and Transcutol® as cosurfactant. Microemulsions were evaluated for various physical parameters including globule size, viscosity, pH and conductivity. Toxicity study of microemulsion was carried out by employing sheep nasal mucosa. The microemulsion was also evaluated by maximal electric shock, and the brain uptake study was done using HPLC method. The microemulsion was stable and transparent with average globule size of 21.03 nm and did not show any toxic symptoms. It showed reduction in the hind limb extension phase and faster recovery from seizures in comparison to oral microemulsion and nasal solution. Higher brain/plasma ratio was obtained with nasal microemulsion in comparison to ratio obtained after intraperitoneal injection of carbamazepine solution.

Preparation and evaluation of an ispaghula based directly compressible matrixing agent for controlled release.

The objective of the present investigation was to prepare and evaluate an ispaghula husk based directly compressible (DC) adjuvant that can be used as matrixing agent using an agglomeration technique. Addition of hydroxypropyl methylcellulose was found necessary to improve cohesion. Lactose (X1), calcium hydrogen phosphate dihydrate (X2) and Avicel PH101 (X3), used along with ispaghula in preparation of agglomerates, were selected as three independent variables in a simplex lattice design affecting compressional and dissolution characteristics of the drug from the DC adjuvant. The agglomerates were evaluated for their flow properties. Tablets were prepared using 70% agglomerates and 30% acetaminophen, a poorly compressible drug, and were subjected to in vitro drug release study. Amounts of the drug released at the end of 60 min (Y60), 300 min (Y300) and 480 min (Y480) were selected as dependent variables in a simplex lattice design. Batch IH05 that contained lactose and calcium hydrogen phosphate dihydrate in a 1:2 ratio could control the release for 12 hours and thus form the basis for twice a-day-dosing.