In Vitro and In Vivo testing of 3D-Printed Amorphous Lopinavir Printlets by Selective Laser Sinitering: Improved Bioavailability of a Poorly Soluble Drug.

The aim of this paper was to investigate the effects of formulation parameters on the physicochemical and pharmacokinetic (PK) behavior of amorphous printlets of lopinavir (LPV) manufactured by selective laser sintering 3D printing method (SLS). The formulation variables investigated were disintegrants (magnesium aluminum silicate at 5-10%, microcrystalline cellulose at 10-20%) and the polymer (Kollicoat® IR at 42-57%), while keeping printing parameters constant. Differential scanning calorimetry, X-ray powder diffraction, and Fourier-transform infrared analysis confirmed the transformation of the crystalline drug into an amorphous form. A direct correlation was found between the disintegrant concentration and dissolution. The dissolved drug ranged from 71.1 ± 5.7% to 99.3 ± 2.7% within 120 min. A comparative PK study in rabbits showed significant differences in the rate and extent of absorption between printlets and compressed tablets. The values for Tmax, Cmax, and AUC were 4 times faster, and 2.5 and 1.7 times higher in the printlets compared to the compressed tablets, respectively. In conclusion, the SLS printing method can be used to create an amorphous delivery system through a single continuous process.

HSPiP and QbD Program-Based Analytical Method Development and Validation to Quantify Ketoconazole in Dermatokinetic Study.

Ketoconazole (KTZ) is the most potential azole anti-mycotic drug. The quantification of KTZ from various layers of the skin after topical application of lipidic nanocarriers is critical. We addressed a sensitive, specific, simple, rapid, reproducible, and economic analytical method to quantify KTZ from the treated skin homogenate using the Hansen solubility parameter (HSP, HSPiP software)-based modeling and experimental design. The software provided various HSP values for KTZ and solvents to compose the mobile phase. The Taguchi model identified the significant sets of factors to develop a robust bioanalytical method with reduced variability. In the optimization, acetonitrile (ACN) concentration (X1 as A) and the pH of mobile phase (X2 as B) were two factors against two responses (Y1: peak area and Y2: retention time). The HPLC (high-performance liquid chromatography) method validation was carried out based on US-FDA guidelines for the developed KTZ formulations (suspension, solid nanoparticles, and commercial product) extracted from the treated rat skin. The experimental solubility of KTZ was found to be maximum in the two solvents (ACN and ethyl acetate), based on HSP values. Surface response methodology (SRM) identified remarkable impact of ACN concentration and the mobile phase pH on the peak area and retention time. Analytical limits (0.17 and 0.50 µg/mL) were established for KTZ-SLNs (extracted from the skin). The method was implemented with high reproducibility, accuracy, and selectivity to quantify KTZ from the treated rat skin.

Preparation and Characterization of 3D-Printed Dose-Flexible Printlets of Tenofovir Disoproxil Fumarate.

The aim of this work was to design pediatric-friendly, dose-flexible orally disintegrating drug delivery systems (printlets) of the antiviral drug tenofovir disoproxil fumarate (TDF) by selective laser sintering (SLS) for potential use in hospitals along with other antiviral drugs. In order to obtain a consistent quality of printlets with desired properties, it is important to understand certain critical quality attributes for their main and interactions effect. The printlets were optimized by Box-Behnken's design of the experiment by varying process variables while keeping the composition constant. The composition contained 16.3% TDF, 72.7% polyvinyl pyrrolidone K16-18, 8% magnesium aluminum silicate, 3% Candurin® NXT Ruby Red, and 0.3% colloidal silicon dioxide. The process variables studied were surface (X1), chamber temperatures (X2), and laser scanning speed (X3). The range of variable levels was 75-85°C for X1, 50-70°C for X2, and 200-240 mm/s for X3, respectively. The responses studied were hardness, disintegration time, dissolution, physiochemical, and pharmacokinetic characterization. X-ray powder diffraction indicated partial or complete conversion of the crystalline drug into amorphous form in the printlets. Comparative pharmacokinetics between Viread® (generic) and printlets in rats were superimposable. Pharmacokinetic parameters showed statistically insignificant differences between the two formulations in terms of Tmax, Cmax, and AUC of (p > 0.05). Printlets were bioequivalent to Viread® as per FDA bioequivalence criteria. Thus, the SLS printing method showed the fabrication of dose-flexible printlets with quality, and in vivo performance equivalent to commercial tablets.

Very-Rapidly Dissolving Printlets of Isoniazid Manufactured by SLS 3D Printing: In Vitro and In Vivo Characterization.

The focus of this research was to understand the effects of formulation and processing variables on the very-rapidly dissolving printlets of isoniazid (INH) manufactured by the selective laser sintering (SLS) three-dimensional (3D) printing method, and to characterize their physicochemical properties, stability, and pharmacokinetics. Fifteen printlet formulations were manufactured by varying the laser scanning speed (400-500 mm/s, X1), surface temperature (100-110 °C, X2), and croscarmellose sodium (CCS, %, X3), and the responses measured were weight (Y1), hardness (Y2), disintegration time (DT, Y3), and dissolution (Y4). Laser scanning was the most important processing factor affecting the responses. DT was very rapid (≥3 s), and dissolution (>99%) was completed within 3 min. The root-mean-square error in the studied responses was low and analysis of variance (ANOVA) was statistically significant (p < 0.05). X-ray micro-computed tomography (micro-CT) images showed very porous structures with 24.6-34.4% porosity. X-ray powder diffraction and differential scanning calorimetry data indicated partial conversion of the crystalline drug into an amorphous form. The printlets were stable at 40 °C/75% RH with no significant changes in assay and dissolution. Pharmacokinetic profiles of the printlets and compressed tablets were superimposable. In conclusion, the rapidly dissolving printlets of the INH were stable, and oral bioavailability was similar to that of compositionally identical compressed tablets.

Simultaneous estimation of paclitaxel and erlotinib in plasma by liquid chromatography/(+) electrospray tandem mass spectrometry: application in formulation development and pharmacokinetics.

The bio-analytical method was developed and validated for simultaneous detection and quantification of paclitaxel (PAC) and erlotinib (ERL) in plasma samples. The sample preparation process was accomplished by liquid-liquid extraction technique. The dried and reconstituted samples were subjected to chromatography on Discovery -C18 (50 × 4.6 × 5µm) column and a mobile phase, composed of a mixture of 0.1% formic acid in water: acetonitrile (70:30, v/v), in isocratic mode at a flow rate of 0.6 mL/min. Liquid chromatography coupled to tandem mass spectrometry detection in positive ion mode was selected to provide optimal selectivity and sensitivity. The mass transitions of erlotinib, erlotinib13C6, Paclitaxel and docetaxel were m/z 394.5→278.4, m/z 400.4→284.5, m/z 876.6→308.4 and m/z 830.0→304.0 respectively. The linearity in the calibration curves was obtained in the concentration range of 3.6 - 1006.7 ng/ml (r ≥ 0.99) for erlotinib and 5.3 - 1500.0 ng/mL for paclitaxel with an LLOQ (lower limit of quantification) of 3.6 and 5.3 ng/ml respectively. The run time was achieved in 2.5 min only, for all the analytes.

Preparation and characterization of dicarboxylic acids salt of aripiprazole with enhanced physicochemical properties.

The focus of present work was to prepare salt of aripiprazole (APZ) with dicarboxylic acids to improve physicochemical properties the drug. Dicarboxylic acids used in the study were malonic acid, maleic acid and succinic acid. The salts were prepared with solubilization-crystallization method. The salts were characterized for pH-solubility, dissolution, and stabilities. The Fourier infrared spectroscopy, X-ray powder diffraction, differential scanning calorimetry and near infrared chemical imaging indicated formation of new solid phase. pH-solubility profiles of the salts were similar to the drug except higher solubility were observed in the salts at all tested pH. The highest solubility was observed for APZ-Malonate salt among all the prepared salts. The solubility curve was inverted 'V' shape for APZ-maleate and APZ-succinate while it was inverted 'U' shape for APZ-malonate. The water solubility of APZ, APZ-malonate, APZ-maleate and APZ-succinate were 0.07 ± 0.02, 3503.9 ± 37.4, 269.3 ± 6.9 and 729.4 ± 9.4 µg/mL, respectively. The dissolution was 2.9 ± 0.4, 18.4 ± 3.9, 19.5 ± 1.4 and 36.6 ± 4.0% in 45 min for APZ, APZ-maleate, APZ-malonate, and APZ-succinate. The stabilities of the salts were similar to the drug. Thus, salts improved the physicochemical properties of the drug, and have similar stability profiles as that of APZ.

Potential Application of USP Paddle and Basket Dissolution Methods in Discriminating for Portioned Moist Snuff and Snus Smokeless Tobacco Products.

The focus of the study was to develop discriminatory dissolution methods for portioned snus and moist snuff sub-categories of smokeless tobacco products (STPs) using USP basket and paddle apparatuses. Skoal Classic Wintergreen (SCW) and CORESTA CRP1.1 pouches were used as test products. The dissolution was performed at 10, 20, 30, 40, and 50 rpm basket or paddle speed in 500 ml artificial saliva pH 6.8. The products were also characterized for assay, pH, particle size, and loss on drying. The dissolution profiles were evaluated for amount/% of nicotine dissolved, time to reach plateau, and profiles comparison by f2 and f1 factors. The nicotine assay was 13.3 ± 0.2 and 7.6 ± 0.1 mg/pouch for SCW and CRP1.1, respectively. The nicotine dissolved in 30 min from SCW and CRP1.1 were 38.4-81.8 and 37.6-88.1, and 50.5-64.9 and 72.3-92.1% by paddle and basket methods, respectively. The f2 and f1 values were ≤ 39.2 and ≥ 42.1 and ≤ 43.2 and ≥ 34.1 for basket methods and paddle methods. RSD were less than 20% at all points of dissolution profiles, and dissolution plateau were achieved in 30 min at some of the tested conditions. In summary, dissolution methods based on basket and paddle can be used as a performance test for STPs.

Coating characterization by hyperspectroscopy and predictive dissolution models of tablets coated with blends of cellulose acetate and cellulose acetate phthalate.

The objective of current research was to develop the models of dissolution prediction of tablets coated with cellulose acetate (CA 320S or CA 398-10) and cellulose acetate phthalate (C-A-P) blends. Independent variables selected were coating percent (X1) and percent of CA 320S or CA 398-10 (X2) in the blend. Dependent variables selected were dissolution in 1 (Y1), 8 (Y2), and 24 h (Y3). Diclofenac sodium core tablets were coated with blend of either CA 320S and C-A-P or CA 398-10 and C-A-P at approximately 5, 7.5, and 10% weight gain. CA 320S and CA 398-10 content in the corresponding blends varied from 33.3-66.7% and 25.0-50.0% relative to C-A-P, respectively. Dissolution was performed in phosphate buffer 6.8 using USP apparatus 2. Coated tablets were also characterized for surface morphology and coating uniformity by near infrared hyperspectroscopy. Y1, Y2, and Y3 were statistically (p < 0.05) affected by X2 in CA 320S/C-A-P and CA 398-10/C-A-P blends coated tablets. On the other hand, X1 had statistically significant (p < 0.05) effect only on the Y3 in CA 320S/C-A-P while Y1 was statistically (p < 0.05) affected by X2 in CA 398-10/C-A-P. Analysis of variance also indicated statistically significant (p < 0.05) effect of the studied variables on the dependent variables for both the blends. The models were verified by independent experiment. Model predicted and empirical values of Y1, Y2, and Y3 were close with maximum residual of 7.0%. In conclusion, dissolution can be modulated by varying composition of blend, polymer type, and coating weight.

HSPiP, Computational Modeling, and QbD-Assisted Optimized Method Validation of 5-Fluorouracil for Transdermal Products.

This study addressed the simplest and most efficient HPLC (high-performance liquid chromatography) method for the estimation of 5-fluorouracil (5-FU) from rat blood plasma by implementing the Hansen solubility parameters (HSP), computation prediction program, and QbD (quality by design) tool. The mobile phase selection was based on the HSP predictions and experimental data. The Taguchi model identified seven variables (preoptimization) to screen two factors (mobile phase ratio as A and column temperature as B) at three levels as input parameters in "CCD (central composite design)" optimization (retention time as Y1 and peak area as Y2). The stability study (freeze-thaw cycle and short- and long-term stability) was conducted in the rat plasma. Results showed that HSPiP-based HSP values and computational model-based predictions were well simulated with the experimental solubility data. Acetonitrile (ACN) was relatively suitable over methanol as evidenced by the experimental solubility value, HSP predicted parameters (δh of 5-FU - δh of ACN = 8.3-8.3 = 0 as high interactive solvent whereas δh of 5-FU - δh of methanol = 8.3-21.7 = -13.4), and instrumental conditions. CCD-based dependent variables (Y1 and Y2) exhibited the best fit of the model as evidenced by a high value of combined desirability (0.978). The most robust method was adopted at A = 96:4 and B = 40 °C to get earlier Y1 and high Y2 as evidenced by high desirability (D) = 0.978 (quadratic model with p < 0.0023). The estimated values of LLOD and LLOQ were found to be 0.11 and 0.36 µg/mL, respectively with an accuracy range of 94.4-98.7%. Thus, the adopted method was the most robust, reliable, and reproducible methodology for pharmacokinetic parameters after the transdermal application of formulations in the rat.

Hansen Solubility Parameters and QbD-Oriented HPLC Method Development and Validation for Dermatokinetic Study of a Miconazole-Loaded Cationic Nanoemulsion in Rat Model.

Miconazole (MCZ) is a potential antifungal drug to treat skin infections caused by Candida, Tinea pedis (athlete's foot fungal infection), Tinea cruris (jock itching in the groin and buttocks), and Tinea corporis (red scaly rash on the skin). The current study focused on Hansen parameter-based solvent selection (HSPiP software) and method development optimization using an experimental design tool for sensitive, accurate, reproducible, economic, rapid, robust, and precise methodology to quantify MCZ in rat plasma. Moreover, a Taguchi design was used for screening two independent factors (flow rate and ACN content). Quality by design (QbD) was employed to optimize and identify the right ratio of mobile phase composition and its impact on the peak and retention time. The elution of MCZ was achieved using methanol and acetonitrile (15:85 v/v ratio) at a retention time of 6 min and optimal flow rate (1 mL/min). Finally, the method was validated based on accuracy, precision, linearity, selectiveness, and high recovery at varied concentrations as per the International Council for Harmonization (ICH) guidelines. The method was linear (r2 = 0.999) over the explored concentration range (250-2000 ng/mL) at 270 nm detection wavelength. The optimized method was used to quantify in vivo pharmacokinetic (PK) study after transdermal application of MCZ-loaded formulations (MCNE11, MNE11, MCZ-Sol, and MCZ-MKT). HSP-oriented solvent selection and quality by design-based optimized process variables and composition in the optimized analytical methodology were quite convincing and have been a cutting-edge MCZ analysis method so far. The validated method was robust, economic, and rapid with high specificity and selectivity.

GastroPlus- and HSPiP-Oriented Predictive Parameters as the Basis of Valproic Acid-Loaded Mucoadhesive Cationic Nanoemulsion Gel for Improved Nose-to-Brain Delivery to Control Convulsion in Humans.

Oral and parenteral delivery routes of valproic acid (VA) are associated with serious adverse effects, high hepatic metabolism, high clearance, and low bioavailability in the brain. A GastroPlus program was used to predict in vivo performance of immediate (IR) and sustained release (SR) products in humans. HSPiP software 5.4.08 predicted excipients with maximum possible miscibility of the drug. Based on the GastroPlus and HSPiP program, various excipients were screened for experimental solubility, nanoemulsions, and respective gel studies intended for nasal-to-brain delivery. These were characterized by size, size distribution, polydispersity index, zeta potential, morphology, pH, % transmittance, drug content, and viscosity. In vitro drug release, ex vivo permeation profile (goat nasal mucosa), and penetration studies were conducted. Results showed that in vivo oral drug dissolution and absorption were predicted as 98.6 mg and 18.8 mg, respectively, from both tablets (IR and SR) at 8 h using GastroPlus. The predicted drug access to the portal vein was substantially higher in IR (115 mg) compared to SR (82.6 mg). The plasma drug concentration-time profile predicted was in good agreement with published reports. The program predicted duodenum and jejunum as the prime sites of the drug absorption and no effect of nanonization on Tmax for sustained release formulation. Hansen parameters suggested a suitable selection of excipients. The program recommended nasal-to-brain delivery of the drug using a cationic mucoadhesive nanoemulsion. The optimized CVE6 was associated with the optimal size (113 nm), low PDI (polydispersity index) (0.26), high zeta potential (+34.7 mV), high transmittance (97.8%), and high strength (0.7% w/w). In vitro release and ex vivo permeation of CVE6 were found to be substantially high as compared to anionic AVE6 and respective gels. A penetration study using confocal laser scanning microscopy (CLSM) executed high fluorescence intensity with CVE6 and CVE6-gel as compared to suspension and ANE6. This might be attributed to the electrostatic interaction existing between the mucosal membrane and nanoglobules. Thus, cationic nanoemulsions and respective mucoadhesive gels are promising strategies for the delivery of VA to the brain through intransal administration for the treatment of seizures and convulsions.

In Vitro and In Vivo Characterization of the Transdermal Gel Formulation of Desloratadine for Prevention of Obesity and Metabolic Syndrome.

Chronic use of antihistamines can induce abnormalities in lipid absorption with potential excessive accumulation of lipids in the mesentery that can lead to the development of obesity and a metabolic syndrome. The focus of the present work was to develop a transdermal gel formulation of desloratadine (DES) to prevent/reduce obesity and metabolic syndromes. Nine formulations were prepared to contain hydroxypropyl methylcellulose (2-3%), DES (2.5-5.0%), and Transcutol® (15-20%). The formulations were evaluated for cohesive and adhesive properties, viscosity, drug diffusion through synthetic and pig ear skin, and pharmacokinetics in New Zealand white rabbits. Drug permeation was faster through the skin compared to synthetic membranes. The drug had good permeation, as indicated by very short lag time (0.08-0.47 h) and high flux (59.3-230.7 µg/cm2.h). The maximum plasma concentration (Cmax) and area under the curve (AUC) of transdermal gel formulations were 2.4 and 3.2 fold that of the Clarinex tablet formulation. In conclusion, as indicated by the higher bioavailability, transdermal gel formulation of DES may decrease the dose of the drug, compared to commercial formulation. It has the potential to reduce or eliminate metabolic syndromes associated with oral antihistamine therapy.

Mechanistic of Vesicular Ethosomes and Elastic Liposomes on Permeation Profiles of Acyclovir across Artificial Membrane, Human Cultured EpiDerm, and Rat Skin: In Vitro-Ex Vivo Study.

Acyclovir (ACV) controls cutaneous herpes, genital herpes, herpes keratitis, varicella zoster, and chickenpox. From previously reported ACV formulations, we continued to explore the permeation behavior of the optimized ACV loaded optimized ethosome (ETHO2R) and elastic liposome (ELP3R) and their respective carbopol gels across artificial membrane, cultured human EpiDerm, and rat skin. Transepidermal water loss (TEWL), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and atomic force microscopy (AFM) were used to investigate the mechanistic perspective of permeation behavior. The size values of reformulated ELP3-R and ETHO2-R were observed as 217 and 128 nm, respectively (close to previous report), whereas their respective gels showed as 231 and 252 nm, respectively. ETHO2R showed high elasticity, %EE, and low vesicle size. These were investigated for the diffusion rate of the drug permeation (3 h) across the artificial membrane, cultured human EpiDerm, and rat skin. ETHO2GR showed the highest permeation flux (78.42 µg/cm2/h), diffusion coefficient (8.24 × 10-5 cm2/h), and permeation coefficient (0.67 × 10-3 cm/h) of ACV across synthetic membrane, whereas diffusion coefficient (2.4 × 10-4 cm2/h) and permeation coefficient (0.8 × 10-3 cm/h) were maximum across EpiDerm for ETHO2GR. ETHO2R suspension showed maximized permeation flux (169.58 µg/cm2/h) and diffusion rate (0.293 mg/cm2/h1/2), suggesting the rapid internalization of vesicles with cultured skin cells at low viscosity. A similar observation was revealed using rat skin, wherein the permeation flux (182.42 µg/cm2/h), permeation coefficient (0.3 × 10-2 cm/h), and diffusion rate (0.315 mg/cm2/h1/2) of ETHO2R were relatively higher than ELP3R and ELP3GR. Relative small size (128 nm), low viscosity, ethanol-mediated ultra-deformability, high drug entrapment (98%), and elasticity (63.2) are associated with ETHO2R to provide remarkable permeation behavior across the three barriers. The value of TEWL for ETHO2R (21.9 g/m2h) was 3.71 times higher than untreated control (5.9 g/m2h), indicating ethanol-mediated maximized surficial skin lipid perturbation at 3 h of application, whereas the respective ETHO2GR-treated rat skin had TEWL value (18.6 g/m2h) slightly lower than ETHO2R due to gel-based hydration into the skin. SEL, CLSM, and AFM provided a mechanistic perspective of ETHO2R and ELP3R-mediated permeation across rat skin and carrier-mediated visualization (skin-vesicle interaction). AFM provided detailed nanoscale surface roughness topographical parameters of treated and untreated rat skin as supportive data to SEM and CLSM. Thus, ethosomes ETHO2R and respective gel assisted maximum permeation of ACV across rat skin and cultured human EpiDerm to control cutaneous herpes infection and herpes keratitis.

Pyrimethamine 3D printlets for pediatric toxoplasmosis: design, pharmacokinetics, and anti-toxoplasma activity.

OBJECTIVES: The focus of the present research is to develop printlet formulations of pyrimethamine (PMT). METHODS: Printlets formulation of PMT were developed by screening design by varying laser scanning speed, Kollidon® VA 64, polyvinylpyrrolidone, and disintegrant. RESULTS: Laser scanning speed, Kollidon® VA, and disintegrant had statistically significant effect on hardness, disintegration time, and/or dissolution (p < 0.05). Dissolution was almost 100% in 30 min. X-ray powder diffraction indicated partial amorphous transformation of the crystalline drug. Pharmacokinetic and anti-toxoplasma activity profiles of the printlets and compressed tablets were superimposable with no statistical difference (p > 0.05). CONCLUSION: Clinical performance of the printlets would be similar to the compressed tablets.

Impact of miconazole nitrate ferrying cationic and anionic nanoemulsion and gels on permeation profiles of across EpiDerm, artificial membrane, and skin: Instrumental evidences.

Based on our previous report, the study was extended to investigate the impact of miconazole nitrate (MCN) loaded cationic/anionic nanoemulsions and nanoemulsion gels on permeation behaviour across artificial-membrane, EpiDerm, and rat skin. Nanoemulsions and gels were evaluated for size, charge, viscosity, size-distribution, pH, and percent entrapment efficiency (%EE). In vitro drug diffusion across artificial membrane and EpiDerm were conducted to get diffusion coefficients. Permeation profiles were studied using rat skin to investigate mechanistic insight of formulated mediated permeation followed by CLSM (confocal laser scanning microscopy), SEM (scanning electron microscopy), AFM (atomic force microscopy), and irritation studies. Results showed that MCNE11-Rh (probed cationic nanoemulsion at pH âˆ¼ 7.2) and MNE11-Rh (probed anionic nanoemulsion at pH âˆ¼ 7.2) showed size values of 158 nm and 145 nm, respectively whereas MCNE11-GR (probed cationic nanoemulsion gel at pH âˆ¼ 6.8) and MNE11-GR (probed anionic nanoemulsion gel at pH âˆ¼ 6.8) exhibited size values 257 nm and 243 nm, respectively. The %EE values were found to be as 91.5 % and 89.6 % for MCNE11-Rh and MNE11-Rh, respectively. The gels (∼6000 cP) elicited relatively high viscosity than nanoemulsions (∼3300 - 3500 cP). MCNE11-GR showed the highest values of permeation flux, diffusion rate, diffusion coefficient (D), and permeation coefficient (P) across artificial membrane, EpiDerm, and rat skin which may be attributed to three potential factors (cationic charge, composition, and hydration by the hydrophilic gel) working in tandem. Transepidermal water loss (TEWL) by the MCNE11-GR was maximum (14.4 g/m2h) than control (6.1 g/m2h) indicating augmented interaction of MCNE11-Rh with skin components. Conclusively, cationic nanoemulsion gel was promising carrier for enhanced permeation and the drug access to the dermal region to treat deep seated fungal infections.

Formulation Characterization and Pharmacokinetic Evaluation of Amorphous Solid Dispersions of Dasatinib.

The aim of this study was to improve the physicochemical properties and oral bioavailability of dasatinib (DST) by the amorphous solid dispersion (ASD) approach using cellulose acetate butyrate (CAB) as a carrier. Various formulations of ASD (DST:CAB 1:1 to 1:5) were prepared by the solvent evaporation method. ASDs were characterized for physicochemical attributes, stability and pharmacokinetics. Scanning electron microscopy, Fourier transformed infrared, X-ray powder diffraction, and differential scanning calorimetry confirmed the transformation of the crystalline drug into amorphous phase. ASD formation resulted in a 3.7−4.9 fold increase in dissolution compared to DST or physical mixture. The ASDs formulation exhibited relative stability against transformation from the unstable amorphous phase to a stable crystalline phase that was indicated by spectral and X-ray powder diffraction data, and insignificant (p > 0.05) decrease in dissolution. Tmax, Cmax and AUC0-∞ of ASD were 4.3-fold faster and 2.0 and 1.5 fold higher than the corresponding physical mixture. In conclusion, the ASD of DST significantly improved dissolution and oral bioavailability which may be translated into a reduction in dose and adverse events.

In-use stability assessment of FDA approved metformin immediate release and extended release products for N-Nitrosodimethylamine and dissolution quality attributes.

Metformin is a widely used first-line oral antidiabetic agent. TheFood and Drug Administration (FDA) confirmed the presence of the ofN-nitrosodimethylamine (NDMA) impurity, a carcinogenic, above the acceptable daily intake (ADI, 96 ng/day) in certain metformin products. The objective of the present study was to assess in-use stability of commercial metformin products for NDMA and dissolution quality attributes. Four immediate-release (M1-M4) and six extended-rerelease (M5-M10) metformin products were evaluated in the stability testing. All products were repacked in pharmacy vials and stored at 30 °C/75% RH for 12 weeks. Five products (M2, M3, M5, M7 and M10) had NDMA level above ADI limit (96 ng/day) before in-use stability exposure. NDMA in M2 (1164 ± 52.9 ng/tablet) and M3 (3776 ± 351.9 ng/tablet) products were 12 and 39 folds of ADI, respectively. Similarly, ER products, M5 (191 ± 94.1 ng/tablet), M7 (1473 ± 47.3 ng/tablet) and M10 (423 ± 55.8 ng/tablet) exhibited NDMA of 1.9, 15.3 and 4.4 folds of ADI, respectively. The impurity level significantly (p < 0.05) increased after 12-week stability exposure to 2.72, 2.47, 2.23 and 2.78 folds of initial values in M2, M3, M7 and M10. In summary, these findings suggested that carcinogenic impurity generation was affected by in-use stability condition exposure and it is expected that several more products currently in the market may also be recalled soon.

In-Situ Implant Formulation of Laurate and Myristate Prodrugs of Dolutegravir for Ultra-Long Delivery.

The focus of present work was to synthesize prodrugs of dolutegravir (DTG) for ultra-long delivery purpose. The prodrug was synthesized by esterification of hydroxyl group with carboxyl group of fatty acid (lauric or myristic acid). The prodrugs were characterized by differential scanning calorimetry, X-ray powder diffraction, nuclear magnetic resonance, Fourier transformed infrared, near infrared-chemical imaging, pH-solubility, partition coefficient, and stability (solid and liquid). Stability studies were performed by exposing the powder drugs to 40°C/75% RH for three months and buffer solutions at room temperature for 72 h. The prodrugs and drug were formulated into in-situ implant using biodegradable polymer. Thermal, spectral, and diffractometric data indicated formation of new chemical and solid forms. Formation of prodrugs resulted in lowering of melting point of DTG from 191.1°C to 163.7 and 140.7°C for DTG-Laurate and DTG-Myristate prodrugs, respectively. A decrease in solubility of 18.2-115.9 and 124.5-1594.9 folds was observed for DTG-Laurate and DTG-Myristate, respectively compared to DTG. Similarly, the prodrugs were highly lipophilic compared to DTG. Solid-state and pH-stability profiles of DTG and prodrugs were comparable. Implant formulation released 60.1% in 77 days compared to 95.6% in 35 days in the case of DTG-Myristate and DTG, respectively. In summary, combining prodrug and drug delivery approaches can be utilized for delivering drug for ultra-long period.

Development and Validation Of A Discriminatory Dissolution Method for Portioned Moist Snuff and Snus.

Portioned moist snuff and snus, two subcategories of smokeless tobacco products (STP) were dissolution tested as a quality control test. A USP Apparatus 4 was employed to develop and validate the method. The method was assessed based on time to reach nicotine dissolution plateau, percentage difference between two profiles at each time point, relative standard deviation (RSD), and f1 (similarity) and f2 (dissimilarity) values. Based on these criteria, 200 ml volume and 8 ml/min flow were found be discriminatory. The amount of nicotine dissolved from the nine products varied widely (2.0-3.4, 2.1-4.1, 3.3-4.6, 5.5-6.6, 6.9-9.1, 11.5-14.2, 12.5-14.6, 14.0-15.5, and 15.5-19.6 mg/pouch at 60 min). RSDs of the dissolution ranges were more than 20% at earlier time points and less than 20% at later timepoints. The developed method produced distinct profiles for all the tested products, which was further confirmed by f1>15 and f2<50 values. In conclusion, the developed method was discriminatory and can be employed as a quality control test and to differentiate among moist snuff and snus products.

Raw Materials, Technology, Healthcare Applications, Patent Repository and Clinical Trials on 4D Printing Technology: An Updated Review.

After the successful commercial exploitation of 3D printing technology, the advanced version of additive manufacturing, i.e., 4D printing, has been a new buzz in the technology-driven industries since 2013. It is a judicious combination of 3D printing technologies and smart materials (stimuli responsive), where time is the fourth dimension. Materials such as liquid crystal elastomer (LCE), shape memory polymers, alloys and composites exhibiting properties such as self-assembling and self-healing are used in the development/manufacturing of these products, which respond to external stimuli such as solvent, temperature, light, etc. The technologies being used are direct ink writing (DIW), fused filament fabrication (FFF), etc. It offers several advantages over 3D printing and has been exploited in different sectors such as healthcare, textiles, etc. Some remarkable applications of 4D printing technology in healthcare are self-adjusting stents, artificial muscle and drug delivery applications. Potential of applications call for further research into more responsive materials and technologies in this field. The given review is an attempt to collate all the information pertaining to techniques employed, raw materials, applications, clinical trials, recent patents and publications specific to healthcare products. The technology has also been evaluated in terms of regulatory perspectives. The data garnered is expected to make a strong contribution to the field of technology for human welfare and healthcare.