Physiochemical and Microbiological Stability of Azathioprine Suspensions in PCCA Base, SuspendIt.

Azathioprine is used to treat the symptoms of rheumatoid arthritis and for the prevention of transplant rejection. A review of the therapeutic uses of Azathioprine reveals the need for flexibility in dosing. This flexibility is readily achieved using an oral liquid dosage form. However, no commercial liquid dosage form of Azathioprine currently exists. Azathioprine is commercially available only as a 50-mg tablet. An extemporaneously compounded suspension from pure drug powder would provide a flexible, customizable option to meet unique patient needs with convenient and accurate dosing options. The purpose of this study was to determine the physicochemical and microbiological stability of extemporaneously compounded Azathioprine suspensions in the PCCA Base, SuspendIt. This base is a sugar-free, paraben free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. The study design included two Azathioprine concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust stability-indicating high-performance liquid chromatographic assay for the determination of the chemical stability of Azathioprine in PCCA SuspendIt was developed and validated. Suspensions of Azathioprine were prepared in PCCA SuspendIt at 10-mg/mL and 50-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in amber plastic prescription bottles at two temperature conditions (5°C and 25°C). Samples were assayed initially, and on the following time points (days): 7, 14, 28, 49, 63, 90, 119, and 182. Physical data such as pH, viscosity, and appearance were also noted. Microbiological stability was tested. All measurements were obtained in triplicate. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period and is protected against microbial growth. The study showed that Azathioprine concentrations did not go below 96.8% of the label claim (initial drug concentration) at both temperatures studied. No microbial growth was observed. The pH values remained constant. The viscosity of the suspensions allowed easy re-dispersal of the drug particles upon shaking. This study demonstrates that Azathioprine is physically, chemically, and microbiologically stable in PCCA SuspendIt for 182 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for Azathioprine in a liquid dosage form, with an extended beyond-use date to meet patient needs.

Ionic Liquid Cross-Linked High-Absorbent Polymer Hydrogels: Kinetics of Swelling and Dye Adsorption.

The use of polymer gels for the removal of toxic chemicals from wastewater is an important area in terms of both academic and industrial research. This work presents a simple approach to the fabrication of chemically cross-linked cationic hydrogel adsorbents using designed ionic liquid-based cross-linkers and their successful use in the removal of organic dyes. Two different ionic liquid cross-linkers, [VIm-4VBC][Cl] (ILA)/[DMAEMA-4VBC][Cl] (ILB), are synthesized by the simple nucleophilic substitution reaction of 4-vinylbenzyl chloride (4VBC) separately with 1-vinylimidazole (VIm) and 2-(dimethylamino)ethyl methacrylate (DMAEMA). Cross-linked poly(acrylamide) (CPAam) and poly(2-hydroxyethyl methacrylate) (CPHEMA) hydrogels are then prepared from the corresponding monomers and as-synthesized cross-linkers (ILA and ILB) by free radical polymerization in the presence of a redox initiator combining ammonium persulfate (APS) and N,N,N',N'-tetramethylethylenediamine (TEMED). The dried CPAam and CPHEMA xerogels exhibit macroporous morphology and high thermal stability. The hydrogel samples exhibit high swelling behavior, and the diffusion of water molecules into the hydrogels follows pseudo-Fickian kinetics. The cationic cross-linking sites in the hydrogel networks allow preferable binding with anionic dyes, and these dye uptake capacities are determined using different model anionic dyes via UV-vis spectroscopy. The dye adsorption onto these hydrogels follows a pseudo-second-order kinetic model. The adsorption mechanism is also analyzed by employing intraparticle diffusion and Boyd kinetic models. The relationship between the maximum equilibrium adsorption capacity (qm) of the hydrogels for eosin B (EB) dye and the equilibrium EB concentration can be better described by Langmuir and Freundlich isotherm models, and the estimated qm using the Langmuir isotherm can reach more than 100 mg g-1. The cross-linked hydrogels can be easily regenerated and have a recycling efficiency of >80% for up to three consecutive dye adsorption-desorption cycles, which is promising for their use in wastewater treatment.

Stimuli-Responsive Triblock Terpolymer Conversion into Multi-Stimuli-Responsive Micelles with Dynamic Covalent Bonds for Drug Delivery through a Quick and Controllable Post-Polymerization Reaction.

Stimuli-responsive copolymers are of great interest for targeted drug delivery. This study reports on a controllable post-polymerization quaternization with 2-bromomethyl-4-fluorophenylboronic acid of the poly(4-vinyl pyridine) (P4VP) block of a common poly(styrene)-b-poly(4-vinyl pyridine)-b-poly(ethylene oxide) (SVE) triblock terpolymer in order to achieve a selective responsivity to various diols. For this purpose, a reproducible method was established for P4VP block quaternization at a defined ratio, confirming the reaction yield by 11B, 1H NMR. Then, a reproducible self-assembly protocol is designed for preparing stable micelles from functionalized stimuli-responsive triblock terpolymers, which are characterized by light scattering and by cryogenic transmission electron microscopy. In addition, UV-Vis spectroscopy is used to monitor the boron-ester bonding and hydrolysis with alizarin as a model drug and to study encapsulation and release of this drug, induced by sensing with three geminal diols: fructose, galactose and ascorbic acid. The obtained results show that only the latter, with the vicinal diol group on sp2-hybridized carbons, was efficient for alizarin release. Therefore, the post-polymerization method for triblock terpolymer functionalization presented in this study allows for preparation of specific stimuli-responsive systems with a high potential for targeted drug delivery, especially for cancer treatment.

Physicochemical and Microbiological Stability of Amitriptyline Hydrochloride Oral Liquid Dosage Forms in PCCA Base, SuspendIt.

Amitriptyline hydrochloride is indicated for the relief of symptoms of depression. A review of the therapeutic uses of amitriptyline hydrochloride reveals the need for flexibility in dosing. This flexibility is readily achieved using an oral liquid dosage form. However, no commercial liquid dosage form of amitriptyline currently exists. Amitriptyline hydrochloride is commercially available only as 10-mg, 25-mg, 50-mg, 75-mg, 100-mg, and 150-mg tablets. An extemporaneously compounded suspension from pure drug powder would provide a flexible, customizable option to meet unique patient needs with convenient and accurate dosing options. The purpose of this study was to determine the physicochemical and microbiological stability of extemporaneously compounded amitriptyline hydrochloride suspensions in PCCA Base, SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. The study design included two amitriptyline hydrochloride concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust stability- indicating high-performance liquid chromatographic assay for the determination of the chemical stability of amitriptyline hydrochloride in PCCA SuspendIt was developed and validated. Suspensions of amitriptyline hydro- chloride were prepared in PCCA SuspendIt at 1-mg/mL and 5-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in amber plastic prescription bottles at two temperature conditions (5°C and 25°C). Samples were assayed initially, and on the following time points (days): 7, 14, 28, 49, 63, 91, 119, and 185. Physical data such as pH, viscosity, and appearance were also noted. Microbiological stability was tested. All measurements were obtained in triplicate. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period and is protected against microbial growth. The study showed that amitriptyline hydrochloride concentrations did not go below 99.8% of the label claim (initial drug concentration) at both temperatures studied. No microbial growth was observed. The pH values remained constant. The viscosity of the suspensions allowed easy re-dispersal of the drug particles upon shaking. This study demonstrates that amitriptyline hydrochloride is physically, chemically, and microbiologically stable in PCCA SuspendIt for 185 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for amitriptyline hydrochloride in a liquid dosage form, with an extended beyond-use date to meet patient needs.

Physicochemical and Microbiological Stability of Extemporaneously Compounded Hydrocortisone Oral Suspensions in PCCA Base, SuspendIt.

Hydrocortisone is indicated in the treatment of primary or secondary adrenal insufficiency. The oral dosage regimen of hydrocortisone needs to be individualized in the treatment of congenital adrenal hyperplasia, especially in pediatric patients. A review of the therapeutic uses of hydrocortisone reveals the need for flexibility in dosing. This flexibility is readily achieved using an oral liquid dosage form. However, no commercial liquid dosage form of hydrocortisone currently exists. Hydrocortisone is commercially available as 5-mg, 10-mg, and 20-mg tablets. An extemporaneously compounded suspension from pure drug powder would provide a convenient option to meet unique patient needs. The purpose of this study was to determine the physicochemical and microbiological stability of extemporaneously compounded hydrocortisone suspensions in PCCA Base, SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. The study design included two hydrocortisone concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust stability-indicating high-performance liquid chromatographic assay for the determination of the chemical stability of hydrocortisone in SuspendIt was developed and validated. Suspensions of hydrocortisone were prepared in SuspendIt at 1-mg/mL and 20-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in plastic amber prescription bottles at two temperature conditions (5°C and 25°C). Samples were assayed initially and on the following days: 7, 15, 28, 45, 60, 91, 120, and 185. Physical data such as pH, viscosity, and appearance were also noted. Microbiological stability was tested. All measurements were obtained in triplicate. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period and is protected against microbial growth. The study showed that hydrocortisone concentrations did not go below 94% of the label claim (initial drug concentration) at both temperatures studied. No microbial growth was observed. Viscosity and pH values did not change significantly. This study demonstrates that hydrocortisone is physically, chemically, and microbiologically stable in SuspendIt for 185 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for hydrocortisone in a liquid dosage form, with an extended beyond-use date to meet patient needs.

Physicochemical and Microbiological Stability of Compounded Metronidazole Suspensions in PCCA SuspendIt.

Metronidazole is indicated for the treatment of trichomoniasis, amebiasis, and anaerobic bacterial infections. The dosage regimen of metronidazole needs to be individualized in the treatment of trichomoniasis, in patients with hepatic impairment, and in pediatric as well as geriatric patients. A review of the therapeutic uses of metronidazole reveals the need for flexibility in dosing. This flexibility is readily achieved using an oral liquid dosage form. However, no commercial liquid dosage form of metronidazole currently exists. Metronidazole is commercially available only as 250-mg and 500-mg film-coated tablets. An extemporaneously compounded suspension from pure drug powder or commercial tablets would provide a convenient option to meet unique patient needs. The purpose of this study was to determine the physicochemical and microbiological stability of extemporaneously compounded metronidazole suspensions in PCCA SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. The study design included two metronidazole concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust stability-indicating ultra-performance liquid chromatographic assay for the determination of the chemical stability of metronidazole in PCCA SuspendIt was developed and validated. Suspensions of metronidazole were prepared in PCCA SuspendIt at 25-mg/mL and 50-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in plastic amber prescription bottles at two temperature conditions (5ÆC and 25ÆC). Samples were assayed initially and on the following time points (days): 7, 14, 28, 42, 59, 90, 122, and 180. Physical data such as pH, viscosity, and appearance were also noted. Microbiological stability was also tested. All measurements were obtained in triplicate. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period and is protected against microbial growth. The study showed that metronidazole concentrations did not go below 97% of the label claim (initial drug concentration) at both temperatures studied. No microbial growth was observed. Viscosity and pH values also did not change significantly. This study demonstrates that metronidazole is physically, chemically, and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for metronidazole in a liquid dosage form, with an extended beyond-use-date to meet patient needs.

Carbon Dot Cross-Linked Gelatin Nanocomposite Hydrogel for pH-Sensing and pH-Responsive Drug Delivery.

Delivery of therapeutics to the intestinal region bypassing the harsh acidic environment of the stomach has long been a research focus. On the other hand, monitoring a system's pH during drug delivery is a crucial diagnosis factor as the activity and release rate of many therapeutics depend on it. This study answered both of these issues by fabricating a novel nanocomposite hydrogel for intestinal drug delivery and near-neutral pH sensing at the same time. Gelatin nanocomposites (GNCs) with varying concentrations of carbon dots (CDs) were fabricated through simple solvent casting methods. Here, CDs served a dual role and simultaneously acted as a cross-linker and chromophore, which reduced the usage of toxic cross-linkers. The proposed GNC hydrogel sample acted as an excellent pH sensor in the near-neutral pH range and could be useful for quantitative pH measurement. A model antibacterial drug (cefadroxil) was used for the in vitro drug release study at gastric pH (1.2) and intestinal pH (7.4) conditions. A moderate and sustained drug release profile was noticed at pH 7.4 in comparison to the acidic medium over a 24 h study. The drug release profile revealed that the pH of the release medium and the percentage of CDs cross-linking influenced the drug release rate. Release data were compared with different empirical equations for the evaluation of drug release kinetics and found good agreement with the Higuchi model. The antibacterial activity of cefadroxil was assessed by the broth microdilution method and found to be retained and not hindered by the drug entrapment procedure. The cell viability assay showed that all of the hydrogel samples, including the drug-loaded GNC hydrogel, offered acceptable cytocompatibility and nontoxicity. All of these observations illustrated that GNC hydrogel could act as an ideal pH-monitoring and oral drug delivery system in near-neutral pH at the same time.

Physicochemical Stability of Compounded Allopurinol Suspensions in PCCA Base, SuspendIt.

Allopurinol is an orally administered inhibitor of xanthine oxidase used primarily in the treatment of hyperuricemia associated with gout. Allopurinol reduces serum and urinary uric acid concentrations. Its use should be individualized for each patient. The dosage of allopurinol to accomplish full control of gout and to lower serum uric acid to normal or near-normal levels varies with the severity of the disease, and needs to be flexible to permit precise, customized dose titration for individual patients. This flexibility is readily achieved using an oral liquid dosage form. However, no commercial liquid dosage form of allopurinol currently exists. Allopurinol is commercially available as 100-mg and 300-mg scored tablets. An extemporaneously compounded suspension from pure drug powder or commercial tablets would provide a convenient option to meet unique patient needs. The purpose of this study was to determine the physicochemical stability of extemporaneously compounded allopurinol suspensions in the PCCA Base SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. The study design included two allopurinol concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust stability-indicating ultra-performance liquid chromatography assay for the determination of the chemical stability of allopurinol in SuspendIt was developed and validated. Suspensions of allopurinol were prepared in SuspendIt at 10.0-mg/mL and 20.0-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in plastic amber prescription bottles at two temperature conditions (5°C and 25°C). Samples were assayed initially and at the following time points: 7 days, 14 days, 30 days, 45 days, 60 days, 88 days, 120 days, and 182 days. Physical data such as pH, viscosity, and appearance were also noted. All measurements were obtained in triplicate. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period. The study showed that allopurinol concentrations did not go below 93% of the label claim (initial drug concentration) at both temperatures studied. Viscosity and pH values also did not change significantly. This study demonstrates that allopurinol is physically and chemically stable in SuspendIt for 180 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for allopurinol in a liquid dosage form, with an extended beyond-use-date to meet patient needs.

Targeted Delivery of Doxorubicin Liposomes for Her-2+ Breast Cancer Treatment.

The adverse side effects and toxicity caused by the non-targeted delivery of doxorubicin has emphasized the demand of emerging a targeted delivery system. The goal of this study is to enhance the delivery of doxorubicin by formulating an aptamer-labeled liposomal nanoparticle delivery system that will carry and deliver doxorubicin specifically into Her-2+ breast cancer cells. Twelve liposomal batches were prepared using different saturated (HSPC and DPPC) and unsaturated (POPC and DOPC) lipids by thin film hydration. The liposomes were characterized for their particle size, zeta potential, and drug encapsulation efficiency. The particles were also assessed for in vitro toxicity and DOX delivery into the breast cancer cells. The formulations, F1 through F12, had a small particle size of less than 200 nm and a high entrapment efficiency of about 88 ± 5%. The best formulation, F5, had a particle size of 101 ± 14nm, zeta potential of + 5.63 ± 0.46 mV, and entrapment efficiency of ≈ 93%. The cytotoxicity studies show that the DOX-loaded liposomal formulations are more effective in killing cancer cells than the free DOX in both MCF-7 and SKBR-3 cells. The uptake studies show a significant increase in the uptake of the aptamer-labeled liposomes (i.e., F5) by more than 60% into Her-2+ MCF-7 and SKBR-3 breast cancer cells compare to non-aptamer-labeled nanoparticles. F5 also shows ≈ 1.79-fold increase in uptake of DOX in the Her-2+ cells compared to the Her-2- cells. This preliminary study indicates that aptamer-labeled F5 nanoparticles among several batches showed the highest uptake as well as the targeted delivery of doxorubicin into Her-2+ breast cancer cells. Thus, aptamer targeted approach results in substantial reduction in the dose of DOX and improves the therapeutic benefits by promoting the target specificity.

Aptamer-functionalized Hybrid Nanoparticles to Enhance the Delivery of Doxorubicin into Breast Cancer Cells by Silencing P-glycoprotein.

OBJECTIVE: The MDR of metastatic breast cancer cells is accompanied by the overexpression of P-gp transporter. This study has been focused to determine whether silencing the expression of P-gp by aptamer-labeled siRNA nanoparticles could enhance the delivery of doxorubicin into breast cancer cells in culture. METHODOLOGY: The nanoparticle F-31 was prepared using DOTAP, cholesterol, and PLGA, and then incorporating Mal-PEG to facilitate aptamer-binding. The nanoparticles were surface-functionalized with aptamer A6, which targets Her-2 receptors overexpressed on the surface of breast cancer cells. RESULTS: This study has shown that the uptake of Dox by Dox-resistant 4T1-R is significantly less than Dox-sensitive 4T1-S which is partly attributed to the higher expression of drug-efflux pump P-gp on the surface of the resistant cells. The targeted knockdown of P-gp has been enhanced when the particles carrying P-gp siRNA was labeled with aptamer. Concurrently, the uptake of Dox into the Dox-resistant 4T1-R breast cancer cells has increased significantly when the P-gp was silenced by P-gp siRNA-encapsulated aptamer-labeled nanoparticles. CONCLUSIONS: This preliminary study concludes that downregulating P-gp expression by targeted delivery of P-gp siRNA using aptamer-labeled lipid-based hybrid nanoparticles could effectively increase the intracellular trafficking of doxorubicin in Dox-resistant mouse breast cancer cells.

Physicochemical Stability of Compounded Amlodipine Besylate Suspensions in PCCA Base, SuspendIt.

Amlodipine besylate is an antihypertensive agent recommended for the management of hypertension in children and adolescents. The commercially available 2.5-mg, 5-mg, and 10-mg amlodipine besylate tablets do not provide the necessary flexibility in dosing needed for treating children. This flexibility is readily achieved using an oral, liquid dosage form. However, no commercial liquid dosage form of amlodipine currently exists. An extemporaneously compounded suspension from pure drug powder or commercial tablets would provide a convenient option to meet unique patient needs. The purpose of this study was to determine the physicochemical stability of extemporaneously compounded amlodipine besylate suspensions in the PCCA Base, SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. The study design included two amlodipine besylate concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust stabilityindicating high-performance liquid chromatographic assay for the determination of the chemical stability of amlodipine besylate in SuspendIt was developed and validated. Suspensions of amlodipine were prepared in SuspendIt at 0.5-mg/mL and 10.0-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in plastic amber prescription bottles at two temperature conditions (5°C and 25°C). Samples were assayed initially, and at the following time points: 7 days, 14 days, 29 days, 46 days, 60 days, 90 days, 120 days, and 180 days. Physical data such as pH, viscosity, and appearance were also noted. All measurements were obtained in triplicate. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period. This study demonstrates that amlodipine besylate is physically and chemically stable in SuspendIt for 90 days in the refrigerator and 7 days at room temperature, retaining 90% of the label claim (initial drug concentration) at both concentrations. The pH values did not change significantly. The viscosity of the refrigerated samples at both concentrations decreased slightly, while that of the room temperature samples showed a marked increase in viscosity. This study provides a viable, compounded alternative for amlodipine in a liquid dosage form, with an adequate beyond-use-date to meet patient needs. The study further provides stability documentation over a bracketed amlodipine concentration range of 0.5 mg/mL to 10.0 mg/mL, allowing compounding pharmacists more flexibility in customizing their formulations.

Physicochemical Stability of Compounded Naltrexone Hydrochloride Solutions in PCCA Base SuspendIt.

Naltrexone hydrochloride is an orally active narcotic antagonist used to facilitate rapid transition from methadone maintenance. The dosing schedule of naltrexone hydrochloride in detoxification protocols needs to be flexible to permit precise, customized dose titration for individual patients. This flexibility is readily achieved using an oral liquid dosage form. However, no commercial liquid dosage form of naltrexone hydrochloride currently exists. Naltrexone hydrochloride is commercially available as a scored, filmcoated, 50-mg tablet. An extemporaneously compounded suspension from pure drug powder or commercial tablets would provide a convenient option to meet unique patient needs. The purpose of this study was to determine the physicochemical stability of extemporaneously compounded naltrexone hydrochloride solutions in PCCA base SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. The study design included two naltrexone hydrochloride concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust stability-indicating HPLC assay for the determination of the chemical stability of naltrexone hydrochloride in SuspendIt was developed and validated. Solutions of naltrexone hydrochloride were prepared in SuspendIt at 0.5-mg/mL and 5.0-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in plastic, amber prescription bottles at two temperature conditions (5°C and 25°C). Samples were assayed initially, and at the following time points: 7 days, 14 days, 29 days, 44 days, 61 days, 90 days, 120 days, and 180 days. Physical data such as pH, viscosity, and appearance were also noted. All measurements were obtained in triplicate. A stable extemporaneous preparation is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period. The study showed that naltrexone hydrochloride concentrations did not go below 94% of the label claim (initial drug concentration) at both temperatures studied. Viscosity and pH values also did not change significantly. This study demonstrates that naltrexone hydrochloride is physically and chemically stable in SuspendIt for 180 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for naltrexone hydrochloride in a liquid dosage form, with an extended beyond-use date to meet patient needs.

Stability of Compounded Ursodiol Suspensions in PCCA Base, SuspendIt.

Ursodiol (ursodeoxycholic acid) is a nontoxic, naturally occurring bile acid that constitutes 1% to 2% of human bile. It suppresses hepatic synthesis of cholesterol, aids in the desaturation of biliary cholesterol, and aids in the dissolution of cholesterol gallstones. Ursodiol is commercially available as a 300-mg capsule and a 250-mg tablet. However, no commercial liquid dosage form of ursodiol exists. An extemporaneously compounded suspension from pure drug powder or commercial tablets/capsules would provide an alternative option to meet unique patient needs. The purpose of this study was to determine the physicochemical stability of extemporaneously compounded ursodiol suspensions in PCCA base SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. It thickens upon standing to minimize settling of any insoluble drug particles and becomes fluid upon shaking to allow convenient pouring during administration to the patient. The study design included two ursodiol concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust, stability-indicating high-performance liquid chromatographic assay for the determination of the chemical stability of ursodiol in SuspendIt was developed and validated. Suspensions of ursodiol were prepared in SuspendIt at 50-mg/mL and 100-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in plastic amber prescription bottles at two temperature conditions (5°C and 25°C). Samples were assayed initially and at the following time points: 7 days, 14 days, 30 days, 42 days, 59 days, 91 days, 120 days, and 181 days. Physical data such as pH, viscosity, and appearance were also noted. All measurements were obtained in triplicate. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period. The study showed that ursodiol concentration did not go below 97% of the label claim (initial drug concentration) at both temperatures studied. Viscosity and pH values also did not change significantly. This study demonstrates that ursodiol is physically and chemically stable in SuspendIt for 181 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for ursodiol in a liquid-dosage form, with an extended beyond-use-date to meet patient needs.

Poly[oligo(2-ethyl-2-oxazoline)acrylate]-Based Poly(ionic liquid) Random Copolymers with Coexistent and Tunable Lower Critical Solution Temperature- and Upper Critical Solution Temperature-Type Phase Transitions.

The synthesis of a series of dual thermosensitive nonionic-ionic random copolymers with varying compositions by reversible addition-fragmentation chain transfer polymerization is described. These copolymers contain oligo(2-ethyl-2-oxazoline)acrylate (OEtOxA) and either triphenyl-4-vinylbenzylphosphonium chloride ([VBTP][Cl]) or 3- n-butyl-1-vinylimidazolium bromide ([VBuIm][Br]) ionic liquid (IL) units. The copolymers having low content of ionic poly(ionic liquid) (PIL) (P[VBTP][Cl]/P[VBuIm][Br]) segments show only lower critical solution temperature (LCST)-type phase transition with almost linear increase of their cloud points with increasing percentage of ionic PIL segments. Furthermore, LCST-type cloud points ( TcLs) are found very sensitive and tunable with respect to the nature and concentration of halide ions (X- = Cl-, Br-, and I-) and copolymer compositions. However, copolymers with high content of ionic PIL segments show both LCST-type followed by upper critical solution temperature (UCST)-type phase transitions in the presence of halide ions. Dual LCST- and UCST-type phase behaviors are prominent and repeatable for many heating/cooling cycles. Both types of cloud points are found to be sensitive to copolymer compositions, concentration, and nature and concentration of the halide ions. The phase behaviors of both types of copolymers with a very high ionic content (>90%) are exactly similar to that of P[VBTP][Cl] or P[VBuIm][Br] homopolymers showing only UCST-type phase transition in the presence of halide ions. The inherent biocompatibility of the P(OEtOxA) segment along with the interesting dual thermoresponsiveness makes these copolymers highly suitable candidates for biomedical applications including drug delivery.

Chemical Tuning of Zwitterionic Ionic Liquids for Variable Thermophysical Behaviours, Nanostructured Aggregates and Dual-Stimuli Responsiveness.

The design and synthesis of a series of zwitterionic ionic liquids (ZILs) to understand the structure-property relationship towards an increase of the thermal stability, a variation of the glass transition temperature, the shape-tuning of nanostructured aggregates and the tuning of the stimuli responsiveness are demonstrated. The substitution reaction of imidazole with various aliphatic and aromatic bromides followed by the reaction of the corresponding substituted imidazoles with bromoalkyl carboxylic acids of varying spacer length produces the ZILs. In aqueous solution, a ZIL molecule either exist in its ionic liquid (substituted imidazolium bromide) form or its zwitterionic (substituted imidazolium alkyl carboxylate) form with an isoelectric point (pI) depending on the pH value of the solution. Upon changing the pH to near or above the pI, the aqueous ZIL solution undergoes transition from a transparent to a turbid phase due to the formation of insoluble hierarchical nanostructured aggregates of various morphologies, such as spheres, tripods, tetrapods, fern-like, flower-like, dendrites etc. depending on the pH of the solution and the nature of the alkyl/vinyl/aryl substituents. Upon heating the solution a phase transition occurs from turbid to transparent, exhibiting a distinct reversible upper critical solution temperature (UCST)-type cloud point (Tcp ). It is observed that the cloud point varies with the nature of the substituent, an increase of the concentration of the ZIL as well as with changes of the pH of the solution.

Physicochemical Stability of an Oral Suspension of Trimethoprim 20 mg/mL in Combination with Sulfadiazine 200 mg/mL in PCCA Base SuspendIt.

Trimethoprim is a diaminopyrimidine antibacterial agent that, like sulfonamides, inhibits bacterial folic acid synthesis, but at a different stage in the metabolic pathway. It has a similar spectrum of activity to the sulfonamides and is given by mouth or by injection, either alone or in conjunction with a sulfonamide, such as sulfadiazine. Sulfadiazine is a bacteriostatic antibacterial agent that interferes with folic acid synthesis in susceptible bacteria. The combination of the two drugs produces a synergistic effect against both Gram-positive and Gram-negative aerobic bacteria, by inhibiting enzymes in the folic acid pathways, which in turn inhibits bacterial thymidine synthesis. There are no published studies of the stability of the combination of trimethoprim and sulfadiazine in a liquid dosage form. An extemporaneously compounded suspension from pure drug powders or commercial tablets would provide an alternative option to meet unique patient needs. The purpose of this study was to determine the physicochemical stability of trimethoprim combined with sulfadiazine in PCCA base SuspendIt. PCCA base SuspendIt is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. It thickens upon standing to minimize settling of any insoluble drug particles and becomes fluid upon shaking to allow convenient pouring during administration to the patient. A robust stability-indicating high-performance liquid chromatographic assay for the simultaneous determination of trimethoprim and sulfadiazine in SuspendIt was developed and validated. This assay was used to determine the chemical stability of both drugs in SuspendIt. Samples were prepared and stored under three different temperature conditions (5°C, 25°C, 40°C), and assayed using the high-performance liquid chromatographic assay at pre-determined intervals over an extended period of time as follows: 0, 7, 14, 30, 45, 60, 91, 120, and 182 days at each designated temperature. Physical data such as pH, viscosity, appearance, and average particle size were also monitored. The study showed that drug concentration did not go below 90% of the label claim (initial drug concentration) at room temperature and in the refrigerator. The pH values also did not change significantly. There was some variability in viscosity and average particle size. This study demonstrates that trimethoprim and sulfadiazine are physically and chemically stable in combination in SuspendIt for 182 days at room temperature and in the refrigerator, thus providing a viable, compounded alternative for both drugs in a liquid dosage form, with an extended beyond-use-date to meet patient needs.

Stability of Spironolactone Oral Suspension in PCCA Base, SuspendIt.

Spironolactone (Aldactone) is a potassium-sparing diuretic used to treat hypertension and heart failure and may also be used to treat edema resulting from kidney disease, low potassium levels, or excess aldosterone. No commercial liquid dosage form of spironolactone exists. An extemporaneously compounded suspension from pure drug powder or commercial tablets would provide an alternative option to meet unique patient needs. The purpose of this study was to determine the physicochemical stability of spironolactone in the PCCA base SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. It thickens upon standing to minimize settling of any insoluble drug particles and becomes fluid upon shaking to allow convenient pouring during administration to the patient. A robust stability-indicating highperformance liquid chromatographic assay for the determination of spironolactone in PCCA base SuspendIt was developed and validated. This assay was used to determine the chemical stability of the drug in SuspendIt. Samples were prepared and stored under three different temperature conditions (5°C, 25°C, 40°C) and assayed using the high-performance liquid chromatographic assay at pre-determined intervals over an extended period of time as follows: 0, 7, 14, 29, 46, 60, 90, 120, and 180 days at each designated temperature. Physical data such as pH, viscosity, and appearance were also monitored. The study showed that drug concentration did not go below 90% of the label claim (initial drug concentration) at all three temperatures studied. Viscosity and pH values also did not change significantly. This study demonstrates that spironolactone is physically and chemically stable in SuspendIt for 180 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for spironolactone in a liquid dosage form, with an extended beyond-use date to meet patient needs.

Novel siRNA formulation to effectively knockdown mutant p53 in osteosarcoma.

OBJECTIVES: The tumor suppressor p53 plays a crucial role in the development of osteosarcoma. The primary objective of this study is to develop and optimize lipid based nanoparticle formulations that can carry siRNA and effectively silence mutant p53 in 318-1, a murine osteosarcoma cell line. METHODS: The nanoparticles were composed of a mixture of two lipids (cholesterol and DOTAP) and either PLGA or PLGA-PEG and prepared by using an EmulsiFlex-B3 high pressure homogenizer. A series of studies that include using different nanoparticles, different amount of siRNAs, cell numbers, incubation time, transfection media volume, and storage temperature was performed to optimize the gene silencing efficiency. KEY FINDINGS: Replacement of lipids by PLGA or PLGA-PEG decreased the particle size and overall cytotoxicity. Among all lipid-polymer nanoformulations, nanoparticles with 10% PLGA showed highest mutant p53 knockdown efficiency while maintaining higher cell viability when a nanoparticle to siRNA ratio equal to 6.8:0.66 and 75 nM siRNA was used. With long term storage the mutant p53 knockdown efficiency decreased to a greater extent. CONCLUSIONS: This study warrants a future evaluation of this formulation for gene silencing efficiency of mutant p53 in tissue culture and animal models for the treatment of osteosarcoma.

Aptamer-functionalized hybrid nanoparticle for the treatment of breast cancer.

PURPOSE: Resistance to chemotherapeutic agents such as doxorubicin is a major reason for cancer treatment failure. At present the treatment option for metastatic breast cancer is very poor. Therefore, development of an effective therapeutic strategy to circumvent MDR of metastatic breast cancer is highly anticipated. The MDR of metastatic breast cancer cells was accompanied with the overexpression of P-gp transporter. Even though the overexpression of P-gp could be minimized by silencing with siRNA, the question is how they can be selectively targeted to the cancer cells. We propose that aptamer surface labeling of the nanoparticles could enhance the selectively delivery of p-gp siRNA into the metastatic breast cancer cells. Our hypothesis is that conjugating nanoparticles with a cancer cell specific aptamer should allow selective delivery of therapeutic drugs to tumor cells leading to enhanced cellular toxicity and antitumor effect as compared to unconjugated nanoparticles. The primary objective of this study is to develop a targeted nanocarrier delivery system for siRNA into breast cancer cells. DESIGN METHODS: For targeted delivery, Aptamer A6 has been used which can bind to Her-2 receptors on breast cancer cells. For aptamer binding to particle surface, maleimide-terminated PEG-DSPE (Mal-PEG) was incorporated into the nanoparticles. Initially, three blank hybrid nanoparticles (i.e. F21, F31, and F40) out of nine different formulations prepared by high pressure homogenization (HPH) using different amount of DOTAP, cholesterol, PLGA or PLGA-PEG and Mal-PEG were chosen. Then protamine sulfate-condensed GAPDH siRNA (TRITC conjugated; red) or P-gp siRNA was encapsulated into those nanoparticles. Finally, the particles were incubated with aptamer A6 (FITC conjugated; green) for surface labeling. RESULTS: Aptamer labeled-nanoparticles having PLGA are smaller in size than those having PLGA-PEG. Surface charge was reduced when the particles were labeled with aptamer. Cell transfection was increased significantly in Her-2 (+) SKBR-3 and 4T1-R cells but not in Her-2 poorly expressed MDA MB-231 and MCF-7 cells. The knockdown of P-gp was increased significantly when the particles were labeled with aptamer. No significant cellular toxicity was observed for any of these formulations. CONCLUSION: This preliminary study concludes that aptamer-functionalized hybrid nanoparticles could be used to deliver P-gp targeted siRNA into the breast cancer cells to overcome chemoresistance.

LRP-1 Pathway Targeted Inhibition of Vascular Abnormalities in the Retina of Diabetic Mice.

PURPOSE: The cell surface LDL (low-density lipoprotein) receptor-related protein-1 (LRP-1) is important for lipid transport and several cell signaling processes. Human apolipoprotein E (apoE) is a ligand of LRP-1. We previously reported that a short peptide (apoEdp) mimicking the LRP-1 binding region of apoE prevents hyperglycemia-induced retinal endothelial cell dysfunction in vitro. The in-vivo outcome of apoE-based peptidomimetic inhibition of LRP-1 in the treatment of diabetic retinopathy is unknown. METHODS: Six months after streptozotocin induction of diabetes, male C57Bl/6 mice were intravitreally inoculated with apoEdp in a controlled release formulation. On the 15th day post-apoEdp treatment, mouse retinas were harvested to examine (1) blood-retinal-barrier (BRB) permeability by Evans blue dye, inflammatory leukostasis by concanavalin staining of leukocytes and LRP-1 pathway-related protein expression by Western blot analysis and gelatin zymography. RESULTS: Intravitreal apoEdp treatment of diabetic mice significantly reduced Evans blue extravasation and the number of adherent leukocytes in the diabetic mouse retinas. ApoEdp treatment inhibited the expression of extracellular matrix (ECM) degrading proteases heparanase and MMP-2, and restores the BRB tight junction proteins occludin and ZO-1. ApoEdp treatment also inhibited Wnt/ß-catenin-related expression of pro-inflammatory molecules ICAM-1, HIF-1α, and VEGF through negative regulation by LRP-1. CONCLUSION: Intravitreal apoEdp treatment of diabetic mice resulted a significant decrease in retinal vascular abnormalities through downregulation of LRP-1-related ECM protein degradation and Wnt/ß-catenin-related pro-angiogenic molecules.