Preparation of biodegradable microspheres and matrix devices containing naltrexone

CD44 tagged hyaluronic acid - chitosan liposome carrier for the delivery of berberine and doxorubicin into lung cancer cells

Liposomes are unique biomolecular, capable of loading both hydrophilic and hydrophobic molecules and delivered into the biological system. Liposomes (L) coated with hyaluronic acid (HA) and chitosan (CS) carrier system was fabricated. Berberine (BER) and doxorubicin (DOX) were encapsulated to enhance drug proliferation and therapeutic effect in lung cancer cells. The FTIR, XRD, SEM, and TEM techniques were carried out for functional group identification, crystallinity, and surface morphology analysis, respectively. In-vitro drug release confirms the sustained release of BER and DOX in various physiological environments. HA-CS@BER&DOX-L has good penetration ability and higher cytotoxicity effect in the A549 cells, and the IC50 value of HA-CS@BER&DOX-L is 89.19 μg/300 μL. The pure liposome showed a negligible cytotoxicity effect, and the HA-CS@BER&DOX-L could efficiently induce the apoptosis of A549 cells. The cellular uptake analysis of the HA-CS@BER&DOX-L effectively targeted and entered the A549 cells and clearly observed C. elegans images. Hence, the proposed system will be a potential treatment methodology to enhance the cytotoxicity of the A549 cancer cells and be useful to future drug administration methodology development.

Microfluidic-Assisted Formulation of ε-Polycaprolactone Nanoparticles and Evaluation of Their Properties and In Vitro Cell Uptake

The nanoprecipitation method was used to formulate ε-polycaprolactone (PCL) into fluorescent nanoparticles. Two methods of mixing the phases were evaluated: introducing the organic phase into the aqueous phase dropwise and via a specially designed microfluidic device. As a result of the nanoprecipitation process, fluorescein-loaded nanoparticles (NPs) with a mean diameter of 127 ± 3 nm and polydispersity index (PDI) of 0.180 ± 0.009 were obtained. The profiles of dye release were determined in vitro using dialysis membrane tubing, and the results showed a controlled release of the dye from NPs. In addition, the cytotoxicity of the NPs was assessed using an MTT assay. The PCL NPs were shown to be safe and non-toxic to L929 and MG63 cells. The results of the present study have revealed that PCL NPs represent a promising system for developing new drug delivery systems.

Thin film hydration versus modified spraying technique to fabricate intranasal spanlastic nanovesicles for rasagiline mesylate brain delivery: Characterization, statistical optimization, and in vivo pharmacokinetic evaluation

Rasagiline mesylate (RM) is a monoamine oxidase inhibitor that is commonly used to alleviate the symptoms of Parkinson's disease. However, it suffers from low oral bioavailability due to its extensive hepatic metabolism in addition to its hydrophilic nature which limits its ability to pass through the blood-brain barrier (BBB) and reach the central nervous system where it exerts its pharmacological effect. Thus, this study aims to form RM-loaded spanlastic vesicles for intranasal (IN) administration to overcome its hepatic metabolism and permit its direct delivery to the brain. RM-loaded spanlastics were prepared using thin film hydration (TFH) and modified spraying technique (MST). A 2³ factorial design was constructed to study and optimize the effects of the independent formulation variables, namely, Span type, Span: Brij 35 ratio, and sonication time on the vesicles᾽ characteristics in each preparation technique. The optimized system prepared using MST (MST 2) has shown higher desirability factor with smaller PS and higher EE%; thus, it was selected for further in vivo evaluation where it revealed that the extent of RM distribution from the intranasally administered spanlastics to the brain was comparable to that of the IV drug solution with significantly high brain-targeting efficiency (458.47%). These results suggest that the IN administration of the optimized RM-loaded spanlastics could be a promising, non-invasive alternative for the efficient delivery of RM to brain tissues to exert its pharmacological activities without being dissipated to other body organs which subsequently may result in higher pharmacological efficiency and better safety profile.

Engineered PLGA microspheres for extended-release of naltrexone: in vitro, in vivo, and IVIVR

Poly(lactide-co-glycolide) (PLGA)-based formulation is one of the most often used parenteral extended-release forms to deliver various therapeutics. VIVITROL^® as a commercialized PLGA microsphere formulation encapsulates naltrexone, a narcotic antagonist for opioid addiction and alcohol dependency. However, no U.S. Food and Drug Administration-approved generic product of naltrexone PLGA microsphere formulation has entered the market. The availability of generic naltrexone PLGA microspheres in low-income countries will broaden patients' accessibility to the safe, effective, and more affordable drug. A major challenge in developing such generic forms is the sensitivity of the drug-loaded microspheres' critical characteristics to the small manufacturing changes, even in formulations with the same compositions as the reference product. In this study, we evaluated the different key manufacturing parameters on the physicochemical, in vitro and in vivo release characteristics of naltrexone microspheres to develop a generic form of naltrexone PLGA microspheres. The selected formulations demonstrated a significant similarity in physicochemical characteristics and release profiles (f2 > 50) to the reference product, VIVITROL^®. A strong relationship was observed between in vitro release profile of naltrexone as against its corresponding in vivo profile. It helped to roughly predict the in vivo release behavior of the different manufactured formulations by their corresponding in vitro release profiles.

Composites Based on Gellan Gum, Alginate and Nisin-Enriched Lipid Nanoparticles for the Treatment of Infected Wounds

Due to growing antimicrobial resistance to antibiotics, novel methods of treatment of infected wounds are being searched for. The aim of this research was to develop a composite wound dressing based on natural polysaccharides, i.e., gellan gum (GG) and a mixture of GG and alginate (GG/Alg), containing lipid nanoparticles loaded with antibacterial peptide-nisin (NSN). NSN-loaded stearic acid-based nanoparticles (NP_NSN) were spherical with an average particle size of around 300 nm and were cytocompatible with L929 fibroblasts for up to 500 µg/mL. GG and GG/Alg sponges containing either free NSN (GG + NSN and GG/Alg + NSN) or NP_NSN (GG + NP_NSN and GG/Alg + NP_NSN) were highly porous with a high swelling capacity (swelling ratio above 2000%). Encapsulation of NSN within lipid nanoparticles significantly slowed down NSN release from GG-based samples for up to 24 h (as compared to GG + NSN). The most effective antimicrobial activity against Gram-positive Streptococcus pyogenes was observed for GG + NP_NSN, while in GG/Alg it was decreased by interactions between NSN and Alg, leading to NSN retention within the hydrogel matrix. All materials, except GG/Alg + NP_NSN, were cytocompatible with L929 fibroblasts and did not cause an observable delay in wound healing. We believe that the developed materials are promising for wound healing application and the treatment of bacterial infections in wounds.

Comparison of lipid liquid crystal formulation and Vivitrol® for sustained release of Naltrexone: In vitro evaluation and pharmacokinetics in rats

Camurus' FluidCrystal® injection depot is a lipid liquid crystal (LLC) phase formation-based method, comprising of glycerol dioleate (GDO) and soy phosphatidylcholine (SPC), together with minute quantities of N-methyl-2-pyrrolidone solvent (NMP). The present study aimed to develop a method for LLC using sorbitan monooleate (LLC-SMO) instead of GDO to prepare a one-month sustained-release formulation of naltrexone (NTX) that is applied for the treatment of autism and treating alcohol dependence. The optical characteristics of the LLC were assessed by polarizing light microscopy (PLM) to reveal the presence of lamellar, hexagonal, and cubic mesophases. Furthermore, in vitro release of NTX and NMP, degradation, pharmacokinetics, and histopathology of LLC-GDO and LLC-SMO in rats were evaluated and compared to those of Vivitrol®. The PLM images revealed that the structure of LLC-SMO is hexagonal, similar to LLC-GDO. The in vitro release of NTX and its pharmacokinetic results in rats indicted that the LLC-SMO system is more uniform than LLC-GDO and Vivitrol® during 35 days. Histopathological results of LLC-GDO and LLC-SMO confirmed the biocompatibility of our LLC delivery systems. Taken together these data demonstrate that the LLC-SMO-based method, was efficient enough to sustain the release of NTX in vitro and in vivo, confirming the biocompatible nature of this delivery system.

Preparation and characterization of ethylcellulose microspheres for sustained-release of pregabalin

Background and purpose:

Pregabalin is used in the treatment of epilepsy, chronic pain, and other psychological disorders. Preparation of pregabalin in the sustained-release formulation will enhance patient compliance and reduce the incidence of side effects. The aim of this study was to prepare sustained-release microspheres for pregabalin utilizing ethylcellulose and evaluate the processing factors that influence the fabrication and the performance of the prepared microspheres.

Experimental approach:

The microspheres were prepared using the water-oil-oil double emulsion solvent evaporation method. Microspheres were characterized for particle size, encapsulation efficiency, and in vitro drug release. The influence of the processing variables on the characteristics of the prepared microspheres was studied. Microspheres solid-state characterization performed using differential scanning calorimetry, Fourier transform infrared spectroscopy and scanning electron microscopy.

Findings/Results:

The results described in the context of the current work illustrated the suitability of the water-oil-oil system in the preparation of sustained-release microspheres for pregabalin. The optimum formulation was prepared at a drug to polymer ratio of 1:3 w/w, stirring speed of 600 rpm, surfactant concentration of 1.5%, and external phase volume of 150 mL. This formula produced microspheres particle size in the range 600-1000 μm, with 87.6% yield, and 80.14 ± 0.53% encapsulation efficiency. Drug release from the microspheres was found to be diffusion controlled, with a pH-independent behavior.

Conclusion and implication

The current work presented a successful attempt to fabricate a sustained-release microsphere comprising pregabalin. This will help overcome the frequent dosing problems with conventional pregabalin dosage forms and improve product performance.

Lipoparticles for Synergistic Chemo-Photodynamic Therapy to Ovarian Carcinoma Cells: In vitro and in vivo Assessments

PURPOSE

Lipoparticles are the core-shell type lipid-polymer hybrid systems comprising polymeric nanoparticle core enveloped by single or multiple pegylated lipid layers (shell), thereby melding the biomimetic properties of long-circulating vesicles as well as the mechanical advantages of the nanoparticles. The present study was aimed at the development of such an integrated system, combining the photodynamic and chemotherapeutic approaches for the treatment of multidrug-resistant cancers.

METHODS

For this rationale, two different sized Pirarubicin (THP) loaded poly lactic-co-glycolic acid (PLGA) nanoparticles were prepared by emulsion solvent evaporation technique, whereas liposomes containing Temoporfin (mTHPC) were prepared by lipid film hydration method. Physicochemical and morphological characterizations were done using dynamic light scattering, laser doppler anemometry, atomic force microscopy, and transmission electron microscopy. The quantitative assessment of cell damage was determined using MTT and reactive oxygen species (ROS) assay. The biocompatibility of the nanoformulations was evaluated with serum stability testing, haemocompatibility as well as acute in vivo toxicity using female albino (BALB/c) mice.

RESULTS AND CONCLUSION

The mean hydrodynamic diameter of the formulations was found between 108.80 ± 2.10 to 405.70 ± 10.00 nm with the zeta (ζ) potential ranging from -12.70 ± 1.20 to 5.90 ± 1.10 mV. Based on the physicochemical evaluations, the selected THP nanoparticles were coated with mTHPC liposomes to produce lipid-coated nanoparticles (LCNPs). A significant (p< 0.001) cytotoxicity synergism was evident in LCNPs when irradiated at 652 nm, using an LED device. No incidence of genotoxicity was observed as seen with the comet assay. The LCNPs decreased the generalized in vivo toxicity as compared to the free drugs and was evident from the serum biochemical profile, visceral body index, liver function tests as well as renal function tests. The histopathological examinations of the vital organs revealed no significant evidence of toxicity suggesting the safety and efficacy of our lipid-polymer hybrid system.

Floating Microspheres of Enalapril Maleate as a Developed Controlled Release Dosage Form: Investigation of the Effect of an Ionotropic Gelation Technique

OBJECTIVES

The purpose of this study was to provide a control drug delivery system through a newly approved work to enhance the absorption and bioavailability of enalapril maleate loaded floating microspheres by ionotropic gelation technique using a hydrophilic carrier.

MATERIALS AND METHODS

Eleven developed formulations of floating microspheres were prepared by ionotropic gelation using different concentrations of sodium alginate, iota-carrageenan, sodium bicarbonate, calcium chloride, and the drug. These microspheres were characterized using a diversity of parameters like micrometric properties, percentage yield, entrapment efficiency, in vitro buoyancy, in vitro drug release, and kinetics of drug release. The optimum formula was evaluated and identified for drug-excipients compatibility using fourier transform-infrared spectroscopy (FT-IR), surface morphology, powder X-ray diffraction (XRD), and differential scanning calorimetry (DSC).

RESULTS

From the results, F4 was selected as the optimum formula since it provides a faster and premium release of drug from the matrix (91.4%). Kinetics of drug release was found to depend on both diffusion and erosion mechanisms, as the correlation coefficient (R2) was best fitted with Korsmeyer's model and the release exponent (n) was shown to be between 0.43 and 0.84. Scanning electron microscopy images demonstrated spherical, discrete, and freely flowing microspheres with a particle size of 199.4±0.04 μm. Optimum buoyancy properties, percentage yield, and drug entrapment efficiency were achieved. FT-IR showed no interaction between enalapril and the polymers. DSC and XRD showed the miscibility of the drug with the polymers while maintaining the stable crystalline properties of enalapril loaded in the prepared microspheres.

CONCLUSION

The developed floating microspheres of enalapril maleate can be considered a promising controlled drug delivery system, thereby improving patient compliance.

Submicron-Sized Nanocomposite Magnetic-Sensitive Carriers: Controllable Organ Distribution and Biological Effects

Although new drug delivery systems have been intensely developed in the past decade, no significant increase in the efficiency of drug delivery by nanostructure carriers has been achieved. The reasons are the lack of information about acute toxicity, the influence of the submicron size of the carrier and difficulties with the study of biodistribution in vivo. Here we propose, for the first time in vivo, new nanocomposite submicron carriers made of bovine serum albumin (BSA) and tannic acid (TA) and containing magnetite nanoparticles with sufficient content for navigation in a magnetic field gradient on mice. We examined the efficacy of these submicron carriers as a delivery vehicle in combination with magnetite nanoparticles which were systemically administered intravenously. In addition, the systemic toxicity of this carrier for intravenous administration was explicitly studied. The results showed that (BSA/TA) carriers in the given doses were hemocompatible and didn’t cause any adverse effect on the respiratory system, kidney or liver functions. A combination of gradient-magnetic-field controllable biodistribution of submicron carriers with fluorescence tomography/MRI imaging in vivo provides a new opportunity to improve drug delivery efficiency.

Opioid Addiction: Social Problems Associated and Implications of Both Current and Possible Future Treatments, including Polymeric Therapeutics for Giving Up the Habit of Opioid Consumption

BACKGROUND

Detoxification programmes seek to implement the most secure and compassionate ways of withdrawing from opiates so that the inevitable withdrawal symptoms and other complications are minimized. Once detoxification has been achieved, the next stage is to enable the patient to overcome his or her drug addiction by ensuring consumption is permanently and completely abandoned, only after which can the subject be regarded as fully recovered.

METHODS

A systematic search on the common databases of relevant papers published until 2016 inclusive.

RESULTS AND CONCLUSION

Our study of the available oral treatments for opioid dependence has revealed that no current treatment can actually claim to be fully effective. These treatments require daily oral administration and, consequently, regular visits to dispensaries, which in most cases results in a lack of patient compliance, which causes fluctuations in drug plasma levels. We then reviewed alternative treatments in the available scientific literature on polymeric sustained release formulations. Research has been done not only on release systems for detoxification but also on release systems for giving up the habit of taking opioids. These efforts have obtained the recent authorization of polymeric systems for use in patients that could help them to reduce their craving for drugs.

Study of Effect of Different Factors in Formulation of Micro and Nanospheres with Solvent Evaporation Technique

Background:

There are various methods of formulation of micro and nanospheres such as solvent evaporation, solvent removal, polymerization, hot-melt encapsulation, coacervation, phase/wet inversion, spray drying, spray congealing etc. Amongst these all, solvent evaporation is one of the most widely used, researched, easy, accessible methods and for which many patents have been applied. It is thus imperative to understand the basics of effect of formulation variables and design of solvent evaporation method which will be covered in this review article.

Objective:

To discuss the various formulation factors while designing the robust micro and nanospherical systems with better morphology, entrapment and release of the drugs.

Method:

Systematic analysis of the relevant literature, bibliographies, and interactions with investigators.

Results:

From the investigation of different literatures, it was found that various factors of solvent evaporation technique may be controlled in order to design the micro and nanospheres of suitable morphology, entrapment and release characters.

Conclusion:

Various factors like type of polymer used, weight, viscosity, hydrophilicity, concentration, polymer ratio, stirring speed, emulsifier concentration, concentration of cross-linking agents, type of solvent used, rate of addition of solvent etc. Affect the yield, morphology, release and entrapment of the drug inside the system. Hence, these factors play crucial role in the design of a robust micro and nanospherical system.

Jafarzadeh Kashi T, Dinarvand R, Tahriri M, Rakhshan V, Esfandyari-Manesh M. Preparation, Characterization and Evaluation of Drug Release Properties of Simvastatin-loaded PLGA Microspheres

Microspheres formulated from poly (D, L-lactic-co-glycolide) (PLGA), a biodegradable polymer, have been extensively evaluated as a drug delivery system. In this study, the preparation, characterization and drug release properties of the PLGA microspheres were evaluated. Simvastatin (SIM)-loaded PLGA microspheres were prepared by oil-in-water emulsion/solvent evaporation method. The microspheres were then frozen to -80 °C, they were freeze dried for 24 h. Characterization of SIM-loaded PLGA microspheres was evaluated by X-ray diffraction analysis, Fourier transform infrared spectroscopy analysis, and scanning electron microscopy (SEM). Drug release potential was evaluated by UV-spectrophotometry. The experimental results revealed that SIM-loaded PLGA microspheres can be successfully obtained through solvent evaporation method with appropriate morphologic characteristics and high encapsulation efficiency. The drug release pattern from polymeric microspheres in the phosphate buffered saline medium was measured during a 21-day period using UV-spectrophotometry. The correlation coefficient value (r²= 0.9878) of the trend lines of the graph showed that the SIM-loaded PLGA microspheres best fit with zero order release pattern. No burst release was observed with polymeric matrix. The drug release characteristic of the microspheres ascertained that the release was about 27% for SIM-loaded microspheres, which occurred within the first 6 days after maintaining the microspheres in phosphate buffer saline. Also, the microspheres successfully presented a slow release and the duration of the release lasted for more than 21 days. It can be concluded that SIM-loaded PLGA microspheres hold great promise for using as a drug-delivery system in biomedical applications, especially in drug delivery systems and tissue engineering.

Chitosan lactate wafer as a platform for the buccal delivery of tizanidine HCl: in vitro and in vivo performance

Tizanidine HCl is a skeletal muscle relaxant that suffers from extensive hepatic metabolism resulting in 34-40% oral bioavailability. It also suffers from short half-life (2.1-4.2h) that necessitates frequent administration thus reducing patient compliance. In addition, tizanidine HCl is water soluble, so it is a challenging candidate for controlled drug delivery. In our study, tizanidine was encapsulated in chitosan lactate beads cross-linked with sodium tripolyphosphate. The beads were further incorporated into chitosan lactate wafer to be easily applied to buccal mucosa, aiming to bypass the hepatic metabolism. A central composite face-centered design was applied to statistically optimize the formulation variables; tripolyphosphate concentration, chitosan lactate concentration and polymer/drug ratio. The optimized formula suggested by the software composed of; 3.03% tripolyphosphate, 4.92% chitosan lactate and 2.13 polymer/drug ratio. It provided encapsulation efficiency of 56.5% and controlled tizanidine release over 8h. It is also characterized by being mucoadhesive and nonirritant. Pharmacokinetic parameters of tizanidine from the optimized formula were compared to those of the immediate release tablet, Sirdalud(®), as reference in human volunteers using a randomized crossover design. Significant increase was observed for Tmax and AUC(0-∞). The increase in relative bioavailability of TIZ from the optimized formula was 2.27 fold.

Applicability of non-halogenated methyl propionate to microencapsulation

Applicability of methyl propionate to microencapsulation was evaluated with regard to volatility, capability of forming emulsions, and their quality. An emulsion-based technique was then developed to encapsulate progesterone into poly-d,l-lactide-co-glycolide microspheres. Their characteristics were compared with those prepared using ethyl acetate. Our results demonstrated that methyl propionate had greater evaporative tendency and less water miscibility than ethyl acetate did. The former allowed us to prepare good microspheres. Their average volume mean diameter was 68.3 ± 1.7 μm with a span index of 0.91 ± 0.13. Progesterone did not undergo polymorphic transition during microencapsulation, and its encapsulation efficiency ranged from 41.80 ± 1.83 to 85.64 ± 1.95%. Residual methyl propionate in various microspheres was found to be 0.97 ± 0.03 to 1.54 ± 0.07%. Such microsphere characteristics were quite similar to those prepared by the ethyl acetate-based microencapsulation process. Overall, our findings reflect that methyl propionate has a potential to become an invaluable solvent for microencapsulation.

In vitro biocompatibility and bioactivity of microencapsulated heparan sulfate

The glycosaminoglycan sugar heparan sulfate (HS) is an attractive agent for the repair of bone defects due to its ability to regulate endogenous growth factors. The sustained delivery of HS to the localized wound site over the period of healing which can last for over 1 month may prove advantageous for its therapeutic use. In this study we investigated the encapsulation of HS by the water-in oil-in water (W(1)/O/W(2)) technique in polycaprolactone (PCL) microcapsules as a prolonged delivery device. Encapsulation efficiencies of 70% could be achieved by using a 1:1 mixture of dichloromethane (DCM) and acetone as the solvent in the organic phase, while DCM alone gave poor encapsulation. Although addition of polyvinyl alcohol (PVA) to the drug phase did not affect the size or drug loading of the microcapsules, it did however produce a large change in the morphology and drug distribution, which resulted in different release rates. Release from capsules made with PVA in the drug phase reached 60% after 40 days, while those made with water in the drug phase completed release after 20 days. In vitro biocompatibility studies were performed and detected no increase in cell death in human mesenchymal stem cells (hMSC) or induction of an inflammatory response in macrophages after exposure to release products from HS-loaded microcapsules. The released HS retained its ability to increase the proliferation of hMSC after the encapsulation process. These results indicate that encapsulation of HS by the W(1)/O/W(2) method creates a promising device for the repair of bone tissue.

Efficacy and tolerability of naltrexone in the treatment of alcohol dependence: oral versus injectable delivery

Oral naltrexone, an opioid antagonist, reduces relapse and heavy drinking in alcohol-dependent patients. However, oral delivery is associated with poor compliance and adverse events. To enhance treatment outcome and reduce side effects, injectable extended-release naltrexone formulations have been developed. Currently, there are no studies available directly comparing oral and injectable formulations of naltrexone in alcohol-dependent patients. This paper reviews the efficacy and adverse events of oral versus injectable extended-release naltrexone. Therefore, data were extracted from two recently published reviews about oral naltrexone in the treatment of alcohol dependence. Pooled outcomes were compared with reported outcomes of recent studies on injectable extended-release naltrexone. Injectable naltrexone seems to be effective in the management of alcohol dependence. Although inconclusive, the available results indicate that the expected advantages of injectable naltrexone over oral naltrexone still have to be proven. Randomized studies with direct comparisons of oral and injectable naltrexone are urgently needed.

Improved entrapment efficiency of hydrophilic drug substance during nanoprecipitation of poly(l)lactide nanoparticles

The purpose of this research was to improve the entrapment efficiency of a model hydrophilic drug substance, sodium cromoglycate, loaded inside polylactic acid nanoparticles by a modified nanoprecipitation method. The effect of formulation parameters was studied to improve the entrapment efficiency of the drug substance inside the nanoparticles. Several parameters (changes in the amount of model drug, solvent selection, electrolyte addition, pH alteration) were tested in order to increase the loading of the hydrophilic drug in the hydrophobic nanoparticles. Lowering of the pH was the most efficient way to increase the drug loading; up to approximately 70% of the sodium cromoglycate used in the particle formation process could be loaded inside the particles. The loading efficiency without the pH change was around 10% to 15% at maximum. The crystallinity values and crystal habits of the sodium cromoglycate nanoparticles were studied (x-ray diffraction) before and after the lowering of the pH. The change in pH conditions during the nanoprecipitation process did not affect markedly the crystallinity properties of the drug substance. According to this study, it is possible to improve the entrapment efficiency of hydrophilic sodium cromoglycate inside of the nanoparticles by small changes in the process parameters without alterations in the physical properties of the original drug substance.