Optimization of In Situ Gel-Forming Chlorhexidine-Encapsulated Polymeric Nanoparticles Using Design of Experiment for Periodontitis.

Periodontitis is a chronic inflammatory disease of the gums caused by pathogenic microorganisms damaging and destroying periodontal tissues. Chlorhexidine digluconate (CHX) is a commonly used antimicrobial agent for the treatment of periodontitis. However, it has many drawbacks, such as toxicity due to the high dosage required, low prolonged release, and low adhesion in the periodontal pocket. The objective of this study was to develop and optimize CHX-encapsulated polymeric nanoparticles (NPs) loaded into in situ gel-forming (ISGF) using design of experiment (DoE) to improve the treatment of periodontitis and overcome these limitations. CHX-NPs were optimized from 0.046%w/v chitosan, 0.05%w/w gelatin, and 0.25%w/w CHX. After that, the optimized of CHX-NPs was loaded into a thermosensitive ISGF, which was a mixture of 15%w/v Poloxamer 407 and 1% hydroxypropyl methylcellulose (HPMC). The optimized CHX-NPs, loaded into ISGF, was evaluated by measuring gelling temperature and time, pH, viscosity, compatibility, in vitro drug release, antibacterial activity, cytotoxicity, and stability. The results showed that the size, PDI, and zeta potential of optimized CHX-NPs were 53.07±10.17 nm, 0.36±0.02, and 27.63±4.16 mV, respectively. Moreover, the optimized ISGF loading CHX-NPs showed a gelling temperature at 34.3±1.2°C within 120.00±17.32 s with a pH value of 4.06. The viscosity of the formulations at 4°C was 54.33±0.99 cP. The DSC and FTIR showed no interaction between ingredients. The optimal formulations showed a prolonged release of up to 7 days while providing potential antibacterial activity and were safe for normal gingival fibroblast cells. Moreover, the formulations had high stability at 4°C and 25°C for 3 months. In conclusion, the study achieved the successful development of ISGF loading CHX-NPs formulations for effectiveness use in periodontal treatment.

Development of Carboxymethyl Chitosan Nanoparticles Prepared by Ultrasound-Assisted Technique for a Clindamycin HCl Carrier.

Polymeric nanoparticles are one method to modify the drug release of small hydrophilic molecules. In this study, clindamycin HCl was used as a model drug loaded in carboxymethyl chitosan nanoparticles cross-linked with Ca2+ ions (CMCS-Ca2+). The ultrasonication with experimental design was used to produce CMCS-Ca2+ nanoparticles loading clindamycin HCl. The model showed that the size of nanoparticles decreased when amplitude and time increased. The nanoparticle size of 318.40 ± 7.56 nm, decreased significantly from 543.63 ± 55.07 nm (p < 0.05), was obtained from 75% of amplitude and 180 s of time, which was one of the optimal conditions. The clindamycin loading content in this condition was 34.68 ± 2.54%. The drug content in nanoparticles showed an inverse relationship with the size of the nanoparticles. The sodium carboxymethylcellulose film loading clindamycin HCl nanoparticles exhibited extended release with 69.88 ± 2.03% drug release at 60 min and a gradual increase to 94.99 ± 4.70% at 24 h, and demonstrated good antibacterial activity against S. aureus and C. acne with 40.72 ± 1.23 and 48.70 ± 1.99 mm of the zone of inhibition at 24 h, respectively. Thus, CMCS-Ca2+ nanoparticles produced by the ultrasound-assisted technique could be a potential delivery system to modify the drug release of small hydrophilic antibiotics.

Extraction of Tropical Fruit Peels and Development of HPMC Film Containing the Extracts as an Active Antibacterial Packaging Material.

In recent years, instead of the use of chemical substances, alternative substances, especially plant extracts, have been characterized for an active packaging of antibacterial elements. In this study, the peels of mangosteen (Garcinia mangostana), rambutan (Nephelium lappaceum), and mango (Mangifera indica) were extracted to obtain bioactive compound by microwave-assisted extraction (MAE) and maceration with water, ethanol 95% and water-ethanol (40:60%). All extracts contained phenolics and flavonoids. However, mangosteen peel extracted by MAE and maceration with water/ethanol (MT-MAE-W/E and MT-Ma-W/E, respectively) contained higher phenolic and flavonoid contents, and exhibited greater antibacterial activity against Staphylococcus aureus and Escherichia coli. Thus, both extracts were analyzed by liquid chromatograph-mass spectrometer (LC-MS) analysis, α-mangostin conferring antibacterial property was found in both extracts. The MT-MAE-W/E and MT-Ma-W/E films exhibited 30.22 ± 2.14 and 30.60 ± 2.83 mm of growth inhibition zones against S. aureus and 26.50 ± 1.60 and 26.93 ± 3.92 mm of growth inhibition zones against E. coli. These clear zones were wider than its crude extract approximately 3 times, possibly because the film formulation enhanced antibacterial activity with sustained release of active compound. Thus, the mangosteen extracts have potential to be used as an antibacterial compound in active packaging.

Chitosan-based self-assembled nanocarriers coordinated to cisplatin for cancer treatment.

Polymeric nanocarriers were prepared via a dialysis method using three chitosan derivatives, N-benzyl-N,O-succinyl chitosan (BSCT), N-naphthyl-N,O-succinyl chitosan (NSCT), and N-octyl-N-O-succinyl chitosan (OSCT) and were coordinated to cisplatin. The nanocarrier properties and cytotoxicity on the human carcinoma cells, HN22 (head and neck), were investigated. In addition, intracellular cisplatin accumulation, apoptosis induction and toxicity on renal cells were also evaluated. The findings revealed that the succinyl groups of the polymers were perfectly deprotonated and bound with cisplatin by co-ordinate bonds at pH 8.5. Among the derivatives, BSCT exhibited the highest cisplatin loading and release in simulated physiological medium. The cytotoxicities on HN22 cells of cisplatin-loaded BSCT nanocarriers were lower than that of free cisplatin, however, they presented a greater percentage of early apoptosis in HN22 cells and could decrease cisplatin induced renal cell death. In conclusion, the BSCT self-assembly nanocarrier might be a cisplatin carrier for sustained release, which provides prolonged antitumour treatment and reduced nephrotoxicity.

Surfactants enhance recovery of poorly soluble drugs during microdialysis sampling: Implications for in vitro dissolution-/permeation-studies.

Aim of this project was to investigate the applicability of a recently developed in vitro microdialysis-sampling approach in connection with a dissolution-/permeation (D/P) system, especially the impact of surfactants within the perfusion fluid. The D/P-system is based on side-by-side chambers, separated by a barrier that simulates the intestinal barrier. Here, in contrast to conventional D/P-systems, the dissolution of the drug (donor chamber concentration) is followed by microdialysis sampling. This approach appears promising, because it is expected not to disturb the dynamic interplay between drug-dissolution (-release) and drug permeation. Furthermore, it should allow quantification of the unbound (free) drug concentration. In the first step, it was assessed, if the addition of the anionic surfactant sodium dodecyl sulphate (SDS) to the perfusate of the microdialysis system affects the recovery of the (slightly) water-soluble model drug acyclovir and the poorly water soluble model drug celecoxib (CXB). SDS had no influence on acyclovir-recovery, but substantially enhanced CXB-recovery, partly due to improved extraction efficiency, partly due to inhibition of loss of CXB due to non-specific binding to surfaces and the probe. The fraction of CXB recovered from aqueous CXB-solutions by microdialysis sampling using SDS-containing perfusates correlated well with the celecoxib concentration in the samples, but was found independent of the SDS-concentrations (above critical micelle concentration). In the next step microdialysis sampling with SDS-containing perfusates was assessed for celecoxib solutions in fasted state simulated intestinal fluid (FaSSIF) and compared to that in buffer. In FaSSIF, the measured CXB-concentrations were far below the overall CXB concentration, likely representing the free celecoxib, i.e. the fraction of drug, which is not associated with taurocholate surfactant micelles. In buffer, the measured concentrations matched the overall CXB concentrations. By the use of SDS-containing perfusates microdialysis sampling enabled reliable quantification of minute amounts of free CXB, which renders its use promising for dissolution-/permeation experiments with other poorly soluble drugs.

An Abraded Surface of Doxorubicin-Loaded Surfactant-Containing Drug Delivery Systems Effectively Reduces the Survival of Carcinoma Cells.

An effective antitumor remedy is yet to be developed. All previous approaches for a targeted delivery of anticancer medicine have relied on trial and error. The goal of this study was to use structural insights gained from the study of delivery systems and malignant cells to provide for a systematic approach to the development of next-generation drugs. We used doxorubicin (Dox) liposomal formulations. We assayed for cytotoxicity via the electrical current exclusion method. Dialysis of the samples yielded information about their drug release profiles. Information about the surface of the delivery systems was obtained through synchrotron small-angle X-ray scattering (SAXS) measurements. SAXS measurements revealed that Dox-loading yielded an abraded surface of our Dox liposomal formulation containing soybean oil, which also correlated with an effective reduction of the survival of carcinoma cells. Furthermore, a dialysis assay revealed that a higher burst of Dox was released from soybean oil-containing preparations within the first five hours. We conclude from our results that an abraded surface of Dox-loaded drug delivery system increases their efficacy. The apparent match between surface geometry of drug delivery systems and target cells is suggested as a steppingstone for refined development of drug delivery systems. This is the first study to provide a systematic approach to developing next-generation drug carrier systems using structural insights to guide the development of next-generation drug delivery systems with increased efficacy and reduced side effects.

Effect of ultrasonication, pH and heating on stability of apricot gum-lactoglobuline two layer nanoemulsions.

The objectives of this study were to evaluate the effect of apricot gum-lactoglobuline (AG/LgC) ratio, thermal treatment, sonication with different times and amplitudes and pH, on double layer sunflower oil in water emulsion stability. The emulsion stability was determined by the evaluation of emulsion performance indices including particle size, zeta potential, creaming and emulsion volume stability during 10 days of storage. Applying AG and LgC with the ratio of 12.5:1 AG:LgC, in order to obtain double layer oil in water emulsion, could result in a completely stable nano-emulsions during 10 days storage in room temperature. The ultrasound treatment significantly increased the emulsion stability. A 10min ultrasound treatment with the amplitude of 25% was the optimum conditions for ultra-sonication. The best temperature for thermal treatment and the best pH, in order to improve the emulsion's stability, was 50°C and 3, respectively.

Spontaneous emulsification of nifedipine-loaded self-nanoemulsifying drug delivery system.

Self-nanoemulsifying drug delivery system (SNEDDS) can be used to improve dissolution of poorly water-soluble drugs. The objective of this study was to prepare SNEDDS by using ternary phase diagram and investigate their spontaneous emulsifying property, dissolution of nifedipine (NDP), as well as the pharmacokinetic profile of selected SNEDDS formulation. The results showed that the composition of the SNEDDS was a great importance for the spontaneous emulsification. Based on ternary phase diagram, the region giving the SNEDDS with emulsion droplet size of less than 300 nm after diluting in aqueous medium was selected for further formulation. The small-angle X-ray scattering curves showed no sharp peak after dilution at different percentages of water, suggesting non-ordered structure. The system was found to be robust in different dilution volumes; the droplet size was in nanometer range. In vitro dissolution study showed remarkable increase in dissolution of NDP from SNEDDS formulations compared with NDP powders. The pharmacokinetic study of selected SNEDDS formulation in male Wistar rats revealed the improved maximum concentration and area under the curve. Our results proposed that the developed SNEDDS formations could be promising to improve the dissolution and oral bioavailability of NDP.

Role of simplex lattice statistical design in the formulation and optimization of microemulsions for transdermal delivery.

Microemulsions (ME) have gained attention as an alternative pharmaceutical formulation for transdermal delivery systems. However, the complicated relationships between various ME compositions (causal factors) and their characteristics (response variable) have not been fully comprehended. To overcome this problem, the design and development of ME for transdermal delivery was performed in our study using Design Expert(®) Software. The model formulations of ME were prepared according to the ME region obtained from pseudo-ternary phase diagrams using the simplex lattice design as an optimization technique. In this study, ketoprofen-loaded ME composed of oleic acid, Cremophor(®) RH40, ethanol and water were prepared, and their characteristics (e.g., size, charge, conductivity, pH, viscosity, drug content, loading capacity and skin permeation flux) were evaluated. The ME having an appropriate skin permeation flux was used as the basis for optimization. The skin permeation flux of the experimental ME was very close to the flux predicted by Design Expert(®) Software and was significantly greater than that for the commercial product. Possible mechanisms for the enhancement of the skin permeation of the ME were also investigated using Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). This finding provided an understanding of the relationship between the causal factors and response variables, as shown in the response surfaces. Moreover, these results indicated that the simple lattice design was beneficial for the pharmaceutical development of ME for transdermal delivery.

Determination of nanostructure of liposomes containing two model drugs by X-ray scattering from a synchrotron source.

Small-angle X-ray scattering has been employed to study how the introduction of paracetamol and acetylsalicylic acid into a liposome bilayer system affects the system's nanostructure. An X-ray scattering model, developed for multilamellar liposome systems [Pabst et al. (2000), Phys. Rev. E, 62, 4000-4009], has been used to fit the experimental data and to extract information on how structural parameters, such as the number and thickness of the bilayers of the liposomes, thickness of the water layer in between the bilayers, size and volume of the head and tail groups, are affected by the drugs and their concentration. Even though the experimental data reveal a complicated picture of the drug-bilayer interaction, they clearly show a correlation between nanostructure, drug and concentration in some aspects. The localization of the drugs in the bilayers is discussed.

Evaluation of the mechanism of skin enhancing surfactants on the biomembrane of shed snake skin.

The aim of the present work was to investigate the effects of different surfactants at various concentrations as a skin penetration enhancer through the biomembrane of the shed skin of Naja kaouthia. Additionally, the enhancer mechanism(s) of each class of surfactants were evaluated using physical characterization techniques, such as scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and small and wide angle X-ray scattering (SWAXS). Our results showed that skin permeability increased with increasing concentrations of surfactants and the degree of increase was higher for the model hydrophilic permeant, deuterium dioxide (D(2)O), than the lipophilic permeant, ketoprofen (KP). Ionic surfactants, sodium lauryl sulfate (SLS) and cetyl trimethyl ammonium bromide (CTAB), demonstrated higher enhancement ability than the polyoxyethylene (20) sorbitan mono-oleate (Tween 80) non-ionic surfactant, which was consistent with the results from physical characterization studies. Increasing amounts of permeated drug resulted in an increase in membrane interactions. From our observations, it can be assumed that SLS and CTAB can be localized inside the biomembrane and thereby enhance drug permeation mainly through interactions with intercellular lipids in the stratum corneum (SC) and the creation of a perturbed microenvironment among lipid alkyl chains and polar head groups.