Formulation development and evaluation of metformin chewing gum with bitter taste masking

Background:

Medicated gums are intended to be chewed and act either locally, absorbed via the buccal mucosa or swallowed with saliva. We prepared the metformin gum to overcome its side effects including vomiting, diarrhea, and abdomen discomfort. Furthermore, it could be useful for those who have swallowing problems.

Materials and Methods:

Metformin hydrochloride (250 mg) with suitable sweeteners was mixed manually for 5 min. This mixture was spray dried, freeze dried, or directly mixed with chewing gum base. Glycerin, xylitol, and menthol were added and the produced paste was kept in the freezer for 2 h to be stable. As the metformin shows bitter taste, we tried to mask this unpleasant taste with using different methods explained. The releasing pattern was evaluated by using a mechanical chewing machine. The best formulation with the optimized releasing pattern, suitable physicochemical properties and pleasant taste were selected. Content uniformity, releasing percent, and other physicochemical properties were identified as well. Taste, flavor, and appearance characteristics were evaluated by using a self-made questionnaire based on the hedonic test method.

Results:

The chewing gum dosage content was about 86.2%. The release rate of metformin chewing gum was about 70% after 5 min of mastication. Masking the bitter taste of drug was achieved by using acesulfame-isomalt as sweeteners and prepared it by freeze drying equipment.

Conclusion:

Metfornin chewing gum had suitable appearance and appropriate invitro characteristics that fallow the pharmacopeia suggestions. This chewable gum showed bitterness suppression with a suitable release rate.

Comparing different sterol containing solid lipid nanoparticles for targeted delivery of quercetin in hepatocellular carcinoma

Quercetin (QT) is a potential chemotherapeutic drug with low solubility that seriously limits its clinical use. The aim of this study was enhancing cellular penetration of QT by sterol containing solid lipid nanoparticles (SLNs) which make bilayers fluent for targeting hepatocellular carcinoma cells. Three variables including sterol type (cholesterol, stigmasterol and stigmastanol), drug and sterol content were studied in a surface response D-optimal design for preparation of QT-SLNs by emulsification solvent evaporation method. The studied responses included particle size, zeta potential, drug loading capacity and 24 h release efficiency (RE24%). Scanning electron and atomic force microscopy were used to study the morphology of QT-SLNs and their thermal behavior was studied by DSC analysis. Cytotoxicity of QT-SLNs was determined by MTT assay on HepG-2 cells and cellular uptake by fluorescence microscopy method. Optimized QT-SLNs obtained from cholesterol and QT with the ratio of 2:1 that showed particle size of 78.0 ± 7.0 nm, zeta potential of -22.7 ± 1.3 mV, drug loading efficiency of 99.9 ± 0.5% and RE24 of 56.3 ± 3.4%. IC50 of QT in cholesterol SLNs was about six and two times less than free QT and phytosterol SLNs, respectively, and caused more accumulation of QT in HepG2 cells. Blank phytosterol SLNs were toxic on cells.

Feasibility of haloperidol-anchored albumin nanoparticles loaded with doxorubicin as dry powder inhaler for pulmonary delivery

Haloperidol (Hal) is a ligand that can target sigma 2 receptors over-expressed in non-small cell lung cancer. Hal targeted nanoparticles of bovine serum albumin (BSA) were prepared for pulmonary delivery of doxorubicin (DOX). The conjugation was confirmed by Fourier transform infrared spectroscopy (FTIR) and (1)H nuclear magnetic resonance ((1)H NMR) spectroscopic methods. Nanoparticles were prepared by desolvation method from BSA-Hal and were loaded with DOX. They were characterized for their morphology, particle size, zeta potential, drug loading and release efficiency. The optimized nanoparticles were spray-dried using trehalose, l-leucin and mannitol as dry powder inhaler (DPI) in different inlet temperatures between 80 and 120°C. The obtained nanocomposites were characterized for their aerodynamic diameter, specific surface area (cm(2)/g) and fine particle fraction (FPF) by a Cascade Impactor device. The optimized nanoparticles showed particle size of 218 nm, zeta potential of -25.4 mV, drug entrapment efficiency of 89% and release efficiency of 56% until 2 h. After spray drying of these nanoparticles, the best results were obtained from mannitol with an inlet temperature of 80°C which produced a mean aerodynamic diameter of 4.58 μm, FPF of 66% and specific surface area of 6302.99 cm(2)/g. The obtained results suggest that the designed DPI could be a suitable inhaler for targeted delivery of DOX in pulmonary delivery.

Association between HDL particles size and myeloperoxidase/ paraoxonase-1 (MPO/PON1) ratio in patients with acute coronary syndrome

Myeloperoxidase (MPO) and paraoxonase-1 (PON1) are inflammatory and anti-inflammatory enzymes, respectively that have been involved in the pathogenesis of coronary artery disease (CAD). In this study we sought to evaluate the relations of MPO and PON1 with high density lipoprotein (HDL) mean size in patients with acute coronary syndrome (ACS). Collectively, 50 control subjects and 50 patients with ACS were participated in this study. MPO level and PON1 activity was determined using immunoassay and colorimetric methods, respectively. HDL mean size was determined by a dynamic light scattering methodology. Other clinical risk factors were also determined by standard methods. The MPO/PON1 ratio amount was significantly higher in patients with ACS (1.49±1.10) than in control subjects (0.21±0.14) (P<0.01). There was a significant correlation between MPO/PON1 ratio and HDL mean size in patients with ACS. Amount of the enzymes and their relations to HDL particle size in patients with ACS may play a part in the pathogenesis of ACS. Also, MPO/PON1 ratio may be a robust predictor of ACS.

Preparation and characterization of a sustained release buccoadhesive system for delivery of terbutaline sulfate

Terbutaline sulfate exhibits extensive first pass metabolism and a short elimination half life which makes frequent oral administration of the drug inevitable. A novel buccoadhesive controlled delivery system of the drug can easily overcome the problem. A two-layered core tablet composed of a fast release layer made of mannitol, lactose, PEG and the drug attached to a sustained release layer composed of drug, varying ratios of HPMC, Carbomer 934 (CP), and lactose capped with a buccoadhesive cup coated with an impermeable backing layer was developed. Buccoadhesive cup initially optimized for bioadhesion strength using HPMC and CP with various ratios. Drug transport through buccal membrane indicated a high permeability coefficient (0.00105 cm/sec). All tablets were acceptable with regard to drug contents, thickness, weight variations, hardness and drug content uniformity. The CP:HPMC 2:1 mixture showed the best mucoadhesion properties and was selected as excipient for the cup layer. Swelling index was higher for formulations containing greater amount of lactose and lower percentage of polymers. Fast release layer released its entire content within 15 min while sustained release layer lasted for 12 h. Drug release controlled by a combination of diffusion and chain relaxation mechanism.

Targeting etoposide to acute myelogenous leukaemia cells using nanostructured lipid carriers coated with transferrin

The aim of the present study was to evaluate the diverse properties of transferrin (Tf)-conjugated nanostructured lipid carriers (NLCs) prepared using three different fatty amines, including stearylamine (SA), dodecylamine (DA) and spermine (SP), and two different methods for Tf coupling. Etoposide-loaded NLCs were prepared by an emulsion-solvent evaporation method followed by probe sonication. Chemical coupling of NLCs with Tf was mediated by an amide linkage between the surface-exposed amino group of the fatty amine and the carboxyl group of the protein. The physical coating was performed in a Ringer-Hepes buffer medium. NLCs were characterized by their particle size, zeta potential, polydispersity index, drug entrapment percentage, drug release profiles and Tf-coupling efficiency. The cytotoxicity of NLCs on K562 acute myelogenous leukaemia cells was studied by MTT assay, and their cellular uptake was studied by a flow cytometry method. SA-containing NLCs showed the lowest particle size, the highest zeta potential and the largest coupling efficiency values. The drug entrapment percentage and the zeta potential decreased after Tf coupling, but the average particle size increased. SP-containing formulations released their drug contents comparatively slower than SA- or DA-containing NLCs. Unconjugated NLCs released moderately more drug than Tf-NLCs. Flow cytometry studies revealed enhanced cellular uptake of Tf-NLCs compared to unconjugated ones. Blocking Tf receptors resulted in a significantly higher cell survival rate for Tf-NLCs. The highest cytotoxic activity was observed in the chemically coupled SA-containing nanoparticles, with an IC(50) value of 15-fold lower than free etoposide.

Optimization of LDL targeted nanostructured lipid carriers of 5-FU by a full factorial design

Background:

Nanostructured lipid carriers (NLC) are a mixture of solid and liquid lipids or oils as colloidal carrier systems that lead to an imperfect matrix structure with high ability for loading water soluble drugs. The aim of this study was to find the best proportion of liquid and solid lipids of different types for optimization of the production of LDL targeted NLCs used in carrying 5-Fu by the emulsification-solvent evaporation method.

Materials and Methods:

The influence of the lipid type, cholesterol or cholesteryl stearate for targeting LDL receptors, oil type (oleic acid or octanol), lipid and oil% on particle size, surface charge, drug loading efficiency, and drug released percent from the NLCs were studied by a full factorial design.

Results:

The NLCs prepared by 54.5% cholesterol and 25% of oleic acid, showed optimum results with particle size of 105.8 nm, relatively high zeta potential of –25 mV, drug loading efficiency of 38% and release efficiency of about 40%. Scanning electron microscopy of nanoparticles confirmed the results of dynamic light scattering method used in measuring the particle size of NLCs.

Conclusions:

The optimization method by a full factorial statistical design is a useful optimization method for production of nanostructured lipid carriers.

Synthesis of octadecylamine-retinoic acid conjugate for enhanced cytotoxic effects of 5-FU using LDL targeted nanostructured lipid carriers

The aim of the present study was to reduce 5-FU side effects by targeted nanostructured lipid carriers (NLCs) to LDL receptors that are over expressed in colorectal carcinoma and also use of a new synthesized conjugate of retinoic acid as a cytotoxic agent. Fatty acyl amide derivative of retinoic acid was synthesized by its conjugation to octadecylamine with the expectation to improve its loading capacity in NLCs of 5-FU. The NLCs were prepared by an emulsification-solvent evaporation method using cholesterol and cholesteryl stearate. Physical properties and drug release were studied in NLCs. The cytotoxicity of NLCs loaded with 5-FU and retinoic acid conjugate was studied on colon cancer cells (HT29) using MTT assay. To confirm that drug targeting has been done through LDL receptors, APO-E was omitted from the cell culture and the MTT assay was repeated. FTIR and (1)H NMR spectra confirmed successful production of the conjugate. Results showed the IC(50) of free 5-FU was about 7.6 μM while in comparable concentration, the cytotoxicity of 5-FU loaded in NLCs containing the retinoic acid conjugate was nearly 2 fold of NLCs just loaded with 5-FU and more than 5 fold of free 5-FU. The retinoic acid conjugate loaded NLCs prepared by cholesterol can target LDL receptors of HT29 cells and seems promising in reducing 5-FU dose in colorectal cancer.

Development and evaluation of a novel pellet-based tablet system for potential colon delivery of budesonide

Budesonide, a potent glucocorticoid, is used for the treatment of inflammatory bowel diseases. Current available oral formulations of budesonide have low efficacy against ulcerative colitis because of the premature drug release in the upper part of the gastrointestinal tract. In this paper a pH- and time-controlled colon-targeted pellet-based tablet of budesonide was established. Pellet cores were prepared by extrusion-spheronization method and further coated with xanthan gum (barrier layer), Eudragit NE30D and L30D55 combination (inner layer), and Eudragit FS30 (as enteric layer) sequentially to achieve the required release profile. The coated pellets then compressed into tablets using inert tabletting granules of Cellactose or Pearlitol. Release studies, performed in simulated gastric, intestinal, and colon pH were used in sequence to mimic the gastrointestinal transit. The influence of formulation variables like barrier layer thickness, inner layer composition, and enteric coat thickness on drug release were investigated and the coated pellets that contained 12% weight gain in xanthan gum layer, Eudragit L30D55 and Eudragit NE30D with a ratio of 3 : 7 in inner layer with 30% weight gain and 25% weight gain in Eudragit FS layer were found to protect the drug release in stomach and small intestine and 83.35 ± 2.4 of budesonide was released at 24 h. The drug release from the tablets prepared using 40% Cellactose 80 as tableting excipient was found to be closely similar to that of uncompressed pellets.

Galactosylated nanostructured lipid carriers for delivery of 5-FU to hepatocellular carcinoma

The aim of the present study was to design a targeted delivery system of 5-fluorouracil (5-FU) for hepatocellular carcinoma (HCC). Lactobionic acid (LB) was conjugated to stearyl amine (SA) by a chemical reaction. The nanostructured lipid carriers (NLCs), containing LB conjugate, lecithin, glyceryl monostearate, oil [oleic acid (OA) or Labrafac 5 or 10%], and 5-FU, were dissolved in alcohol/acetone, the oil phase was added to the aqueous phase containing Tween 80 or Solutol(®) HS15 (0.25 or 0.5%), and NLCs were prepared by an emulsification-solvent diffusion method. Physical properties and drug release were studied in NLCs. The thiazolyl blue tetrazolium bromide assay was used to study the cytotoxicity of NLCs on HepG(2) cells, and the cellular uptake of NLCs was determined by flow cytometry. Fourier transform infrared spectroscopy and (1)H-NMR spectra confirmed the successful conjugation of LB and SA. The optimized NLCs consisted of 0.5% Solutol HS15 and 10% OA oil. The particle size of these nanoparticles was 139.2 nm, with a zeta potential of -18 mV, loading efficiency of 34.2%, release efficiency after 2 hours of the release test was 72.6%, and crystallinity was 0.63%. The galactosylated NLCs of 5-FU were cytotoxic on the HepG(2) cell line in a half concentration of 5-FU and seems promising in reducing 5-FU dose in HCC.

Stability evaluation of freeze-dried Lactobacillus paracasei subsp. tolerance and Lactobacillus delbrueckii subsp. bulgaricus in oral capsules

Freeze-drying is a common preservation technology in the pharmaceutical industry. Various studies have investigated the effect of different cryoprotectants on probiotics during freeze-drying. However, information on the effect of cryoprotectants on the stability of some Lactobacillus strains during freeze-drying seems scarce. Therefore, the aim of the present study was to establish production methods for preparation of oral capsule probiotics containing Lactobacillus paracasei subsp. tolerance and Lactobacillus delbrueckii subsp. Bulgaricus. It was also of interest to examine the effect of various formulations of cryoprotectant media containing skim milk, trehalose and sodium ascorbate on the survival rate of probiotic bacteria during freeze-drying at various storage temperatures. Without any cryoprotectant, few numbers of microorganisms survived. However, microorganisms tested maintained higher viability after freeze-drying in media containing at least one of the cryoprotectants. Use of skim milk in water resulted in an increased viability after lyophilization. Media with a combination of trehalose and skim milk maintained a higher percentage of live microorganisms, up to 82%. In general, bacteria retained a higher number of viable cells in capsules containing freeze-dried bacteria with sodium ascorbate after three months of storage. After this period, a marked decline was observed in all samples stored at 23°C compared to those stored at 4°C. The maximum survival rate (about 72-76%) was observed with media containing 6% skim milk, 8% trehalose and 4% sodium ascorbate.

Pectin Film Coated Pellets for Colon-targeted Delivery of Budesonide: In-vitro/In-vivo Evaluation in Induced Ulcerative Colitis in Rat

The main objective of this study was to prepare colon-specific pellets of budesonide, using pectin as film coating. Pellet cores of budesonide were prepared by extrusion / spheronization technique. Pectin, in different ratios was combined with Eudragit RS30D, Eudragit NE30D or Surelease to produce film coating. The dissolution profiles of pectin coated pellets were investigated in pH of 1.2 (2 h), pH of 7.4 (4 h) and pH of 6.8 in the absence as well as presence of rat cecal contents (18 h). Finally the selected formulation was evaluated on trinitrobenzenesulfonic acid (TNBS) induced ulcerative colitis in rat model, in comparison with conventional UC treatments. The dissolution profiles of pectin coated pellets showed that the release of budesonide in presence of rat cecal content depended on adjuvant polymer, the ratio of pectin to polymer and film thickness. Coated pellets, prepared out of pectin and Surelease at a ratio of 1:3 at coating level of 35% (w/w), could increase budesonide release statistically in presence of rat cecal content, while they released no drug in pH of 1.2 and 7.4. Animal experiments revealed the therapeutic efficacy of pectin/Surelease-coated pellets of budesonide in alleviating the conditions of TNBS-induced colitis model as reflected by weight gain, as well as improvement of clinical, macroscopic and microscopic parameters of induced colitis. This confirmed the ability of the optimized formulation for targeted drug delivery of budesonide to colon.