New oral solid dosage form for furosemide oral administration

Formulation and In Vitro Evaluation of Furosemide Floating Matrix Tablets Using Boswellia papyrifera Resin as Matrix Forming Polymer

The stomach and upper part of the small intestine are where furosemide is primarily absorbed when treating edema brought on by congestive heart failure (CHF), hepatic cirrhosis, renal impairment, and nephrotic syndrome. This narrow absorption window is responsible for furosemide's limited oral bioavailability. So creating a gastroretentive floating tablet could be beneficial. Natural polymers are advised for use in medication delivery because they are readily available in nature, biodegradable, relatively inexpensive, biocompatible, and nontoxic. Olibanum is a natural plant-based polymer obtained from Boswellia genus of trees and mainly composed of alcohol-soluble resin (65-85%). Ethiopia is rich in Boswellia species, with Boswellia papyrifera being the most important oleo-gum resin-producing tree species. In order to formulate a gastroretentive floating matrix tablet of furosemide, this study looked at the use of naturally occurring, locally available B. papyrifera resin as a matrix-forming polymer. By directly compressing B. papyrifera resin and HPMC K4M as matrix-forming polymers and sodium bicarbonate as a gas-generating agent, floating matrix tablets were created. The effects of the formulation variables polymer type, polymer concentration, polymer ratio, and percentage of the floating agent on the floating lag time, total floating time (duration), and cumulative drug release in 12 hours were investigated. Furosemide floating tablets formulated employing higher (40%) polymer concentrations (olibanum resin, HPMC K4M, or in combination) and 10% sodium bicarbonate as gas-generating agent demonstrated a floating lag time of less than 6 minutes and a sustained release with a total floating time of more than 12 hours. Comparing the release characteristics of floating tablets made with 40% of a total polymer and 10% of NaHCO3 revealed that the medicine is released very slowly when polymers were combined. The matrix-forming polymer, olibanum resin, obtained from B. papyrifera, was effectively used to make furosemide floating matrix tablets. The olibanum resin from B. papyrifera can therefore be used as a potential substitute matrix-forming polymer in the production of effervescent floating matrix tablets.

Formulation and characterization of sustainable bioadhesive films for wound treatment based on barley β-glucan extract obtained using the high power ultrasonic technique

β-glucan is a well-known functional and bioactive food ingredient. Recently, some studies highlighted several interesting pharmacological activities, such as hypocholesterolemic, hypoglycemic, immunomodulatory, antitumor, antioxidant and anti-inflammatory. The aim of this study is to evaluate a novel application of β-glucan, obtained from barley, for the development of formulations for skin use. Several water suspensions were obtained from barley flour of different particle sizes treated by high power ultrasonic (HPU) technique. Barley flour fraction in the range of 400-500 μm allowed to obtain a stable suspension, represented both by a water soluble and water insoluble fraction of β-glucans, that showed excellent film forming ability. The plasticizer sorbitol as well as the bioadhesive biopolymer acacia gum were added to this suspension in order to obtain a gel suitable to prepare films by casting. The obtained films demonstrated suitable mechanical properties and ability to stimulate in vitro keratinocytes growth suggesting its possible application in dermatological field as for wound treatment. This study demonstrated the dual use of barley suspension: as excipient and as active ingredient.

Effect of functional excipients on the dissolution and membrane permeation of furosemide formulated into multiple-unit pellet system (MUPS) tablets

The effect of functional excipients (i.e. chitosan, sodium lauryl sulphate, NaHCO₃, and CaCO₃) formulated in multiple-unit pellet system (MUPS) tablets has been investigated on the dissolution and permeability of furosemide, a BCS class IV compound. Spherical beads were produced and compressed into MUPS tablets. MUPS tablet formulations were evaluated for hardness, disintegration, mass variation, friability, and dissolution (pH 1.2, pH 4.6, and pH 7.4). Ex vivo permeability studies were conducted across excised pig tissues (pyloric antrum and duodenal region) on selected experimental MUPS tablet formulations. Histological analysis was conducted on the tissues after exposure to selected experimental MUPS tablet formulations. Dissolution results in the 0.1 M HCl (pH 1.2) showed the highest effect of the excipients on furosemide release. Dissolution parameters showed increased dissolution of furosemide for the MUPS tablet formulations containing functional excipients: a 4.5-10-fold increase in the AUC values, the %_max showed a 60-70% increase and up to a 19-fold increase in DRi was seen. Permeability results revealed a 2.5-fold higher cumulative percentage transport for selected formulations. The results proved that functional excipients incorporated into beads, compressed into MUPS tablet formulations increased furosemide release as well as permeation across excised intestinal tissues.

Preparation of Ginkgolide Solid Dispersions with Low-Molecular-Weight Chitosan and Assessment of their Protective Effect on Isoproterenol- Induced Myocardial Injury

BACKGROUND

Ginkgolides are widely used in cardio-protective therapy; however, poor bioavailability currently limits their application.

OBJECTIVE

The purpose of this study was to demonstrate whether solid dispersions prepared with Low- Molecular-Weight Chitosan (LMWC) could improve the protective effect of ginkgolides on Myocardial Injury (MI).

METHODS

Ginkgolide Solid Dispersions (GKSD) were prepared with LMWC. Their properties were then characterized using differential scanning calorimetry, X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. In vivo pharmacokinetic studies were performed in rats, and the protective effect of GKSD on MI was investigated by western blotting and immunohistochemical analyses.

RESULTS

Drug dissolution testing showed that GDSD were released at a significantly higher rate than ginkgolides, dissolved by alternative methods, suggesting that LMWC facilitates the release of ginkgolides. Differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy all showed that GKSD was amorphous. In-vivo testing revealed larger AUC_0-t, higher C_max, and shorter T_max for GKSD compared to that in original ginkgolides. Myocardial injury was induced in rats with isoproterenol to test the protective effect of GKSD. GKSD alleviated MI and reduced myocardial fibrosis, as observed by Hematoxylin and Eosin staining. Compared with the crude drug group, the secretion of malonyl dialdehyde and nitric oxide and expression of NOX-2 and NOX-4 were lower. The activities of the cardiac marker enzymes SOD, CAT, GPX, GPX-1, and GSH were higher in GKSD-administered rats, indicating a beneficial effect of GKSD in eliminating free radicals during myocardial injury. Additionally, western blotting and immunohistochemical analysis showed that GKSD markedly reduced the expression of signaling proteins RHOA, ROCK1, ROCK2, and RAC1.

CONCLUSION

Solid dispersions prepared with low molecular weight chitosan improved the oral bioavailability of ginkgolide and enhanced its protective effect on myocardial injury.

Formulation and in vitro evaluation of self-nanoemulsifying liquisolid tablets of furosemide

Self-nanoemulsifying drug delivery systems (SNEDDS) were used to enhance the dissolution rate of furosemide as a model for class IV drugs and the system was solidified into liquisolid tablets. SNEDDS of furosemide contained 10% Castor oil, 60% Cremophor EL, and 30% PEG 400. The mean droplets size was 17.9 ± 4.5 nm. The theoretical model was used to calculate the amounts of the carrier (Avicel PH101) and coating materials (Aerosil 200) to prepare liquisolid powder. Carrier/coating materials ratio of 5/1 was used and Ludipress was added to the solid system, thus tablets with hardness of 45 ± 2 N were obtained. Liquisolid tablets showed 2-folds increase in drug release as compared to the generic tablets after 60 min in HCl 0.1 N using USP apparatus-II. Furosemide loaded SNEDDS tablets have great prospects for further in vivo studies, and the theoretical model is useful for calculating the adequate amounts of adsorbents required to solidify these systems.

Evaluating ternary systems with oligosaccharides as a strategy to improve the biopharmaceutical properties of furosemide

Novel ternary systems with β-cyclodextrin or maltodextrin and triethanolamine as the third component were developed with the aim of improving the oral bioavailability of furosemide. These new solids were characterized by solid-state nuclear magnetic resonance, Fourier transform infrared and Raman spectroscopy, X-ray powder diffractometry, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. The solubility, dissolution and stability (chemical and physical) were studied. Among the most important results, it was observed that both ternary systems showed an important enhancement in the solubility of the drug. In particular, the system obtained by combination of β-cyclodextrin and TEA exhibited improvement in the dissolution profiles and photo-stability of furosemide compared with the binary system previously reported. Moreover, this system constitutes an interesting therapeutic alternative as it did not produce cellular toxicity compared with free furosemide. In conclusion, the results obtained revealed that this ternary system establishes a promising approach for oral delivery of the drug.

New Technological Approach for Glycyrrethic Acid Oral and Topical Administration

Background:

18β- glycyrrhetinic acid (Gly) is the major bioactive component of licorice roots and rhizomes of the Glycyrrhiza glabra species. It shows many activities such as antiviral, anti-inflammatory, antioxidant, antimicrobial, and antifungal, however, its use in the health field is very limited due to the low water solubility.

Methods:

This paper deals with the development of a new technological approach for Gly dissolution rate enhancement. It consists of Gly intercalation (guest) in the interlamellar spaces between the inorganic spaces (host) of the anionic clays “hydrotalcites” (HTlc) to obtain hybrids MgAl-HTlc-Gly and ZnAl-HTlc-Gly. Gly can find applications in both systemic and local therapies, thus advantages of the use of the hybrids in these two fields were investigated.

Results:

Gly dissolution rate from hybrids in the intestinal environment, site in which it is preferentially absorbed, resulted enhanced (ZnAl-HTlc-Gly > MgAl-HTlc-Gly) compared to the crystalline form, thereby, making them suitable for oral administration as dry powder in hard capsules.

:

For a local therapy, bioadhesive, vaginal emulgels loaded with the hybrids were developed. These showed suitable mucoadhesive property to the vaginal mucosa, necessary to prolong the residence time in the application site. The emulgel containing ZnAl-HTlc-Gly showed a faster and higher release profile than that containing MgAl- HTlc-Gly.

Conclusions:

The obtained results suggest that Gly intercalation into HTlc, especially in ZnAl-HTlc, allows to enhance Gly dissolution when the hybrids are formulated both as oral or topical products.

Development and Characterization of Eudragit®-Based Electrospun Nanofibrous Mats and Their Formulation into Nanofiber Tablets for the Modified Release of Furosemide

Furosemide, a chloride channel blocker ordinarily used as a high-ceiling or loop diuretic, is practically insoluble in water and dilute acids. Due to its acidic nature, furosemide is mostly absorbed in the stomach and in the upper small intestine. Efforts have focused on the development of sustained release systems of furosemide in order to improve the effectiveness of the drug, which exhibits poor aqueous solubility and poor permeability. Recently, electrospun nanofibrous drug delivery systems have emerged as promising alternative solid-dosage forms due to their advantages of high porosity, high surface to volume ratio, and high drug-loading efficacy. Herein, a number of nanofibrous mats composed of different types of Eudragit® polymers in various concentrations and combinations loaded with furosemide were designed, successfully electrospun, and characterized using SEM, FTIR, DSC, and TGA analyses. The nanofibrous nonwovens were formulated in nanofiber tablets and the release profile of furosemide from them was evaluated at pH 1.2 and 6.8 and compared to that of physical mixture matrix tablets of analogous composition as well as to that of a commercial formulation. It was found that the release of furosemide was compatible with the gastroretentive and slower intestinal release requirements with a well-defined absorption window, while some nanofiber formulations could act as furosemide carriers in emergency situations where a relatively fast onset of its action is required, as in the case of critically ill post-traumatic patients.

Influence of Solvent Composition on the Performance of Spray-Dried Co-Amorphous Formulations

Ball-milling is usually used to prepare co-amorphous drug–amino acid (AA) mixtures. In this study, co-amorphous drug–AA mixtures were produced using spray-drying, a scalable industrially preferred preparation method. The influence of the solvent type and solvent composition was investigated. Mixtures of indomethacin (IND) and each of the three AAs arginine, histidine, and lysine were ball-milled and spray-dried at a 1:1 molar ratio, respectively. Spray-drying was performed at different solvent ratios in (a) ethanol and water mixtures and (b) acetone and water mixtures. Different ratios of these solvents were chosen to study the effect of solvent mixtures on co-amorphous formulation. Residual crystallinity, thermal properties, salt/partial salt formation, and powder dissolution profiles of the IND–AA mixtures were investigated and compared to pure crystalline and amorphous IND. It was found that using spray-drying as a preparation method, all IND–AA mixtures could be successfully converted into the respective co-amorphous forms, irrespective of the type of solvent used, but depending on the solvent mixture ratios. Both ball-milled and spray-dried co-amorphous samples showed an enhanced dissolution rate and maintained supersaturation compared to the crystalline and amorphous IND itself. The spray-dried samples resulting in co-amorphous samples were stable for at least seven months of storage.

Nanostructured hybrids for the improvement of folic acid biopharmaceutical properties

OBJECTIVES

Folic acid (FA) is an important source for the prevention of many diseases. However, its use is limited because the very low solubility (<10 mg/l particularly in the gastric environment) responsible for the incomplete adsorption of the administered dose. This study proposes a technological strategy to overcome this problem enhancing FA dissolution rate by means of a formulation able to make completely bioavailable the whole administered dose.

METHODS

Folic acid was intercalated in the layered double hydroxides (LDHs) MgAl-LDH and ZnAl-LDH. The obtained inorganic-organic nanostructured hybrids MgAl-LDH-FA and ZnAl-LDH-FA were deeply characterized and used to prepare immediate release tablets presenting very simple compositions. The hybrids, both as simple powders and as tablets, were submitted to in-vitro release studies mimic the gastric environment conducted both in sink and non-sink conditions.

KEY FINDINGS

Folic acid release from hybrids, as single powders or as tablets, resulted enhanced in both experiments in comparison with crystalline FA.

CONCLUSIONS

Obtained results showed that FA-LDH nanostructured hybrids are a promising strategy able to enhance the active ingredient dissolution at low pH values representing a promising approach suitable to realize innovative and effective nutraceutical products.

Formulation design of oral pediatric Acetazolamide suspension: dose uniformity and physico-chemical stability study

CONTEXT

The formulation of an active pharmaceutical ingredient (API) as oral solution or suspension in pediatrics is a habitual practice, due to the non-existence of many commercialized medicines in pediatric doses. It is also the simplest way to prepare and administer them to this vulnerable population. The design of a formulation that assures the dose and the system stability depends on the physico-chemical properties of the API.

OBJECTIVE

In this study, we formulate a class IV API, Acetazolamide (AZM) as suspension for oral administration to pediatric population. The suspension must comply attributes of quality, safety and efficacy for this route of administration.

MATERIALS AND METHODS

We use simple compounding procedures, as well as fewer pure excipients, as recommended for children. Mass and uniformity content assays and physical and chemical stability studies were performed. To quantify the API an UPLC method was used.

RESULTS AND DISCUSSION

We verified the physico-chemical stability of the suspensions and that they passed the mass test of the European Pharmacopeia (EP), but not the dose uniformity test.

CONCLUSIONS

This reveals that AZM must be formulated as liquid forms with a more complex system of excipients (not usually indicated in pediatrics), or otherwise solid forms capable of assuring uniformity of mass and dose for every dosage unit.

pH-triggered drug release from biodegradable microwells for oral drug delivery

Microwells fabricated from poly-L-lactic acid (PLLA) were evaluated for their application as an oral drug delivery system using the amorphous sodium salt of furosemide (ASSF) as a model drug. Hot embossing of PLLA resulted in fabrication of microwells with an inner diameter of 240 μm and a height of 100 μm. The microwells were filled with ASSF using a modified screen printing technique, followed by coating of the microwell cavities with a gastro-resistant lid of Eudragit® L100. The release behavior of ASSF from the coated microwells was investigated using a μ-Diss profiler and a UV imaging system, and under conditions simulating the changing environment of the gastrointestinal tract. Biorelevant gastric medium (pH 1.6) was employed, after which a change to biorelevant intestinal release medium (pH 6.5) was carried out. Both μ-Diss profiler and UV imaging release experiments showed that sealing of microwell cavities with an Eudragit® layer prevented drug release in biorelevant gastric medium. An immediate release of the ASSF from coated microwells was observed in the intestinal medium. This pH-triggered release behavior demonstrates the future potential of PLLA microwells as a site-specific oral drug delivery system.

Physical-chemical properties of furosemide nanocrystals developed using rotation revolution mixer

Recently, several approaches have been reported to improve the dissolution rate and bioavailability of furosemide, a class IV drug. However, to the best of our knowledge, none of them proposed nanocrystals. In the last decade, nanocrystals successfully addressed solubility issues by increasing surface area and saturation solubility, both leading to an increase in the dissolution rate of poor water soluble drugs. The preparation of furosemide nanocrystals was by a rotation revolution mixer method. Size distribution and morphology were performed using laser diffraction and scanning electron microscopy, respectively. In addition, differential scanning calorimetry, thermogravimetry, X-ray powder diffraction (XRD) and low frequency shift-Raman spectroscopy allowed investigating the thermal properties and crystalline state. Solubility saturation and intrinsic dissolution rate (IDR) studies were conducted. The thermal analysis revealed lower melting range for the nanocrystals comparing to furosemide. Moreover, a slight crystalline structure change to the amorphous state was observed by XRD and confirmed by low frequency shift Raman. The particle size was reduced to 231 nm with a polydispersity index of 0.232, a 30-fold reduction from the original powder. Finally, the saturation solubility and IDR showed a significant increase. Furosemide nanocrystals showed potential for development of innovative formulations as an alternative to the commercial products.

Development and characterization of solid dispersion for dissolution improvement of furosemide by cogrinding method

PURPOSE

The purpose of this study was to prepare and characterize solid dispersion formulation of furosemide to enhance dissolution rate.

METHODS

Solid dispersions with different drug: carrier ratios were prepared by cogrinding method using crospovidone and microcrystalline cellulose as carrier. The physical state and interactions between the drug and carrier were characterized by Fourier transform infrared spectroscopic (FT-IR) and X ray diffraction (XRD).

RESULTS

Solid dispersions (especially with drug: Carrier ratio of 1:2) showed a higher dissolution rate than their respective physical mixture and pure furosemide. Dissolution rate in pH 5.8 was also higher than pH 1.2. The XRD analysis showed that crystalline form was changed to the amorphous state in the solid dispersions. FT-IR analysis did not show any physicochemical interactions in the solid dispersion formulations. Release kinetic of formulations were fitted best to the Weibull and Wagner log probability (linear kinetic) as well as suggested 2 and Gompertz (non-linear kinetic) models.

CONCLUSION

The dissolution properties of furosemide were improved with the use of hydrophilic carriers in solid dispersions due to change in the crystalline form of the drug and more intimate contact between drug and carriers which was dependent on the type and ratio of carrier as well as dissolution medium pH.

Gastroretentive inorganic-organic hybrids to improve class IV drug absorption

Therapeutic efficacy of some orally administered molecules is often conditioned by their solubility in physiological fluids as well as their absorption. The last aspect becomes more limitative and conditioning drug plasmatic profiles when the active ingredient is preferentially absorbed in a specific region of the gastrointestinal tract. A case is represented by furosemide (FURO) preferentially absorbed in the stomach, site in which, because of its acidic nature, is poorly soluble. To solve this problem new oral solid formulations have been developed. The inorganic-organic hybrid MgAl-HTlc-FURO has been formulated in tablet in which floating and mucoadhesion properties have been combined. Swellable (Methocel K4, Methocel K15, Methocel K100 M, hydroxypropyl methyl cellulose) or swellable/erodible polymers (Methocel E50 LV, Methocel K100 LV), used to obtain the floating, were combined to Carbopol(®) (971P or 974P) to confer mucoadhesion capacity. Prepared tablets were deeply characterized in terms of hydration capacity, erosion %, buoyancy lag time/floating time and mucoadhesion. The most suitable tablets selected from these preliminary tests, submitted to in vitro release studies, showed a sustained release of FURO. This is useful to maintain the therapeutic concentrations for a long time, in comparison to conventional dosage forms, thanking to the enhancement of formulation residence time in the stomach.

Melt dispersion granules: formulation and evaluation to improve oral delivery of poorly soluble drugs - a case study with valsartan

Solid dispersion (SD) technique is a promising strategy to improve the solubility and dissolution of BCS class II drugs. However, only few products are marketed till today based on SD technology due to poor flow properties and stability. The present work was intended to solve these problems by using combination approach, melt dispersion and surface adsorption technologies. The main aim of the present work is to improve the absorption in the stomach (at lower pH) where the absorption window exists for the drug by improving the dissolution, resulting in the enhancement of oral bioavailability of poorly soluble, weakly acidic drug with pH dependant solubility, i.e. valsartan. Melt dispersion granules were prepared in different ratios using different carriers (Gelucire 50/13, PEG 8000 and Pluronic F-68) and lactose as an adsorbent. Similarly, physical mixtures were also prepared at corresponding ratios. The prepared dispersion granules and physical mixtures were characterized by FTIR, DSC and in vitro dissolution studies. DSC studies revealed reduction in the crystallinity with a possibility of presence of amorphous character of drug in the dispersion granules. From dissolution studies, valsartan Gelucire dispersion (GSD4; 1:4 ratio) showed complete drug release in 30 min against the plain drug which showed only 11.31% of drug release in 30 min. Pharmacokinetic studies of optimized formulation in male Wistar rats showed 2.65-fold higher bioavailability and 1.47-fold higher Cmax compared to pure drug. The melt dispersion technology has the potential to improve dissolution and the bioavailability of BCS class II drugs.

Biorelevant characterisation of amorphous furosemide salt exhibits conversion to a furosemide hydrate during dissolution

Biorelevant dissolution behaviour of the amorphous sodium salt and amorphous acid forms of furosemide was evaluated, together with investigations of the solid state changes during in vitro dissolution in medium simulating the conditions in the small intestine. UV imaging of the two amorphous forms, as well as of crystalline furosemide salt and acid showed a higher rate of dissolution of the salt forms in comparison with the two acid forms. The measured dissolution rates of the four furosemide forms from the UV imaging system and from eluted effluent samples were consistent with dissolution rates obtained from micro dissolution experiments. Partial least squares-discriminant analysis of Raman spectra of the amorphous acid form during flow through dissolution showed that the amorphous acid exhibited a fast conversion to the crystalline acid. Flow through dissolution coupled with Raman spectroscopy showed a conversion of the amorphous furosemide salt to a more stable polymorph. It was found by thermogravimetric analysis and hot stage microscopy that the salt forms of furosemide converted to a trihydrate during dissolution. It can be concluded that during biorelevant dissolution, the amorphous and crystalline furosemide salt converted to a trihydrate, whereas the amorphous acid exhibited fast conversion to the crystalline acid.