Witepsol H15 Research Articles

Formulation, characterization, and in vitro evaluation release nimesulide from different rectal suppository bases

Nimesulide is a poorly water-soluble, non-steroidal anti-inflammatory drug for both systemic and topical application. The aim of the study was to assess the influence of the type of base and surfactants (Tween80, Span80, soy lecithin, sodium lauryl sulphate) on drug release from rectal suppositories. Suppositories were prepared in the Unquator® using Cacao butter, Witepsol H15 and PEG1500:PEG400 as a base. The physicochemical properties of the prepared suppositories were in accordance to the Pharmacopoeia’s requirements. In vitro dissolution profile of the formulations was evaluated using USP apparatus 1. It has been shown that most of the nimesulide was released from suppositories prepared on PEG base. Addition of 2% surfactant to lipophilic base suppositories, significantly increased the amount of nimesulide released from all the investigated formulae. Among the formulations containing surfactants, only Witepsol H15 with Span 80 released a nearly complete drug during 210 minutes. The results indicate that the First-Order model is the best fit with the nimesulide in-vitro release from lipophilic suppositories, while the Higuchi model - to the PEG suppositories. The drug release kinetics from suppositories showed that the Cacao butter bases adequately fit data for zero-order kinetics model, while the Higuchi model - for the PEG suppositories.

Research on the composition development of suppositories with echinacea and study of their stability

The purpose of the work was to experimentally substantiate the composition and study the stability of extemporal suppositories with Echinacea, intended for use in complex therapy and prevention of genitourinary diseases.
 Materials and methods. The object of the study was samples of suppositories made by pouring using liquid Echinacea extract as an active pharmaceutical ingredient. Cocoa butter, Witepsol H15 and Witepsol W35 were used as suppository bases. The study was carried out using modern physicochemical, pharmaco-technological and microbiological methods.
 Results. On the basis of the carried out physicochemical and pharmaco-technological studies, it was found that in the manufacture of suppositories using liquid Echinacea extract, Cocoa butter or Witepsol can be used as a suppository bases. The main indicators of the quality of suppository samples were also studied: organoleptic characteristics, average weight, melting point, time of complete deformation, microbiological purity, meeting the requirements of the State Pharmacopoeia.
 Conclusions. As a result of the carried out physicochemical, pharmaco-technological and microbiological studies, a suppository base was selected for the creation of extemporal suppositories for the treatment and prevention of genitourinary diseases, the main quality indicators were established that meet the requirements of the State Pharmacopoeia of Ukraine, and the shelf life of the suppositories is 10 days.

Development, Characterization and In Vivo Pharmacokinetic Assessment of Rectal Suppositories Containing Combination Antiretroviral Drugs for HIV Prevention.

Receptive anal intercourse (RAI) contributes significantly to HIV acquisition underscoring the need to develop HIV prevention options for populations engaging in RAI practices. We explored the feasibility of formulating rectal suppositories with potent antiviral drugs for on-demand use. A fixed-dose combination of tenofovir (TFV) and elvitegravir (EVG) (40 mg each) was co-formulated in six different suppository bases (three fat- and three water-soluble). Fat-soluble witepsol H15 and water-soluble polyethylene glycol (PEG) based suppositories demonstrated favorable in vitro release and were advanced to assess in vivo pharmacokinetics following rectal administration in macaques. In vivo drug release profiles were similar for both suppository bases. Median concentrations of TFV and EVG detected in rectal fluids at 2 h were 1- and 2-logs higher than the in vitro IC50, respectively; TFV-diphosphate levels in rectal tissues met or exceeded those associated with high efficacy against rectal simian HIV (SHIV) exposure in macaques. Leveraging on these findings, a PEG-based suppository with a lower dose combination of tenofovir alafenamide (TAF) and EVG (8 mg each) was developed and found to achieve similar rectal drug exposures in macaques. This study establishes the utility of rectal suppositories as a promising on-demand strategy for HIV PrEP and supports their clinical development.

Development and Stability Study of an Omeprazole Suppository for Infants.

Background and ObjectiveOmeprazole is a proton pump inhibitor (PPI) that is used in acid suppression therapy in infants. In this study we aimed to develop a pediatric omeprazole suppository, with good physical and chemical stability, suitable for pharmaceutical batch production.MethodsThe composition of the suppository consisted of omeprazole, witepsol H15 and arginine (L) base. To achieve evenly distributed omeprazole suspension suppositories, the temperature, stirring rate, and arginine (L) base amount were varied. A previously validated quantitative high-performance liquid chromatography–ultraviolet method was modified and a long-term stability study was performed for one year.ResultsEvenly distributed omeprazole suspension suppositories were obtained by adding 100 mg arginine (L) base and pouring at a temperature of 34.7 °C and a stirring speed of 200 rpm. The long-term stability study showed no signs of discoloration and a stable omeprazole content between 90 and 110% over 1 year if stored in the dark at room temperature.ConclusionWe developed a pediatric omeprazole suppository. This formulation may provide a good alternative to manipulated commercial or extemporaneously compounded omeprazole oral formulations for infants. Clinical studies are needed to establish efficacy and safety in this young population.

Effect of Selected Surfactants on Kinetics of Meloxicam Release from Rectal Suppositories

The use of surfactants in suppository formulations has been suggested to improve the bioavailability of poorly soluble drugs. In the present study, different kinds of surfactants were investigated to understand their influence on meloxicam release from suppositories formulated with a lipophilic base. Tween 80, Span 80, soy lecithin and sodium lauryl sulfate were the surfactants used in this study. The suppositories were prepared in a recipe mixer using Witepsol H15 and cacao oleum as a base. The suppositories with and without the addition of surfactants were examined using physicochemical tests according to the Polish Pharmacopeia, the uniformity of mass of single-dose preparation test, the content uniformity test, the softening time determination of lipophilic suppositories test, the disintegration test of suppositories, and the dissolution test. All the prepared formulations complied with the pharmacopeia requirements. The prepared suppositories were evaluated for in vitro drug release immediately after preparation and after storage. The results revealed that the bioavailability of meloxicam was to 36 % from suppositories formulated with Witepsol H15 and 23.4 % those formulated with cacao oleum. Addition of surfactants to the suppository base significantly influenced both the amount and rate of meloxicam released into the phosphate buffer. The highest release rate of meloxicam was observed with the formulation prepared on a Witepsol H15 base with Tween 80. Present results have confirmed the possibility of using surfactants in suppository formulations, in order to improve the dissolution rate of meloxicam in vitro. As a consequence, a faster onset of pharmacodynamic action and better therapeutic effects of the medication can be obtained.

Improve Solubility of Acetamidophenol from PEG and Witepsol Suppositories via Formation of Inclusion Complex by β-Cyclodextrin with a Controlled Release Profile

Acetamidophenol (ACP) is used to treat mild to moderate pain and reduce fever, but low water solubility and poorly dissolution of this compound restricted its bioavailability. To overcome these problems and enhance the solubility of ACP, inclusion complex between ACP and β-cyclodextrin (β-CD) is formed with various mass ratios of β-CD:ACP (1:1, 1:2, 1:4, 1:8), and the effect of complex formation on solubility and release of ACP from PEG and Witepsol-based suppositories through rectal route of administration is investigated. Inclusion complexes formed with various ratios of β-CD:ACP and loaded in the formulation of suppositories by fusion method utilizing different suppository bases, i.e., Witepsol H15 and polyethylene glycol (4000, 400). FTIR, SEM, and XRD results indicate formation of inclusion complex between β-CD and ACP. Physical characteristics and in vitro drug release of the obtained suppositories are determined by several tests such as weight variation, melting point, hardness, and release rate. Results indicate that PEG-based suppositories containing β-CD:ACP 1:1 mass ratio show the best in vitro drug release characteristic which released 19.3% of ACP after 8 h.

Preparation and characterization of intravaginal vardenafil suppositories targeting a complementary treatment to boost in vitro fertilization process

Vaginal route has been recently considered as a potential route for systemic delivery of drugs with poor oral bioavailability. Vardenafil (VDF) is a relatively new phosphodiesterase-5 inhibitor that exhibits a limited oral bioavailability (≈15%) due to extensive first-pass metabolism. In this study, we attempted to enhance the systemic bioavailability of VDF via its formulation within vaginal suppositories. Witepsol H15 and Suppocire NA50 were adopted as lipophilic suppository bases while polyethylene glycol 4000/400 and glycerogelatin were used as hydrophilic suppository bases. The effect of different base types and/or the incorporation of bioadhesive polymer on in vitro release of VDF were evaluated. The in vivo fate and organ biodistribution of VDF following intravaginal (IVG) administration were also investigated. VDF release from water-soluble bases was higher than that from lipophilic bases. The incorporation of bioadhesive polymers, such as Na alginate, remarkably sustained drug release from suppository base. The organ biodistribution study showed a higher Cmax (32 times) and AUC0–4h (20 times) of VDF in uterus following IVG administration of conventional suppositories, compared to oral administration of VDF suspension. In addition, cyclic guanosine monophosphate (cGMP) serum levels, used as an indicator of the in vivo activity of VDF, in animals were higher following IVG administration rather than oral administration. This study suggests that IVG administration of VDF might represent a potential alternative to oral route with superior therapeutic benefits especially when targeting the uterus.

PREPARATION AND IN VITRO EVALUATION OF FAST RELEASE DIAZEPAM SUPPOSITORIES FOR FEBRILE SEIZURES

Objective: The objective of this study was to optimize the best formula for fast release suppositories of diazepam.Methods: Suppositories were prepared by fusion method using Witepsol H15 as oleaginous base, polyethylene glycol as a water-soluble polymer, and Poloxamer 188 as water miscible base. All suppositories were evaluated for physical characteristics, in vitro drug release and kinetic models. The effects of incorporating Tween 80 as a non-ionic surfactant, propylene glycol as a cosolvent, and effervescent pair on the release rate of diazepam from suppositories were investigated. Differential scanning calorimetry and Fourier transform infrared spectrometry were used to characterize physical mixtures of diazepam and the different used bases.Results: Many formulations of diazepam have been prepared and in vitro evaluated. PEG suppositories released diazepam more efficiently than poloxamer and witepsol suppositories. The including of an effervescent pair in the formulation of suppositories greatly enhanced the release of diazepam. The addition of tween 80 to witepsol suppositories, PG to poloxamer suppositories, increased the rate and extent of diazepam release.Conclusion: Fast release of diazepam has been obtained from suppositories containing the effervescent pair (formula F3), which also have good physical properties.

PREPARATION AND IN VITRO EVALUATION OF FAST RELEASE DIAZEPAM SUPPOSITORIES FOR FEBRILE SEIZURES

Objective: The objective of this study was to optimize the best formula for fast release suppositories of diazepam.Methods: Suppositories were prepared by fusion method using Witepsol H15 as oleaginous base, polyethylene glycol as water-soluble polymer and poloxamer 188 as water miscible base. All suppositories were evaluated for physical characteristics, in vitro drug release and kinetic models. The effects of incorporating Tween 80 as a nonionic surfactant, propylene glycol as a cosolvent, and effervescent pair on the release rate of diazepam from suppositories were investigated. Differential scanning calorimetry and Fourier transform infrared spectrometry were used to characterize physical mixtures of diazepam and the different used bases.Results: Fast release of diazepam has been obtained from suppositories containing the effervescent pair. Many formulations of diazepam have been prepared and in vitro evaluated. PEG suppositories released diazepam more efficiently than poloxamer and Witepsol suppositories. The including of an effervescent pair in the formulation of suppositories greatly enhanced the release of diazepam. The addition of Tween 80 to Witepsol suppositories, PG to poloxamer suppositories, increased the rate and extent of diazepam release.Conclusion: Fast release of diazepam has been obtained from suppositories containing the effervescent pair (formula F3), which also have good physical properties.

Influence of storage conditions on the physical and release properties of piroxicam suppositories formulated with lipophilic bases

This study investigated the effect of storage conditions on physical and release properties of lipophilic-based piroxicam suppositories with a view to determining the most desirable conditions for their storage. Piroxicam 20 mg suppositories were prepared by fusion method using cocoa butter, Witepsol H15® and Witepsol W35® to which 2 %w/w Tween 20® was added. Physical and dissolution properties of the suppositories were determined by established methods after preparation and at 4-month intervals for 12-month storage on the shelf (27.5 ± 0.9 °C to 32.5 ±0.8 °C) and in the refrigerator (4 ± 1 °C). The suppositories stored in the refrigerator hardened at the fourth month, with fat “blooming” observed on cocoa butter-based suppositories at 8th month. Melting points of cocoa butter-based suppositories remained below 37.5 °C on storage, while those formulated with Witepsol H15® and Witepsol W35® increased to 42.1 °C and 44.0 °C, respectively. Cocoa butter-based suppositories stored on the shelf showed decrease in melting range and mechanical strength compared with those stored in the refrigerator. There was increase in mechanical strength and disintegration time of the witepsol-based suppositories on aging. Release of piroxicam from witepsol bases decreased significantly (P < 0.05) on storage either in the refrigerator or on the shelf, while those formulated with cocoa butter base increased. In conclusion, piroxicam suppositories formulated with cocoa butter would require storage in the refrigerator, while long-term storage of those formulated with Witepsol H15® and Witepsol W35® in the refrigerator might not be desirable.Keywords: Piroxicam suppositories; Lipophilic bases; Storage conditions; Physical properties; Release properties

The effect of a lipid composition and a surfactant on the characteristics of the solid lipid microspheres and nanospheres (SLM and SLN)

Solid lipid microparticles (SLM) were produced by a two-step process that, firstly, involved the emulsification of the molten lipid phase in a heated aqueous phase and, secondly, the system cooling. Compritol 888 ATO and Precirol ATO 5, including their mixtures with Miglyol 812 or Witepsol H15 were used as lipid components (10–30% w/w). The average size of the SLM prepared with Compritol and Tween 80 as an emulsifier was 3–7μm and the influence of lipid concentration and thermal sterilization was not large. Dispersions of SLM with Precirol (10–20% w/w) gellified upon storage. SLM stabilized with another surfactant, Tego Care 450, were larger in size and measured 40μm on average. The use of the sonication step (5–15min) in hot formulations containing 5% w/w of Compritol resulted in the formation of the solid lipid nanoparticles (SLN) with average size 200–300nm. The smallest SLN size (below 100nm on average) was obtained in SLN that contained Tego Care and an antimicrobial agent Euxyl PE 9010; such combination evoked synergism between the surfactant and Euxyl components.

Preparation and In vitro Evaluation of Naproxen Suppositories.

The aim of this work was to develop the best formulations for naproxen suppositories. The effects of different bases and surfactants on the physicochemical characteristics of the suppositories were determined by several tests such as weight variation, melting point, assay, hardness, and release rate. All formulations met the standard criteria for tested physicochemical parameters; weight variation (97-112%), content uniformity (97-105%), melting point (4.66-8.7 min) and hardness tests (>5400 g). Based on release rate studies, hydrophilic, and lipophilic bases without surfactants were not suitable bases for naproxen suppository. Amongst the formulations containing surfactants only Witepsol H15 with 0.5% w/w of Tween 80 and Witepsol W35 with 0.5% of cetylpyridinium chloride were suitable and released nearly complete drug during 30 and 60 min, respectively. This study demonstrates the effects of incorporation of known agents on the in vitro release characteristics of naproxen suppository.

Formulation and Evaluation of Fixed Dose Combination Suppositories Containing Stavudine, Lamivudine and Nevirapine for Pediatric Applications

Suppositories are the convenient way of administering drugs in infants. In view of the lack of suitable pediatric antiretroviral formulations in the market, suppositories containing fixed dose combination (FDC) of stavudine, lamivudine and nevirapine (SLN) were developed to allow administration of the correct weight-related dose in pediatric HIV patients as recommended by WHO. Suppositories containing 10 mg of stavudine, 40 mg of lamivudine and 70 mg of nevirapine were prepared by the fusion method using Witepsol H15 semi-synthetic suppository base. All the prepared suppositories were evaluated for various physical parameters like weight variation, melting point, drug content and hardness. The rate and extent of drug release was evaluated using USP apparatus I and samples were analyzed by a validated UV-multicomponent method. The use of surfactants significantly increased the drug release from formulations manufactured with Witepsol H 15 fatty base. The development of pediatric fixed-dose combination formulations represent a new era and mark an important milestone for children living with HIV/AIDS.

Pediatric suppositories of sulpiride solid dispersion for treatment of Tourette syndrome: in vitro and in vivo investigations.

Pharmaceutical development was adopted in the current study to propose a pediatric rectal formulation of sulpiride as a substitute to the available oral or parenteral formulations in the management of Tourette syndrome (TS). The goal was to formulate a product that is easy to use, stable, and highly bioavailable and to achieve a rapid clinical efficacy. Towards this aim, sulpiride solid dispersion (SD) with tartaric acid at a weight ratio of 1:0.25 was incorporated into different suppository bases, namely witepsol W25, witepsol H15, witepsol E75, suppocire NA, suppocire A, glycerogelatin, and polyethylene glycols. The formulae were evaluated in vitro using different pharmacotechnical methods such as visual, melting, weight and content uniformities, drug release, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and X-ray diffraction (XRD) analyses. In vivo bioavailability was also assessed in rabbits to compare the bioavailability of either raw sulpiride-incorporated or its SD-incorporated witepsol H15-based suppositories to its oral suspension (reference). Sulpiride SD-incorporated witepsol H15 formulation showed acceptable in vitro characteristics with a bioavailability of 117% relative to oral dosing, which excel that in humans (27% after dosing of oral product). In addition, the proposed formula not only passed the 6-month stability study but also proposed a promising scale-up approach. Hence, it showed a great potential for pediatric product development to manage TS in rural areas.

Optimization of the production of solid Witepsol nanoparticles loaded with rosmarinic acid

During the last decade there has been a growing interest in the formulation of new food and nutraceutical products containing compounds with antioxidant activity. Unfortunately, due to their structure, certain compounds such as polyphenols, in particular rosmarinic acid (RA) are not stable and may interact easily with matrices in which they are incorporated. To overcome such limitations, the formulation of loaded polyphenols nanoparticles can offer an efficient solution to protect such compounds. Based on this rationale, the aim of this study was to prepare solid lipid nanoparticles (SLNs) loaded with RA using a hot melt ultrasonication method, where Witepsol H15 was used as lipid and Polysorbate 80 (Tween 80) as surfactant, following a 32 fractional factorial design, resulting in the use of 3 different percentages of surfactant (viz. 1, 2 and 3%, v/v) and lipid (0.5, 1.0 and 1.5%, w/v). The stability of the nanoparticles systems were tested during 28d in aqueous solution stored at refrigeration temperature (ca. 5°C), tracking the mean particle size of different formulations by photon correlation spectroscopy. To confirm RA entrapment, thermal analyses of the nanoparticles by DSC and FTIR were performed. The association efficiencies percentages (AE%) were determined using HPLC to quantitatively assess the RA in supernatants. Results showed that Witepsol H15 produced nanoparticles with initial mean diameters between 270 and 1000nm, yet over time, a slight increase occurred, but without occurrence of aggregation. The AE% showed a high percentage of encapsulation (ca. 99%), which reveals low polyphenol releases from SLNs throughout storage time. In general, results showed a successful production of SLNs with properties that can be used to food applications.

Identification and evaluation of agents isolated from traditionally used herbs against Ophiophagus hannah venom

The aim of this study was firstly to identify active molecules in herbs, that are traditionally used for the treatment of snake bite, such as Curcuma antinaia, Curcuma contravenenum, Andrographis paniculata, and Tanacetum parthenium; secondly to test similar structurally related molecules and finally to prepare and evaluate an efficient formulation against Ophiophagus hannah venom intoxification. Three labdane based compounds, including labdane dialdehyde, labdane lactone, and labdane trialdehyde and two lactones including 14-deoxy-11,12-didehydroandrographolide and parthenolide were isolated by column chromatography and characterised. Using the isolated rat phrenic nerve-hemidiaphragm preparation, the antagonistic effect of crude extracts, isolated compounds and prepared formulations were measured in vitro on the inhibition of the neuromuscular transmission. Inhibition on muscle contraction, produced by the 5 μg/mL venom, was reversed by test agents in organ bath preparations. A labdane trialdehyde, isolated from C. contravenenum, was identified as the best antagonising agent in the low micromolar range. Tests on formulations of the most potent C. contravenenum extract showed, that the suppository with witepsol H15 was an effective medicine against O. hannah venom. This study elucidated the active compounds, accounting for the antivenin activity of traditionally used herbs and suggested the most suitable formulation, which may help to develop potent medicines for the treatment of snake bite in the future.

ミアンセリン坐剤の院内製剤化へ向けた物理薬剤学的特性からのアプローチ

We tried to optimize the formulation for the hospital preparation of mianserin hydrochloride (MS) suppositories. MS as the raw material for the preparation was obtained from Tetramide tablets (MS-T), which were ground. The physicopharmaceutical properties of MS suppositories with bases of Witepsol H15 (H15), Witepsol W35 (W35) and Witepsol S55 (S55) were compared to choose the optimal base for the suppositories. The preparation strength correlated negatively among the three bases. The heat of fusion of MS-H15 suppositories was significantly low relative to MS-W35 and MS-S55 suppositories. The average drug release rate of MS-H15 suppositories exhibited the highest level on moment analysis. Comprehensive evaluation of the properties of MS suppositories, including the heat of fusion due to the solubility of the preparation and the drug release rate indicated that H15 was the optimal base for MS suppositories. Additionally, we examined the optimal mixing rate of ground MS-T and H15. The preparation strength positively correlated with an increased mixing rate of ground MS-T. The mean dissolution time (MDT) of suppositories was reduced with an increased mixing rate of ground MS-T. These results suggested that 0.10 g ground MS-T combined with 0.8 g H15 as the base was the optimal formulation for the hospital preparation of MS suppositories.

EFFECT OF DIFFERENT NON IONIC SURFACTANTS ON THE IN-VITRO RELEASE RATE OF A NON STEROIDAL ANTI-INFLAMMATORY DRUG FROM SOME LIPOPHILIC SUPPOSITORY BASES

Formulation of tolmetin sodium suppositories was carried out using different lipophilic bases as Novatta, suppocir NA10. suppocir W35, suppocir AM, Witepsol E75 and Witepsol H15. The in vitro release study of 200 mg tolmetin sodium suppository from these bases was performed in Sorensen's phosphate buffer (pH 7.4) at 37 °C. The results obtained revealed that Novatta and suppocir W35 gave the highest release rate followed by suppocir NA10, Witesol E75, Witepsol H15 and Suppocir AM respectively. The effect of type and concentrations of different non ionic surfactants as polysorbate 20, polysorbate 60, polysorbate 80, Brij 35, Brij 58, Myrj 53 and Myrj 59 on the drug release from suppocir AM was investigated.

Physicochemical properties, in vitro release and in vivo evaluation of tramadol hydrochloride rectal suppository and rectal gel

Abstract Background: Tramadol is a centrally acting analgesic drug. Rectal administration of tramadol is useful in the treatment of post-operative pain or malignant pain in cases where it cannot be administered orally. In Thailand, tramadol is available only as a capsule for oral use and as a solution for injection. Objective: Develop tramadol hydrochloride rectal suppositories and rectal gel preparations. Methods: Tramadol rectal suppository and rectal gel were prepared. Physicochemical properties (viscosity, gel strength, mucoadhesive force) and the in vitro release of tramadol hydrochloride were investigated from different bases (Witepsol H15, polyethylene glycol, poloxamer, and hydroxyethylcellulose). The analgesic activity of rectal tramadol hydrochloride using the hot plate test was evaluated in rats. Results: Tramadol hydrochloride rectal gel using poloxamer was more mucoadhesive to the rectal mucous membrane than was the gel with the hydroxyethylcellulose base. Tramadol hydrochloride was released rapidly in vitro from both the Witepsol H15 and polyethylene glycol bases. It was completely released from the polyethylene glycol suppository base within 15 minutes. The amount of tramadol hydrochloride release from the Witepsol H15 suppository base was about 93% at 120 minutes. When using poloxamer or hydroxyethylcellulose as a rectal base, tramadol hydrochloride was released from both bases rapidly and completely released within 15 minutes. Administration of a tramadol hydrochloride suppository in rats exhibited a more pronounced analgesic effect with the polyethylene glycol base than with the Witepsol H15-based suppositories. The rectal gel had a less pronounced analgesic effect when made with the hydroxyethylcellulose base than with the poloxamer base. Conclusion: Tramadol hydrochloride suppositories and rectal gels with different bases showed rapid and almost complete drug release from the bases, prolonging the latency of a nociceptive response in in vivo experiments.

Preparation and evaluation of fenoterol hydrobromide suppositories

Fenoterol HBr is a bronchodilator known to be subject to first pass effect after oral administration. The aim of this study was to prepare and evaluate fenoterol HBr suppositories. Suppositories were prepared by a fusion method using different fatty bases, viz. Witepsol H15, Witepsol E75, Suppocire AP, and Suppocire BM, as well as different hydrophilic bases, viz. polyethylene glycol and poloxamer bases. In vitro release studies revealed a greater release of the drug from hydrophilic bases than from fatty bases. The effect of incorporating different types and concentrations of non-ionic surfactants (Tween 60 and Span 20) on the release rate of the drug from Witepsol H15, as a model fatty base, was investigated. Results showed an enhanced release at low surfactant concentrations. A very fast 100% drug release was achieved when the drug was incorporated as an aqueous solution in Witepsol H15 (F17). This formula was selected to test the effect of fenoterol HBr suppositories on histamine-induced bronchospasms in Guinea pigs. No dyspnea of the animals was recorded for up to 30 min. In addition, thermogel liquid suppositories of different poloxamer 188 and poloxamer 407 proportions in the presence of sodium alginate as a mucoadhesive polymer were prepared. The different formulations behaved similarly concerning sustainment of drug release, however, only the formula containing 15% poloxamer 188 and 25% poloxamer 407 (F20) showed optimal gelation at body temperature. In conclusion, among the studied suppository bases there are bases suitable for fast release of the drug like F17 and hydrophilic bases especially polyethylene glycol, as well as other bases for sustained release applications of fenoterol HBr like fatty and thermogel bases.