Oral sustained delivery of atenolol from floating matrix tablets-formulation and in vitro evaluation

Bioequivalence Study of Atenolol Tablets in Healthy Chinese Subjects Under Fasting and Fed Conditions

Atenolol, a cardioselective β1-blocker, exhibits efficacy in treating cardiovascular diseases. We conducted a single-center, randomized, open, single-dose, 2-preparation, 2-cycle, 2-sequence, double-crossover trial with a 7-day washout period to investigate the pharmacokinetics, bioequivalence (BE), and safety of test and reference atenolol tablets (25 mg) in healthy Chinese volunteers. Forty-eight healthy participants were randomized into the fasting and fed arms. After administering a single oral dose of the test or reference formulation (25 mg), plasma atenolol concentrations were measured using liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were obtained from concentration-time profiles. In total, 23 and 24 individuals were included in the fasting and fed arms, respectively. The mean concentration-time profiles for both formulations were similar, and Cmax, AUC0-t, and AUC0-∞ were within the BE range of 80%-125%. Thirteen adverse events (AEs) were observed in 7 participants in the fasting arm; 1 withdrew from the trial early owing to an AE. In the fed arm, 20 AEs were observed in 8 participants, and none withdrew from the trial. All adverse reactions were grade I, with no serious AEs or deaths. Therefore, the 2 tablets are bioequivalent in healthy Chinese individuals under fasting and fed conditions, supporting their further clinical development.

Design, preparation, and in vitro evaluation of gastroretentive floating matrix tablet of mitiglinide

The present research is focused on developing floating matrix tablets of mitiglinide to prolong its gastric residence time for better absorption. Gastroretentive tablets were prepared using a direct compression technique with hydroxypropyl methylcellulose K15M (HPMC K15M) and sodium alginate as matrix-forming polymers and sodium bicarbonate as the gas-forming agent. A 32 full factorial design was adopted to optimize the flotation and release profile of the drug. The concentration of HPMC K15M and sodium alginate were taken as the independent variables, and the floating lag time, time required for 50% drug release, and time required for 90% drug release were taken as dependent variables. The compatibility between drug and excipients was assessed by Fourier transform infrared (FTIR) spectroscopy. The prepared tablets were evaluated for different parameters such as hardness, friability, drug content, floating time, in vitro dissolution, and stability. Dissolution data were analyzed using various kinetic models to ascertain the mechanism of drug release. Finally, a radiographic study was conducted to estimate the retention time of the optimized floating matrix tablets of mitiglinide inside the body. The results revealed that all the physical properties of the developed formulations were within standard limits. The formulation M3, with the maximum amount of both independent variables, was considered to be the optimized formulation based on the desirability value. In addition, the optimized M3 formulation showed stability for over 6 months, as evidenced by insignificant changes in lag time, drug release pattern, and other physical properties. Furthermore, radiographic examination indicated that the tablets remained afloat in gastric fluid for up to 12 h in the rabbit’s stomach. In conclusion, the developed floating matrix tablet of mitiglinide could be regarded as a promising formulation that could release the drug in the stomach at a controlled rate and, hence, offer better management of type II diabetes.

Preparation of Sterculia foetida-pullulan-Based Semi-interpenetrating Polymer Network Gastroretentive Microspheres of Amoxicillin Trihydrate and Optimization by Response Surface Methodology

Objectives

In this study, a novel Sterculia foetida and pullulan-based semi-interpenetrating polymer network gastroretentive microsphere formulation was prepared using the emulsion crosslinking method and optimized by central composite design.

Materials and Methods

The effects of the amounts of glutaraldehyde, S. foetida, and pullulan on the percent drug entrapment efficiency (EE), percent mucoadhesion at 12 h, and percent in vitro drug release at 12 h were optimized. The microspheres were characterized using scanning electron microscopy, fourier transform infrared spectroscopy, and differential scanning calorimetry.

Results

The formulation containing 4% v/v glutaraldehyde, 8.28% w/v pullulan, and 2.14% w/v S. foetida had 88.75±1.18% EE, 80.43±1.2% drug release at 12 h, and 81.73±1.50% mucoadhesion at 12 h, which was considered optimum and was used in an in vivo radiographic study.

Conclusion

Semi-interpenetrating polymer network microspheres loaded with amoxicillin trihydrate were successfully prepared using S. foetida and pullulan. The prolonged retention of microspheres in the stomach with sustained drug release could effectively act against Helicobacter pylori reservoirs in the stomach and improve the therapeutic effect of amoxicillin trihydrate against H. pylori.

Design and optimization of nano invasomal gel of Glibenclamide and Atenolol combination: in vitro and in vivo evaluation

Background

There are many circumstances where chronic disease is associated with other disorders, especially in diseases such as diabetes with noncommunicable disease risk factors, such as hypertension. The current therapies for treating such chronic comorbid diseases are limited and challenging due to the difficulties in overcoming the side effects from complex therapeutic treatment regimen. The present study is aimed to develop and optimize the combinational nano invasomal gel of Glibenclamide (GLB) and Atenolol (ATN) as a novel combination therapy for comorbid treatment of diabetic hypertensive patients. The developed formulations were characterized for various parameters, including in-vitro skin permeation, skin irritation, in-vivo antidiabetic, and antihypertensive activities.

Results

OCNIG showed that the % entrapment efficiency of GLB is 96.67 ± 0.65% and % entrapment efficiency of ATN is 93.76 ± 0.89%, flux of GLB (240.43 ± 1.76 μg/cm2/h), and flux of ATN (475.2 ± 1.54 μg/cm2/h) which was found to conform to the expected value. The results indicated desired release and permeation profiles. Optimized formulation showed significant pharmacokinetic properties, which shows improvement in bioavailability by 134.30% and 180.32% respectively for two drugs, when compared to marketed oral preparation. Pharmacodynamic studies showed improved and prolonged management of diabetes and hypertension in Wistar rats, compared to oral and drug-loaded nano invasomes formulations.

Conclusion

Overall, the results showed that nano invasomal gel was found to be a useful and promising transdermal delivery system for the treatment of concurrent diseases.

Potential combination topical therapy of anal fissure: development, evaluation, and clinical study†

To treat anal fissure, internal anal sphincterotomy may be associated with surgical risks and incidence of incontinence. Botulinum toxin injection into the anal sphincter is invasive and expensive. Headache and hypotension hindered topical treatment with glyceryl trinitrate. Greater patient compliance, potentiated efficacy, reduced side effects, and lower cost are the major advantages offered by the combination therapy. Therefore, combination topical gels of nifedipine (NIF), lidocaine hydrochloride (LDH) and betamethasone valerate (BMV) were prepared and evaluated regarding viscosity, pH, drug content, and in vitro release. Compatibility study of drug-drug and drug-excipient mixtures preceded the formulation. Stability study was performed. A prospective randomized clinical trial was conducted for six weeks to assess the efficacy of the optimized formula in the treatment of anal fissure either acute (AAF, 37 patients) or chronic (CAF, 34 patients) in comparison with three single drug market products. The compatibility was indicated except in case of LDH with each of poloxamer 407 (P407), methylparaben, and propylparaben as well as BMV with P407. The gels showed acceptable viscosity ranges, tolerated pH values, and drugs content limits complying with the pharmacopeial limit. The gel containing 10% Transcutol^® (F2) was selected as optimized formula due to the significant (p < 0.05) enhancement in NIF release. The recommended storage temperature was 8 °C. In comparison with the market products, the optimized gel can be represented as a potential combination therapy of acute and chronic anal fissures as suggested by significantly increased healing% and significantly reduced pain, bleeding, anal discharge and itching without side effects.

Design and in vitro/in vivo evaluation of sustained-release floating tablets of itopride hydrochloride

Purpose

The aim of the present study was to improve the bioavailability of itopride (ITO) and sustain its action by formulating as a floating dosage form.

Materials and methods

Sustained-release floating tablets of ITO hydrochloride (HCl) were prepared by direct compression using different hydrocolloid polymers such as hydroxypropyl methylcellulose and ethylcellulose and/or methacrylic acid polymers Eudragit RSPM and Carbopol 934P. The floating property was achieved using an effervescent mixture of sodium bicarbonate and anhydrous citric acid (1:1 mol/mol). Hardness, friability, content uniformity, and dissolution rate of the prepared floating tablets were evaluated. The formulation F₁₀ composed of 28.5% Eudragit RSPM, 3% NaHCO₃, and 7% citric acid provided sustained drug release.

Results

In vitro results showed sustained release of F₁₀ where the drug release percentage was 96.51%±1.75% after 24 hours (P=0.031). The pharmacokinetic results indicated that the area under the curve (AUC_0–∞) of the prepared sustained-release floating tablets at infinity achieved 93.69 µg·h/mL compared to 49.89 µg·h/mL for the reference formulation (Ganaton^®) and the relative bioavailability of the sustained-release formulation F₁₀ increased to 187.80% (P=0.022).

Conclusion

The prepared floating tablets of ITO HCl (F₁₀) could be a promising drug delivery system with sustained-release action and enhanced drug bioavailability.

Formulation and evaluation of atenolol floating bioadhesive system using optimized polymer blends

Introduction:

Oral sustained release gastro retentive dosage forms offer several advantages for drugs having absorption from the upper gastrointestinal tract to improve the bioavailability of medications which have narrow absorption window. The aim of the study was to develop a floating bioadhesive drug delivery system exhibiting a unique combination of floatation and bioadhesion to prolong the residence in the stomach using atenolol as a model drug.

Methods:

Prior to compression, polymeric blend(s) were evaluated for flow properties. The tablets were prepared by direct compression method using bioadhesive polymer like Carbopol 934P and hydrophilic polymers like HPMC K4M, HPMC K15M, and HPMC K100M. The prepared tablets were evaluated for physical characteristics, bioadhesive strength, buoyancy lag time, swelling index and in vitro drug release studies.

Results:

The mean bioadhesive strength was found to be in the range of 16.2 to 52.1 gm. The optimized blend (F11) showed 92.3% drug releases after 24 hrs. Whilst, increase in concentration of carbopol 934P, bioadhesive strength and swelling index was increased with slow release. The n values of optimized formulations were found in the range of 0.631-0.719 indicating non-fickian anomalous type transport mechanism.

Conclusion:

The study aided in developing an ideal once-a-day gastro retentive floating drug delivery system with improved floating, swelling and bioadhesive characteristics with better bioavailability.

Design, Development and Optimization of S (-) Atenolol Floating Sustained Release Matrix Tablets Using Surface Response Methodology

The objective of this present investigation was to develop and formulate floating sustained release matrix tablets of s (-) atenolol, by using different polymer combinations and filler, to optimize by using surface response methodology for different drug release variables and to evaluate the drug release pattern of the optimized product. Floating sustained release matrix tablets of various combinations were prepared with cellulose-based polymers: Hydroxypropyl methylcellulose, sodium bicarbonate as a gas generating agent, polyvinyl pyrrolidone as a binder and lactose monohydrate as filler. The 3² full factorial design was employed to investigate the effect of formulation variables on different properties of tablets applicable to floating lag time, buoyancy time, % drug release in 1 and 6 h (D_{1 h,}D_{6 h}) and time required to 90% drug release (t_90%). Significance of result was analyzed using analysis of non variance and P < 0.05 was considered statistically significant. S (-) atenolol floating sustained release matrix tablets followed the Higuchi drug release kinetics that indicates the release of drug follows anomalous (non-Fickian) diffusion mechanism. The developed floating sustained release matrix tablet of improved efficacy can perform therapeutically better than a conventional tablet.

Influence of different types of low substituted hydroxypropyl cellulose on tableting, disintegration, and floating behaviour of floating drug delivery systems

The object of the present study is to evaluate the effect of application of low-substituted hydroxypropyl cellulose (L-HPC) 11 and B1 as excipients promoting floating in gastroretentive tablets. Directly compressed tablets were formed based on experimental design. Face-centred central composite design was applied with two factors and 3 levels, where amount of sodium alginate (X₁) and L-HPC (X₂) were the numerical factors. Applied types of L-HPCs and their 1:1 mixture were included in a categorical factor (X₃). Studied parameters were floating lag time, floating time, floating force, swelling behaviour of tablets and dissolution of paracetamol, which was used as a model active substance. Due to their physical character, L-HPCs had different water uptake and flowability. Lower flowability and lower water uptake was observed after 60 min at L-HPC 11 compared to L-HPC B1. Shorter floating times were detected at L-HPC 11 and L-HPC mixtures with 0.5% content of sodium alginate, whereas alginate was the only significant factor. Evaluating results of drug release and swelling studies on floating tablets revealed correlation, which can serve to help to understand the mechanism of action of L-HPCs in the field development of gastroretentive dosage forms.

Floating elementary osmotic pump tablet (FEOPT) for controlled delivery of diethylcarbamazine citrate: a water-soluble drug

The present work investigates the feasibility of the design of a novel floating elementary osmotic pump tablet (FEOPT) to prolong the gastric residence of a highly water-soluble drug. Diethylcarbamazine citrate (DEC) was chosen as a model drug. The FEOPT consisted of an osmotic core (DEC, mannitol, and hydrophilic polymers) coated with a semipermeable layer (cellulose acetate) and a gas-generating gelling layer (sodium bicarbonate, hydrophilic polymers) followed by a polymeric film (Eudragit RL 30D). The effect of formulation variables such as concentration of polymers, types of diluent, and coat thickness of semipermeable membrane was evaluated in terms of physical parameters, floating lag time, duration of floatation, and in vitro drug release. The Fourier transform infrared and X-ray diffraction analysis were carried out to study the physicochemical changes in the drug excipients powder blend. The integrity of the orifice and polymeric film layer was confirmed from scanning electron microscopy image. All the developed FEOPT showed floating lag time of less than 8 min and floating duration of 24 h. A zero-order drug release could be attained for DEC. The formulations were found to be stable up to 3 months of stability testing at 40°C/75% relative humidity.