In vitro pharmaco-equivalence analysis of diclofenac potassium oral film-coated tablet relative to marketed generics

Context: Diclofenac potassium, a potent member of the non-steroidal anti-inflammatory drugs (NSAIDs) that is commonly used for acute analgesia and multiple inflammatory conditions, has various marketed tablet brands available. However, quality parameters of tablet dosage forms may vary across different brands. Aims: To evaluate critical quality attributes, including in vitro dissolution characteristics of four diclofenac potassium immediate-release (IR) tablet brands (labeled A–D) collected from Saudi Arabia market. Methods: All brands were tested for conformity with the United States Pharmacopoeia, through evaluation of weight variation, hardness, friability, disintegration, and dissolution. Dissolution profiles were compared using model-dependent and-independent approaches relative to the innovator A. Results: Data showed that the samples were compliant in terms of weight variation, hardness and friability. Disintegration time (DT) for brands B and D was below USP specifications whereas that of brand C was higher. Brand B and D had higher dissolution efficiency (DE) and similar mean dissolution time (MDT) compared with innovator. Brand C had lower DE and greater MDT compared with innovator. Weibull model of drug-release kinetics was found to be the best fit for all samples. Conclusions: In summary, brand C, unlike brands B and D, appears to relatively undermine the purpose of a diclofenac IR formulation, given its longer DT, lower DE and slower dissolution release compared with the innovator. These differences are potentially attributable to variations in tablet additives and manufacturing processing across different pharmaceutical industries

Topical piroxicam in vitro release and in vivo anti-inflammatory and analgesic effects from palm oil esters-based nanocream

During recent years, there has been growing interest in use of topical vehicle systems to assist in drug permeation through the skin. Drugs of interest are usually those that are problematic when given orally, such as piroxicam, a highly effective anti-inflammatory, anti-pyretic, and analgesic, but with the adverse effect of causing gastrointestinal ulcers. The present study investigated the in vitro and in vivo pharmacodynamic activity of a newly synthesized palm oil esters (POEs)-based nanocream containing piroxicam for topical delivery

Stability Studies of Nano-Scaled Emulsions Containing Ibuprofen for Topical Delivery

Biphasic systems, like emulsions and nano-scaled emulsions, are naturally unstable. The extent and rate of the destabilization process differ from system to another. The stability of such systems upon storage is an important aspect to ensure their abilities to exert the expected effects and consequently render them pharmaceutically acceptable. In the present study, the stability of the nano-scaled emulsion containing newly synthesized palm oil esters (POEs) was assessed under different storage conditions and over specified durations. Three nano-scaled emulsion formulae were chosen for this investigation. They basically comprised ibuprofen as the active ingredient, triethanolamine aqueous solution pH 7.4 as the external phase, POEs as the oil phase, Tween 80 as an emulsifier, Carbopol® 940 as the rheology modifier and menthol or limonene as penetration promoters. The evaluation processes were carried out at several temperatures (4, 25 and 40 °C) with factors, such as droplets size, electrical conductivity, drug content, pH and flow properties were relatively held constant. The data collectively showed that all formulations were stable over an observation period of three months.Keywords: Ibuprofen, nano-scaled emulsion, palm oil esters, stabilit

Stability Studies of Nano-Scaled Emulsions Containing Ibuprofen for Topical Delivery

Biphasic systems, like emulsions and nano-scaled emulsions, are naturally unstable. The extent and rate of the destabilization process differ from system to another. The stability of such systems upon storage is an important aspect to ensure their abilities to exert the expected effects and consequently render them pharmaceutically acceptable. In the present study, the stability of the nano-scaled emulsion containing newly synthesized palm oil esters (POEs) was assessed under different storage conditions and over specified durations. Three nano-scaled emulsion formulae were chosen for this investigation. They basically comprised ibuprofen as the active ingredient, triethanolamine aqueous solution pH 7.4 as the external phase, POEs as the oil phase, Tween 80 as an emulsifier, Carbopol® 940 as the rheology modifier and menthol or limonene as penetration promoters. The evaluation processes were carried out at several temperatures (4, 25 and 40 °C) with factors, such as droplets size, electrical conductivity, drug content, pH and flow properties were relatively held constant. The data collectively showed that all formulations were stable over an observation period of three months.Keywords: Ibuprofen, nano-scaled emulsion, palm oil esters, stabilit

Study of Pseudoternary Phase Diagram Behaviour and the Effect of Several Tweens and Spans on Palm Oil Esters Characteristics

Palm oil esters are high molecular weight esters oil that has been newly synthesized by University Putra Malaysia researchers. It has received a lot of attention for its pharmaceutical and chemical application. The aim of this study is to study the effects of the palm oil esters with different HLB surfactant mixture on the ternary diagrams behaviour and to confine the various systems resulted from these combinations. These systems include traditional emulsion, gel area, transpernat micro-emulsion area, O/W and W/O emulsions. In this study, pseudoternary phase diagrams of water, POEs and non-ionic surfactant mixture of several HLB values were constructed using water titration method. The resultant mixtures collected after each addition and mixing of water were analysed visually, along with conductivity, dilution in water and dye test (methylene blue) to classify them as O/W emulsion (transparent and opaque) or W/O (opaque) and liquid or gel. As a conclusion, palm oil esters were found to be suitable for the formulation of different types of emulsion. Additionally, different HLB value of non-ionic surfactant(s) exhibited different pseudoternary phase diagram characteristics.Keywords: palm oil esters, Tween, Span, Pseudoternary phase diagram, O/W emulsio

Modification and Validation of an HPLC Method for Quantification of Piroxicam

Piroxicam is a NSAID that is widely used in the treatment of joint pain and osteoarthritis. The objectives of the study were to modify and validate HPLC method so as to obtain an accurate, sensitive and precise method to quantify piroxicam concentrations without interference from the other ingredients presence in the formulation. The method published by Owen et al. was adapted and modified to suit the above requirements. The modification was carried out on the mobile phase as the mobile phase used by the authors was not able to separate the drug peak from the interference of the formulation excipients. The modified mobile phase consisted of 5 mM of disodium hydrogen phosphate adjusted to pH 3 with concentrated ortho phosphoric acid, methanol, acetonitrile and glacial acetic acid at ratios of 27:20:52:1 respectively. The method was validated and found to be specific, precise, accurate and reproducible even when run at different times of the same day or on different times on different days. The limit of detection and quantification were determined to be 0.035 μg/ml and 0.0625 μg/ml respectively. It could be concluded that this method could be used to determine piroxicam concentration in the samples collected from in vitro study of permeability through the synthetic membrane and excised rat skin.Keywords: Piroxicam, HPLC, Quantification analysis, Modification

Study of Pseudoternary Phase Diagram Behaviour and the Effect of Several Tweens and Spans on Palm Oil Esters Characteristics

Palm oil esters are high molecular weight esters oil that has been newly synthesized by University Putra Malaysia researchers. It has received a lot of attention for its pharmaceutical and chemical application. The aim of this study is to study the effects of the palm oil esters with different HLB surfactant mixture on the ternary diagrams behaviour and to confine the various systems resulted from these combinations. These systems include traditional emulsion, gel area, transpernat micro-emulsion area, O/W and W/O emulsions. In this study, pseudoternary phase diagrams of water, POEs and non-ionic surfactant mixture of several HLB values were constructed using water titration method. The resultant mixtures collected after each addition and mixing of water were analysed visually, along with conductivity, dilution in water and dye test (methylene blue) to classify them as O/W emulsion (transparent and opaque) or W/O (opaque) and liquid or gel. As a conclusion, palm oil esters were found to be suitable for the formulation of different types of emulsion. Additionally, different HLB value of non-ionic surfactant(s) exhibited different pseudoternary phase diagram characteristics.Keywords: palm oil esters, Tween, Span, Pseudoternary phase diagram, O/W emulsio

Modification and Validation of an HPLC Method for Quantification of Piroxicam

Piroxicam is a NSAID that is widely used in the treatment of joint pain and osteoarthritis. The objectives of the study were to modify and validate HPLC method so as to obtain an accurate, sensitive and precise method to quantify piroxicam concentrations without interference from the other ingredients presence in the formulation. The method published by Owen et al. was adapted and modified to suit the above requirements. The modification was carried out on the mobile phase as the mobile phase used by the authors was not able to separate the drug peak from the interference of the formulation excipients. The modified mobile phase consisted of 5 mM of disodium hydrogen phosphate adjusted to pH 3 with concentrated ortho phosphoric acid, methanol, acetonitrile and glacial acetic acid at ratios of 27:20:52:1 respectively. The method was validated and found to be specific, precise, accurate and reproducible even when run at different times of the same day or on different times on different days. The limit of detection and quantification were determined to be 0.035 μg/ml and 0.0625 μg/ml respectively. It could be concluded that this method could be used to determine piroxicam concentration in the samples collected from in vitro study of permeability through the synthetic membrane and excised rat skin.Keywords: Piroxicam, HPLC, Quantification analysis, Modification

Sympathetic overactivity prevails over the vascular amplifier phenomena in a chronic kidney disease rat model of hypertension

We examined whether increased sympathetic nerve activity (SNA) accounts for enhanced depressor responses to ganglionic blockade in the Lewis polycystic kidney (LPK) model of chronic kidney disease (CKD) or whether it reflects increased vascular responses to vasodilation (vascular amplifier). Under urethane anesthesia, depressor responses to ganglionic blockade (hexamethonium, 0.5-40 mg/kg i.v.), and direct vasodilation (sodium nitroprusside [SNP], 2.5-40 μg/kg i.v. and adenosine, 3-300 μg/kg i.v.) were compared in the LPK with normotensive Lewis and spontaneously hypertensive rats (SHR) (total n = 37). Hexamethonium (8 mg/kg) produced a greater depressor response in the LPK (-51 ± 3 mmHg) compared with Lewis (-31 ± 3 mmHg, P < 0.05) but not SHR (-46 ± 3 mmHg). In LPK, the ratio of the hexamethonium/vasodilator MAP responses was greater when compared with Lewis (hexamethonium/SNP 1.34 ± 0.1 vs. 0.9 ± 0.09 and hexamethonium/adenosine: 2.28 ± 0.3 vs. 1.16 ± 0.1, both P < 0.05) but not SHR. Results for systolic blood pressure (SBP) were comparable. The slope of the relationship between the fall in SBP induced by hexamethonium and normalized low frequency (LFnu) power was also greater in the LPK (17.93 ± 3.26 mmHg/LFnu) compared with Lewis (2.78 ± 0.59 mmHg/LFnu, P = 0.001) and SHR (3.36 ±0.72 mmHg/LFnu, P = 0.003). These results indicate that in the LPK, sympathetic activity predominates over any vascular amplifier effect, supporting increased sympathetic vasomotor tone as a major contributor to hypertension in this model of CKD.11 page(s