In vitro release of ketoprofen suppositories using the USP basket and the flow-through cell dissolution methods

In order to study the release characteristics of ketoprofen suppositories under the hydrodynamic environment generated by USP Apparatus 1 and 4, the dissolution profiles of the Mexican reference product (100 mg) were determined. Phosphate buffer pH 8 and 1% sodium lauryl sulfate (SLS) aqueous solutions were proved as dissolution mediums. Baskets were rotated at 100 rpm with USP Apparatus 1 and different flow rates from 16-32 mL/min with USP Apparatus 4 were used. Drug samples were taken and quantified during 60 min by UV analysis at 260 nm. Mean dissolution time (MDT) and dissolution efficiency (DE) were calculated by model-independent methods. Data were also fitted to several kinetic models. Poor dissolution was found in both dissolution mediums when USP basket method was used (< 10% dissolved) while better results were obtained with USP Apparatus 4 when 1% SLS at 24 mL/min was used (43.6% dissolved, MDT of 25.5 min and DE of 25.0%). Kinetics showed a great variability when the USP Apparatus 1 was used, and Gompertz fitted well for data of 1% SLS at 24 mL/min (R(2)(adjusted) > 0.99). The results suggest the need to establish an adequate dissolution method to evaluate the release kinetics of ketoprofen from suppositories.

Comparative in vitro dissolution study of carbamazepine immediate-release products using the USP paddles method and the flow-through cell system

Dissolution profiles of four carbamazepine immediate-release generic products (200 mg tablets) and the reference product Tegretol® were evaluated using the USP paddles method and an alternative method with the flow-through cell system, USP Apparatus 4. Under official conditions all products met the Q specification, dissolution profiles of generic products were similar to the dissolution profile of the reference product (f 2 > 50) and model-independent parameters showed non significant differences to the reference product except mean dissolution time for product A (p < 0.05). On the other hand, when the flow-through cell system was used, none of the products met the pharmacopeial specification at 15 min and product A did not reach dissolution criteria at 60 min, dissolution profiles of all generic products were not similar to the reference product profile (f 2 < 50) and all model-independent parameters showed significant differences compared to the reference product (p < 0.05). Weibull's model was more useful for adjusting the dissolution data of all products in both USP apparatuses and Td values showed significant differences compared to the reference product (p < 0.05) when USP Apparatus 4 was used. These results indicate that the proposed method, using the flow-through cell system, is more discriminative in evaluating both, rate and extent of carbamazepine dissolution process from immediate-release generic products.

[Cross sectional geriatric assessment of Mexican older people]

BACKGROUND

Due to the progressive aging of our population, it is imperative to evaluate the life conditions and health limitations of older people.

AIM

To report the results of an integral geriatric evaluation of Mexican older people.

MATERIAL AND METHODS

A cross-sectional assessment of 324 older subjects of a median age of 70 years (57% females) beneficiaries of the Mexican Institute of Social Security of the city of Querétaro. Social, demographic, medical, functional and cognitive variables were evaluated.

RESULTS

Of the studied subjects, 37% were illiterate, 61% lived with a partner and 47% were dedicated to household activities. Thirty three percent had visual impairment, 54% had hearing impairment, 39% had urinary incontinence, 26% reported falls in the last six months, 34% had nutritional problems, 38% were functionally dependent, 49% had sleeping problems, 25% had cognitive impairment and 25% had depression.

CONCLUSIONS

The general health outlook of this population is encouraging, considering that more than half are not functionally impaired.

The antispasmodic activity of Buddleja scordioides and Buddleja perfoliata on isolated intestinal preparations

The antispasmodic activity of extracts from the aerial parts of Buddleja scordioides and Buddleja perfoliata (family: Scrophulariaceae) was studied on isolated tissue preparations from rabbit and guinea pig intestine. The chloroformic extract from the plants exhibited a significant relaxation on the spontaneous contraction of isolated rabbit jejunum at concentrations ranging from 1 to 400 microg/ml, and also caused an inhibitory effect on both K+ and Ca2+ induced contractions in the same tissue. The extracts at moderate doses (50 microg/ml) reduced 5-hydroxytryptamine (5-HT), acetylcholine and histamine induced contractions on isolated guinea pig ileum. Therefore, B. scordioides and B. perfoliata possess similar relaxant mechanism of action, in view of the fact that both inhibit K+ induce contraction and act through serotoninic, muscarinic and histaminic receptors. So, these data support the idea that the extracts may interfere either with calcium mobilization from intracellular stores, or with calcium interaction with regulatory proteins (e.g., calmodulin), or in other steps in the calcium signaling pathway. This leads us to suggest that the spasmolytic effect of both Buddleja species on smooth muscular contractility are due to the same or similar compounds occurring in these two species, which might be present in similar quantities.

Pharmacological study of antispasmodic activity of Mirabilis jalapa Linn flowers

INTRODUCTION

Mirabilis jalapa Linn is a well-studied plant. The indigenous people of Mexico use Mirabilis jalapa to cure many infirmities including dysentery, diarrhea, muscular pain and abdominal colic. In the present investigation, we have further characterized some pharmacological properties of an extract of Mirabilis jalapa flowers; therefore, we intend to contribute to understand the pharmacological effects and clarify the complex use of this medicinal plant.

RESULTS

The extract of Mirabilis jalapa (1-1000 mug/mL) exhibits an inhibitory effect (IC(50)=18+/-0.7 micorg/mL) on gut smooth muscle contractility whereas it stimulates the contraction of rabbit aortic muscle (EC(50)=11.60+/-0.26 micorg/mL) in a concentration-dependent manner.

CONCLUSIONS

These effects were not due to either ACh or HIS receptors blockage, IP(3), cAMP, cGMP, Ca(2+) release from intracellular storage, or protein kinase mediated contraction-relaxation mechanisms. The effects inducted by the Mirabilis jalapa extract may involve a serotoninergic mechanism, which, in turn, interacts with other adrenergic systems. Further studies are necessary to identify the active compounds within the extract and to elucidate the mechanism of action.