Topical gel formulation and stability assessment of platelet lysate based on turbidimetric method

Platelet-rich growth factors have attracted attentions of scientists and clinical practitioners who are involved in wound healing and regenerative medicine extensively, according to their unprecedented potential of promoting and catalyzing healing process. Platelet-rich growth factors are cost-benefit, available and are more stable than recombinant human growth factors. These appealing characteristics have converted PRGF to one of the popular candidate for treatment of variety of wounds. According to these valuable properties, we decided to formulate and assess the effect of different excipients on the stability of such valuable protein based formulations. Different excipients have been chosen according to their effectiveness on the stability of proteins and their application in the other similar formulations. The stabilizing effect of excipients was evaluated by measuring heat-induced aggregation of growth factors by turbidimetric assay. Glycerol, glycine and dextrose were chosen as stabilizing excipient for these formulations. The results show that dextrose has more stabilizing effect on prevention of heat induced aggregation of the platelet lysate growth factors than glycerol and glycine. All of the formulations also contained antioxidant, chelating agents, preservative and carbopol 934 in order to form appropriate gel

Application of rapid and simple liquid chromatography method for determination of bioequivalence of generic lamotrigine tablets in healthy Iranian volunteers

A simple and rapid chromatography method was developed for determination of lamotrigine in human plasma. The method was used to compare the pharmacokinetic [PK] parameters of 50 mg generic and the reference lamotrigine [Lamictal] tablets in healthy Iranian volunteers. High performance liquid chromatography - ultraviolet method was developed and validated to determine lamotrigine concentration in plasma samples. The method was linear over the range of 0.1 to 15 microg/ml. The accuracy and precision were within the acceptable range. Limits of detection and quantification were calculated 0.06 and 0.10 microg/mL, respectively. A randomized, single-dose, two-period, two-sequence crossover study was carried out in healthy subjects receiving either the test or the reference products in each period. Pharmacokinetic parameters were determined by non-compartmental PK model. Bioequivalency between the generic and the reference product was investigated according to the guidance for industry issued by US Food Drug Administration. AUC0-t, AUC0 and Cmax were calculated for the generic product 12.50 +/- 2.76 microg.h/mL, 15.04 +/- 3.66 microg.h/mL and 0.38 +/- 0.08 microg/mL, respectively. The 90% confidence interval for the test/reference ratios were laid in the range of 0.80-1.25 for the log-transformed PK parameters. The generic product is bioequivalent and can be prescribed by practitioners while indicated, however the AUC and Cmax were lower in Iranian population if compared to the literature, which requires further investigations

effects of some permeability enhancers on the percutaneous absorption of lidocaine

local anesthesia of the intact skin is difficult because of the barrier properties of skin to epicutaneous penetration of local anesthetic drugs. Using local anesthetics with combination of penetration enhancers could overcome this problem. The main objective of this study was to assess the effects of some permeability enhancers on the percutaneous permeation of lidocaine. The effect of polysorbate 80, polysorbate 20, dimethylsulfoxide [DMSO], tert-butyl cyclohexanol [TBCH], and a-terpinol in different concentrations and various ratios of lidocaine to enhancers was evaluated. The results showed that polysorbate 80 and polysorbate 20 has no detectable penetration enhancing effects in guinea pig skin mounted to diffusion cells. The same results were obtained to water/oil] ratio and the type of oil phase [liguid paraffin vs. castor oil]. Addition of DMSO to the previous formulations had a comiderable enhancing effect According to the data, the extent of lidocaine permeation was proportional to me concentration of DMSO in fAese formulations. The best results belonged to the addition of terpenes but interestingly there wasn't any linear relationship between the concentrations of alpha terpinol/ or TBCH and the duration of antinociceptive effects of lidocaine. Based on the results of this study the ratio of 1: 4 from a- terpinol or TBCH to lidocaine results in a better antinociceptive effect and a- terpinol was the best one among of these compounds. This effect was proven with in vivo tail-immersion test to assess the antinociceptive effect of formulations which have shown more penetration

effect of HLB on the release profile of atenolol from ethyl cellulose-coated tablets

It is possible to alter the permeability of ethyl cellulose membrane with certain materials such as surfactants. In this study the effect of surfactant concentration and different HLB values on the release rate of atenolol from ethyl cellulose-coated tablets was evaluated. The results showed that when the concentration of surfactant increased, the rate of drug release also increased. The kinetics of atenolol release from these tablets also depended on surfactant concentration and their total HLB value. The data showed that there was an optimum HLB for an optimum rate of drug release. When the HLB value was increased to 9, the release rate increased and the kinetics of drug release approached a zero order model. But, further increase in HLB value up to 15 did not have any additional significant effect on the release rate of atenolol from these film-coated tablets