Nokhodchi Ali, Norouzi-Sani Shabnam, Siahi-Shadbad Mohmmad Reza, Lotfipoor Farzaneh, Saeedi Majid
School of Pharmacy, Tabriz Medical Sciences University, Tabriz, Iran.
Eur J Pharm Biopharm. 2002 Nov;54(3):349-56. doi: 10.1016/s0939-6411(02)00120-0.
Hydrophilic and lipophilic polymers are widely used excipients to control the release rate of drugs from matrices. Researchers found that surfactants are able to control the release rate of drugs. The aim of the present investigation is to determine the effects of surfactant type, its concentration and the different ratios of surfactants on the release rate of highly soluble drug (propranolol HCl). In this study, sodium lauryl sulphate (SLS) as an anionic surfactant, cetyl trimethyl ammonium bromide (CTAB) as a cationic surfactant, Tween 65 and Arlacel 60 as non-ionic surfactants were selected. The different concentrations of surfactants were incorporated into hydroxypropylmethylcellulose-Eudragit matrices and then dissolution rate of the drug from the matrices were evaluated at pH 1.2 or 6.8. The results showed that the release rate of propranolol decreased as the concentration of SLS increased. This is due to that SLS is able to form complex with propranolol. In contrast Tween 65 caused an increase in the release rate of the drug. Cationic surfactant (CTAB) had little effect on the release rate of the drug. It was shown that as the ratio of CTAB:SLS increased the release rate of propranolol increased from matrices. This indicated that as CTAB is able to interact with SLS molecules, therefore number of the interacting anionic molecules with the cationic drug was decreased. It can be concluded that, the type and ionization of surfactant, hydrophilicity and lipophilicity of surface active agent and various ratios of surfactants are important factors in controlling the release rate of propranolol.
亲水性和疏水性聚合物是广泛用于控制药物从基质中释放速率的辅料。研究人员发现表面活性剂能够控制药物的释放速率。本研究的目的是确定表面活性剂类型、其浓度以及表面活性剂的不同比例对高溶性药物（盐酸普萘洛尔）释放速率的影响。在本研究中，选择了月桂基硫酸钠（SLS）作为阴离子表面活性剂，十六烷基三甲基溴化铵（CTAB）作为阳离子表面活性剂，吐温65和司盘60作为非离子表面活性剂。将不同浓度的表面活性剂加入羟丙基甲基纤维素-丙烯酸树脂基质中，然后在pH 1.2或6.8下评估药物从基质中的溶解速率。结果表明，随着SLS浓度的增加，普萘洛尔的释放速率降低。这是因为SLS能够与普萘洛尔形成复合物。相反，吐温65导致药物释放速率增加。阳离子表面活性剂（CTAB）对药物释放速率影响不大。结果表明，随着CTAB:SLS比例的增加，普萘洛尔从基质中的释放速率增加。这表明由于CTAB能够与SLS分子相互作用，因此与阳离子药物相互作用的阴离子分子数量减少。可以得出结论，表面活性剂的类型和离子化、表面活性剂的亲水性和疏水性以及表面活性剂的各种比例是控制普萘洛尔释放速率的重要因素。
