Pectins having a combination of unexpectedly high molecular weights and low degrees of methylation have been isolated. These high molecular weight, low degree of methylation pectins form gels at unexpectedly low concentrations. Such pectins can be obtained by extracting homogenized Aloe Vera plants or portions thereof. These pectins can be used to prepare pharmaceutical compositions comprising pharmacological agents encapsulated in a pectin gel, for application to animals and humans so as to provide controlled release of the pharmacological agent.